The impact of Fintech firms on bank performance: analysing the South African case (2009-2021)
- Authors: Runyowa, Simon Simbarashe
- Date: 2024-10-11
- Subjects: Fintech South Africa , Banks and banking South Africa , Financial institutions South Africa , Bank management , Payment system
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/462812 , vital:76337
- Description: The growth of the Fintech Firm sector globally was inevitable, given the changes in consumer behaviour, expectations, and the ever-changing and evolving nature of technology. The sector saw a sharp increase during the 2008 Global Financial Crisis and was driven by digital payments, government policy, less stringent regulation, and technological innovation. Unsurprisingly, South Africa was home to a mature and developing Fintech sector primarily driven by money transfers and mobile payments putting Fintech firms in the same market segment as traditional banks but with a more extensive potential customer base through offering easily accessible and lower-cost services. The relationship between the growth of the Fintech firm sector and Bank performance was widely researched within the literature with varying results. The study aimed to add to the body of literature and determine the nature of this relationship in the South African context. The study primarily aimed to determine the relationship and impact of the growth of the Fintech firm payments segment on the performance of the South African Banking sector. Additionally, the study aimed to measure the sector's growth by creating a Fintech Growth Index. Using the Ordinary Least Squares, Fixed Effect and the Generalized Method of Moments estimation techniques, estimations between Bank performance variables and the Fintech growth Index were analysed between 2009 and 2021. Firstly, the study found the growth of the Fintech payments segment to be positive. Secondly, the study found that the growth of the payment segment had a negative relationship and impact on the financial performance of South African banks. The findings of this study have implications for the development and regulatory framework of the South African Fintech sector as well as its interaction with the South African banking sector. Furthermore, policymakers may find that the growth of the Fintech Firm sector has overall positive benefits for financial inclusion for South African consumers. The study recommended that future research be taken to address the gap in the literature regarding the growth of the South African Fintech sector. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2024
- Full Text:
- Authors: Runyowa, Simon Simbarashe
- Date: 2024-10-11
- Subjects: Fintech South Africa , Banks and banking South Africa , Financial institutions South Africa , Bank management , Payment system
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/462812 , vital:76337
- Description: The growth of the Fintech Firm sector globally was inevitable, given the changes in consumer behaviour, expectations, and the ever-changing and evolving nature of technology. The sector saw a sharp increase during the 2008 Global Financial Crisis and was driven by digital payments, government policy, less stringent regulation, and technological innovation. Unsurprisingly, South Africa was home to a mature and developing Fintech sector primarily driven by money transfers and mobile payments putting Fintech firms in the same market segment as traditional banks but with a more extensive potential customer base through offering easily accessible and lower-cost services. The relationship between the growth of the Fintech firm sector and Bank performance was widely researched within the literature with varying results. The study aimed to add to the body of literature and determine the nature of this relationship in the South African context. The study primarily aimed to determine the relationship and impact of the growth of the Fintech firm payments segment on the performance of the South African Banking sector. Additionally, the study aimed to measure the sector's growth by creating a Fintech Growth Index. Using the Ordinary Least Squares, Fixed Effect and the Generalized Method of Moments estimation techniques, estimations between Bank performance variables and the Fintech growth Index were analysed between 2009 and 2021. Firstly, the study found the growth of the Fintech payments segment to be positive. Secondly, the study found that the growth of the payment segment had a negative relationship and impact on the financial performance of South African banks. The findings of this study have implications for the development and regulatory framework of the South African Fintech sector as well as its interaction with the South African banking sector. Furthermore, policymakers may find that the growth of the Fintech Firm sector has overall positive benefits for financial inclusion for South African consumers. The study recommended that future research be taken to address the gap in the literature regarding the growth of the South African Fintech sector. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2024
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Discovery and classification of compact radio sources in the MeerKAT Galactic Centre data
- Authors: Rammala, Isabella Dineo
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432218 , vital:72852
- Description: Access restricted. Expected release date in 2025. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2023
