Aptamer-based biosensor for prostate specific antigen detection using cobalt phthalocyanine-exfoliated graphite composites
- Authors: Benise, Emihle
- Date: 2024-04-04
- Subjects: Aptamer , Exfoliated graphite nano-platelets , Phthalocyanines , Impedance spectroscopy , Prostate-specific antigen
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/434850 , vital:73110
- Description: The work focuses on the development of biosensors and their use for the detection of prostate specific antigen (PSA). Four cobalt phthalocyanines (CoPcs) complexes: (1) cobalt tetra pyridyloxy phthalocyanine, (2) cobalt tetra acetamidophenoxy phthalocyanine, (3) cobalt tris(acetamidophenoxy) mono benzoic acid phthalocyanine, and (4) cobalt tris(acetamidophenoxy) mono propionic acid phthalocyanine, an exfoliated graphite (EG), and aptamer are used to make probes for PSA detection. Each complex is π-π stacked onto the EG to form EG-CoPc(π-π) hybrid which was used to modify a glassy carbon electrode (GCE). EG and CoPc were also used to modify the GCE sequential (seq) with CoPc on top to give GCE-EG-CoPc(seq). For the detection PSA, PSA specific aptamer was either sequential added or covalently linked to complexes 3 and 4 on the modified electrodes and was only sequentially added onto complexes 1 and 2 modified electrodes. Electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) were the techniques used for the detection of PSA. The electrodes were found to be selective in bovine serum albumin, glucose and cysteine and stable when 50 DPV scans were run. Electrodes gave good % recovery when human serum was spiked with different PSA concentrations. , Thesis (MSc) -- Faculty of Science, Chemistry, 2024
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- Date Issued: 2024-04-04
An Investigation into the challenges of translating mathematical terminologies into Xitsonga
- Authors: Sambo, Tintswalo Teressa
- Date: 2024-04
- Subjects: Mathematical linguistics , Mathematics , Translating and interpreting
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63495 , vital:73382
- Description: Mathematics in South Africa is one of the subjects that is considered ‘difficult’ by many learners. The proof of this statement is reflected by the low mathematical pass rate in many South African schools. One of the challenges that has been highlighted by learners and teachers is that the language of mathematics is challenging. This implies that learners find it difficult to understand some of the mathematical terminologies and content that is being taught. The main reason for the challenge of grasping mathematical terminologies that has been cited by learners and educators is the language of learning and teaching (LOLT). Mathematics is taught in English in most South African schools even though many learners speak one of the indigenous South African official languages (if one excludes English and Afrikaans) at home and get to use and be exposed to English as the medium of learning and teaching only at school. While mathematics remains a challenge in South Africa, research shows that when home languages are used in a mathematics classroom, it enhances the learners understanding. However, it is not always simple to transfer mathematics from English to an African language. There are complexities associated with translation that include the lack of vocabulary in the target language which in this case is Xitsonga. The lack of terminologies in Xitsonga is one of the challenges that occur during the process of translation. This purpose of this research is to examine the challenges of translating mathematical terminologies from English into Xitsonga and to find the strategies that can be used to assist learners to improve their understanding of mathematics. As such, a qualitative research method will be used to select the mathematical terminologies extracted froma mathematics bilingual dictionary with the aim of examining the quality of the translation and identifying the challenges that have been experience by translators. , Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 2024
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- Date Issued: 2024-04
The use of creative-arts therapies in treating trauma-related mental health conditions in South Africa: perspectives from three practising creative-arts therapists
- Authors: Makube, Tshegofatso Bennia Basetsana
- Date: 2023-10-13
- Subjects: Arts Therapeutic use , Mental health South Africa , Mental health services South Africa , Health services accessibility South Africa , Psychological trauma , Stigma (Social psychology) , Mental illness Social aspects South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425399 , vital:72235
