Investigations of water deficit interactions with heat and elevated carbon dioxide in wheat
- Authors: Mavindidze, Peter
- Date: 2021-02
- Subjects: Plants--Effect of heat on , Growth (Plants)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20664 , vital:46422
- Description: Future climate is predicted to be characterised by elevated carbon dioxide (eCO2), as well as more incidences of heat and water deficit. eCO2 has been widely reported as enhancing growth, biomass and grain yield. To investigate the interactive effects of abiotic stresses on genotypic performance, an experiment was established in open-top chambers at the University of Rhodes eCO2 facility in Grahamstown, South Africa. The specific objectives of the study were: i) to evaluate the effects of eCO2 on wheat grain yield, yield components and grain quality under heat and terminal water deficit conditions; ii) to identify cultivar sources of tolerance to combined water deficit and heat stress under eCO2; iii) to identify appropriate stress indices that can be used as screening tools for tolerance to combined effects of water deficit and heat stress under eCO2. A total of 19 wheat genotypes were evaluated in three environments varying in CO2, temperature and water deficit during the 2019 winter season. The experiment was laid out in a split-split plot design arranged in blocks inside the chambers. The parameters recorded were: leaf water potential (LWP), biomass content (TB), number of productive tillers (NPT), days to flowering (DTA), days to maturity (DTM), plant height (PH), thousand kernel weight (TKW), number of kernels per spike (KPS), kernel weight per spike (KWS) and total grain weight (TGW). The following stress indices were determined: tolerance index, stress tolerance, yield susceptibility index, mean productivity, geometric mean productivity, stress intensity index and yield index. Elevated atmospheric CO2 ameliorated the negative effects of combined heat and water deficit stress by enhancing LWP, NPT, KPS, TB and TGW. Wheat genotypes responded the same way to CO2 with respect to grain yield. Furthermore, adequate water supply mitigated the adverse effects of heat stress. In addition, the combined effects of eCO2, heat and water deficit are confounding and hypo-additive in nature. The separation of environmental effects revealed that significant genotypic responses on grain yield and biomass were caused by heat and water deficit stress, while eCO2 mitigated their negative effects, promoting growth and reproduction. Both Principal component analysis (PCA) biplot analysis and cultivar superiority measure proved to be reliable statistical tools since they managed to identify 13-5HTSBWYT-H18, Ncema and SST8135 as having both specific adaptations to future climates as well as wide adaption to multiple environments. The genotypes may be used as sources (parents for crosses) for wide adaptation in breeding programmes in the wake of predicted future climate environments. PCA biplot analysis identified mean productivity (MP) and geometric mean productivity (GMP) as the best indices; hence can also be as secondary traits complimenting traditional agronomic and physiological traits in wheat breeding under environments varying in water availability, CO2 and temperature. The interactive effects of eCO2 with heat and water deficit stress did not significantly compromise the grain physical characteristics, flour extraction, protein content, falling number and flour ash. eCO2 ameliorated the negative effects of heat and water deficit by increasing protein content by 4.75 percent , Thesis (MSc) (Crop Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Mavindidze, Peter
- Date: 2021-02
- Subjects: Plants--Effect of heat on , Growth (Plants)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20664 , vital:46422
- Description: Future climate is predicted to be characterised by elevated carbon dioxide (eCO2), as well as more incidences of heat and water deficit. eCO2 has been widely reported as enhancing growth, biomass and grain yield. To investigate the interactive effects of abiotic stresses on genotypic performance, an experiment was established in open-top chambers at the University of Rhodes eCO2 facility in Grahamstown, South Africa. The specific objectives of the study were: i) to evaluate the effects of eCO2 on wheat grain yield, yield components and grain quality under heat and terminal water deficit conditions; ii) to identify cultivar sources of tolerance to combined water deficit and heat stress under eCO2; iii) to identify appropriate stress indices that can be used as screening tools for tolerance to combined effects of water deficit and heat stress under eCO2. A total of 19 wheat genotypes were evaluated in three environments varying in CO2, temperature and water deficit during the 2019 winter season. The experiment was laid out in a split-split plot design arranged in blocks inside the chambers. The parameters recorded were: leaf water potential (LWP), biomass content (TB), number of productive tillers (NPT), days to flowering (DTA), days to maturity (DTM), plant height (PH), thousand kernel weight (TKW), number of kernels per spike (KPS), kernel weight per spike (KWS) and total grain weight (TGW). The following stress indices were determined: tolerance index, stress tolerance, yield susceptibility index, mean productivity, geometric mean productivity, stress intensity index and yield index. Elevated atmospheric CO2 ameliorated the negative effects of combined heat and water deficit stress by enhancing LWP, NPT, KPS, TB and TGW. Wheat genotypes responded the same way to CO2 with respect to grain yield. Furthermore, adequate water supply mitigated the adverse effects of heat stress. In addition, the combined effects of eCO2, heat and water deficit are confounding and hypo-additive in nature. The separation of environmental effects revealed that significant genotypic responses on grain yield and biomass were caused by heat and water deficit stress, while eCO2 mitigated their negative effects, promoting growth and reproduction. Both Principal component analysis (PCA) biplot analysis and cultivar superiority measure proved to be reliable statistical tools since they managed to identify 13-5HTSBWYT-H18, Ncema and SST8135 as having both specific adaptations to future climates as well as wide adaption to multiple environments. The genotypes may be used as sources (parents for crosses) for wide adaptation in breeding programmes in the wake of predicted future climate environments. PCA biplot analysis identified mean productivity (MP) and geometric mean productivity (GMP) as the best indices; hence can also be as secondary traits complimenting traditional agronomic and physiological traits in wheat breeding under environments varying in water availability, CO2 and temperature. The interactive effects of eCO2 with heat and water deficit stress did not significantly compromise the grain physical characteristics, flour extraction, protein content, falling number and flour ash. eCO2 ameliorated the negative effects of heat and water deficit by increasing protein content by 4.75 percent , Thesis (MSc) (Crop Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
Keratinous poultry waste valorization through novel keratinases of C. cucumeris and S. multivorium isolated from poultry sludge
- Authors: Qaphela, Hendrick
- Date: 2021-02
- Subjects: Food--Biotechnology , Poultry , Poultry industry
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20860 , vital:46640
- Description: Annually, about 55 percent of keratinous wastes are generated from various agro-industrial processing farms in South Africa. These wastes are difficult to handle due to structural integrity; hence, they constitute environmental issues due to the disposal means. Degradation of keratinous wastes using microbial-based technology has been deemed advantageous as it generates products with high-end values. Therefore, in this study, chicken feather and soil samples were collected from a local poultry farm, and bacteria were isolated using basal salt media supplemented with chicken feathers. The isolates were evaluated for proteolytic and keratinolytic potentials. The potent isolates were identified through 16S rDNA sequence and phylogenetic analysis. Fermentation media were optimized for enhanced keratinase production, and the amino acids liberated in the media during feather biodegradation were quantified. The biochemical properties of the keratinases produced were likewise determined. Ten (10) proteolytic bacteria were obtained from 20 isolates recovered from the samples with a diameter of halo on skimmed milk agar plate ranging from 15.5 ± 0.71 (mm) for isolate coded as PSW-15 to 28 ± 1.41 (mm) for isolate coded as PSW-08. The proteolytic bacteria showed variable keratinolytic potentials with percentage feather degradation that ranged from 29 percent for PSW-11 to 84 percent for PSW-14, and keratinase activity ranging from 99.99 U/mL for PSW-15 to 761.82 U/mL for PSW-14. The most potent isolates coded as PSW-14 and PSW-16 were identified as Chryseobacterium cucumeris FHN1 and Sphingobacterium multivorum HNFx. Their nucleotide sequences were submitted to the GenBank as MW16587 and MK82939, respectively. The optimization of fermentation conditions; C. cucumeris FHN1 showed improved activity at pH 5 - 6, inoculum size (4 percent, v/v), chicken feather concentration (1 percent, w/v), fermentation temperature (25o C). Similarly, S. multivorum HNFx showed optimal activity at pH 4.0, inoculum size (5 percent, v/v), chicken feather concentration (2.5 percent, w/v), and fermentation temperature (25-30 oC). C. cucumeris FHN1 and S. multivorum HNFx showed maximum keratinase production of 485.54 U/mL and 526.36 U/mL at 96 h and 72 h of incubation period respectively. Serine, aspartic acid, glutamic acid, and proline were the most abundant amino acids in the degraded chicken feathers, and upon quantitation, the following concentration was respectively obtained; 3.71, 3.4, 4.19 and 4.35 (g/100g sample) against C. cucumeris FHN1. While S. multivorum HNFx yielded aspartic acid (2.04 g/100g sample) and glutamic acid (2.0 g/100g sample) in high concentration. The keratinases showed optimal catalytic efficiency at pH and temperature of 8.0 and 90 oC, respectively. C. cucumeris FHN1 keratinase was inhibited by metal ion chelating agents; EDTA and 1,10-phenanthroline, suggesting a metallo-type of protease. The enzyme showed remarkable stability after pre-treatment with DTT, Fe2+, Fe3+ and Cu2+, with respective residual activity of 108 percent, 102 percent, 114 percent, and 104 percent. The S. multivorum HNFx keratinase; activity was not inhibited by serine- and metallo-protease inhibitors. It maintained the following residual activity against the following chemical agents; DTT (124 percent), hydrogen peroxide (152 percent), DMSO (161 percent), triton X-100 (152 percent), tween-80 (101 percent), and metal ions; Fe2+ (128 percent), Fe3+ (104 percent), K+ (117 percent), Ca2+ (104 percent), Na+ (103 percent), Ba2+ (115 percent), Al3+ (126 percent). The enzyme showed a substantial loss of catalytic efficiency after pre-incubation with various laundry detergents. The keratinases' remarkable stability in the presence of various chemical agents and metal ions tested suggests biotechnological and industrial application potentials. Consequently, the isolates portend industrial relevance for keratinous waste valorization and an excellent source of keratinases of industrial relevance. , Thesis (MSc) (Microbiology) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Qaphela, Hendrick
- Date: 2021-02
- Subjects: Food--Biotechnology , Poultry , Poultry industry
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20860 , vital:46640
- Description: Annually, about 55 percent of keratinous wastes are generated from various agro-industrial processing farms in South Africa. These wastes are difficult to handle due to structural integrity; hence, they constitute environmental issues due to the disposal means. Degradation of keratinous wastes using microbial-based technology has been deemed advantageous as it generates products with high-end values. Therefore, in this study, chicken feather and soil samples were collected from a local poultry farm, and bacteria were isolated using basal salt media supplemented with chicken feathers. The isolates were evaluated for proteolytic and keratinolytic potentials. The potent isolates were identified through 16S rDNA sequence and phylogenetic analysis. Fermentation media were optimized for enhanced keratinase production, and the amino acids liberated in the media during feather biodegradation were quantified. The biochemical properties of the keratinases produced were likewise determined. Ten (10) proteolytic bacteria were obtained from 20 isolates recovered from the samples with a diameter of halo on skimmed milk agar plate ranging from 15.5 ± 0.71 (mm) for isolate coded as PSW-15 to 28 ± 1.41 (mm) for isolate coded as PSW-08. The proteolytic bacteria showed variable keratinolytic potentials with percentage feather degradation that ranged from 29 percent for PSW-11 to 84 percent for PSW-14, and keratinase activity ranging from 99.99 U/mL for PSW-15 to 761.82 U/mL for PSW-14. The most potent isolates coded as PSW-14 and PSW-16 were identified as Chryseobacterium cucumeris FHN1 and Sphingobacterium multivorum HNFx. Their nucleotide sequences were submitted to the GenBank as MW16587 and MK82939, respectively. The optimization of fermentation conditions; C. cucumeris FHN1 showed improved activity at pH 5 - 6, inoculum size (4 percent, v/v), chicken feather concentration (1 percent, w/v), fermentation temperature (25o C). Similarly, S. multivorum HNFx showed optimal activity at pH 4.0, inoculum size (5 percent, v/v), chicken feather concentration (2.5 percent, w/v), and fermentation temperature (25-30 oC). C. cucumeris FHN1 and S. multivorum HNFx showed maximum keratinase production of 485.54 U/mL and 526.36 U/mL at 96 h and 72 h of incubation period respectively. Serine, aspartic acid, glutamic acid, and proline were the most abundant amino acids in the degraded chicken feathers, and upon quantitation, the following concentration was respectively obtained; 3.71, 3.4, 4.19 and 4.35 (g/100g sample) against C. cucumeris FHN1. While S. multivorum HNFx yielded aspartic acid (2.04 g/100g sample) and glutamic acid (2.0 g/100g sample) in high concentration. The keratinases showed optimal catalytic efficiency at pH and temperature of 8.0 and 90 oC, respectively. C. cucumeris FHN1 keratinase was inhibited by metal ion chelating agents; EDTA and 1,10-phenanthroline, suggesting a metallo-type of protease. The enzyme showed remarkable stability after pre-treatment with DTT, Fe2+, Fe3+ and Cu2+, with respective residual activity of 108 percent, 102 percent, 114 percent, and 104 percent. The S. multivorum HNFx keratinase; activity was not inhibited by serine- and metallo-protease inhibitors. It maintained the following residual activity against the following chemical agents; DTT (124 percent), hydrogen peroxide (152 percent), DMSO (161 percent), triton X-100 (152 percent), tween-80 (101 percent), and metal ions; Fe2+ (128 percent), Fe3+ (104 percent), K+ (117 percent), Ca2+ (104 percent), Na+ (103 percent), Ba2+ (115 percent), Al3+ (126 percent). The enzyme showed a substantial loss of catalytic efficiency after pre-incubation with various laundry detergents. The keratinases' remarkable stability in the presence of various chemical agents and metal ions tested suggests biotechnological and industrial application potentials. Consequently, the isolates portend industrial relevance for keratinous waste valorization and an excellent source of keratinases of industrial relevance. , Thesis (MSc) (Microbiology) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
Keratinous poultry wastes valorization through novel keratinases of Chryseobacterium cucumeris and Sphingobacterium multivorum isolated from poultry sludge
- Hendrick, Qaphela https://orcid.org/0000-0001-7529-8129
- Authors: Hendrick, Qaphela https://orcid.org/0000-0001-7529-8129
- Date: 2021-02
- Subjects: Agricultural wastes , Factory and trade waste
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21400 , vital:48537
- Description: Annually, about 55percent of keratinous wastes are generated from various agro-industrial processing farms in South Africa. These wastes are difficult to handle due to structural integrity; hence, they constitute environmental issues due to the disposal means. Degradation of keratinous wastes using microbial-based technology has been deemed advantageous as it generates products with high-end values. Therefore, in this study, chicken feather and soil samples were collected from a local poultry farm, and bacteria were isolated using basal salt media supplemented with chicken feathers. The isolates were evaluated for proteolytic and keratinolytic potentials. The potent isolates were identified through 16S rDNA sequence and phylogenetic analysis. Fermentation media were optimized for enhanced keratinase production, and the amino acids liberated in the media during feather biodegradation were quantified. The biochemical properties of the keratinases produced were likewise determined. Ten (10) proteolytic bacteria were obtained from 20 isolates recovered from the samples with a diameter of halo on skimmed milk agar plate ranging from 15.5 ± 0.71 (mm) for isolate coded as PSW-15 to 28 ± 1.41 (mm) for isolate coded as PSW-08. The proteolytic bacteria showed variable keratinolytic potentials with percentage feather degradation that ranged from 29percent for PSW-11 to 84percent for PSW-14, and keratinase activity ranging from 99.99 U/mL for PSW-15 to 761.82 U/mL for PSW-14. The most potent isolates coded as PSW-14 and PSW-16 were identified as Chryseobacterium cucumeris FHN1 and Sphingobacterium multivorum HNFx. Their nucleotide sequences were submitted to the GenBank as MW16587 and MK82939, respectively. The optimization of fermentation conditions; C. cucumeris FHN1 showed improved activity at pH 5 - 6, inoculum size (4percent, v/v), chicken feather concentration (1percent, w/v), fermentation temperature (25o C). Similarly, S. multivorum HNFx showed optimal activity at pH 4.0, inoculum size (5percent, v/v), chicken feather concentration (2.5percent, w/v), and fermentation temperature (25-30 oC). C. cucumeris FHN1 and S. multivorum HNFx showed maximum keratinase production of 485.54 U/mL and 526.36 U/mL at 96 h and 72 h of incubation period respectively. Serine, aspartic acid, glutamic acid, and proline were the most abundant amino acids in the degraded chicken feathers, and upon quantitation, the following concentration was respectively obtained; 3.71, 3.4, 4.19 and 4.35 (g/100g sample) against C. cucumeris FHN1. While S. multivorum HNFx yielded aspartic acid (2.04 g/100g sample) and glutamic acid (2.0 g/100g sample) in high concentration. The keratinases showed optimal catalytic efficiency at pH and temperature of 8.0 and 90 oC, respectively. C. cucumeris FHN1 keratinase was inhibited by metal ion chelating agents; EDTA and 1,10-phenanthroline, suggesting a metallo-type of protease. The enzyme showed remarkable stability after pre-treatment with DTT, Fe2+, Fe3+ and Cu2+, with respective residual activity of 108percent, 102percent, 114percent, and 104percent. The S. multivorum HNFx keratinase; activity was not inhibited by serine- and metallo-protease inhibitors. It maintained the following residual activity against the following chemical agents; DTT (124percent), hydrogen peroxide (152percent), DMSO (161percent), triton X-100 (152percent), tween-80 (101percent), and metal ions; Fe2+ (128percent), Fe3+ (104percent), K+ (117percent), Ca2+ (104percent), Na+ (103percent), Ba2+ (115percent), Al3+ (126percent). The enzyme showed a substantial loss of catalytic efficiency after pre-incubation with various laundry detergents. The keratinases' remarkable stability in the presence of various chemical agents and metal ions tested suggests biotechnological and industrial application potentials. Consequently, the isolates portend industrial relevance for keratinous waste valorization and an excellent source of keratinases of industrial relevance. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Hendrick, Qaphela https://orcid.org/0000-0001-7529-8129
