MeerKAT observations of three high-redshift galaxy clusters
- Authors: Manaka, Sinah Mokatako
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/422367 , vital:71936
- Description: Galaxy clusters are the largest, gravitationally-bound structures in the Universe, formed through the hierarchical merger of smaller structures. The most accepted view is that the merging process injects energy into the intracluster medium (ICM) and re-accelerates pre-existing particles and compresses magnetic fields, generating, eventually, synchrotron emission. Such radio emission appears as radio halos, i.e. central Mpc-size diffuse structures, mostly visible in merging or unrelaxed clusters and with a spatial correspondence with the thermal gas component of the ICM. Observations have probed radio halo properties mostly for clusters withM500 > 6×1014 M⊙ at intermediate redshifts (0.3 < z < 0.4), providing support to their connection between mergers, which provide the necessary energy to re-accelerate particles via turbulence. Probing the redshift evolution of radio halos is an important test of the turbulent re-acceleration scenario, as fewer halos are expected at high redshift, given the same mass interval. In this thesis, we present MeerKAT observations at 1.28 GHz of three high-redshift (PSZ2G254.08- 58.45, PSZ2G255.60-46.18 and PSZ2G277.76-51.74, in the 0.42 ≲ z ≲ 0.46 range) clusters, with masses M500 ≳ 6.2 × 1014 M⊙, selected for their disturbed dynamical state – inferred from existing X-ray observations. Our observations reached rms noise values between 20 and 23.5 μJy beam−1, with ∼ 4′′ angular resolution. No evidence of diffuse emission is found at ii full resolution. Low-resolution (∼ 30′′) images achieved rms noise levels of 30-50 μJy beam−1, amongst the deepest observations of high-redshift targets. One radio halo was detected in the least massive cluster PSZ2G254.08-58.45 extending over ∼ 500 kpc, with a 1.20 } 0.08 mJy integrated flux density. We placed a ∼1 mJy upper limit at 95% confidence level on the radio halo flux density for the other two targets. The radio-halo detection is consistent with the recent P1.4 GHz − M500 correlation from Cuciti et al. (2021b), while the upper limit on PSZ2G255.60-46.18 is consistent with being on the correlation. On the other hand, the upper limit on PSZ2G277.76-51.74 places the radio halo well below the correlation. Recently a 1.5 GHz survey (Giovannini et al., 2020) detected a slightly higher fraction of radio halos in clusters in the same redshift range, with power and size typically higher than what we found in our observations. Both observations are, however, not inconsistent with each other. Our results, although with limited statistics, do not disfavour the current scenario of radiohalo formation based on the turbulent re-acceleration model. , Thesis (MSc) -- Faculty of Science, Physics and Electronics, 2023
- Full Text:
- Date Issued: 2023-03-29
- Authors: Manaka, Sinah Mokatako
- Date: 2023-03-29
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/422367 , vital:71936
- Description: Galaxy clusters are the largest, gravitationally-bound structures in the Universe, formed through the hierarchical merger of smaller structures. The most accepted view is that the merging process injects energy into the intracluster medium (ICM) and re-accelerates pre-existing particles and compresses magnetic fields, generating, eventually, synchrotron emission. Such radio emission appears as radio halos, i.e. central Mpc-size diffuse structures, mostly visible in merging or unrelaxed clusters and with a spatial correspondence with the thermal gas component of the ICM. Observations have probed radio halo properties mostly for clusters withM500 > 6×1014 M⊙ at intermediate redshifts (0.3 < z < 0.4), providing support to their connection between mergers, which provide the necessary energy to re-accelerate particles via turbulence. Probing the redshift evolution of radio halos is an important test of the turbulent re-acceleration scenario, as fewer halos are expected at high redshift, given the same mass interval. In this thesis, we present MeerKAT observations at 1.28 GHz of three high-redshift (PSZ2G254.08- 58.45, PSZ2G255.60-46.18 and PSZ2G277.76-51.74, in the 0.42 ≲ z ≲ 0.46 range) clusters, with masses M500 ≳ 6.2 × 1014 M⊙, selected for their disturbed dynamical state – inferred from existing X-ray observations. Our observations reached rms noise values between 20 and 23.5 μJy beam−1, with ∼ 