- Description: Multiple factors contribute to the prevailing mental health conditions of South Africans. According to Kaminer and Eagle (2010, p.8), 75% of South Africans are trauma survivors, half of whom have experienced multiple traumas, some directly and some indirectly. However, many trauma survivors are not adequately treated due to the limited access and availability of mental health specialists in the country. Thus, mainstream medical treatments ought to be supplemented by alternative forms of therapy such as creative-arts therapy that cater to the wide demographic range of citizens in South Africa. This research aims to explore the efficacy of creative-arts therapies as a treatment for trauma-related mental health conditions in South Africa from the perspectives of three practising creative-arts therapists. The research is a qualitative study and uses Interpretive Phenomenological Analysis (IPA) to interpret the data. The research participants consisted of three accredited creative-art therapists practising in Music, Art, and Dance. The participants were interviewed using semi-structured, in-depth interviews which were conducted online. The interview data was transcribed and analysed using the IPA framework provided by Smith, Flowers and Larkin (2009). The results yielded three superordinate themes which were supported by eight subordinate themes. The results suggest that creative-arts therapies are underutilized in South Africa due to a lack of public awareness and general (mis)perceptions about mental health conditions. Furthermore, access to these therapies in formal settings is limited as they are not offered as treatment options in public health facilities, which negatively impacts the viability of creative-arts therapies practice in the country. Creative-arts therapies offer several unique benefits to individuals of all ages, backgrounds and abilities as they do not require prior artistic knowledge or experience to participate in treatment. In addition, they are non-verbal which helps to bridge the language and cultural barriers that often arise as a result of South Africa’s diverse cultural population. Finally, creative-arts therapies are an effective method of treating mental health conditions incurred through trauma as they focus on accessing stored trauma in the body or unconscious mind through a natural and non-judgemental platform of creative expression. As a result, they address the physical, emotional, psychological, and cognitive effects of trauma while empowering the individual. In conclusion, this research suggests that creative-arts therapies are highly effective in the treatment of trauma-related mental health conditions, particularly in a country like South Africa which experiences high incidents of trauma. They should be better integrated into public health care facilities so that they are accessible to the general public. This will result in an increase in the use of creative-arts therapies as a treatment option for mental health conditions, particularly those related to trauma. It would also help to address the limited awareness and poor perceptions of the nature of mental health, mental illness, mental health care and mental health care services. , Thesis (MMus) -- Faculty of Humanities, Music and Musicology, 2023
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- Date Issued: 2023-10-13
Habitat use by Juvenile coastal fish in subtidal vegetated habitats of Algoa Bay;s shallow water seascape
- Authors: Mkhize,Thembani
- Date: 2022-12
- Subjects: Sailing ships -- South Africa -- Algoa Bay --History , Marine fishes -- Algoa Bay -- South Africa , Fish improvement habitat
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59788 , vital:62429
- Description: Structurally complex habitats such as seagrass, mangroves, and seaweed are important as nurseries in estuaries and nearshore marine environments. While numerous studies have focussed on structurally complex vegetated habitats in estuaries, few studies have focussed on vegetated nursery habitats (particularly seaweed) in coastal areas and their importance. The main aim of this project is to examine the nature of shallow water vegetated habitat (Zostera capensis seagrass and Plocamium corallorhiza macroalga) usage by juvenile fish in the Algoa Bay shallow water seascape (Swartkops Estuary and Flat Rocks nearshore subtidal reef). This aim was achieved by quantifying and comparing complexity of these two habitat-forming species, and the fish assemblages (relative abundance, richness, size structure and behaviour) across the two habitats. To measure and compare complexity of Z. capensis and P. corallorhiza, canopy height, density and leaf/blade width were sampled. In addition to these structural complexity indices, Fractal D (dimensionless complexity indices) was also quantified using Image software. Zostera capensis (1553.3 Indiv/m2 ) had a slightly higher mean density compared to P. corallorhiza (1303.7 Indiv/m2 ) but the difference was not significant. When sites (within each habitat) were compared, density did not show any significant differences between