- Date: 2021-02
- Subjects: Agricultural wastes , Factory and trade waste
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21400 , vital:48537
- Description: Annually, about 55percent of keratinous wastes are generated from various agro-industrial processing farms in South Africa. These wastes are difficult to handle due to structural integrity; hence, they constitute environmental issues due to the disposal means. Degradation of keratinous wastes using microbial-based technology has been deemed advantageous as it generates products with high-end values. Therefore, in this study, chicken feather and soil samples were collected from a local poultry farm, and bacteria were isolated using basal salt media supplemented with chicken feathers. The isolates were evaluated for proteolytic and keratinolytic potentials. The potent isolates were identified through 16S rDNA sequence and phylogenetic analysis. Fermentation media were optimized for enhanced keratinase production, and the amino acids liberated in the media during feather biodegradation were quantified. The biochemical properties of the keratinases produced were likewise determined. Ten (10) proteolytic bacteria were obtained from 20 isolates recovered from the samples with a diameter of halo on skimmed milk agar plate ranging from 15.5 ± 0.71 (mm) for isolate coded as PSW-15 to 28 ± 1.41 (mm) for isolate coded as PSW-08. The proteolytic bacteria showed variable keratinolytic potentials with percentage feather degradation that ranged from 29percent for PSW-11 to 84percent for PSW-14, and keratinase activity ranging from 99.99 U/mL for PSW-15 to 761.82 U/mL for PSW-14. The most potent isolates coded as PSW-14 and PSW-16 were identified as Chryseobacterium cucumeris FHN1 and Sphingobacterium multivorum HNFx. Their nucleotide sequences were submitted to the GenBank as MW16587 and MK82939, respectively. The optimization of fermentation conditions; C. cucumeris FHN1 showed improved activity at pH 5 - 6, inoculum size (4percent, v/v), chicken feather concentration (1percent, w/v), fermentation temperature (25o C). Similarly, S. multivorum HNFx showed optimal activity at pH 4.0, inoculum size (5percent, v/v), chicken feather concentration (2.5percent, w/v), and fermentation temperature (25-30 oC). C. cucumeris FHN1 and S. multivorum HNFx showed maximum keratinase production of 485.54 U/mL and 526.36 U/mL at 96 h and 72 h of incubation period respectively. Serine, aspartic acid, glutamic acid, and proline were the most abundant amino acids in the degraded chicken feathers, and upon quantitation, the following concentration was respectively obtained; 3.71, 3.4, 4.19 and 4.35 (g/100g sample) against C. cucumeris FHN1. While S. multivorum HNFx yielded aspartic acid (2.04 g/100g sample) and glutamic acid (2.0 g/100g sample) in high concentration. The keratinases showed optimal catalytic efficiency at pH and temperature of 8.0 and 90 oC, respectively. C. cucumeris FHN1 keratinase was inhibited by metal ion chelating agents; EDTA and 1,10-phenanthroline, suggesting a metallo-type of protease. The enzyme showed remarkable stability after pre-treatment with DTT, Fe2+, Fe3+ and Cu2+, with respective residual activity of 108percent, 102percent, 114percent, and 104percent. The S. multivorum HNFx keratinase; activity was not inhibited by serine- and metallo-protease inhibitors. It maintained the following residual activity against the following chemical agents; DTT (124percent), hydrogen peroxide (152percent), DMSO (161percent), triton X-100 (152percent), tween-80 (101percent), and metal ions; Fe2+ (128percent), Fe3+ (104percent), K+ (117percent), Ca2+ (104percent), Na+ (103percent), Ba2+ (115percent), Al3+ (126percent). The enzyme showed a substantial loss of catalytic efficiency after pre-incubation with various laundry detergents. The keratinases' remarkable stability in the presence of various chemical agents and metal ions tested suggests biotechnological and industrial application potentials. Consequently, the isolates portend industrial relevance for keratinous waste valorization and an excellent source of keratinases of industrial relevance. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
Synthesis and characterization of molybdenum dichalcogenides nanoparticles via solution-processed technique for photovoltaic applications
- Authors: Shelter, Chikukwa Evernice
- Date: 2021-02
- Subjects: Nanoparticles , Colloids
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20653 , vital:46417
- Description: Energy generated from non-renewable energy sources has a drawback of prompted outflow of ozone harming substances. These drawbacks of the non-renewable energy have quickened innovative work of renewable power sources, since they have an advantage of the provision of a better, preserved, decent environment that is free from natural contamination and commotion. Photovoltaic devices are prevalent in improving the green energy utilization and defeating the natural concerns yielded from the current most overwhelming energy sources. Herein, the synthesis, characterization, and application of Molybdenum chalcogenide nanoparticles (NP) as alternative sources in the absorber layer of quantum dot solar sensitized cells (QDSSCs) is discussed. The MoS2 NPs were synthesized from the aliphatic and aromatic dithiocarbamate (DTC) ligands and complexes as precursors. The successful synthesis of the DTC ligands and MoDTC complexes was confirmed through characterization with a variety of techniques including 1H and 13C-NMR, Raman Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-visible spectroscopy (UV-VIS), Thermogravimetric analysis (TGA) and Derivative thermogravimetric (DTG) analysis. The synthesized MoDTC complexes (precursors) were further used in the synthesis of MoS2 nanoparticles. A bottom -up colloidal approach was employed for the synthesis of the MoX2 NPs. The successful synthesis of the NP was confirmed as the results from the diffractive peaks obtained from XRD which were positive and agreed in comparison with the standard. The diffractive peaks were shown in the planes (100), (002), (100) and (105) for MoS2 nanoparticles; (002), (100), (103) and (110) for MoSe2 and (0002), (0004), (103) as well as (0006) for the MoTe2 nanoparticles. The MoSe2 nanoparticles showed the least size of the nanoparticles followed by MoTe2 and lastly MoS2. These results agreed with the results obtained using SEM analysis. For the optical properties of the nanoparticles, UV-VIS and PL were used, the shift of the peaks from the red shift (600 nm) to the blue shift 270-5 nm and 287-9 nm (UV-VIS) confirmed that the nanoparticles were quantum confined. The application of the MoX2 NPs in QDSSCs was done with MoSe2 showing the greatest PCE of 7.86 percent followed by MoTe2 6.93 percent and lastly MoS2 with a PCE of 6.05 percent and 5.47 percent. , Thesis (MSc) (Chemistry) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Shelter, Chikukwa Evernice
- Date: 2021-02
- Subjects: Nanoparticles , Colloids
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20653 , vital:46417
- Description: Energy generated from non-renewable energy sources has a drawback of prompted outflow of ozone harming substances. These drawbacks of the non-renewable energy have quickened innovative work of renewable power sources, since they have an advantage of the provision of a better, preserved, decent environment that is free from natural contamination and commotion. Photovoltaic devices are prevalent in improving the green energy utilization and defeating the natural concerns yielded from the current most overwhelming energy sources. Herein, the synthesis, characterization, and application of Molybdenum chalcogenide nanoparticles (NP) as alternative sources in the absorber layer of quantum dot solar sensitized cells (QDSSCs) is discussed. The MoS2 NPs were synthesized from the aliphatic and aromatic dithiocarbamate (DTC) ligands and complexes as precursors. The successful synthesis of the DTC ligands and MoDTC complexes was confirmed through characterization with a variety of techniques including 1H and 13C-NMR, Raman Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-visible spectroscopy (UV-VIS), Thermogravimetric analysis (TGA) and Derivative thermogravimetric (DTG) analysis. The synthesized MoDTC complexes (precursors) were further used in the synthesis of MoS2 nanoparticles. A bottom -up colloidal approach was employed for the synthesis of the MoX2 NPs. The successful synthesis of the NP was confirmed as the results from the diffractive peaks obtained from XRD which were positive and agreed in comparison with the standard. The diffractive peaks were shown in the planes (100), (002), (100) and (105) for MoS2 nanoparticles; (002), (100), (103) and (110) for MoSe2 and (0002), (0004), (103) as well as (0006) for the MoTe2 nanoparticles. The MoSe2 nanoparticles showed the least size of the nanoparticles followed by MoTe2 and lastly MoS2. These results agreed with the results obtained using SEM analysis. For the optical properties of the nanoparticles, UV-VIS and PL were used, the shift of the peaks from the red shift (600 nm) to the blue shift 270-5 nm and 287-9 nm (UV-VIS) confirmed that the nanoparticles were quantum confined. The application of the MoX2 NPs in QDSSCs was done with MoSe2 showing the greatest PCE of 7.86 percent followed by MoTe2 6.93 percent and lastly MoS2 with a PCE of 6.05 percent and 5.47 percent. , Thesis (MSc) (Chemistry) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
The acoustic niche and conservation status of the recently described Hogsback caco, Cacosternum thorini (Amphibia: Pyxicephalidae), Hogsback, Eastern Cape, South Africa
- Authors: Kom, Nokuthula
- Date: 2021-02
- Subjects: Amphibians
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20429 , vital:45665
- Description: Animals may compete for acoustic space (acoustic niche) in the same way they do for habitat space. The most intense competition involves individuals with the most similar resource requirements (i.e. conspecifics), but if competition is interspecific, then mate recognition must occur both within and between species. The coexistence of the bronze caco (Cacosternum nanum) and the Hogsback caco (C. thorini) in the Tor Doone area of Hogsback could be interpreted as a result of past competition, which drove acoustic partitioning by means of the evolution of specific calls that do not overlap in frequency. Frogs are known to coexist well with other frog species because of their highly specific advertisement calls, which differ even between closely related species. One of the main aims of the project was to record and provide a description of the call of the recently described Hogsback caco, C. thorini. I identified 30 calling males and recorded each for 10 min in February 2016, yielding a total of 235 calls. Summary values for the calls include duration of 40 ± 14 ms, with 16 ± 5 pulses produced at a pulse-rate of 46 ± 21 s-1 and a mean dominant frequency of 4.19 ± 0.58 kHz. The call of C. thorini differs from those of all other cacos, by its incremental structure (increased number of pulses within consecutive units). My second goal was to use playbacks to investigate the preferred habitat of C. thorini and to compare it with that of C. nanum. I conducted experiments to measure the propagation of C. thorini and C. nanum calls in three different habitats (C. thorini habitat, C. nanum habitat, and grassland with no water bodies). Finally, I investigated the effect of drought and flood on the pools used by males as calling sites, using a buried basin to which I added water in 10 litre aliquots. The optimal water level for call propagation in the artificial pools was half-full. Using playbacks, I tested whether the two species responded to each other’s calls. I found that, although the two species call at the same time and each call in response to the other’s calls, they do not recognise heterospecific calls; they simply respond to noise. I found no evidence of acoustic competition between the two species, and in fact, the abundant, dominant species, C. nanum, was rare in the C. thorini preferred habitat. The results of this study may assist efforts to conserve endemic amphibians in the Amatola Mountains. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Kom, Nokuthula
- Date: 2021-02
- Subjects: Amphibians
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20429 , vital:45665
- Description: Animals may compete for acoustic space (acoustic niche) in the same way they do for habitat space. The most intense competition involves individuals with the most similar resource requirements (i.e. conspecifics), but if competition is interspecific, then mate recognition must occur both within and between species. The coexistence of the bronze caco (Cacosternum nanum) and the Hogsback caco (C. thorini) in the Tor Doone area of Hogsback could be interpreted as a result of past competition, which drove acoustic partitioning by means of the evolution of specific calls that do not overlap in frequency. Frogs are known to coexist well with other frog species because of their highly specific advertisement calls, which differ even between closely related species. One of the main aims of the project was to record and provide a description of the call of the recently described Hogsback caco, C. thorini. I identified 30 calling males and recorded each for 10 min in February 2016, yielding a total of 235 calls. Summary values for the calls include duration of 40 ± 14 ms, with 16 ± 5 pulses produced at a pulse-rate of 46 ± 21 s-1 and a mean dominant frequency of 4.19 ± 0.58 kHz. The call of C. thorini differs from those of all other cacos, by its incremental structure (increased number of pulses within consecutive units). My second goal was to use playbacks to investigate the preferred habitat of C. thorini and to compare it with that of C. nanum. I conducted experiments to measure the propagation of C. thorini and C. nanum calls in three different habitats (C. thorini habitat, C. nanum habitat, and grassland with no water bodies). Finally, I investigated the effect of drought and flood on the pools used by males as calling sites, using a buried basin to which I added water in 10 litre aliquots. The optimal water level for call propagation in the artificial pools was half-full. Using playbacks, I tested whether the two species responded to each other’s calls. I found that, although the two species call at the same time and each call in response to the other’s calls, they do not recognise heterospecific calls; they simply respond to noise. I found no evidence of acoustic competition between the two species, and in fact, the abundant, dominant species, C. nanum, was rare in the C. thorini preferred habitat. The results of this study may assist efforts to conserve endemic amphibians in the Amatola Mountains. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
The optimisation of transportation methods for abalone (Haliotis midae Linnaeus, 1758 (Mollusca: Gastropoda)) larvae
- Authors: Bajaba, Sharone
- Date: 2021-02
- Subjects: Abalone fisheries , Haliotis midae , Abalone culture
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20561 , vital:46124
- Description: Sea ranching has been identified as a viable method for enhancing the natural stock of overexploited abalone (Haliotis midae). Currently, this process involves transporting live juvenile H. midae to the seeding site where they are released onto the reef however this is both costly and logistically problematic. Transportation of abalone larvae is another cost-effective option, as they are cheaper to produce and can be transported at high densities. A suitable larval transport method is required to minimise larval mortalities and stresses that might compromise settlement. A series of simulated experiments were conducted to optimise transportation systems of abalone (Haliotis midae) larvae. First, two potential transportation modes (Wet (W) and Dry (D) transportation) conducted at a cooler (14˚C) and average ambient (18˚C) temperatures with six replicates of each were compared with control treatments (six replicates) that were not subjected to transport, kept in water at 18˚C. Eighty hours post-initial settlement, the 14W treatment had significantly lower settlement (p=0.03) than the other three treatments (14D, 18W, 18D) and the Control. The Dry method was the prefered method to transport larvae as it is logistically simpler to employ. The second experiment investigated the effect of different stocking densities (200, 400 and 800 larvae cm-2) for the Dry method 18˚C over two transit periods (six and twelve hours) on post-transport settlement and post-settlement survival of H. midae larvae. Compared to the control, there was no difference in the number of settled larvae (p=0.368) and larvae still swimming (p=0.835) across all treatments. This suggested that H. midae larvae can be transported for twelve hours at 800 larvae cm-2 without compromising post-transport settlement or survival. This study’s results and recommendations can be used by abalone farms when there is a need to move abalone H. midae larvae between farms or to seeding sites for sea ranching. Furthermore, other researchers can use these results as a benchmark for larval transportation studies of H. midae and other abalone species. , Thesis (MSc) (Zoology) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Bajaba, Sharone