4′′ angular resolution. No evidence of diffuse emission is found at ii full resolution. Low-resolution (∼ 30′′) images achieved rms noise levels of 30-50 μJy beam−1, amongst the deepest observations of high-redshift targets. One radio halo was detected in the least massive cluster PSZ2G254.08-58.45 extending over ∼ 500 kpc, with a 1.20 } 0.08 mJy integrated flux density. We placed a ∼1 mJy upper limit at 95% confidence level on the radio halo flux density for the other two targets. The radio-halo detection is consistent with the recent P1.4 GHz − M500 correlation from Cuciti et al. (2021b), while the upper limit on PSZ2G255.60-46.18 is consistent with being on the correlation. On the other hand, the upper limit on PSZ2G277.76-51.74 places the radio halo well below the correlation. Recently a 1.5 GHz survey (Giovannini et al., 2020) detected a slightly higher fraction of radio halos in clusters in the same redshift range, with power and size typically higher than what we found in our observations. Both observations are, however, not inconsistent with each other. Our results, although with limited statistics, do not disfavour the current scenario of radiohalo formation based on the turbulent re-acceleration model. , Thesis (MSc) -- Faculty of Science, Physics and Electronics, 2023
- Full Text:
- Date Issued: 2023-03-29
Leader preparedness to manage employee wellness at Continental Tyres
- Authors: O’Reilly, Clynn
- Date: 2022-12
- Subjects: Employee management , Health promotion, Continental Tyres
- Language: English
- Type: Master's theses , Thesis
- Identifier: http://hdl.handle.net/10948/59809 , vital:62436
- Description: Many businesses are becoming more aware of the importance of employee well-being and health. There has been increasing public interest in merging wellness activities with an employer's obligations. This shift toward healthy workplaces and empowered individuals reflects a correlation between organisational well-being and pleasant psychological states. As a result, several programmes such as Employee Assistance Programmes (EAP) and Employee Wellness Programmes were established to address workplace wellness issues. Employee Wellness Programmes are intervention programmes targeted at improving the well-being of employees. The epidemic has underlined what was already obvious prior to the virus's emergence: that firms no longer require hero leaders. Today's most effective leadership at all levels is not about technical knowledge or knowing all the answers. It is about being human, displaying vulnerability, connecting with others, while being able to unlock their potential, in addition to communicating a clear direction. This study was conducted to determine the preparedness of leaders to manage employee wellness at lower, middle and upper management levels at Continental Tyres South Africa (SA). For this study, primary data was collected by means of semistructured interviews. Qualitative data was collected by conducting interviews with employees from lower, middle and upper management. Face-to-face interviews, using open ended questions, were used to assess managers’ preparedness to address staff wellbeing. Employee wellbeing is a vital component for any organisation's performance in all facets of business operations, according to the findings. Fundamental training is required to ensure leaders are prepared to deal with employee wellness issues. The absence of this training is a major contributor to inadequate policies, procedures, and cultures that should promote employee wellness in an organisation. The lack of training that would contribute to leader preparedness in managing employee wellness has been apparent in this study. Another emerging conclusion that was highlighted in this study is the lack of prioritisation of wellness initiatives and awareness of resources available to employees. This conclusion is a key factor in understanding why there is such a iii deficiency in fundamental training for leaders within the organisation. The lack of prioritisation could have a direct impact on the lack of training offered to leaders in the organisation. , Thesis (MBA) -- Faculty of Business and Economic Science, 2022
- Full Text:
- Date Issued: 2022-12
- Authors: O’Reilly, Clynn
- Date: 2022-12
- Subjects: Employee management , Health promotion, Continental Tyres
- Language: English
- Type: Master's theses , Thesis
- Identifier: http://hdl.handle.net/10948/59809 , vital:62436