sites. Canopy height of Z. capensis (56.9 cm) was significantly higher compared to P. corallorhiza (16.6 cm), with no significant differences between sites. On the other hand, P. corallorhiza (0.9 cm) blades were significantly wider than Z. capensis (0.2 cm) leaves. Fractal D values followed the same trend as leaf/blade width with, with P. corallorhiza (1.8) having significantly higher Fractal D values than Z. capensis (1.5). The last two indices also had a positive relationship as Fractal D increased with increasing leaf/blade width. These results show that overall P. corallorhiza is more structurally complex than Z. capensis. Calibrated mini stereo underwater remote video systems (mini stereo-RUVs) were optimised in these two studied habitats to ensure they were suitable to measure and identify juvenile fishes. A pilot optimization study found that a minimum of five deployments and a minimum of 45 minutes filming duration is required to study fish assemblages in these two habitats. For comparison of fish assemblages and assessment of habitat use by fish, mini stereo-RUVs were deployed in both habitats (three sites per habitat) and were left to record for 60 minutes for a v total of five sampling occasions in seagrass and seven sampling occasions in macroalga between 7 September 2020 and 9 April 2021. Collected videos were analysed, with relative abundance (MaxN), richness and fish length extracted. Fish behaviour was also analysed and compared between habitats. Mean fish MaxN was slightly higher in Z. capensis (3.4) than in P. corallorhiza (2.9), although this result was not significant. Species diversity was significantly higher in P. corallorhiza as shown by both richness (Z. capensis = 11 and P. corallorhiza = 18) and the Shannon diversity index (Z. capensis = 1.3 and P. corallorhiza = 1.7). Both habitats were dominated by species from the family Sparidae, with six estuary-associated marine species common between the two habitats. Both Z. capensis and P. corallorhiza were dominated by juvenile fish, with more than 70 % of measured fish being juveniles. Fish length was not significantly different in the two habitats. Juvenile fish assemblages were significantly distinct between the two habitats (ANOSIM). In terms of habitat use, fish behaviour analysis showed that fish use both habitats as nurseries. There was no significant difference in fish behaviour in the two habitats and fish behaviours associated with higher levels of habitat use (slow meandering and feeding) were the most common behaviours in both habitats. Although not significant, feeding behaviour (also associated with a high degree of habitat use) was observed more in macroalga than in the seagrass habitat. Although none of the studied complexity indices could be related to abundance, both leaf/blade width and Fractal Dimension showed a positive relationship with the number of species recorded, while canopy height showed a strong negative relationship with the number of species. Overall, this study shows that Plocamium corallorhiza red macroalga in the shallow marine environment may be as important in shallow marine environments as Zostera capensis seagrass in estuaries as nursery habitats for marine fi , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2022
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- Date Issued: 2022-12
The impact of Taxation and corruption on economic growth in South Africa
- Authors: Rabinda, Aluwani Malvin
- Date: 2022-12
- Subjects: Taxation , Corrupt practices , Economic development -- South Africa
- Language: English
- Type: Master's theses , Thesis
- Identifier: http://hdl.handle.net/10948/59832 , vital:62444
- Description: Developing countries, such as South Africa, have been on a mission to reduce corruption, particularly in the public sector, and to collect as much revenue as possible through taxation to fund the government expenditures. Low levels of corruption, preferable zero and higher tax collections, can boost a country's economic growth and development by creating jobs and increasing economic activity, which leads to economic growth. South Africa is one of the economies that are characterised by high levels of corruption. For South Africa to attract more foreign investors in the country, it should ensure that resources are used efficiently and that any act of corruption is punished. This study looked at the effects of taxation and corruption on economic growth from 1975 to 2019. An econometric analysis technique was used in the study to test the impact of taxation and corruption on economic growth. The augmented Dickey–Fuller method was used to test for unit root. According to the results of the tests, unit root l(1) is rejected in favour of the stationarity alternative. The empirical analysis used the Autoregressive Distributed Lag Model (ARDL) bounds testing approach of cointegration advocated by Pesaran, Shin, and Smith (2001) to examine for the longrun equilibrium among taxation and corruption on economic growth. The Wald causality test was also used to investigate the causal relationship between taxation, corruption, and economic growth. According to the Bounds test results, there is long-run co-integrating positive relationship between trade openness and GDP, gross capital formation, Corruption, and income taxation. Furthermore, when dependent variable was tested for longrun impact, the results confirmed that taxation and corruption have insignificant impact on economic growth. Trade openness, as a percentage of GDP, has insignificant positive relationship with economic growth in South Africa. Gross Capital Formation, as a percentage of GDP, is positively related to economic growth. Furthermore, short-run findings suggest a positive significant relationship between trade openness as a percentage of Gross domestic product. Corruption and income taxation have negative and insignificant effect on GDP in the short term. Furthermore, GDP and gross capital formation have negative relationship. V Government should also encourage the culture of transparency and accountability as far as corruption is concerned to stimulate economic growth. This will also create a culture where government officials are called upon to explain their government expenditure patterns and be held accountable for any misuse of any funds flowing into the country. , Thesis (MCom)-- Faculty of Business and Economic Science, 2022
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- Date Issued: 2022-12
A sea is brewing
- Authors: Mama, Sibongakonke
- Date: 2022-10-14
- Subjects: Creative writing (Higher education) South Africa , Xhosa poetry 21st century , South African poetry (English) 21st century , Psychic trauma in literature , Women in literature , Diaries -- Authorship , Books Reviews
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406281 , vital:70255
- Description: My thesis is a collection of poems that draws on the complexity of not belonging in places, with people, or within families. I engage my own alienation as well as that of my parents, black people generally, and women in particular. I take inspiration from Uruguayan poet Fabián Severo’s autobiographical long poem, Night in the North, which chronicles the poet’s experience of growing up in linguistic and cultural borderlands. I am also influenced by Chilean poet Carmen García’s ability to move between the concrete and the abstract in translations of her poems from the collection Gotas sobre loza fría. As much as my poems traverse a metaphysical space, they are also set in concrete places – Tutura, Gcuwa, Johannesburg, and Cape Town. Like Chilean artist Cecilia Vicuña’s Spit Temple, I move between the physical and spiritual realms for a better understanding of my estrangement. I also draw on South African poet Mangaliso Buzani’s book, a naked bone, for its fluid combination of line and prose poetry. I write in isiXhosa and English as a reflection of my mixed cultural and linguistic existence. I seek to harness rhythm and harmony, as well as the quiet, between words. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2022
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- Date Issued: 2022-10-14
The application of the prescription act in labour disputes
- Authors: Mncanca, Siyamthanda
- Date: 2022-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55498 , vital:52375
- Description: It is inevitable that in an employment relationship grievances and conflicts may emerge.1 This is attested to by the large volume of 193 732 disputes that were referred to the Commission for Conciliation, Mediation and Arbitration (CCMA) during the 2018/19 financial year.2 In the event where an employee is dismissed from work and he decides to challenge the dismissal, section 191 of the Labour Relations Act (LRA) grants the employee a right to refer the matter to the CCMA for conciliation or arbitration.3 The purpose of referring the disputes to the CCMA is to support an establishment of a voluntary, free of charge and expeditious mechanisms for labour disputes settlement and allow parties to resolve their disputes through a consensus based process before taking the route of a court process.4 There are time frames that are provided for the referral of disputes to the CCMA. Section 191 determines these time frames by stating that an employee must refer their alleged unfair dismissal to the CCMA within 30 days or 90 days when a dispute relates to an unfair labour practice in accordance with section 191(1)(b)(ii) of the LRA.5 The rationale behind these time frames was outlined in the Constitutional Court (CC) judgement of Toyota SA Motors (Pty) Ltd v CCMA,6 as a means to bring about the expeditious resolution of labour disputes which by their nature, require speedy resolution. , Thesis (L.L.M.) -- Faculty of Law, Mercantile Law, 2022