- Date: 2021-02
- Subjects: Abalone fisheries , Haliotis midae , Abalone culture
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20561 , vital:46124
- Description: Sea ranching has been identified as a viable method for enhancing the natural stock of overexploited abalone (Haliotis midae). Currently, this process involves transporting live juvenile H. midae to the seeding site where they are released onto the reef however this is both costly and logistically problematic. Transportation of abalone larvae is another cost-effective option, as they are cheaper to produce and can be transported at high densities. A suitable larval transport method is required to minimise larval mortalities and stresses that might compromise settlement. A series of simulated experiments were conducted to optimise transportation systems of abalone (Haliotis midae) larvae. First, two potential transportation modes (Wet (W) and Dry (D) transportation) conducted at a cooler (14˚C) and average ambient (18˚C) temperatures with six replicates of each were compared with control treatments (six replicates) that were not subjected to transport, kept in water at 18˚C. Eighty hours post-initial settlement, the 14W treatment had significantly lower settlement (p=0.03) than the other three treatments (14D, 18W, 18D) and the Control. The Dry method was the prefered method to transport larvae as it is logistically simpler to employ. The second experiment investigated the effect of different stocking densities (200, 400 and 800 larvae cm-2) for the Dry method 18˚C over two transit periods (six and twelve hours) on post-transport settlement and post-settlement survival of H. midae larvae. Compared to the control, there was no difference in the number of settled larvae (p=0.368) and larvae still swimming (p=0.835) across all treatments. This suggested that H. midae larvae can be transported for twelve hours at 800 larvae cm-2 without compromising post-transport settlement or survival. This study’s results and recommendations can be used by abalone farms when there is a need to move abalone H. midae larvae between farms or to seeding sites for sea ranching. Furthermore, other researchers can use these results as a benchmark for larval transportation studies of H. midae and other abalone species. , Thesis (MSc) (Zoology) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
Valorization of chicken feather through dekeratinization by keratinolytic Bacillus species to amino acid
- Authors: Matches, Lupho
- Date: 2021-02
- Subjects: Proteolytic enzymes , Poultry -- Processing
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20451 , vital:45667
- Description: The poultry meat processing sector generates chicken feathers as by-products, and they are 90percent keratin in composition. Keratin is an insoluble and structural protein that shows recalcitrance to hydrolysis by classical proteolytic enzymes, including trypsin, pepsin, and papain. Keratinases are a group of proteolytic enzymes endowed with keratin degradation into peptides and amino acids. They are recently gaining traction for their multifaceted potential application in the green industrial space. Hence, keratinolytic bacteria previously isolated from dumpsite were identified using 16S rDNA sequencing. The optimal fermentation conditions were determined for enhanced extracellular keratinase production and chicken feather degradation. Also, the amino acid analysis of the chicken feather hydrolysates was carried out. The biochemical properties of the keratinases were also determined. Based on 16S rDNA sequencing and phylogenetic analysis, the isolates coded as SSN-02 and HSN-03 showed a high percentage of sequence homology with Bacillus spp.; hence, they were identified as Bacillus sp. NFH5 and Bacillus sp. FHNM, respectively. Bacillus sp. NFH5 showed optimal keratinase production of 1149.99 ± 80.99 U/mL after 96 h of incubation time, in optimized fermentation conditions that included pH (4.0), chicken feather (1.5percent, w/v), inoculum size (3percent, v/v) and temperature (30 oC). Similarly, Bacillus sp. FHNM demonstrated the maximum keratinase production of 480 ± 41.14 U/mL 144 h post cultivation, in optimized fermentation conditions with pH (7.0), chicken feather (2.0percent, w/v), inoculum size (3percent, v/v) and temperature (30 oC). For Bacillus sp. NFH5 chicken feather hydrolysate, the amino acids in relatively higher concentration (>1.0g/100g sample) include arginine (1.8), serine (1.16), aspartic acid (1.95), glutamic acid (2.47), proline (1.16) and glycine (1.45). Bacillus sp. FHNM feather hydrolysates, contained (g/100g of sample): arginine (1.9), serine (1.4), aspartic acid (2.5), glutamic acid (2.51), glycine (1.51), proline (1.13), leucine (1.030, histidine (1.25), and lysine (1.06) (g/100g of sample) in high concentration. The keratinases were optimally active at pH 8.0. Bacillus sp. FHNM showed an optimal temperature of 100 oC; while Bacillus sp. NFH5 keratinase displayed optimal activity at 90 oC. EDTA and 1,10-phenanthroline inhibited the keratinases, and the inhibition pattern indicated that they belong to metalloprotease. Keratinase from Bacillus sp. FHNM showed considerable residual activity in the presence of Co²⁺ (93percent), Fe³⁺ (99percent), and K⁺ (94percent). Bacillus sp. NFH5 keratinase retained 92percent, 92percent, 93percent of the original activity against Ba²⁺, Na⁺ and Fe³⁺ treatment. Bacillus sp. FHNM keratinase was remarkably stable after 60 min of detergents treatment with residual activity of 89percent, 96percent, 81percent, 73percent, 96percent, 88percent, 88percent and 98percent for Omo, Surf, Ariel, Sunlight, Prowash, Freshwave, Sky, and Evaklin, respectively. Maq impacted the enzyme stability negatively, with residual activity of 48percent after 60 min of incubation. Additionally, keratinase Bacillus sp. NFH5 retained 68percent, 78percent, 80percent, 84percent, 57percent, 80percent, 98percent, 106percent and 106percent of the original activity against Omo, Surf, Ariel, Sunlight, Maq, Prowash, Freshwave, Sky and Evaklin, respectively. Therefore, these results suggest that Bacillus spp. could be ideal candidates for sustainable production of active keratinases and valorization of the abundantly generated keratinous biomass. The stability displayed by keratinases from Bacillus sp. FHNM and Bacillus sp. NFH5 suggests their promising candidacy for detergent formulation. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Matches, Lupho
- Date: 2021-02
- Subjects: Proteolytic enzymes , Poultry -- Processing
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20451 , vital:45667
- Description: The poultry meat processing sector generates chicken feathers as by-products, and they are 90percent keratin in composition. Keratin is an insoluble and structural protein that shows recalcitrance to hydrolysis by classical proteolytic enzymes, including trypsin, pepsin, and papain. Keratinases are a group of proteolytic enzymes endowed with keratin degradation into peptides and amino acids. They are recently gaining traction for their multifaceted potential application in the green industrial space. Hence, keratinolytic bacteria previously isolated from dumpsite were identified using 16S rDNA sequencing. The optimal fermentation conditions were determined for enhanced extracellular keratinase production and chicken feather degradation. Also, the amino acid analysis of the chicken feather hydrolysates was carried out. The biochemical properties of the keratinases were also determined. Based on 16S rDNA sequencing and phylogenetic analysis, the isolates coded as SSN-02 and HSN-03 showed a high percentage of sequence homology with Bacillus spp.; hence, they were identified as Bacillus sp. NFH5 and Bacillus sp. FHNM, respectively. Bacillus sp. NFH5 showed optimal keratinase production of 1149.99 ± 80.99 U/mL after 96 h of incubation time, in optimized fermentation conditions that included pH (4.0), chicken feather (1.5percent, w/v), inoculum size (3percent, v/v) and temperature (30 oC). Similarly, Bacillus sp. FHNM demonstrated the maximum keratinase production of 480 ± 41.14 U/mL 144 h post cultivation, in optimized fermentation conditions with pH (7.0), chicken feather (2.0percent, w/v), inoculum size (3percent, v/v) and temperature (30 oC). For Bacillus sp. NFH5 chicken feather hydrolysate, the amino acids in relatively higher concentration (>1.0g/100g sample) include arginine (1.8), serine (1.16), aspartic acid (1.95), glutamic acid (2.47), proline (1.16) and glycine (1.45). Bacillus sp. FHNM feather hydrolysates, contained (g/100g of sample): arginine (1.9), serine (1.4), aspartic acid (2.5), glutamic acid (2.51), glycine (1.51), proline (1.13), leucine (1.030, histidine (1.25), and lysine (1.06) (g/100g of sample) in high concentration. The keratinases were optimally active at pH 8.0. Bacillus sp. FHNM showed an optimal temperature of 100 oC; while Bacillus sp. NFH5 keratinase displayed optimal activity at 90 oC. EDTA and 1,10-phenanthroline inhibited the keratinases, and the inhibition pattern indicated that they belong to metalloprotease. Keratinase from Bacillus sp. FHNM showed considerable residual activity in the presence of Co²⁺ (93percent), Fe³⁺ (99percent), and K⁺ (94percent). Bacillus sp. NFH5 keratinase retained 92percent, 92percent, 93percent of the original activity against Ba²⁺, Na⁺ and Fe³⁺ treatment. Bacillus sp. FHNM keratinase was remarkably stable after 60 min of detergents treatment with residual activity of 89percent, 96percent, 81percent, 73percent, 96percent, 88percent, 88percent and 98percent for Omo, Surf, Ariel, Sunlight, Prowash, Freshwave, Sky, and Evaklin, respectively. Maq impacted the enzyme stability negatively, with residual activity of 48percent after 60 min of incubation. Additionally, keratinase Bacillus sp. NFH5 retained 68percent, 78percent, 80percent, 84percent, 57percent, 80percent, 98percent, 106percent and 106percent of the original activity against Omo, Surf, Ariel, Sunlight, Maq, Prowash, Freshwave, Sky and Evaklin, respectively. Therefore, these results suggest that Bacillus spp. could be ideal candidates for sustainable production of active keratinases and valorization of the abundantly generated keratinous biomass. The stability displayed by keratinases from Bacillus sp. FHNM and Bacillus sp. NFH5 suggests their promising candidacy for detergent formulation. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
Waste keratinous biomass valorization and characterization of keratinases produced by exiguobacteria species
- Authors: Dlume, Tutuka
- Date: 2021-02
- Subjects: Factory and trade waste -- Biodegradation , Bioremediation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20695 , vital:46438
- Description: Keratinous wastes are emanating in a million tons, as by-products, from various agro-industrial processing plants. Consequently, they create a serious solid waste problem in the environment due to poor handling. Microbial keratinases are proteolytic enzymes that effectively participate in keratin-rich biomass hydrolyses such as feathers, nail, hair, hooves, and horns. Therefore, proper management of these wastes via recycling into useful products is ecologically imperative. Biodegradation of keratin-rich biomass has been identified as an economical and environmentally friendly way of transforming these recalcitrant agro wastes into useful products, hence the motivation for this study. Feather degrading bacterial strains previously isolated from a municipal dumpsite and coded as SSB-02 and SSB-03 was identified through 16S rDNA sequencing and phylogenetic analysis. The fermentation conditions for keratinase production were optimized. The protein and amino acids constituents of the hydrolyzed chicken feather were analyzed. The biochemical properties of the keratinase produced were determined. Also, the effect of laundry detergents on the stability of the keratinase was studied. The isolates coded as SSB-02 and SSB-03 showed a high percentage of sequence homology with Exguobacterium spp., hence they were identified as Exiguobacterium sp. FBH5 and Exiguobacterium acetylicum FHBD, respectively. Exiguobacterium sp. FBH5 showed the highest extracellular keratinase production of 934.58 ± 27.27 U/mL at 72 h of incubation; in optimized fermentation conditions that included pH (5.0), temperature (30 oC), and chicken feather (0.5percent, w/v). Similarly, E. acetylicum FHBD displayed optimal keratinase production of 1023.64 ± 25.71 U/mL at 120 h of fermentation and improved fermentation conditions that involved pH (3.0), temperature (35 oC) and chicken feathers (0.5-1.5percent; w/v). The amino acid analysis showed that arginine, aspartic acid and glutamic acid were the most abundant amino acids cleaved from the degradation of chicken feathers by Exiguobacterium sp. FBH5 at a respective concentration of 1.16, 1.28 and 1.45 (g/100g sample). Additionally, hydrolysate that emanated from E. indicum FHBD degradation of feather showed high concentrations of arginine, serine, aspartic acid, glutamic acid, and glycine at the respective concentration (g/100g sample) of 1.2, 1.12, 1.34, 1.58 and 1.29. The keratinases were optimally active at pH and temperature of 8.0 and 50 oC, respectively. EDTA and PMSF did not highly repress keratinolytic proteases' activity, and this inhibitory pattern suggests that they may belong to a mixed protease family. Keratinase from E. acetylicum FHBD was highly stable in the presence of SDS, with 99percent residual activity and displayed variable stability in other chemical agents tested. A similar stability pattern was observed with keratinase from Exiguobacterium sp. FBH5, although the enzyme lost about 40percent of its original activity in the presence of SDS. Evaluation of metal ion stability indicated that E. acetylicum FHBD keratinase was remarkably stable in the presence of Fe3+, Mg2+, Cu2+, Zn2+, and Ba2+, with residual activity of 94percent, 88percent, 89percent, 90percent, and 97percent, respectively. Similarly, Exiguobacterium sp. FBH5 keratinase was considerably stable after treatment with Co2+, K+, and Zn2+ as it displayed a residual activity of 85percent, 84percent and 93percent, respectively. The study of the keratinases stability in laundry detergents showed that E. acetylicum FHBD keratinolytic proteases was activated in the presence of Omo, Surf, Sunlight, and Pro wash after 60 min of pre-incubation compared to 30 min, with residual activity of 94 ± 2.94percent, 91 ± 2.53percent, 95 ± 2.89percent and 87 ± 2.89percent respectively. Likewise, Exiguobacterium sp. FBH5 keratinase activity was promoted after 60 min of incubation compared to 30 min, with a residual enzyme activity of 79percent, 84percent, 101percent, 103percent and 105percent and 106percent for Ariel, Surf, Prowash, Freewave, Sky and Evaklin, respectively. Therefore Exiguobacterium spp., demonstrated excellent keratinolytic potentials that could be exploited for sustainable development of bio-innovative products. The study keratinases' properties suggest their industrial and biotechnological application potentials, especially as bio-additive in the formulation of laundry detergents. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Dlume, Tutuka
- Date: 2021-02
- Subjects: Factory and trade waste -- Biodegradation , Bioremediation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20695 , vital:46438