- Description: Many businesses are becoming more aware of the importance of employee well-being and health. There has been increasing public interest in merging wellness activities with an employer's obligations. This shift toward healthy workplaces and empowered individuals reflects a correlation between organisational well-being and pleasant psychological states. As a result, several programmes such as Employee Assistance Programmes (EAP) and Employee Wellness Programmes were established to address workplace wellness issues. Employee Wellness Programmes are intervention programmes targeted at improving the well-being of employees. The epidemic has underlined what was already obvious prior to the virus's emergence: that firms no longer require hero leaders. Today's most effective leadership at all levels is not about technical knowledge or knowing all the answers. It is about being human, displaying vulnerability, connecting with others, while being able to unlock their potential, in addition to communicating a clear direction. This study was conducted to determine the preparedness of leaders to manage employee wellness at lower, middle and upper management levels at Continental Tyres South Africa (SA). For this study, primary data was collected by means of semistructured interviews. Qualitative data was collected by conducting interviews with employees from lower, middle and upper management. Face-to-face interviews, using open ended questions, were used to assess managers’ preparedness to address staff wellbeing. Employee wellbeing is a vital component for any organisation's performance in all facets of business operations, according to the findings. Fundamental training is required to ensure leaders are prepared to deal with employee wellness issues. The absence of this training is a major contributor to inadequate policies, procedures, and cultures that should promote employee wellness in an organisation. The lack of training that would contribute to leader preparedness in managing employee wellness has been apparent in this study. Another emerging conclusion that was highlighted in this study is the lack of prioritisation of wellness initiatives and awareness of resources available to employees. This conclusion is a key factor in understanding why there is such a iii deficiency in fundamental training for leaders within the organisation. The lack of prioritisation could have a direct impact on the lack of training offered to leaders in the organisation. , Thesis (MBA) -- Faculty of Business and Economic Science, 2022
- Full Text:
- Date Issued: 2022-12
The design of an automotive academy for Mercedes Benz in Gately, East London
- Authors: Dustan,Cameron
- Date: 2021-12
- Subjects: Automobile factories -- South Africa -- East London -- Designs and plans , Automobiles -- Design and construction
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58860 , vital:60221
- Description: The purpose of this project is to investigate the automotive industry in East London, specifically Mercedes-Benz, in order to propose extensions of the skills development academy and exhibition spaces as an integral part of a larger campus of education. The Mercedes-Benz factory precinct in East London is one of the four largest in the world and is the biggest in Africa, creating grounds for extension. In East London, there is plenty of unemployment and many are seeking jobs in the industrial areas which are mainly automotive. Due to most of the industry being owned by Mercedes-Benz, it is crucial to engage in high levels of education and to provide opportunities for growth within the industry and expansion of skills. Students at the academy will learn different skills in the automotive manufacturing trade and will be guaranteed jobs after their studies are completed. The skills academy will form part of an educational precinct which will establish a narrative for the timeline of Mercedes-Benz. The project will hopefully provide more job opportunities and skills training for the locals of East London as well as to contribute to the economy of the automotive industry. Much like cars, industry works as a machine; there are bits and pieces that need to puzzle together in order to create a working and living machine. The automotive skills academies are exactly that for the industry, a piece of the puzzle which ensures the working of the industry as a whole, now and in the future. Without these skills academies, the automotive industry would subsequently lose its fundamental