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- Date Issued: 2022-04
The prominence of choral music in the search for, and preservation of, an African identity: A study focusing on the role of choral composers in the formation of black nationalism during and after the colonial era in South Africa
- Authors: Nelani, Athenkosi
- Date: 2021-10-29
- Subjects: Choral music South Africa , Choral singing South Africa , Black people Race identity South Africa , Black nationalism South Africa , Composers, Black South Africa , Amakwaya
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190965 , vital:45045
- Description: In South Africa, choral music has been prominent in schools, churches, and community choirs since the 19th century. However, the majority of South Africans know little of the history of indigenous choral music. This study investigates the origins of South African indigenous choral music, its canonic figures, and their contribution to this genre in promoting an African identity among the indigenous people of South Africa. Using the methodological lens of historical ethnomusicology, this thesis explores the genesis of choral music in South Africa. Choral music was introduced to the region when it was first colonised by the Dutch East India Company in 1652. Missionaries established institutions in the villages of the local people and translated the Bible and hymn books into the local languages. These actions had lasting consequences for music, and choral singing was greatly advanced. In addition, in this work early composers of South African indigenous choral music are recognised in an effort to establish a choral canon. Three definitive choral periods are recognised, namely those of the first-generation, second-generation, and post-colonial composers. Using this historical framework, this thesis investigates the social and political influence these composers had on African identity during the liberation struggles in the late colonial era and during the early apartheid period. The history and compositions of the composers are discussed, including how they used their compositions as political tools and as mouthpieces to communicate societal issues of concern to the indigenous people during and after the colonial era. , Thesis (MMus) -- Faculty of Humanities, Music and Musicology, 2021
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- Date Issued: 2021-10-29
The Relationship between capital adequacy and profitability under Basel III in the Namibian banking sector
- Authors: Pomuti, Esther Kaulinawa
- Date: 2021-10-29
- Subjects: Banks and banking Namibia , Banks and banking, International Law and legislation , Bank capital Law and legislation Namibia , Rate of return Namibia , Basle Committee on Banking Supervision , Ratio analysis , Basel III (2010)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191909 , vital:45178
- Description: Globally, capital adequacy is one of the most central topics for both regulatory authorities and banks. It promotes stability and intends to reduce bank insolvency. It also represents the most important element of banks’ profitability (Profits are the first line of defense against losses from credit loss in a bank). After the collapse of Bretton Woods in 1973, many banks incurred large foreign currency losses, with Banks outside Germany having taken heavy losses on their unsettled trades with Herstatt Bank in Cologne, West Germany, when it collapsed in June 1974. This study empirically tests the relationship between changes in the capital adequacy ratio under Basel III and return on equity (ROE) of the Namibian banking sector and whether such relationships exist in the short run or long run. The study used panel quarterly data for a sample of three Namibian commercial banks from the year 1999 to 2019.It employed one panel unit root tests namely: Im, Pesaran and Shin W-stat (IPS). To test the existence of a long-run relationship (equilibrium) or effect between the dependent and independent variables, the study employed the Panel Co-integration methods using Pedroni and Kao (Engle-Granger based) tests. The study carried out the Hausman test to determine the best approach for analysis and determined the PMG approach to be the preferable model for analysis. Various diagnostic tests such as multicollinearity through the correlation analysis, autocorrelation, and heteroscedasticity and cross-sectional dependence tests were carried out to determine if the data set is well-modelled and if the results can be taken seriously. The study’s results under the PMG model showed that ROE and CAR have a positive significant relationship in the short run. A dummy variable to capture the connection between ROE and CAR before and after BASEL III shows that the relationship is positive and significant indicating that ROE increases more when there is capital regulation than when there is no capital regulation. The study also concluded that there is no long run relationship between CAR and ROE. Finally, the interaction effect between the dummy variable and CAR is negative but significant and thus indicating that the positive relationship does not persist post Basel III. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2021