- Description: Keratinous wastes are emanating in a million tons, as by-products, from various agro-industrial processing plants. Consequently, they create a serious solid waste problem in the environment due to poor handling. Microbial keratinases are proteolytic enzymes that effectively participate in keratin-rich biomass hydrolyses such as feathers, nail, hair, hooves, and horns. Therefore, proper management of these wastes via recycling into useful products is ecologically imperative. Biodegradation of keratin-rich biomass has been identified as an economical and environmentally friendly way of transforming these recalcitrant agro wastes into useful products, hence the motivation for this study. Feather degrading bacterial strains previously isolated from a municipal dumpsite and coded as SSB-02 and SSB-03 was identified through 16S rDNA sequencing and phylogenetic analysis. The fermentation conditions for keratinase production were optimized. The protein and amino acids constituents of the hydrolyzed chicken feather were analyzed. The biochemical properties of the keratinase produced were determined. Also, the effect of laundry detergents on the stability of the keratinase was studied. The isolates coded as SSB-02 and SSB-03 showed a high percentage of sequence homology with Exguobacterium spp., hence they were identified as Exiguobacterium sp. FBH5 and Exiguobacterium acetylicum FHBD, respectively. Exiguobacterium sp. FBH5 showed the highest extracellular keratinase production of 934.58 ± 27.27 U/mL at 72 h of incubation; in optimized fermentation conditions that included pH (5.0), temperature (30 oC), and chicken feather (0.5percent, w/v). Similarly, E. acetylicum FHBD displayed optimal keratinase production of 1023.64 ± 25.71 U/mL at 120 h of fermentation and improved fermentation conditions that involved pH (3.0), temperature (35 oC) and chicken feathers (0.5-1.5percent; w/v). The amino acid analysis showed that arginine, aspartic acid and glutamic acid were the most abundant amino acids cleaved from the degradation of chicken feathers by Exiguobacterium sp. FBH5 at a respective concentration of 1.16, 1.28 and 1.45 (g/100g sample). Additionally, hydrolysate that emanated from E. indicum FHBD degradation of feather showed high concentrations of arginine, serine, aspartic acid, glutamic acid, and glycine at the respective concentration (g/100g sample) of 1.2, 1.12, 1.34, 1.58 and 1.29. The keratinases were optimally active at pH and temperature of 8.0 and 50 oC, respectively. EDTA and PMSF did not highly repress keratinolytic proteases' activity, and this inhibitory pattern suggests that they may belong to a mixed protease family. Keratinase from E. acetylicum FHBD was highly stable in the presence of SDS, with 99percent residual activity and displayed variable stability in other chemical agents tested. A similar stability pattern was observed with keratinase from Exiguobacterium sp. FBH5, although the enzyme lost about 40percent of its original activity in the presence of SDS. Evaluation of metal ion stability indicated that E. acetylicum FHBD keratinase was remarkably stable in the presence of Fe3+, Mg2+, Cu2+, Zn2+, and Ba2+, with residual activity of 94percent, 88percent, 89percent, 90percent, and 97percent, respectively. Similarly, Exiguobacterium sp. FBH5 keratinase was considerably stable after treatment with Co2+, K+, and Zn2+ as it displayed a residual activity of 85percent, 84percent and 93percent, respectively. The study of the keratinases stability in laundry detergents showed that E. acetylicum FHBD keratinolytic proteases was activated in the presence of Omo, Surf, Sunlight, and Pro wash after 60 min of pre-incubation compared to 30 min, with residual activity of 94 ± 2.94percent, 91 ± 2.53percent, 95 ± 2.89percent and 87 ± 2.89percent respectively. Likewise, Exiguobacterium sp. FBH5 keratinase activity was promoted after 60 min of incubation compared to 30 min, with a residual enzyme activity of 79percent, 84percent, 101percent, 103percent and 105percent and 106percent for Ariel, Surf, Prowash, Freewave, Sky and Evaklin, respectively. Therefore Exiguobacterium spp., demonstrated excellent keratinolytic potentials that could be exploited for sustainable development of bio-innovative products. The study keratinases' properties suggest their industrial and biotechnological application potentials, especially as bio-additive in the formulation of laundry detergents. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
Anti-oxidant and cytotoxicity activity against the HCC70 Breast cancer cell line of aqueous and methanolic extracts of two red algae species from the Eastern Cape Coast, South Africa
- Authors: Basera, Afra Tsitsi
- Date: 2021
- Subjects: Drug resistance in cancer cells , Oxidative stress
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22589 , vital:52586
- Description: Cancer, despite extensive research, remains one of the leading causes of mortality. Research into plant-derived compounds has gained traction, as some are not cytotoxic towards healthy cells and pose fewer side effects. Marine algae produce secondary metabolites, protecting them from oxidative stress, which causes cardiovascular diseases, cancer, and diabetes. Therefore, this study aimed to evaluate the anticancer potential of selected red algae species, collected from Humewood Beach, Gqeberha in South Africa, against HCC70 (human breast adenocarcinoma) cancer cells. Identification of the species was made through DNA barcoding of the rbcL gene. Methanolic and aqueous extracts of Gelidium pristoides and Laurencia natalensis were evaluated for antioxidant activity, phytochemical content, and anticancer potential. The phytochemical composition was determined using the phenol, flavonoid, flavonol, tannin, and proanthocyanidin content assays. Antioxidant potential was evaluated using the Ferric reducing antioxidant potential, Diphenyl-1- Picrylhydrazyl (DPPH), nitric oxide, 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activity, and total antioxidant capacity (TAC) assays. The resazurin assay was used to determine the antiproliferative and cytotoxic activity of the methanolic extracts and solid-phase extraction fractions against the HCC70 breast cancer cells. The red algae species were identified as G. pristoides and L. natalensis. The aqueous extract of G. pristoides exhibited significantly higher phenols (24.0 mg/g GAE), tannins (31.6 mg/g TAE), and flavonols content (20.5 mg/g RE) than its methanolic extract, or the aqueous and methanolic extracts of L. natalensis. Methanolic extracts of G. pristoides and L. natalensis exhibited significantly higher proanthocyanidin contents (19.4 mg/g and 15.7 mg/g CE) than their respective aqueous extracts (13.0 mg/g and 11.8 mg/g CE). Flavonoids, however, were absent in both species. The aqueous and methanol extracts of Laurencia natalensis and Gelidium pristoides exhibited low inhibitory activities (less than 50%) against DPPH, ABTS, and nitric oxide radicals. Both species also showed low ferric reducing power. All the extracts were antiproliferative and cytotoxic against the HCC70 breast cancer cells, with L. natalensis exhibiting more significant inhibitory activity. However, its Solid Phase Extraction fractions did not display antiproliferative potential, unlike fraction 4 of G. pristoides. The study results suggest that both G. pristoides and L. natalensis possess bioactive compounds with potential anticancer activity. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021
- Authors: Basera, Afra Tsitsi
- Date: 2021
- Subjects: Drug resistance in cancer cells , Oxidative stress
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22589 , vital:52586
- Description: Cancer, despite extensive research, remains one of the leading causes of mortality. Research into plant-derived compounds has gained traction, as some are not cytotoxic towards healthy cells and pose fewer side effects. Marine algae produce secondary metabolites, protecting them from oxidative stress, which causes cardiovascular diseases, cancer, and diabetes. Therefore, this study aimed to evaluate the anticancer potential of selected red algae species, collected from Humewood Beach, Gqeberha in South Africa, against HCC70 (human breast adenocarcinoma) cancer cells. Identification of the species was made through DNA barcoding of the rbcL gene. Methanolic and aqueous extracts of Gelidium pristoides and Laurencia natalensis were evaluated for antioxidant activity, phytochemical content, and anticancer potential. The phytochemical composition was determined using the phenol, flavonoid, flavonol, tannin, and proanthocyanidin content assays. Antioxidant potential was evaluated using the Ferric reducing antioxidant potential, Diphenyl-1- Picrylhydrazyl (DPPH), nitric oxide, 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activity, and total antioxidant capacity (TAC) assays. The resazurin assay was used to determine the antiproliferative and cytotoxic activity of the methanolic extracts and solid-phase extraction fractions against the HCC70 breast cancer cells. The red algae species were identified as G. pristoides and L. natalensis. The aqueous extract of G. pristoides exhibited significantly higher phenols (24.0 mg/g GAE), tannins (31.6 mg/g TAE), and flavonols content (20.5 mg/g RE) than its methanolic extract, or the aqueous and methanolic extracts of L. natalensis. Methanolic extracts of G. pristoides and L. natalensis exhibited significantly higher proanthocyanidin contents (19.4 mg/g and 15.7 mg/g CE) than their respective aqueous extracts (13.0 mg/g and 11.8 mg/g CE). Flavonoids, however, were absent in both species. The aqueous and methanol extracts of Laurencia natalensis and Gelidium pristoides exhibited low inhibitory activities (less than 50%) against DPPH, ABTS, and nitric oxide radicals. Both species also showed low ferric reducing power. All the extracts were antiproliferative and cytotoxic against the HCC70 breast cancer cells, with L. natalensis exhibiting more significant inhibitory activity. However, its Solid Phase Extraction fractions did not display antiproliferative potential, unlike fraction 4 of G. pristoides. The study results suggest that both G. pristoides and L. natalensis possess bioactive compounds with potential anticancer activity. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021
Pharmacological investigation of Citrus limon leaf extract and its efficacy as biofungicide against potato rot disease
- Authors: Ehiobu, John Meomikem
- Date: 2021
- Subjects: Potatoes -- Diseases and pests , Potato ring rot , Bacterial wilt of potato
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23666 , vital:58278
- Description: Potato, the fourth major staple and economic food crop is readily attacked by fungal pathogens. This is of public and economic importance. Interests have shifted from the age-old rot management by synthetic fungicide to botanicals due to the attended negative effects of the former. The bioactive molecules domicile in plants have been found to possess pharmacological properties against diverse pathogens of plants and animals. This study investigated the pharmacological properties of the Citrus limon leaf extracts of using different leaf solvent extracts and the potential utilization of these extracts in managing potato rot diseases. The tubers were purchased from selected supermarkets within Raymond Mhlaba Local Municipality of the Eastern Cape province of South Africa. A survey study was carried out by using a well-structured designed questionnaire administered to selected supermarkets in three major towns namely; Alice, King Williams Town and Fort Beaufort. The questionnaires were randomly administered to 62 supermarket owners in each of the selected super markets. Rotten potato tubers were randomly collected from these supermarkets. On each occasion, the tubers were packaged in a sterile polythene bag and taken to the laboratory for isolation and identification of the pathogens associated with the disease (rot) using standard mycological techniques. Fresh leaves of Citrus limon were collected from a residential area within the study location, processed and extracted using water, ethanol and acetone solvents before analysing their phytochemical contents, antioxidant properties and antifungal activites against the rotten potato tuber pathogens at graded concentrations of 25g/l, 50g/l and 100g/l. Effects of different temperatures (10-40oC) on the tuber weight loss and mycelia growth were also evaluated. Analysis of the results revealed that the supermarket owners incurred economic loss of 43percentwith annual potato loss incurement of R1501- 2000. The losses occurred more in the warmer summer seasons. About 91percent of the respondents agreed to use any novel botanicals, as alternatives to the increasing artificial fungicides due to their high costs, toxic nature and the environmental hazard effects. Phytochemical results showed that the ethanol extracts yielded the highest total flavonoid quantification of 1052.58±39.44mg GAE/g, followed by phenols (209.72 ± 6.38 GAE/g), alkaloid (12.23percent) and saponin (5.53percent). There was no significant difference in phenol content between the acetone and ethanol; but a significant difference (P < 0.05) was observed for the aqueous extracts of C. limon leaf. The aqueous, acetone and ethanol leaf extracts also showed significantly high antioxidant capacity with the ABTS (67.85percent - 90.85percent), FRAP (128.26 - 182.12 mgRE/g) and DPPH (28.72percent - 33.64percent). The fungal pathogens isolated from rotten potato tubers were identified as Curvularia mebaldsii, Fusarium oxysporum and Penicillium species. The effect of C. limon leaf extracts on the isolates was concentration and extracting solvent dependent. For the aqueous solvent, the mycelial growth of Penicillium species were most inhibited with 95.82 ± 0.11percent, 89.1 ± 0.19percent and 74.81 ± 0.82 percent, followed by F. oxysporum with 76 ± 2.83, 76percent ± 5.95percent and 29.05 ± 3.17percent and Curvularia mebaldsii (68.46 ± 3.0percent, 63.76 ± 2.87 percent and 53.47± 3.64percent) respectively. However, the ethanol and acetone extracts at 100g/l concentrations displayed a 100percent growth inhibition against the three rot fungi. The effects 50g/l ethanol concentration also showed 100percent against both F. oxysporum and C. mebaldsii, but 90.97percent against Penicillium sp. The growth inhibition at 25g/l extract against F. oxysporum were 99percent and 96.52percent for acetone and ethanol extracts respectively, but 96.52percent and 85.57percent against C. mebaldsii and Penicillium sp. respectively. The effects of temperature on the average radial mycelial growth of fungal isolates at 10oC, 20oC, 30oC, and 40oC were 17.53 mm, 28.33 mm, 42.33 mm, and 34.50 mm respectively. The highest percentage weight loss of infected potato was 19.53percent at 30oC, while the lowest was 5.12percent at 10oC. The optimal temperature of maximum activities of the isolates was 30oC and this indicates that healthy potato tubers stored at 30oC will undergo faster fungal deterioration and spoilage than those stored at 10oC. The findings indicated that the ethanol and acetone extracts displayed significantly higher phytochemicals, antioxidant properties and in vitro antifungal activity against the potato rot disease fungal pathogens. Hence, the plant leaf could be considered as a potent bio-fungicides against potato rot disease. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021
- Authors: Ehiobu, John Meomikem
- Date: 2021
- Subjects: Potatoes -- Diseases and pests , Potato ring rot , Bacterial wilt of potato
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23666 , vital:58278
- Description: Potato, the fourth major staple and economic food crop is readily attacked by fungal pathogens. This is of public and economic importance. Interests have shifted from the age-old rot management by synthetic fungicide to botanicals due to the attended negative effects of the former. The bioactive molecules domicile in plants have been found to possess pharmacological properties against diverse pathogens of plants and animals. This study investigated the pharmacological properties of the Citrus limon leaf extracts of using different leaf solvent extracts and the potential utilization of these extracts in managing potato rot diseases. The tubers were purchased from selected supermarkets within Raymond Mhlaba Local Municipality of the Eastern Cape province of South Africa. A survey study was carried out by using a well-structured designed questionnaire administered to selected supermarkets in three major towns namely; Alice, King Williams Town and Fort Beaufort. The questionnaires were randomly administered to 62 supermarket owners in each of the selected super markets. Rotten potato tubers were randomly collected from these supermarkets. On each occasion, the tubers were packaged in a sterile polythene bag and taken to the laboratory for isolation and identification of the pathogens associated with the disease (rot) using standard mycological techniques. Fresh leaves of Citrus limon were collected from a residential area within the study location, processed and extracted using water, ethanol and acetone solvents before analysing their phytochemical contents, antioxidant properties and antifungal activites against the rotten potato tuber pathogens at graded concentrations of 25g/l, 50g/l and 100g/l. Effects of different temperatures (10-40oC) on the tuber weight loss and mycelia growth were also evaluated. Analysis of the results revealed that the supermarket owners incurred economic loss of 43percentwith annual potato loss incurement of R1501- 2000. The losses occurred more in the warmer summer seasons. About 91percent of the respondents agreed to use any novel botanicals, as alternatives to the increasing artificial fungicides due to their high costs, toxic nature and the environmental hazard effects. Phytochemical results showed that the ethanol extracts yielded the highest total flavonoid quantification of 1052.58±39.44mg GAE/g, followed by phenols (209.72 ± 6.38 GAE/g), alkaloid (12.23percent) and saponin (5.53percent). There was no significant difference in phenol content between the acetone and ethanol; but a significant difference (P < 0.05) was observed for the aqueous extracts of C. limon leaf. The aqueous, acetone and ethanol leaf extracts also showed significantly high antioxidant capacity with the ABTS (67.85percent - 90.85percent), FRAP (128.26 - 182.12 mgRE/g) and DPPH (28.72percent - 33.64percent). The fungal pathogens isolated from rotten potato tubers were identified as Curvularia mebaldsii, Fusarium oxysporum and Penicillium species. The effect of C. limon leaf extracts on the isolates was concentration and extracting solvent dependent. For the aqueous solvent, the mycelial growth of Penicillium species were most inhibited with 95.82 ± 0.11percent, 89.1 ± 0.19percent and 74.81 ± 0.82 percent, followed by F. oxysporum with 76 ± 2.83, 76percent ± 5.95percent and 29.05 ± 3.17percent and Curvularia mebaldsii (68.46 ± 3.0percent, 63.76 ± 2.87 percent and 53.47± 3.64percent) respectively. However, the ethanol and acetone extracts at 100g/l concentrations displayed a 100percent growth inhibition against the three rot fungi. The effects 50g/l ethanol concentration also showed 100percent against both F. oxysporum and C. mebaldsii, but 90.97percent against Penicillium sp. The growth inhibition at 25g/l extract against F. oxysporum were 99percent and 96.52percent for acetone and ethanol extracts respectively, but 96.52percent and 85.57percent against C. mebaldsii and Penicillium sp. respectively. The effects of temperature on the average radial mycelial growth of fungal isolates at 10oC, 20oC, 30oC, and 40oC were 17.53 mm, 28.33 mm, 42.33 mm, and 34.50 mm respectively. The highest percentage weight loss of infected potato was 19.53percent at 30oC, while the lowest was 5.12percent at 10oC. The optimal temperature of maximum activities of the isolates was 30oC and this indicates that healthy potato tubers stored at 30oC will undergo faster fungal deterioration and spoilage than those stored at 10oC. The findings indicated that the ethanol and acetone extracts displayed significantly higher phytochemicals, antioxidant properties and in vitro antifungal activity against the potato rot disease fungal pathogens. Hence, the plant leaf could be considered as a potent bio-fungicides against potato rot disease. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021
Effects of paclobutrazol and plant spacing on growth, yield, and after effect on sprout development in seed potatoes (solanum tuberosum l.)