skills and knowledge base. The core concern for this treatise is the expansion of the industry by creating extensions of the Mercedes-Benz skills academy and creating a space which is educational while being a user-friendly building focused on the wellness of workers and rates of productivity to ensure maximized output and the further growth of the industry. The project is based in East London and will hold a pivotal role in the automotive industry. The treatise looks to break away from the hard industrial aspects of the industry and pull away from the static architecture of Mercedes-Benz and the surrounding buildings, to create a vibrant and experiential building with the overarching emphasis on occupational wellness and innovation in the design. , Thesis (MA) -- Faculty of Engineering, the Built Environment and Technology, School of Architecture, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Dustan,Cameron
- Date: 2021-12
- Subjects: Automobile factories -- South Africa -- East London -- Designs and plans , Automobiles -- Design and construction
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58860 , vital:60221
- Description: The purpose of this project is to investigate the automotive industry in East London, specifically Mercedes-Benz, in order to propose extensions of the skills development academy and exhibition spaces as an integral part of a larger campus of education. The Mercedes-Benz factory precinct in East London is one of the four largest in the world and is the biggest in Africa, creating grounds for extension. In East London, there is plenty of unemployment and many are seeking jobs in the industrial areas which are mainly automotive. Due to most of the industry being owned by Mercedes-Benz, it is crucial to engage in high levels of education and to provide opportunities for growth within the industry and expansion of skills. Students at the academy will learn different skills in the automotive manufacturing trade and will be guaranteed jobs after their studies are completed. The skills academy will form part of an educational precinct which will establish a narrative for the timeline of Mercedes-Benz. The project will hopefully provide more job opportunities and skills training for the locals of East London as well as to contribute to the economy of the automotive industry. Much like cars, industry works as a machine; there are bits and pieces that need to puzzle together in order to create a working and living machine. The automotive skills academies are exactly that for the industry, a piece of the puzzle which ensures the working of the industry as a whole, now and in the future. Without these skills academies, the automotive industry would subsequently lose its fundamental skills and knowledge base. The core concern for this treatise is the expansion of the industry by creating extensions of the Mercedes-Benz skills academy and creating a space which is educational while being a user-friendly building focused on the wellness of workers and rates of productivity to ensure maximized output and the further growth of the industry. The project is based in East London and will hold a pivotal role in the automotive industry. The treatise looks to break away from the hard industrial aspects of the industry and pull away from the static architecture of Mercedes-Benz and the surrounding buildings, to create a vibrant and experiential building with the overarching emphasis on occupational wellness and innovation in the design. , Thesis (MA) -- Faculty of Engineering, the Built Environment and Technology, School of Architecture, 2021
- Full Text:
- Date Issued: 2021-12
Bio-utilization of keratinous waste biomass for the production of keratinolytic proteases by Chryseobactreium aquifrigidense isolated from poultry waste dumpsite
- Authors: Bokveld, Amahle
- Date: 2021-02
- Subjects: Keratin
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20550 , vital:46120