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- Date Issued: 2021-10-29
Physiological winners and losers in an ocean warming hotspot: a Case study on argyrosomus off the Namibian coast, with implications for their future management
- Authors: Pringle, Brett Andrew
- Date: 2021-10
- Subjects: Argyrosomus Benguela Current , Ocean temperature Benguela Current , Sciaenidae Benguela Current , Argyrosomus Physiology Benguela Current , Argyrosomus Geographical distribution Climatic factors Benguela Current , Argyrosomus Effect of temperature on Benguela Current , Sciaenidae fisheries Namibia , Fishery management Namibia , Sustainable fisheries Namibia
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188987 , vital:44804
- Description: Anthropogenic-induced climate change is having a profound impact on aquatic ecosystems, and the resilience of fish populations will be determined by how they respond to these impacts. Changes in ocean water temperature is regarded as the most pervasive change, and affects the biological, physiological and distribution response of species, particularly ectotherms. The increasingly variable biological responses to a changing environment suggest that some species and populations will likely prove to be more tolerant than others. The northern Namibian coast is an ocean warming hotspot, with temperatures rising at approximately ten times the global average. These rapid changes are predicted to have a considerable impact on the marine fauna. One recently documented change in distribution is a southern extension of the sciaenid, Argyrosomus coronus, from southern Angola into northern Namibian waters, where it now overlaps with the closely related Namibian species, Argyrosomus inodorus. Understanding how these species perform at current and future temperatures and where they overlap is vital to optimise any adaptive management for the Argyrosomus species, which forms a large component of Namibia’s coastal commercial, recreational and subsistence fisheries. The aim of this study was to quantify the aerobic scope of both species (A. coronus and A. inodorus), to determine which Argyrosomus species will be a winner at the current and future climate predictions and to provide recommendations for the sustainable management of the Namibian Argyrosomus fishery. Intermittent flow-through respirometry was used to quantify standard and maximum metabolic rates for both species across a range of temperatures. Results showed that metabolic rates scaled positively with temperature. It appears that the aerobic scope of A. inodorus was notably higher at most temperatures (12, 15, 18 and 21˚C), while that of A. coronus was only higher at the warmest test temperature of 24˚C. This corresponded with the contemporary biogeographic patterns of each species. Based on these findings, it is likely that the warming ocean conditions in northern Namibia and the cold Lüdertiz upwelling cell south of Walvis Bay will constrain these fish to central Namibia. While both species demonstrated signs of resilience to high temperatures, it is likely that the warming conditions will increasingly favour A. coronus, and that the leading edge of their distribution will shift southward in Namibia. The distribution of A. inodorus is likely to contract, as the energy budget of those on the northern trailing edge will be compromised. To promote the sustainable utilisation of the complex Argyrosomus fishery, adaptive management strategies need to be implemented. This will only be possible with a comprehensive monitoring program, including the collection of genetic data to inform the changing proportions of the two species. To maintain the A. coronus population, the current regulations need to be re-assessed, and harvest slots should be introduced to protect juvenile A. coronus and the fecund large females of both species. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries, 2021
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- Date Issued: 2021-10
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
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- Date Issued: 2021-02
Production, purification and characterization of a multifunctional, thermostable and acido/alkaline stable putative xylanase from the psychrotrophic bacterium, Sphingomonas aerolata
- Authors: Mathibe, Brian Nkanyiso
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/164478 , vital:41122
- Description: Thesis (MSc)--Rhodes University, Faculty of Science, Biochemistry and Microbiology, 2020
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- Date Issued: 2020