- Jokazi, Khuselo Bernad https://orcid.org/0000-0002-8620-9838
- Authors: Jokazi, Khuselo Bernad https://orcid.org/0000-0002-8620-9838
- Date: 2021-01
- Subjects: Potatoes , Plant regulators
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21323 , vital:48406
- Description: Potato (Solanum tuberosum L.) is an herbaceous plant that belongs to the genus Solanum, in the Solanaceae family which is comprised of about 2 800 species (Sahair et al., 2018). Potato domestication can be traced back to the sixteenth century in the South American continent (Hawkes, 1978). The potato crop became a staple food for greater parts of the world towards the end of the seventeenth century. It is not clear when the crop was introduced to the African continent, although the literature indicates that it was grown in some parts of the continent by the late seventeenth century (Hawkes, 1978). Potato is a very bulky crop and is a source of high energy per given area of land (Tsegaw, 2005). Nutritionally, the crop is rich in carbohydrates and provides a considerable amount of protein, with a good balance of amino acids, vitamins (C, B6, and B1, folate), minerals (potassium, phosphorus, calcium, and magnesium), and the micronutrients iron and zinc. Potatoes are also a source of high dietary fiber, especially when eaten unpeeled. In addition, potatoes are rich in antioxidants, including polyphenols, vitamin C, carotenoids, and tocopherols (Bradshaw and Ramsay, 2009). Potatoes play a very important role in the global food system. It is South Africa’s most important vegetable crop (DAFF, 2012). Worldwide, it ranks fourth topmost important food crops following wheat, maize, and rice (Esmaielpour et al., 2011; Bradshaw and Ramsay, 2009), followed by barley (Allemann et al., 2003). South Africa is the 27th largest producer in the world and the 3rd largest producer in Africa after Egypt and Malawi (FAOSTAT, 2015). In the year 2014, potatoes were produced in 51 435 hectares of land, which yielded over 2 million tons (DAFF, 2015). This crop is produced in sixteen producing regions throughout South Africa with the Limpopo, Free State, Western Cape, Mpumalanga, KwaZulu-Natal, and Eastern Cape provinces being the leading regions (DAFF, 2015). Because of the different climatic regions in South Africa, potatoes are planted at different times of the year. As a result, the country enjoys fresh potatoes throughout the year (DAFF, 2014). According to the Potato Industry Research Strategy 2014-17 under Potato South Africa, the past few years have seen a decrease in the area of land under potato production, with an increase in the average yield per area. This yield increment can be accredited to an increase in the production under irrigation system, the use of improved cultivars and seed quality, and the application of research results (PSA, 2014). World potato production indicates that intensive cultivation has led to an increment of potato yields between 1960 and 1999, even though there was a reduction in the area planted with the crop (Fabeiro et al., 2001). However, there is a large gap between potential potato yield and actual yield per hectare. Research undoubtedly holds great potential for narrowing this gap. In order to do so, there is a need to understand the factors limiting potato yield. Temperature, plant spacing, and seed tuber quality are amongst the most significant factors affecting potato growth, yield, and quality. Potatoes are very adaptive; at present, they can be produced in different climatic regions. They are temperate crops, which prefer a cool and humid climate (Haverkort, 1990), but care should be taken to avoid high-stress periods such as temperature extremes. The optimum temperature for haulm growth and net photosynthesis is in the range between 15℃ and 25℃, and 20℃ is the optimum temperature for tuberization. Tuberization is inhibited by temperatures above 29℃, as the photoassimilate partitioning towards the tubers is decreased, leading to an increase in shoot growth (Gawronska et al., 1992). Plant spacing is usually determined by the target market and cultivar. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-01
- Authors: Jokazi, Khuselo Bernad https://orcid.org/0000-0002-8620-9838
- Date: 2021-01
- Subjects: Potatoes , Plant regulators
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21323 , vital:48406
- Description: Potato (Solanum tuberosum L.) is an herbaceous plant that belongs to the genus Solanum, in the Solanaceae family which is comprised of about 2 800 species (Sahair et al., 2018). Potato domestication can be traced back to the sixteenth century in the South American continent (Hawkes, 1978). The potato crop became a staple food for greater parts of the world towards the end of the seventeenth century. It is not clear when the crop was introduced to the African continent, although the literature indicates that it was grown in some parts of the continent by the late seventeenth century (Hawkes, 1978). Potato is a very bulky crop and is a source of high energy per given area of land (Tsegaw, 2005). Nutritionally, the crop is rich in carbohydrates and provides a considerable amount of protein, with a good balance of amino acids, vitamins (C, B6, and B1, folate), minerals (potassium, phosphorus, calcium, and magnesium), and the micronutrients iron and zinc. Potatoes are also a source of high dietary fiber, especially when eaten unpeeled. In addition, potatoes are rich in antioxidants, including polyphenols, vitamin C, carotenoids, and tocopherols (Bradshaw and Ramsay, 2009). Potatoes play a very important role in the global food system. It is South Africa’s most important vegetable crop (DAFF, 2012). Worldwide, it ranks fourth topmost important food crops following wheat, maize, and rice (Esmaielpour et al., 2011; Bradshaw and Ramsay, 2009), followed by barley (Allemann et al., 2003). South Africa is the 27th largest producer in the world and the 3rd largest producer in Africa after Egypt and Malawi (FAOSTAT, 2015). In the year 2014, potatoes were produced in 51 435 hectares of land, which yielded over 2 million tons (DAFF, 2015). This crop is produced in sixteen producing regions throughout South Africa with the Limpopo, Free State, Western Cape, Mpumalanga, KwaZulu-Natal, and Eastern Cape provinces being the leading regions (DAFF, 2015). Because of the different climatic regions in South Africa, potatoes are planted at different times of the year. As a result, the country enjoys fresh potatoes throughout the year (DAFF, 2014). According to the Potato Industry Research Strategy 2014-17 under Potato South Africa, the past few years have seen a decrease in the area of land under potato production, with an increase in the average yield per area. This yield increment can be accredited to an increase in the production under irrigation system, the use of improved cultivars and seed quality, and the application of research results (PSA, 2014). World potato production indicates that intensive cultivation has led to an increment of potato yields between 1960 and 1999, even though there was a reduction in the area planted with the crop (Fabeiro et al., 2001). However, there is a large gap between potential potato yield and actual yield per hectare. Research undoubtedly holds great potential for narrowing this gap. In order to do so, there is a need to understand the factors limiting potato yield. Temperature, plant spacing, and seed tuber quality are amongst the most significant factors affecting potato growth, yield, and quality. Potatoes are very adaptive; at present, they can be produced in different climatic regions. They are temperate crops, which prefer a cool and humid climate (Haverkort, 1990), but care should be taken to avoid high-stress periods such as temperature extremes. The optimum temperature for haulm growth and net photosynthesis is in the range between 15℃ and 25℃, and 20℃ is the optimum temperature for tuberization. Tuberization is inhibited by temperatures above 29℃, as the photoassimilate partitioning towards the tubers is decreased, leading to an increase in shoot growth (Gawronska et al., 1992). Plant spacing is usually determined by the target market and cultivar. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-01
Sedimentology, petrography and geochemistry of the Kuruman Banded Iron Formation in the Prieska area, Northern Cape Province of South Africa
- Mbongonya, Mainly Abongile https://orcid.org/0000-0003-2241-8558
- Authors: Mbongonya, Mainly Abongile https://orcid.org/0000-0003-2241-8558
- Date: 2021-01
- Subjects: Mines and mineral resources -- South Africa , Sedimentology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21345 , vital:48492
- Description: The sedimentary sequences hosted by the Griqualand West Basin within the Transvaal Supergroup, Northern Cape Province of South Africa, contain several iron and manganese ore deposits. Many studies have been conducted in the Griqualand West basin, particularly within the northern Ghaap plateau compartment where most iron and manganese mines are located, with less attention to the southern Prieska Compartment. Thus, the current study is targeted at the Kuruman Formation in the Prieska area to investigate the geological occurrence, including sedimentology, geochemistry, origin, and post-depositional alteration of the banded iron formation (BIF). Four stratigraphic sections were measured, and the fifth section was only mapped for lithology and sedimentary facies. These sections constitute portions of the stratigraphic sequence of the Transvaal Supergroup that occurs within the study area. The stratigraphic sequence of the area comprises nine successional cycles with five upward fining cycles and four upward-coarsening cycles. These cycles reflect fluctuation of the sea level and shallowing- and filling-up processes of the final basin. Four mineral paragenetic groups constituting primary minerals, diagenetic minerals, low-grade minerals, and weathering mineral assemblages were encountered in the area. The primary mineral assemblage includes magnetite, hematite, siderite, chert, quartz, and smectite. The diagenetic assemblage minerals in the area are martite, quartz (cement), illite, calcite, ankerite, and stilpnomelane. Low-grade assemblage minerals are riebeckite, crocidolite, and minnesotaite, whereas goethite, limonite, calcite (calcrete), quartz (silcrete), and clay minerals are the supergene (weathering) assemblage minerals. These mineral assemblages were confirmed by microscope petrography, XRD, SEM-EDX, and diagenesis studies. Eight sedimentary facies including Horizontal-laminated BIF facies (Hlb), Horizontal thin to medium bedded BIF facies (Hbb), Ripple laminated BIF facies (Rlb), Thin to medium bedded mudstone facies (Mbm), Medium to thick-bedded mudstone facies (Tbm), Medium to thick-bedded fine-sandstone facies (Mts), Laminated dolomite stromatolite facies (Ld), and Dome-shaped stromatolitic BIF facies (Dbif) were identified in the field. Five facies associations including Facies association 1 (Hlb + Hbb), Facies association 2 (Hlb + Hbb + Mbm + Tbm), Facies association 3 (Hlb + Hbb + Mbm + Tbm + Rlb), Facies association 4 (Mbm + Tbm + Mts), and Facies association 5 (Ld + Dbif + Mts) have been recognised. Mineralogy, petrography, and geochemical studies indicate that the studied samples have all been subjected to recent weathering that altered the primary mineralogy and the geochemical composition. Mineral assemblages of the Kuruman BIF within the Prieska area are dominated by quartz, which constitutes about 53 wt.percent, followed by the iron oxides averaging about 44 wt.percent. Other minerals such as carbonates and silicates are only occurring in concentrations of less than 3 wt. percent combined. The Prieska BIF is enriched in cobalt, tungsten, molybdenum, barium (Ba), and nickel compared to the BIF in the northern parts of the Griqualand West basin and other localities. Post-depositional mineral alteration studies show that most of the primary minerals had suffered various degrees of alteration. The bulk of quartz, silicate, and iron oxide minerals in the area have been recrystallized, partially replaced, dissolved, or leached out. Multiple formation processes were involved in the origin of the banded iron formation: (1). Deposition of iron-rich mud material in the deep ocean floor and formation of a mixture of iron-rich mud (felutite) on the seafloor; (2). Differentiation of felutite and formation of disseminated iron-oxide from mud; (3). Cohesion and diagenesis of disseminated iron-oxide and formation of iron-rich (magnetite/hematite) and silica-rich (chert/quartz) patches, lenses (pod), microbands, and laminations; (4). Consolidation and compaction, leading to the formation of the final banded iron formation (BIF). , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-01
- Authors: Mbongonya, Mainly Abongile https://orcid.org/0000-0003-2241-8558
- Date: 2021-01
- Subjects: Mines and mineral resources -- South Africa , Sedimentology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21345 , vital:48492
- Description: The sedimentary sequences hosted by the Griqualand West Basin within the Transvaal Supergroup, Northern Cape Province of South Africa, contain several iron and manganese ore deposits. Many studies have been conducted in the Griqualand West basin, particularly within the northern Ghaap plateau compartment where most iron and manganese mines are located, with less attention to the southern Prieska Compartment. Thus, the current study is targeted at the Kuruman Formation in the Prieska area to investigate the geological occurrence, including sedimentology, geochemistry, origin, and post-depositional alteration of the banded iron formation (BIF). Four stratigraphic sections were measured, and the fifth section was only mapped for lithology and sedimentary facies. These sections constitute portions of the stratigraphic sequence of the Transvaal Supergroup that occurs within the study area. The stratigraphic sequence of the area comprises nine successional cycles with five upward fining cycles and four upward-coarsening cycles. These cycles reflect fluctuation of the sea level and shallowing- and filling-up processes of the final basin. Four mineral paragenetic groups constituting primary minerals, diagenetic minerals, low-grade minerals, and weathering mineral assemblages were encountered in the area. The primary mineral assemblage includes magnetite, hematite, siderite, chert, quartz, and smectite. The diagenetic assemblage minerals in the area are martite, quartz (cement), illite, calcite, ankerite, and stilpnomelane. Low-grade assemblage minerals are riebeckite, crocidolite, and minnesotaite, whereas goethite, limonite, calcite (calcrete), quartz (silcrete), and clay minerals are the supergene (weathering) assemblage minerals. These mineral assemblages were confirmed by microscope petrography, XRD, SEM-EDX, and diagenesis studies. Eight sedimentary facies including Horizontal-laminated BIF facies (Hlb), Horizontal thin to medium bedded BIF facies (Hbb), Ripple laminated BIF facies (Rlb), Thin to medium bedded mudstone facies (Mbm), Medium to thick-bedded mudstone facies (Tbm), Medium to thick-bedded fine-sandstone facies (Mts), Laminated dolomite stromatolite facies (Ld), and Dome-shaped stromatolitic BIF facies (Dbif) were identified in the field. Five facies associations including Facies association 1 (Hlb + Hbb), Facies association 2 (Hlb + Hbb + Mbm + Tbm), Facies association 3 (Hlb + Hbb + Mbm + Tbm + Rlb), Facies association 4 (Mbm + Tbm + Mts), and Facies association 5 (Ld + Dbif + Mts) have been recognised. Mineralogy, petrography, and geochemical studies indicate that the studied samples have all been subjected to recent weathering that altered the primary mineralogy and the geochemical composition. Mineral assemblages of the Kuruman BIF within the Prieska area are dominated by quartz, which constitutes about 53 wt.percent, followed by the iron oxides averaging about 44 wt.percent. Other minerals such as carbonates and silicates are only occurring in concentrations of less than 3 wt. percent combined. The Prieska BIF is enriched in cobalt, tungsten, molybdenum, barium (Ba), and nickel compared to the BIF in the northern parts of the Griqualand West basin and other localities. Post-depositional mineral alteration studies show that most of the primary minerals had suffered various degrees of alteration. The bulk of quartz, silicate, and iron oxide minerals in the area have been recrystallized, partially replaced, dissolved, or leached out. Multiple formation processes were involved in the origin of the banded iron formation: (1). Deposition of iron-rich mud material in the deep ocean floor and formation of a mixture of iron-rich mud (felutite) on the seafloor; (2). Differentiation of felutite and formation of disseminated iron-oxide from mud; (3). Cohesion and diagenesis of disseminated iron-oxide and formation of iron-rich (magnetite/hematite) and silica-rich (chert/quartz) patches, lenses (pod), microbands, and laminations; (4). Consolidation and compaction, leading to the formation of the final banded iron formation (BIF). , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-01
Evaluation of surface functionalized electrospun polyacrylonitrile nanofibers for heavy metal ions removal from synthetic wastewater