- Description: Keratin is an insoluble and a fibrous protein that is mostly found in feathers, animal wool, and hair, making them mechanically stable. Avian feathers are the most ubiquitously generated keratinous waste biomass from the poultry processing plants. Keratinous waste biomass valorization could produce amino acids and bioactive peptides. Hence, the bio-recycling of keratin-rich wastes bears an advantage over the chemical and thermal means. In recent times, the microbial keratinases continues to gain traction due to the litany of their potential significance in green technology. Consequently, this study assessed chicken feather degrading and keratinase production potentials of bacteria isolated from a local poultry dumpsite. Soil samples were collected from the poultry dumpsite. Bacteria were isolated using basal salt medium and screened for keratinolytic activity. The identification of potent chicken feather degrading bacterial isolates was through 16S rRNA gene sequence analysis. Keratinase production efficiency of isolates on chicken feather constituted medium was optimized. Hydrolysate's amino acid compositions were quantified, and the keratinases produced was characterized. Out of 22 bacteria isolated from the soil samples, 12 showed a varying degree of proteolytic activity on skimmed milk agar. Four (4) isolates, coded as FPS-01, FPS-07, FPS-09, WDS-06, out of the 12 proteolytic strains further displayed remarkable degradation of the intact chicken feather; percentage degradation ranged from 69 percent for FPS-01 to 88 percent for FPS-09. The extracellular keratinase activity ranged from 610.91 ± 56.57 U/mL for WDS-06 and 834.55 ± 66.86 U/mL for FPS-07. Additionally, the sulfhydryl group concentration quantified from the fermentation broth was 2.22 ± 0.37 (mM), 0.22 ± 0.08 (mM), 2.27 ± 0.09 (mM), and 2.76 ± 0.79 (mM) for FPS-01, FPS-07, FPS-09 and WDS-06, respectively. Based on 16S rRNA gene sequencing and phylogenetic analyses, the isolates FPS-07 and FPS-09 were identified as Chryseobacterium aquifrigidense FANN1 and Chryseobacterium aquifrigidense FANN2. Following the optimization process, the improved fermentation conditions were pH 6, inoculum side (4 percent, v/v), temperature (30 oC), and chicken feather (0.5-1.5 percent, w/v) for FANN1. FANN2 optimal fermentation conditions were pH 6, inoculum (5 percent, v/v), temperature (30 oC), and chicken feather (1.5 percent, w/v). Both bacterial isolates showed the highest extracellular keratinase production after 72 h of the fermentation time. Analysis of the hydrolysates generated from the bacteria fermentation showed a high concentration of arginine, serine, glutamic acid, glycine, proline, valine, and leucine at a respective concentration of 1.13, 1.02, 0.83, 0.94, 0.85, 0.84, and 0.86 (g/100g sample) against FANN1. Similarly, FANN2 generated hydrolysate showed high concentrations of glutamic acid, arginine, serine, aspartic acid, and glycine at this respective abundance 2.52, 1.92, 2.12, 2.25 and 1.9 (g/100g sample). Keratinases from FANN1 and FANN2 showed optimal catalytic efficiency at pH 8 and temperature between 40-50 oC. The enzyme was considerably thermostable at 40 oC and 50 oC after 120 min of preheating. Both FANN1 and FANN2 showed variable residual activity in the presence of the different metal ions. Keratinase from FANN1 recorded the following residual activity of Fe3+ (120 ± 5.06 percent), Ca2+ (100 ± 10.33 percent), Na+ (122 ± 2.95 percent), Al3+ (106 ± 10.33 percent). Likewise, FANN2 keratinase showed remarkable stability against Na+ (108 ± 13.71 percent), Ba2+ (102 ± 0.86 percent), Al3+ (105 ± 2.57 percent), and Ca2+ (96 ± 2.99 percent). Keratinase from FANN1 was catalytically activated after 60 min of pre-treatment with the following detergents, Sunlight (129 percent), Ariel (116 percent), MAQ (151 percent), and Surf (143 percent) compared to the control. FANN2 keratinase showed less stability with laundry detergents after 60 min of preincubation. FANN1 keratinase showed remarkable stability in the presence of chemical agents tested, with residual activity of 90 ± 0.18 percent, 105 ± 7.55 percent, 108 ± 4.31 percent, 123 ± 1.44 percent, 132 ± 1.26 percent, 96 ± 7.19 percent, and 101 ± 3.06 percent for DTT, hydrogen peroxide, DMSO, acetonitrile, triton X-100, tween-80, and SDS, respectively. The enzyme activity was also considerably inhibited by PMSF and EDTA, which suggested a mixed type of protease. Furthermore, keratinase from FANN2 was inhibited by EDTA, and such inhibition pattern grouped it as a metallo-type of protease. The enzyme was also stable in the presence of other chemical agents tested. Therefore, the findings suggest the isolates and their enzymes' relevance to sustainable recycling of recalcitrant keratinous wastes into high-value products with immense application potentials. The remarkable stability shown by keratinases from FANN1 and FANN2, post detergent and chemical agents pre-treatment, indicates promise for the biotechnology and industrial sector. , Thesis(MSc) (Microbiology) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Bokveld, Amahle