- Full Text:
- Authors: Rammala, Isabella Dineo
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432218 , vital:72852
- Description: Access restricted. Expected release date in 2025. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2023
- Full Text:
Labour law and non-standard employment: case studies of selected workplaces in Makhanda
- Authors: Mini, Sifanelwa
- Date: 2023-10-13
- Subjects: Non-standard employment South Africa Makhanda , Job security , Labor market South Africa , Labor laws and legislation South Africa , Work-life balance South Africa , Temporary employment South Africa , Collective bargaining South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425171 , vital:72216
- Description: While precarious and poorly-regulated forms of employment are on the increase worldwide, the patterns vary significantly over time and space. This study sought to understand employees’ perceptions of non-standard employment (NSE), the reasons why employers resort to NSE and why they use particular types of NSE. In addition, the research explored how labour law protections for NSE are applied in particular workplaces. Drawing on the regulation approach, which provides a conceptual framework to explain changes in production and employment relationships under specific spatio-temporal conditions, this study focused on three companies in Makhanda. Furthermore, this study employed a qualitative research method to explore the employees’ perceptions on non-standard work. This was done by using an interpretive approach to explore how workers experience NSE and how Eastern Cape citizens in Makhanda navigate the scourge of unemployment and exploitation in the labour market. Moreover, the research investigated how employees experience the efficacy of their employment rights in the workplace. The employment rights observed in the study include (among others) leave, contract of employment and collective bargaining; all of which are provisions in the Labour Relations Act. The findings in the study do validate the use of NSE as a ‘tool’ to curb high unemployment. However, the study finds that the positive result of job creation does not signify job security for non-standard workers, instead beneath the rhetoric of job creation and investment, lies hidden the exploitation of vulnerable groups of citizens and extension of precarious forms of employment. This is because businesses engage in economic competition locally and globally. Therefore, in order to successfully compete against other, employer’s cut on labour expenses by adopting a “race to the bottom,” the effect of which is paying employees below the minimum wage. Moreover, this study opposes the argument that NSE is a stepping stone to permanent employment. The conditions which prevail in NSE are distinctly different from those in the Standard Employment Relationship (SER), making it difficult for employees to transition to a new labour market. The latter is more aligned with the heterodox approach than it is to the orthodox approach to labour market. , Thesis (MA) -- Faculty of Humanities, Sociology, 2023
- Full Text:
- Authors: Mini, Sifanelwa
- Date: 2023-10-13
- Subjects: Non-standard employment South Africa Makhanda , Job security , Labor market South Africa , Labor laws and legislation South Africa , Work-life balance South Africa , Temporary employment South Africa , Collective bargaining South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425171 , vital:72216
- Description: While precarious and poorly-regulated forms of employment are on the increase worldwide, the patterns vary significantly over time and space. This study sought to understand employees’ perceptions of non-standard employment (NSE), the reasons why employers resort to NSE and why they use particular types of NSE. In addition, the research explored how labour law protections for NSE are applied in particular workplaces. Drawing on the regulation approach, which provides a conceptual framework to explain changes in production and employment relationships under specific spatio-temporal conditions, this study focused on three companies in Makhanda. Furthermore, this study employed a qualitative research method to explore the employees’ perceptions on non-standard work. This was done by using an interpretive approach to explore how workers experience NSE and how Eastern Cape citizens in Makhanda navigate the scourge of unemployment and exploitation in the labour market. Moreover, the research investigated how employees experience the efficacy of their employment rights in the workplace. The employment rights observed in the study include (among others) leave, contract of employment and collective bargaining; all of which are provisions in the Labour Relations Act. The findings in the study do validate the use of NSE as a ‘tool’ to curb high unemployment. However, the study finds that the positive result of job creation does not signify job security for non-standard workers, instead beneath the rhetoric of job creation and investment, lies hidden the exploitation of vulnerable groups of citizens and extension of precarious forms of employment. This is because businesses engage in economic competition locally and globally. Therefore, in order to successfully compete against other, employer’s cut on labour expenses by adopting a “race to the bottom,” the effect of which is paying employees below the minimum wage. Moreover, this study opposes the argument that NSE is a stepping stone to permanent employment. The conditions which prevail in NSE are distinctly different from those in the Standard Employment Relationship (SER), making it difficult for employees to transition to a new labour market. The latter is more aligned with the heterodox approach than it is to the orthodox approach to labour market. , Thesis (MA) -- Faculty of Humanities, Sociology, 2023