- Maqinana, Siphosethu Sesethu
- Authors: Maqinana, Siphosethu Sesethu
- Date: 2020-12
- Subjects: Nanofibers , Nanostructured materials
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20871 , vital:46680
- Description: Heavy metal ions are elements that are discharged into water streams from municipal or industrial waste. In abundance, they can be threating to the environment and human health. Amongst other several convention methods, adsorption has been proven to be the most effective method in the removal of heavy metal ions from wastewater. The aim of this research was to fabricate electrospun polyacrylonitrile (PAN) nanofibers and modify their surface to improve the adsorption efficiency for Chromium and Cadmium metal ions from synthetic wastewater. Electrospun nanofibers PAN nanofibers were fabricated via electrospinning process though careful monitoring of its parameters and modified via two-step process: hydrolysis with sodium hydroxide (NaOH), hydrochloric acid (HCl) and ethylenediamine (EDA). The morphologies, functional groups, thermal stability, chemical composition and crystallinities or amorphous structures of the nanofibers were characterised by Scanning electron microscopy (SEM), Fourier-Transform Infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), Energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD), respectively. The experiments were conducted in batch tests to analyse the effect to pH, contact time and initial concentration of the solution. Ultraviolet-Visible spectroscopy (UV-Vis) was used to analyse the concentration of metal ions. The adsorption equilibrium was reached after 120 min with a maximum adsorption capacity of 301.1 mg/g for Cd(II) ions and 195.02 mg/g for Cr(VI) ions. The adsorption capacity increased with increasing pH and initial concentration of the solution. The adsorption capacity of Cd(II) and Cr(VI) ions was higher at pH 8 and 10, respectively. The equilibrium data was best described using Freundlich isotherm with a maximum adsorption capacity for Cd(II) ions than Cr(VI) ions. Pseudo-second order kinetic model best fitted both heavy metal ions with R2 value of 0.99 for Cr(VI) ions and 0.67 for Cd(II) ions. Heavy metal ions were desorbed from the nanofibers after one regeneration cycle with an equilibrium concentration of 4.83 mg/L for Cr(VI) ions and 43.06 mg/L for Cd(II) ions. , Thesis (MSc) (Chemistry) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2020-12
- Authors: Maqinana, Siphosethu Sesethu
- Date: 2020-12
- Subjects: Nanofibers , Nanostructured materials
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20871 , vital:46680
- Description: Heavy metal ions are elements that are discharged into water streams from municipal or industrial waste. In abundance, they can be threating to the environment and human health. Amongst other several convention methods, adsorption has been proven to be the most effective method in the removal of heavy metal ions from wastewater. The aim of this research was to fabricate electrospun polyacrylonitrile (PAN) nanofibers and modify their surface to improve the adsorption efficiency for Chromium and Cadmium metal ions from synthetic wastewater. Electrospun nanofibers PAN nanofibers were fabricated via electrospinning process though careful monitoring of its parameters and modified via two-step process: hydrolysis with sodium hydroxide (NaOH), hydrochloric acid (HCl) and ethylenediamine (EDA). The morphologies, functional groups, thermal stability, chemical composition and crystallinities or amorphous structures of the nanofibers were characterised by Scanning electron microscopy (SEM), Fourier-Transform Infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), Energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD), respectively. The experiments were conducted in batch tests to analyse the effect to pH, contact time and initial concentration of the solution. Ultraviolet-Visible spectroscopy (UV-Vis) was used to analyse the concentration of metal ions. The adsorption equilibrium was reached after 120 min with a maximum adsorption capacity of 301.1 mg/g for Cd(II) ions and 195.02 mg/g for Cr(VI) ions. The adsorption capacity increased with increasing pH and initial concentration of the solution. The adsorption capacity of Cd(II) and Cr(VI) ions was higher at pH 8 and 10, respectively. The equilibrium data was best described using Freundlich isotherm with a maximum adsorption capacity for Cd(II) ions than Cr(VI) ions. Pseudo-second order kinetic model best fitted both heavy metal ions with R2 value of 0.99 for Cr(VI) ions and 0.67 for Cd(II) ions. Heavy metal ions were desorbed from the nanofibers after one regeneration cycle with an equilibrium concentration of 4.83 mg/L for Cr(VI) ions and 43.06 mg/L for Cd(II) ions. , Thesis (MSc) (Chemistry) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2020-12
Monitoring the impact of deforestation on an aquatic ecosystem using remote sensing: a case study of the Mngazana mangrove forest in the eastern cape province.
- Authors: Madasa, Akhona
- Date: 2020-12
- Subjects: Remote sensing , Mangrove forests , Climatic changes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20815 , vital:46598
- Description: Coastal mangrove vegetation at Mngazana continues to be threatened and reduced periodically due to unmonitored harvesting. Covering an area of 148ha, the Mngazana mangrove forest remains unreserved, thus, research on the Mngazana mangroves is essential in order to monitor their state and sustainable management. Since in-situ monitoring of mangrove areas is both challenging and time-consuming, remote sensing technologies have been used to monitor these ecosystems. This study was carried out to monitor the impact of deforestation using ASTER satellite images over ten years: from 2008 - 2018. Validation was carried out by comparing classification results with the ground-referenced data, which yielded satisfactory agreement, with an overall accuracy of 94.64 percent and Kappa coefficient of 0.93 for 2008; and in 2009, the overall accuracy was 88.62 percent and a Kappa coefficient of 0.85. While the overall accuracy of 95.08 percent and a Kappa coefficient of 0.92 for 2016 and 2018 were observed, the overall accuracy of 93.58 percent and a Kappa coefficient of 0.91 was yielded. NDVI and SAVI indices were used as monitoring indicators. The results obtained in the study indicated that the canopy density of the mangrove forest remained unchanged in the years under investigation. However, insignificant changes in canopy density were identified between 2009 and 2016. , Thesis (MSc) (Applied Remote Sensing & GIS) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2020-12
- Authors: Madasa, Akhona
- Date: 2020-12
- Subjects: Remote sensing , Mangrove forests , Climatic changes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20815 , vital:46598
- Description: Coastal mangrove vegetation at Mngazana continues to be threatened and reduced periodically due to unmonitored harvesting. Covering an area of 148ha, the Mngazana mangrove forest remains unreserved, thus, research on the Mngazana mangroves is essential in order to monitor their state and sustainable management. Since in-situ monitoring of mangrove areas is both challenging and time-consuming, remote sensing technologies have been used to monitor these ecosystems. This study was carried out to monitor the impact of deforestation using ASTER satellite images over ten years: from 2008 - 2018. Validation was carried out by comparing classification results with the ground-referenced data, which yielded satisfactory agreement, with an overall accuracy of 94.64 percent and Kappa coefficient of 0.93 for 2008; and in 2009, the overall accuracy was 88.62 percent and a Kappa coefficient of 0.85. While the overall accuracy of 95.08 percent and a Kappa coefficient of 0.92 for 2016 and 2018 were observed, the overall accuracy of 93.58 percent and a Kappa coefficient of 0.91 was yielded. NDVI and SAVI indices were used as monitoring indicators. The results obtained in the study indicated that the canopy density of the mangrove forest remained unchanged in the years under investigation. However, insignificant changes in canopy density were identified between 2009 and 2016. , Thesis (MSc) (Applied Remote Sensing & GIS) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2020-12
Effect of different fat levels and Moringa oleifera leaf meal (MOLM) inclusion on proximate composition, fatty acid profile, lipid oxidation, and sensory attributes of chicken droëwors
- Authors: Tembela, Nelisiwe
- Date: 2020-11
- Subjects: Moringa oleifera , Meat--Quality , Broilers (Chickens)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20893 , vital:46709
- Description: The objective of the study was to determine the effect of different fat levels and Moringa oleifera leaf meal (MLM) inclusion on sensory attributes (aroma, meat flavour, spicy flavour, texture, colour, and saltiness), lipid oxidation, proximate composition, and fatty acid (FA) profile of chicken droëwors. Firstly, sensory attributes of chicken droëwors with different levels of fat and that of Moringa oleifera leaf meal were determined. In the second experiment, the effect of different fat and MLM inclusion levels on lipid oxidation during drying and storage, proximate composition, and fatty acid profile were also determined. A forty randomly selected consumers of different gender and age were used as the sensory panel. 75 percent of lean chicken meat and 25 percent of chicken fat was used during droëwors preparation. Thereafter, 9 treatments of chicken droëwors were produced, with MLM included either at 0 percent, 0.25 percent, 0.5 percent, and fat included at 10 percent and 15 percent. For fatty acid profile, the total lipid from dry sausage of all treatments was quantitatively extracted using chloroform and methanol in a ratio of 2:1. Lipid oxidation was measured by analyzing thiobarbituric acid reactive substances (TBARS) at intervals during drying (0, 0.25, 0.5, 72h) and after 7 days of storage under ambient conditions. The results showed that consumers like the chicken droëwors when 0.5 percent MLM added to the product. The inclusion of MLM in chicken droëwors had a positive effect on consumer sensory. The results of the study demonstrated that chicken droëwors contained a significantly higher percentage (P<0.05) of C18:1c9 (Oleic) (30.95 to 32.65 percent) acid than other fatty acids. Polyunsaturated fatty acids (PUFAs) were all non-significant (P˃0.05) except for Docosahexanoic, which was observed to be significant (P˂ 0.05) in all treatments except T1. There was no significance (P> 0.05) in mono-unsaturated fatty acids (MUFAs), except for Elaidic, vaccenic, linoleic, y-linoleic, erucic, and arachidonic. Lipid oxidation occurred more rapidly (P<0.05) when MLM was not added. During processing and storage, TBARS were higher (P< 0.05) in chicken droewors. TBARS during storage were lower (P>0.05) with MLM added. Results showed a significant difference (P<0.05) in proximate composition of chicken droëwors, containing on average 16.93±1.29 to 10.79± 1.83/ 100 g moisture, 45.80± 1.65 to 67.56± 2.33/ 100 g protein, 14.37± 2.15 to 26.13± 2.15/100 g ash. The current study resultsgave a summary of the composition of chicken droëwors and showed higher susceptibility to lipid oxidation in chicken droewors. Therefore, Moringa oleifera leaf powder showed antioxidant activity in chicken droëwors, reserved lipid oxidation in the product. In conclusion, MLM could be used as a functional antioxidant preservative in chicken droëwors. , Thesis (MSc) (Animal Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2020-11
- Authors: Tembela, Nelisiwe
- Date: 2020-11
- Subjects: Moringa oleifera , Meat--Quality , Broilers (Chickens)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20893 , vital:46709
- Description: The objective of the study was to determine the effect of different fat levels and Moringa oleifera leaf meal (MLM) inclusion on sensory attributes (aroma, meat flavour, spicy flavour, texture, colour, and saltiness), lipid oxidation, proximate composition, and fatty acid (FA) profile of chicken droëwors. Firstly, sensory attributes of chicken droëwors with different levels of fat and that of Moringa oleifera leaf meal were determined. In the second experiment, the effect of different fat and MLM inclusion levels on lipid oxidation during drying and storage, proximate composition, and fatty acid profile were also determined. A forty randomly selected consumers of different gender and age were used as the sensory panel. 75 percent of lean chicken meat and 25 percent of chicken fat was used during droëwors preparation. Thereafter, 9 treatments of chicken droëwors were produced, with MLM included either at 0 percent, 0.25 percent, 0.5 percent, and fat included at 10 percent and 15 percent. For fatty acid profile, the total lipid from dry sausage of all treatments was quantitatively extracted using chloroform and methanol in a ratio of 2:1. Lipid oxidation was measured by analyzing thiobarbituric acid reactive substances (TBARS) at intervals during drying (0, 0.25, 0.5, 72h) and after 7 days of storage under ambient conditions. The results showed that consumers like the chicken droëwors when 0.5 percent MLM added to the product. The inclusion of MLM in chicken droëwors had a positive effect on consumer sensory. The results of the study demonstrated that chicken droëwors contained a significantly higher percentage (P<0.05) of C18:1c9 (Oleic) (30.95 to 32.65 percent) acid than other fatty acids. Polyunsaturated fatty acids (PUFAs) were all non-significant (P˃0.05) except for Docosahexanoic, which was observed to be significant (P˂ 0.05) in all treatments except T1. There was no significance (P> 0.05) in mono-unsaturated fatty acids (MUFAs), except for Elaidic, vaccenic, linoleic, y-linoleic, erucic, and arachidonic. Lipid oxidation occurred more rapidly (P<0.05) when MLM was not added. During processing and storage, TBARS were higher (P< 0.05) in chicken droewors. TBARS during storage were lower (P>0.05) with MLM added. Results showed a significant difference (P<0.05) in proximate composition of chicken droëwors, containing on average 16.93±1.29 to 10.79± 1.83/ 100 g moisture, 45.80± 1.65 to 67.56± 2.33/ 100 g protein, 14.37± 2.15 to 26.13± 2.15/100 g ash. The current study resultsgave a summary of the composition of chicken droëwors and showed higher susceptibility to lipid oxidation in chicken droewors. Therefore, Moringa oleifera leaf powder showed antioxidant activity in chicken droëwors, reserved lipid oxidation in the product. In conclusion, MLM could be used as a functional antioxidant preservative in chicken droëwors. , Thesis (MSc) (Animal Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2020-11
Effect of Mucuna pruriens based-diets on fatty acids composition and sensory attributes of meat from broiler chickens
- Authors: Makhamba, Nasiphi
- Date: 2020-11
- Subjects: Fatty acids , Broilers (Chickens)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20771 , vital:46554
- Description: The current study was conducted to determine the effect of feeding different inclusion levels of processed Mucuna pruriens on fatty acid composition and sensory attributes of broiler chickens. 120 Cob500 broilers were used in the experiment. The experiment was divided into 4 treatment (0, 10, 15 and 20 percent of Mucuna pruriens) groups, each treatment with 6 replicates (5 birds per replicate) in a completely randomized design. The first treatment (0 percent) was used as control against the three different levels of Mucuna pruriens. The birds were reared in a deep litter system until they reached slaughter weight of 2kg. At day 42 a total of 80 birds were slaughtered and breast muscles were sampled for the evaluation of sensory attributes and fatty acid composition. For sensory evaluation meat samples were prepared and boiled at 80°C until the internal temperature reached 82°C, 40 consumers were used to assess the meat samples and give scores according to 9-point hedonic scale. The fatty acid content was determined and recorded using the gas chromatography. Total saturated fatty acid (SFA), total monounsaturated fatty acid (MUFA), and total polyunsaturated fatty acid (PUFA) of the breast meat were not affected by diets. Omega-6 and omega-3 fatty acid were also not influenced by treatment diets. However, breast muscle from broilers fed 20 percent Mucuna pruriens seed meal inclusion had lower Myristic acid. The sensory attributes; aroma, colour, flavour, juiciness, tenderness and acceptability were assessed, dietary treatments affected the juiciness, tenderness and acceptability of meat, the treatments showed no significant difference on colour, aroma and flavour. Different age groups accepted the meat differently, the respondents that were between 18 and 22 years old gave the highest scores to the acceptability of meat than the other age groups, and different age groups also gave different scores in the aroma of meat. Females and males accepted the meat differently, the female respondents gave higher scores on the flavour of meat than males. Different inclusion levels of Mucuna pruriens positively affected fatty acid composition and sensory attributes of broiler chickens without causing any detrimental effects. , Thesis (MSc) (Animal Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2020-11