- Date: 2021-02
- Subjects: Keratin
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20550 , vital:46120
- Description: Keratin is an insoluble and a fibrous protein that is mostly found in feathers, animal wool, and hair, making them mechanically stable. Avian feathers are the most ubiquitously generated keratinous waste biomass from the poultry processing plants. Keratinous waste biomass valorization could produce amino acids and bioactive peptides. Hence, the bio-recycling of keratin-rich wastes bears an advantage over the chemical and thermal means. In recent times, the microbial keratinases continues to gain traction due to the litany of their potential significance in green technology. Consequently, this study assessed chicken feather degrading and keratinase production potentials of bacteria isolated from a local poultry dumpsite. Soil samples were collected from the poultry dumpsite. Bacteria were isolated using basal salt medium and screened for keratinolytic activity. The identification of potent chicken feather degrading bacterial isolates was through 16S rRNA gene sequence analysis. Keratinase production efficiency of isolates on chicken feather constituted medium was optimized. Hydrolysate's amino acid compositions were quantified, and the keratinases produced was characterized. Out of 22 bacteria isolated from the soil samples, 12 showed a varying degree of proteolytic activity on skimmed milk agar. Four (4) isolates, coded as FPS-01, FPS-07, FPS-09, WDS-06, out of the 12 proteolytic strains further displayed remarkable degradation of the intact chicken feather; percentage degradation ranged from 69 percent for FPS-01 to 88 percent for FPS-09. The extracellular keratinase activity ranged from 610.91 ± 56.57 U/mL for WDS-06 and 834.55 ± 66.86 U/mL for FPS-07. Additionally, the sulfhydryl group concentration quantified from the fermentation broth was 2.22 ± 0.37 (mM), 0.22 ± 0.08 (mM), 2.27 ± 0.09 (mM), and 2.76 ± 0.79 (mM) for FPS-01, FPS-07, FPS-09 and WDS-06, respectively. Based on 16S rRNA gene sequencing and phylogenetic analyses, the isolates FPS-07 and FPS-09 were identified as Chryseobacterium aquifrigidense FANN1 and Chryseobacterium aquifrigidense FANN2. Following the optimization process, the improved fermentation conditions were pH 6, inoculum side (4 percent, v/v), temperature (30 oC), and chicken feather (0.5-1.5 percent, w/v) for FANN1. FANN2 optimal fermentation conditions were pH 6, inoculum (5 percent, v/v), temperature (30 oC), and chicken feather (1.5 percent, w/v). Both bacterial isolates showed the highest extracellular keratinase production after 72 h of the fermentation time. Analysis of the hydrolysates generated from the bacteria fermentation showed a high concentration of arginine, serine, glutamic acid, glycine, proline, valine, and leucine at a respective concentration of 1.13, 1.02, 0.83, 0.94, 0.85, 0.84, and 0.86 (g/100g sample) against FANN1. Similarly, FANN2 generated hydrolysate showed high concentrations of glutamic acid, arginine, serine, aspartic acid, and glycine at this respective abundance 2.52, 1.92, 2.12, 2.25 and 1.9 (g/100g sample). Keratinases from FANN1 and FANN2 showed optimal catalytic efficiency at pH 8 and temperature between 40-50 oC. The enzyme was considerably thermostable at 40 oC and 50 oC after 120 min of preheating. Both FANN1 and FANN2 showed variable residual activity in the presence of the different metal ions. Keratinase from FANN1 recorded the following residual activity of Fe3+ (120 ± 5.06 percent), Ca2+ (100 ± 10.33 percent), Na+ (122 ± 2.95 percent), Al3+ (106 ± 10.33 percent). Likewise, FANN2 keratinase showed remarkable stability against Na+ (108 ± 13.71 percent), Ba2+ (102 ± 0.86 percent), Al3+ (105 ± 2.57 percent), and Ca2+ (96 ± 2.99 percent). Keratinase from FANN1 was catalytically activated after 60 min of pre-treatment with the following detergents, Sunlight (129 percent), Ariel (116 percent), MAQ (151 percent), and Surf (143 percent) compared to the control. FANN2 keratinase showed less stability with laundry detergents after 60 min of preincubation. FANN1 keratinase showed remarkable stability in the presence of chemical agents tested, with residual activity of 90 ± 0.18 percent, 105 ± 7.55 percent, 108 ± 4.31 percent, 123 ± 1.44 percent, 132 ± 1.26 percent, 96 ± 7.19 percent, and 101 ± 3.06 percent for DTT, hydrogen peroxide, DMSO, acetonitrile, triton X-100, tween-80, and SDS, respectively. The enzyme activity was also considerably inhibited by PMSF and EDTA, which suggested a mixed type of protease. Furthermore, keratinase from FANN2 was inhibited by EDTA, and such inhibition pattern grouped it as a metallo-type of protease. The enzyme was also stable in the presence of other chemical agents tested. Therefore, the findings suggest the isolates and their enzymes' relevance to sustainable recycling of recalcitrant keratinous wastes into high-value products with immense application potentials. The remarkable stability shown by keratinases from FANN1 and FANN2, post detergent and chemical agents pre-treatment, indicates promise for the biotechnology and industrial sector. , Thesis(MSc) (Microbiology) -- 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
Literary representations of Zimbabwean migrants’ lives in selected texts
- Authors: Mpofu, Tarisai
- Date: 2018
- Subjects: Human rights -- Zimbabwe , Homelessness in literature , African diaspora in literature
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/3402 , vital:43340
- Description: It has been nearly two decades since Zimbabwe has been engulfed in both political and economic crises which have had untold hardships to the majority of ordinary people. As the hardships worsened it pushed Zimbabweans to migrate to “greener pastures” as a survival strategy. Due to the sheer numbers of people who left the country, migration became a social phenomenon in the country that even literary writers also explored. It is the purpose of this study to analyse literary reactions to migration in Zimbabwe from the turn of the new millennium to date, with particular reference to selected Zimbabwean fiction in the form of the short story and novel. The dissertation examines how Zimbabwean literature represents life in Zimbabwe in the context of this economic malaise that emerged after the year 2000 and the resultant lives of migrants who left the country as a result of this political and economic crisis. Similar to the majority of African literatures, Zimbabwean literature emerges from specific historical events and this study therefore sought to describe literary representations of people’s responses to the crisis and the life of Zimbabwean migrants in the margins of host communities. This study reveals the intricate relationship between literary responses and the conditions that most migrants found themselves in especially as they fled the country and what obtained in host countries. , Thesis (MA) -- Faculty of Humanities, Social Sciences and Law, 2018
- Full Text:
- Date Issued: 2018
- Authors: Mpofu, Tarisai
- Date: 2018
- Subjects: Human rights -- Zimbabwe , Homelessness in literature , African diaspora in literature
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/3402 , vital:43340
- Description: It has been nearly two decades since Zimbabwe has been engulfed in both political and economic crises which have had untold hardships to the majority of ordinary people. As the hardships worsened it pushed Zimbabweans to migrate to “greener pastures” as a survival strategy. Due to the sheer numbers of people who left the country, migration became a social phenomenon in the country that even literary writers also explored. It is the purpose of this study to analyse literary reactions to migration in Zimbabwe from the turn of the new millennium to date, with particular reference to selected Zimbabwean fiction in the form of the short story and novel. The dissertation examines how Zimbabwean literature represents life in Zimbabwe in the context of this economic malaise that emerged after the year 2000 and the resultant lives of migrants who left the country as a result of this political and economic crisis. Similar to the majority of African literatures, Zimbabwean literature emerges from specific historical events and this study therefore sought to describe literary representations of people’s responses to the crisis and the life of Zimbabwean migrants in the margins of host communities. This study reveals the intricate relationship between literary responses and the conditions that most migrants found themselves in especially as they fled the country and what obtained in host countries. , Thesis (MA) -- Faculty of Humanities, Social Sciences and Law, 2018
- Full Text:
- Date Issued: 2018
Critical analysis of anti-corruption strategies, policies, plans and practices- in the selected municipalities in the case of the Eastern Cape, Joe Gqabi District (2008-2011)