- Authors: Makhamba, Nasiphi
- Date: 2020-11
- Subjects: Fatty acids , Broilers (Chickens)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20771 , vital:46554
- Description: The current study was conducted to determine the effect of feeding different inclusion levels of processed Mucuna pruriens on fatty acid composition and sensory attributes of broiler chickens. 120 Cob500 broilers were used in the experiment. The experiment was divided into 4 treatment (0, 10, 15 and 20 percent of Mucuna pruriens) groups, each treatment with 6 replicates (5 birds per replicate) in a completely randomized design. The first treatment (0 percent) was used as control against the three different levels of Mucuna pruriens. The birds were reared in a deep litter system until they reached slaughter weight of 2kg. At day 42 a total of 80 birds were slaughtered and breast muscles were sampled for the evaluation of sensory attributes and fatty acid composition. For sensory evaluation meat samples were prepared and boiled at 80°C until the internal temperature reached 82°C, 40 consumers were used to assess the meat samples and give scores according to 9-point hedonic scale. The fatty acid content was determined and recorded using the gas chromatography. Total saturated fatty acid (SFA), total monounsaturated fatty acid (MUFA), and total polyunsaturated fatty acid (PUFA) of the breast meat were not affected by diets. Omega-6 and omega-3 fatty acid were also not influenced by treatment diets. However, breast muscle from broilers fed 20 percent Mucuna pruriens seed meal inclusion had lower Myristic acid. The sensory attributes; aroma, colour, flavour, juiciness, tenderness and acceptability were assessed, dietary treatments affected the juiciness, tenderness and acceptability of meat, the treatments showed no significant difference on colour, aroma and flavour. Different age groups accepted the meat differently, the respondents that were between 18 and 22 years old gave the highest scores to the acceptability of meat than the other age groups, and different age groups also gave different scores in the aroma of meat. Females and males accepted the meat differently, the female respondents gave higher scores on the flavour of meat than males. Different inclusion levels of Mucuna pruriens positively affected fatty acid composition and sensory attributes of broiler chickens without causing any detrimental effects. , Thesis (MSc) (Animal Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2020-11
The evaluation of growth characteristics, biomass yield, and chemical composition of two cultivars of Panicum maximum (Mombaca and Gatton) and Brachiaria brizantha (Marandu) at different harvesting stages
- Sokupa, Mihle Inga https://orcid.org/0000-0002-3918-1393
- Authors: Sokupa, Mihle Inga https://orcid.org/0000-0002-3918-1393
- Date: 2020-11
- Subjects: Pastures
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21433 , vital:48621
- Description: The objective of this study was to carry out a comparative assessment of growth characteristics, biomass yield and chemical composition of Panicum maximum and Brachiaria brizantha cultivars at different harvesting stages. The field experiment was conducted at the University of Fort Hare research farm in Alice, South Africa. The main factors were three cultivars: Mombaca, Gatton (Panicum maximum) and Marandu (Brachiaria brizantha) and three harvesting stages (6, 10 and 14 weeks after planting). This study was a 3 × 3 factorial set up in a randomized complete block design with three replicates. Characteristics which included plant height, number of leaves and number of tillers were measured in five plants per plot at 2-week intervals from 4 to 14 weeks after planting (WAP). The fresh yield was weighed then oven dried at 65oC for 72 hours then dry matter yield was calculated after drying. The chemical composition (Ash, Fat, ADF, ADL, NDF, CP, Ca, Mg, Na, P, K, Cu, Fe, Zn and Mn) was determined on forage harvested at 6, 10 and 14WAP. Data was analysed using the Statistical Analysis Software in a 3x3 factorial to compute the ANOVA and all means of all treatments were calculated and the difference was tested for significance using the Least Significant Difference (LSD) test at P=0.05. The results showed variations (P<0.05) in plant height, but the number of leaves did not differ (P > 0.05) between the cultivars. The number of tillers were significantly different (P<0.05), the highest number of tillers was observed in Mombaca. Fresh yield showed significant differences at 10 and 14WAP, with Marandu producing the highest Fresh yield. The moisture content was different (P<0.05) across all the three harvests. Varying (P< 0.05) results were also observed in the dry matter yield of the cultivars with Mombaca producing the highest dry matter yield. There were no significant differences (P>0.05) in the ash content of the cultivars. The fat content also showed no significant differences. Variations (P<0.05) occured in the ADF of the cultivars, Marandu had the lowest ADF. The cultivar × WAP interactive effect was significant for ADL content. NDF significantly varied across the cultivars at 6WAP. There were no similarities (P<0.05) in the crude protein during the three harvesting intervals, Mombaca produced the highest CP and the lowest was obtained from Gatton. There was a significant interaction (P<0.05) between the cultivars and harvesting intervals for Calcium (Ca), Magnesium (Mg), Sodium (Na), Potassium (K), K/Ca+Mg, Copper (Cu), Iron (Fe), Zinc (Zn) and Manganese (Mn) contents of the cultivars. However, Phosphorus (P) showed no significant interaction (P>0.05) between the cultivars and harvesting intervals. The results obtained in this study showed that as the grasses grow, the biomass yield produced increases according to the genetic makeup and the factors affecting growth and biomass yield. However, the chemical composition decreased between cultivars. Mombaca showed superior traits in terms of growth biomass yield and chemical composition. Mombaca, which is a Panicum maximum cultivar can be used as a choice in forage production and chemical composition as it can supply both quality and quantity. It can be concluded that there are significant differences in growth characteristics, biomass yield and chemical composition of Panicum maximum and Brachiaria brizantha cultivars at different harvesting stages. It can also be recommended that the best harvesting stage is at 10 WAP, this is because both biomass yield and chemical composition are both satisfactory. , Thesis (MSc) -- Faculty of Science and Agriculture, 2020
- Full Text:
- Date Issued: 2020-11
- Authors: Sokupa, Mihle Inga https://orcid.org/0000-0002-3918-1393
- Date: 2020-11
- Subjects: Pastures
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21433 , vital:48621
- Description: The objective of this study was to carry out a comparative assessment of growth characteristics, biomass yield and chemical composition of Panicum maximum and Brachiaria brizantha cultivars at different harvesting stages. The field experiment was conducted at the University of Fort Hare research farm in Alice, South Africa. The main factors were three cultivars: Mombaca, Gatton (Panicum maximum) and Marandu (Brachiaria brizantha) and three harvesting stages (6, 10 and 14 weeks after planting). This study was a 3 × 3 factorial set up in a randomized complete block design with three replicates. Characteristics which included plant height, number of leaves and number of tillers were measured in five plants per plot at 2-week intervals from 4 to 14 weeks after planting (WAP). The fresh yield was weighed then oven dried at 65oC for 72 hours then dry matter yield was calculated after drying. The chemical composition (Ash, Fat, ADF, ADL, NDF, CP, Ca, Mg, Na, P, K, Cu, Fe, Zn and Mn) was determined on forage harvested at 6, 10 and 14WAP. Data was analysed using the Statistical Analysis Software in a 3x3 factorial to compute the ANOVA and all means of all treatments were calculated and the difference was tested for significance using the Least Significant Difference (LSD) test at P=0.05. The results showed variations (P<0.05) in plant height, but the number of leaves did not differ (P > 0.05) between the cultivars. The number of tillers were significantly different (P<0.05), the highest number of tillers was observed in Mombaca. Fresh yield showed significant differences at 10 and 14WAP, with Marandu producing the highest Fresh yield. The moisture content was different (P<0.05) across all the three harvests. Varying (P< 0.05) results were also observed in the dry matter yield of the cultivars with Mombaca producing the highest dry matter yield. There were no significant differences (P>0.05) in the ash content of the cultivars. The fat content also showed no significant differences. Variations (P<0.05) occured in the ADF of the cultivars, Marandu had the lowest ADF. The cultivar × WAP interactive effect was significant for ADL content. NDF significantly varied across the cultivars at 6WAP. There were no similarities (P<0.05) in the crude protein during the three harvesting intervals, Mombaca produced the highest CP and the lowest was obtained from Gatton. There was a significant interaction (P<0.05) between the cultivars and harvesting intervals for Calcium (Ca), Magnesium (Mg), Sodium (Na), Potassium (K), K/Ca+Mg, Copper (Cu), Iron (Fe), Zinc (Zn) and Manganese (Mn) contents of the cultivars. However, Phosphorus (P) showed no significant interaction (P>0.05) between the cultivars and harvesting intervals. The results obtained in this study showed that as the grasses grow, the biomass yield produced increases according to the genetic makeup and the factors affecting growth and biomass yield. However, the chemical composition decreased between cultivars. Mombaca showed superior traits in terms of growth biomass yield and chemical composition. Mombaca, which is a Panicum maximum cultivar can be used as a choice in forage production and chemical composition as it can supply both quality and quantity. It can be concluded that there are significant differences in growth characteristics, biomass yield and chemical composition of Panicum maximum and Brachiaria brizantha cultivars at different harvesting stages. It can also be recommended that the best harvesting stage is at 10 WAP, this is because both biomass yield and chemical composition are both satisfactory. , Thesis (MSc) -- Faculty of Science and Agriculture, 2020
- Full Text:
- Date Issued: 2020-11
An analysis of special needs in a.a. milne’s children’s series, winnie the pooh, and the updated pooh series authored by david benedictus
- Authors: van Tonder, Tarryn
- Date: 2020-09
- Subjects: children’s literature , Children with disabilities--Education , Special education
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21189 , vital:47393
- Description: A. A. Milne was an author that made an impact on the development of children’s literature that continues today. His collection of books, inspired by his own life experiences, has paved the way for the development of recognising individuals that behave in ways that are contrary to societal norms, a topic that had been given little attention before the Winnie the Pooh books were written. These little children’s books were a front runner in the discussion of disabilities and special needs characters in children’s literature and revealed to children that they did not need to be fearful of individuals who were unlike them. Winnie the Pooh books encouraged sensitivity toward those with disabilities and special needs and illustrated how one could show acceptance in a loving and safe environment. The Winnie the Pooh series incorporates captivating and endearing characters with physical or mental aberrations, thus, educating society, enlightening readers and paving the way for literature to incorporate novel characters that have physical barriers or deformities. Each character in the Winnie the Pooh books is unique in his or her own way, displaying various special needs, character ‘flaws’, personalities and disabilities. These special needs characters are depicted honestly and with a wry sense of humour wherein each is accepted despite his or her foibles. This collection of books opposed the norm in children’s literature of shunning differences and disabilities, but addressed this topic in an open, tolerant manner, enabling children around the globe to embrace the characters because of their uniqueness. A. A Milne defied society’s rules and norms and paved the way for child readers to be introduced to individuals with special needs in a fresh, inviting way, encouraging these young readers to envision affirming experiences in their interactions with special needs individuals. These books endeavoured to positively change perceptions concerning special needs and disabilities. As a result, the Winnie the Pooh books have altered mind-sets and inspired this topic to be brought to the forefront. This project seeks to provide an exploration of special needs within the characters of the Winnie the Pooh collection of books authored by A.A Milne, as well as the contemporary renditions of these books authored by David Benedictus, by analysing the characters through a psychoanalytical lens, as well as providing an extensive examination through the medical and social theories of disability. Thus, the study will provide a thorough, text-based literary analysis by discussing three main areas regarding the topic of special needs in Winnie the Pooh. The three focal areas in this study are as follows: firstly, to analyse the manner in which special needs or disabilities had been previously addressed and depicted in children’s literature; secondly, to identify the special needs traits in each of the Winnie the Pooh characters and examine how each of them are depicted or portrayed in the books written by A. A. Milne and David Benedictus; and thirdly, to examine what the other characters do to illustrate their acceptance of the special needs characters and consider how these books can be used as a tool in bibliotherapy. The analysis of The Winnie the Pooh books is important due to the way they address the topics of acceptance, friendship and love for individuals with special needs and disabilities. This study significantly contributes to the literary debates on the topics of special needs characters and their portrayal in children’s literature. The topic of special needs is on the rise in political and social debates and more efforts are made to create inclusion in society. Literature plays a fundamental role in shaping children’s perspectives on acceptance or fear regarding individuals who differ from them, including those that have special needs or a disability. Characters with special needs or disabilities have constantly been identified as villains, malevolent and rejected by society. A.A. Milne’s portrayal of characters with special needs in a friendly, loving and accepting way has made children from around the world fall in love with these characters. This study will contribute to the growing understanding of special needs and disabilities as represented in literature and contribute to the breadth of research on A.A. Milne’s, Winnie the Pooh books. , Thesis (MA) (English) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2020-09
- Authors: van Tonder, Tarryn
- Date: 2020-09
- Subjects: children’s literature , Children with disabilities--Education , Special education
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21189 , vital:47393