- Authors: Nonjola, Mcebisi Patrick
- Date: 2012-01
- Subjects: Local government -- South Africa -- Eastern Cape , Municipal services -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/25959 , vital:64637
- Description: Corruption is a virus that has infected all sectors of society not only in South Africa but also in the whole world. The various spheres of government are seemingly not immune against this scourge and its paralysing effect on service delivery. There is no universally acceptable definition of corruption. Its causes are diverse, ranging from administrative to socio-economic, and it manifests itself in various ways. The plethora of anti-corruption legislation and agencies has only served to minimise but not to eradicate corruption from the face of the public institutions. In order to scale up its fight against corruption, the Department of Public Service and Administration developed a strategy aimed at preventing, detecting and investigating corruption in government departments. Subsequently, the Department of Local Government and Traditional Affairs, now called Co-operative Governance and Traditional Affairs, developed a similar strategy for the municipalities. The strategy requires inter alia municipalities to develop minimum anti-corruption capacity which entail developing strategies, systems, policies, procedures and plans to prevent, detect and investigate fraud and corruption. The study sought to establish, in selected municipalities in Joe Gqabi District municipality, whether or not they have established the minimum capacity envisaged in the National anti-corruption strategy. The study found municipalities to have progressed at different stages of establishing and ensuring functioning of those systems, policies and plans but none of them had developed anti-corruption strategy. Consequently, the study recommends inter alia that the establishment of minimum anti-corruption capacity be made one of the national key performance indicators which must be incorporated in the performance agreements of the Senior management of municipalities. , Thesis (MPA) -- Faculty of Management and Commerce, 2012
- Full Text:
- Date Issued: 2012-01
- Authors: Nonjola, Mcebisi Patrick
- Date: 2012-01
- Subjects: Local government -- South Africa -- Eastern Cape , Municipal services -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/25959 , vital:64637
- Description: Corruption is a virus that has infected all sectors of society not only in South Africa but also in the whole world. The various spheres of government are seemingly not immune against this scourge and its paralysing effect on service delivery. There is no universally acceptable definition of corruption. Its causes are diverse, ranging from administrative to socio-economic, and it manifests itself in various ways. The plethora of anti-corruption legislation and agencies has only served to minimise but not to eradicate corruption from the face of the public institutions. In order to scale up its fight against corruption, the Department of Public Service and Administration developed a strategy aimed at preventing, detecting and investigating corruption in government departments. Subsequently, the Department of Local Government and Traditional Affairs, now called Co-operative Governance and Traditional Affairs, developed a similar strategy for the municipalities. The strategy requires inter alia municipalities to develop minimum anti-corruption capacity which entail developing strategies, systems, policies, procedures and plans to prevent, detect and investigate fraud and corruption. The study sought to establish, in selected municipalities in Joe Gqabi District municipality, whether or not they have established the minimum capacity envisaged in the National anti-corruption strategy. The study found municipalities to have progressed at different stages of establishing and ensuring functioning of those systems, policies and plans but none of them had developed anti-corruption strategy. Consequently, the study recommends inter alia that the establishment of minimum anti-corruption capacity be made one of the national key performance indicators which must be incorporated in the performance agreements of the Senior management of municipalities. , Thesis (MPA) -- Faculty of Management and Commerce, 2012
- Full Text:
- Date Issued: 2012-01
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