- Description: A. A. Milne was an author that made an impact on the development of children’s literature that continues today. His collection of books, inspired by his own life experiences, has paved the way for the development of recognising individuals that behave in ways that are contrary to societal norms, a topic that had been given little attention before the Winnie the Pooh books were written. These little children’s books were a front runner in the discussion of disabilities and special needs characters in children’s literature and revealed to children that they did not need to be fearful of individuals who were unlike them. Winnie the Pooh books encouraged sensitivity toward those with disabilities and special needs and illustrated how one could show acceptance in a loving and safe environment. The Winnie the Pooh series incorporates captivating and endearing characters with physical or mental aberrations, thus, educating society, enlightening readers and paving the way for literature to incorporate novel characters that have physical barriers or deformities. Each character in the Winnie the Pooh books is unique in his or her own way, displaying various special needs, character ‘flaws’, personalities and disabilities. These special needs characters are depicted honestly and with a wry sense of humour wherein each is accepted despite his or her foibles. This collection of books opposed the norm in children’s literature of shunning differences and disabilities, but addressed this topic in an open, tolerant manner, enabling children around the globe to embrace the characters because of their uniqueness. A. A Milne defied society’s rules and norms and paved the way for child readers to be introduced to individuals with special needs in a fresh, inviting way, encouraging these young readers to envision affirming experiences in their interactions with special needs individuals. These books endeavoured to positively change perceptions concerning special needs and disabilities. As a result, the Winnie the Pooh books have altered mind-sets and inspired this topic to be brought to the forefront. This project seeks to provide an exploration of special needs within the characters of the Winnie the Pooh collection of books authored by A.A Milne, as well as the contemporary renditions of these books authored by David Benedictus, by analysing the characters through a psychoanalytical lens, as well as providing an extensive examination through the medical and social theories of disability. Thus, the study will provide a thorough, text-based literary analysis by discussing three main areas regarding the topic of special needs in Winnie the Pooh. The three focal areas in this study are as follows: firstly, to analyse the manner in which special needs or disabilities had been previously addressed and depicted in children’s literature; secondly, to identify the special needs traits in each of the Winnie the Pooh characters and examine how each of them are depicted or portrayed in the books written by A. A. Milne and David Benedictus; and thirdly, to examine what the other characters do to illustrate their acceptance of the special needs characters and consider how these books can be used as a tool in bibliotherapy. The analysis of The Winnie the Pooh books is important due to the way they address the topics of acceptance, friendship and love for individuals with special needs and disabilities. This study significantly contributes to the literary debates on the topics of special needs characters and their portrayal in children’s literature. The topic of special needs is on the rise in political and social debates and more efforts are made to create inclusion in society. Literature plays a fundamental role in shaping children’s perspectives on acceptance or fear regarding individuals who differ from them, including those that have special needs or a disability. Characters with special needs or disabilities have constantly been identified as villains, malevolent and rejected by society. A.A. Milne’s portrayal of characters with special needs in a friendly, loving and accepting way has made children from around the world fall in love with these characters. This study will contribute to the growing understanding of special needs and disabilities as represented in literature and contribute to the breadth of research on A.A. Milne’s, Winnie the Pooh books. , Thesis (MA) (English) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2020-09
Water restriction and vitamin c supplementation on Xhosa goats during summer: Effect on growth performance, blood biochemical profile, nutrient balance, carcass characteristics and meat quality
- Akinmoladun, Oluwakamisi Festus https://orcid.org/0000-0001-6462-374X
- Authors: Akinmoladun, Oluwakamisi Festus https://orcid.org/0000-0001-6462-374X
- Date: 2020-08
- Subjects: Goats -- Nutrition , Goats -- Feeding and feeds
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22710 , vital:52664
- Description: This study aimed to evaluate the effect of single and extra vitamin C (VC) supplementation on water-stressed Xhosa goats during the summer by evaluating their growth performance, blood biochemical profile, nutrient balance, carcass characteristics and meat qualities. The objectives were to assess the effect of water restriction and vitamin C supplementation by evaluating: firstly, growth performance, heat tolerance responses, and blood metabolites; secondly, intake, nutrient digestibility, nitrogen and mineral balance; thirdly, stress indices, carcass characteristics and meat qualities parameters and lastly, fatty acid profile, oxidative stability of lipids and sensory attributes were evaluated. To achieve these objectives, forty-two (42) goats were divided equally into seven treatments (75-day trial); without water restriction (W0, control); water restriction of 70percent of ad libitum water intake WI (W70); water restriction of 50percent ad libitum WI (W50); water restriction of 70percent of ad libitum WI plus 3g VC daily (W70+); water restriction 50percent of ad libitum WI plus 3g VC daily (W50+); water restriction of 70percent of ad libitumWI plus 3g VC and extra 5gVC given every eight-day (70++); water restriction of 50percent of ad libitum WI plus 3g VC and extra 5gVC given every eight-day (W50++). In the first objective, growth performance parameters, body condition scores, rectal temperature, respiratory rate, heat tolerance response parameters and blood metabolites were measured.Weight loss due to water restriction was reduced by VC supplementation in treated groups. The attenuation effect of VC was significant (P<0.05) in responses to respiratory rate (RR), Na+, K+, Mg2+, Cl-, Ca2+ and urea. Supplementation of VC (either single or multiple) did not (P>0.05) improve the effect of water restriction on body condition scores (BCs), FAMACHA©, glucose, globulin, alanine aminotransferase (ALT) and high-density lipoprotein (HDL). In the second objective, intake, nutrient digestibility, nitrogen and mineral balance were evaluated. The reduced nutrient intake was similar (P>0.05) irrespective of water restrictions and VC supplementations. Water-restriction levels did not affect nutrient intake/metabolic weight. Retained nitrogen increased with water-restriction levels but not influenced by VC. NH3-N decreased with the levels of water restriction while the pH was similar across the water restricted groups. Supplementation of VC had no effect (P>0.05) on apparent digestibility and digestible nutrients induced by water restriction levels. The amount of Ca, K, Mg retained increased (P<0.05) with water-restriction levels. In the third objective, stress indices, carcass characteristics and meat quality parameters were evaluated. The level of plasma cortisol concentration due to water stress was lessened (P<0.05) by VC. Follicle stimulating hormone (FSH), Luteinizing hormone (LH) and insulin were not affected (P>0.05) by levels of water restriction. The hot and carcass weights were lower (P<0.05) in W70+ and W50+ compared to W70 and W50 respectively. Vitamin C treated goats had higher redness (a*) compared to W70, W50 and W0. The shear force and cooking loss increased (P<0.05) with water restriction levels, while thaw loss, pH45min and pH24h were not affected by water restriction levels. In the final objective, the treatments did not affect (P>0.05) the oxidative stability of lipids (TBARS). The moisture and fat content in the water restricted groups were lower (P<0.05) than W0. The consumer meat sensory appearance decreased (P<0.05) with levels of water restrictions. Regardless of VC concentration and supplementation, vaccenic, and docosahexaenoic acid increased (P<0.05) while linolenic acid decreased as the water restriction levels increased. Nonetheless, treatment did not affect (P>0.05) the saturated and unsaturated fatty acids. These studies showed that suboptimal water intake negatively affects the growth performance and nutrient intake of Xhosa goats. However, the reduction in body weight loss and decreased plasma cortisol (chief stress hormone) concentration following vitamin C supplementation (especially at a daily single dose [3g/d]) may well reduce the effect of water stress in goats. , Thesis (PhD) -- Faculty of Science and Agriculture, 2020
- Full Text:
- Date Issued: 2020-08
- Authors: Akinmoladun, Oluwakamisi Festus https://orcid.org/0000-0001-6462-374X
- Date: 2020-08
- Subjects: Goats -- Nutrition , Goats -- Feeding and feeds
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22710 , vital:52664
- Description: This study aimed to evaluate the effect of single and extra vitamin C (VC) supplementation on water-stressed Xhosa goats during the summer by evaluating their growth performance, blood biochemical profile, nutrient balance, carcass characteristics and meat qualities. The objectives were to assess the effect of water restriction and vitamin C supplementation by evaluating: firstly, growth performance, heat tolerance responses, and blood metabolites; secondly, intake, nutrient digestibility, nitrogen and mineral balance; thirdly, stress indices, carcass characteristics and meat qualities parameters and lastly, fatty acid profile, oxidative stability of lipids and sensory attributes were evaluated. To achieve these objectives, forty-two (42) goats were divided equally into seven treatments (75-day trial); without water restriction (W0, control); water restriction of 70percent of ad libitum water intake WI (W70); water restriction of 50percent ad libitum WI (W50); water restriction of 70percent of ad libitum WI plus 3g VC daily (W70+); water restriction 50percent of ad libitum WI plus 3g VC daily (W50+); water restriction of 70percent of ad libitumWI plus 3g VC and extra 5gVC given every eight-day (70++); water restriction of 50percent of ad libitum WI plus 3g VC and extra 5gVC given every eight-day (W50++). In the first objective, growth performance parameters, body condition scores, rectal temperature, respiratory rate, heat tolerance response parameters and blood metabolites were measured.Weight loss due to water restriction was reduced by VC supplementation in treated groups. The attenuation effect of VC was significant (P<0.05) in responses to respiratory rate (RR), Na+, K+, Mg2+, Cl-, Ca2+ and urea. Supplementation of VC (either single or multiple) did not (P>0.05) improve the effect of water restriction on body condition scores (BCs), FAMACHA©, glucose, globulin, alanine aminotransferase (ALT) and high-density lipoprotein (HDL). In the second objective, intake, nutrient digestibility, nitrogen and mineral balance were evaluated. The reduced nutrient intake was similar (P>0.05) irrespective of water restrictions and VC supplementations. Water-restriction levels did not affect nutrient intake/metabolic weight. Retained nitrogen increased with water-restriction levels but not influenced by VC. NH3-N decreased with the levels of water restriction while the pH was similar across the water restricted groups. Supplementation of VC had no effect (P>0.05) on apparent digestibility and digestible nutrients induced by water restriction levels. The amount of Ca, K, Mg retained increased (P<0.05) with water-restriction levels. In the third objective, stress indices, carcass characteristics and meat quality parameters were evaluated. The level of plasma cortisol concentration due to water stress was lessened (P<0.05) by VC. Follicle stimulating hormone (FSH), Luteinizing hormone (LH) and insulin were not affected (P>0.05) by levels of water restriction. The hot and carcass weights were lower (P<0.05) in W70+ and W50+ compared to W70 and W50 respectively. Vitamin C treated goats had higher redness (a*) compared to W70, W50 and W0. The shear force and cooking loss increased (P<0.05) with water restriction levels, while thaw loss, pH45min and pH24h were not affected by water restriction levels. In the final objective, the treatments did not affect (P>0.05) the oxidative stability of lipids (TBARS). The moisture and fat content in the water restricted groups were lower (P<0.05) than W0. The consumer meat sensory appearance decreased (P<0.05) with levels of water restrictions. Regardless of VC concentration and supplementation, vaccenic, and docosahexaenoic acid increased (P<0.05) while linolenic acid decreased as the water restriction levels increased. Nonetheless, treatment did not affect (P>0.05) the saturated and unsaturated fatty acids. These studies showed that suboptimal water intake negatively affects the growth performance and nutrient intake of Xhosa goats. However, the reduction in body weight loss and decreased plasma cortisol (chief stress hormone) concentration following vitamin C supplementation (especially at a daily single dose [3g/d]) may well reduce the effect of water stress in goats. , Thesis (PhD) -- Faculty of Science and Agriculture, 2020
- Full Text:
- Date Issued: 2020-08
The perceived socio-environmental impacts of illegal sand mining along the Umvoti River in KwaDukuza Local Municipality, KwaZulu - Natal Province, South Africa
- Authors: Mbiko, Lubabalo
- Date: 2020-07
- Subjects: Ecosystem health , Biodiversity
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20474 , vital:45669
- Description: This study examined and documented the perceptions of local communities towards the socio-environmental impacts associated with illegal sand mining activities along the Umvoti River, in the KwaDukuza Local Municipality in South Africa. It was imperative to elicit the perceptions of both the local people and the government officials to understand the extent of the socio- environmental effects of illegal sand mining in the study area. To this end, a qualitative research approach was designed and used to collect the data. Data collection techniques employed included site observations and a semi-structured interview schedule with key informants. Additionally, 50 questionnaire surveys were administered to the residents of the Nsikeni and Melville communities within the study area. The results of the study revealed that illegal sand mining along the Umvoti River has contributed significantly to the degradation of grazing and farm lands, including diversion of the river and the destruction of the riparian vegetation. Evidence of water pollution, and air pollution in the form of dust, were also reported. The study observed problems in ecosystem functioning, particularly in regard to the flora and fauna, and there was extensive destruction of the aesthetic beauty of the local landscape. In addition, the study indicated that people and livestock drowned in the deep trenches that were not rehabilitated following illegal sand mining practise that was migrating along the river. Furthermore, illegal sand mining was linked with an increase in poverty and prostitution, as well as the destruction of the infrastructure in the nearby communities. Moreover, community conflicts arose from the differing perceptions on the existence of illegal sand mining in these communities. To curb illegal sand mining, the study recommends that the current legislation on the extraction of mineral commodities in South Africa should be stringently and effectively enforced. The research further recommends that community policing forums should be established and work closely with law enforcement agencies to deal with illegal sand mining activities. Accordingly, the research study recommends the elimination of the current tedious and burdensome process of obtaining amining permit. , Thesis (MPhil) -- Faculty of Science and Agriculture, 2020
- Full Text:
- Date Issued: 2020-07
- Authors: Mbiko, Lubabalo
- Date: 2020-07
- Subjects: Ecosystem health , Biodiversity
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20474 , vital:45669
- Description: This study examined and documented the perceptions of local communities towards the socio-environmental impacts associated with illegal sand mining activities along the Umvoti River, in the KwaDukuza Local Municipality in South Africa. It was imperative to elicit the perceptions of both the local people and the government officials to understand the extent of the socio- environmental effects of illegal sand mining in the study area. To this end, a qualitative research approach was designed and used to collect the data. Data collection techniques employed included site observations and a semi-structured interview schedule with key informants. Additionally, 50 questionnaire surveys were administered to the residents of the Nsikeni and Melville communities within the study area. The results of the study revealed that illegal sand mining along the Umvoti River has contributed significantly to the degradation of grazing and farm lands, including diversion of the river and the destruction of the riparian vegetation. Evidence of water pollution, and air pollution in the form of dust, were also reported. The study observed problems in ecosystem functioning, particularly in regard to the flora and fauna, and there was extensive destruction of the aesthetic beauty of the local landscape. In addition, the study indicated that people and livestock drowned in the deep trenches that were not rehabilitated following illegal sand mining practise that was migrating along the river. Furthermore, illegal sand mining was linked with an increase in poverty and prostitution, as well as the destruction of the infrastructure in the nearby communities. Moreover, community conflicts arose from the differing perceptions on the existence of illegal sand mining in these communities. To curb illegal sand mining, the study recommends that the current legislation on the extraction of mineral commodities in South Africa should be stringently and effectively enforced. The research further recommends that community policing forums should be established and work closely with law enforcement agencies to deal with illegal sand mining activities. Accordingly, the research study recommends the elimination of the current tedious and burdensome process of obtaining amining permit. , Thesis (MPhil) -- Faculty of Science and Agriculture, 2020
- Full Text:
- Date Issued: 2020-07