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Reforging Ockham’s Razor: an enquiry into the ontology of parsimony arguments
- Authors: Dichmont, Thomas
- Date: 2022-10-14
- Subjects: Logic , Metaphysics , Ontology , Knowledge, Theory of , Epistemology , Philosophy and science , Occam's razor
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406736 , vital:70303
- Description: Nearly every philosopher in English-speaking world has heard of Ockham’s Razor, which is given in one of two ways, don’t multiply entities beyond necessity and all things being equal choose the simpler explanation. Yet it is unclear from the scholarship whether the use of Ockham’s Razor is justified in science and philosophy. However, if it can be shown to ‘get’ us truth, it would gain an unequivocal justification, as disputes that are continued after the parties to the substantive truth of one or the other are defined as frivolous. Alternative, one may contend that explanation could have other criteria of success. The implication of a direct connection between the razor and truth comes with ontological commitments, namely a commitment to realism (about universals) and philosophical theism. This is contrary to the razor’s use as a tool of nominalism and naturalism. I argue in this thesis there that the only possible non-circular justification for Ockham’s Razor is truth and that therefore certain philosophical positions are excluded from using the razor to animate their positions. There is an additional, second criteria for the success of our inquiry, namely the justification must in some way be consistent with the razor, which means the chosen explanation for the razor, must be simpler than any of its rivals and not have superfluous entities, otherwise our justification would be contrary to the advice of the razor. We are presented with a Scylla and Charybdis type problem, we avoid a circularity on the one hand and on the other we must not contradict the razor itself, these are contrary intellectual impulses. So firstly I will look at disciplines outside philosophy for some initial inspiration. If we could answer this question in a ‘non’ philosophical way, the problem would have solved itself in a way that require little change of practice. If lawyers or scientist can account for the razor properly, there is not really a problem of justification, at least not a philosophical one. Second, I consider the realist and theist positions, namely an argument of Aristotle’s in the Posterior Analytics and part of Aquinas’ On the Divine Simplicity. Further, I consider the work of Ockham as a nominalist. Lastly, I consider modern and contemporary philosophy, in the form of Hume, Quine and Sober (a modern writer on the razor). The aim here is to ‘stress test’ the philosophical resources of the various systems and analyse the results to see if they can produce a non-circular result. , Thesis (MA) -- Faculty of Humanities, Philosophy, 2022
- Full Text:
- Authors: Dichmont, Thomas
- Date: 2022-10-14
- Subjects: Logic , Metaphysics , Ontology , Knowledge, Theory of , Epistemology , Philosophy and science , Occam's razor
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406736 , vital:70303
- Description: Nearly every philosopher in English-speaking world has heard of Ockham’s Razor, which is given in one of two ways, don’t multiply entities beyond necessity and all things being equal choose the simpler explanation. Yet it is unclear from the scholarship whether the use of Ockham’s Razor is justified in science and philosophy. However, if it can be shown to ‘get’ us truth, it would gain an unequivocal justification, as disputes that are continued after the parties to the substantive truth of one or the other are defined as frivolous. Alternative, one may contend that explanation could have other criteria of success. The implication of a direct connection between the razor and truth comes with ontological commitments, namely a commitment to realism (about universals) and philosophical theism. This is contrary to the razor’s use as a tool of nominalism and naturalism. I argue in this thesis there that the only possible non-circular justification for Ockham’s Razor is truth and that therefore certain philosophical positions are excluded from using the razor to animate their positions. There is an additional, second criteria for the success of our inquiry, namely the justification must in some way be consistent with the razor, which means the chosen explanation for the razor, must be simpler than any of its rivals and not have superfluous entities, otherwise our justification would be contrary to the advice of the razor. We are presented with a Scylla and Charybdis type problem, we avoid a circularity on the one hand and on the other we must not contradict the razor itself, these are contrary intellectual impulses. So firstly I will look at disciplines outside philosophy for some initial inspiration. If we could answer this question in a ‘non’ philosophical way, the problem would have solved itself in a way that require little change of practice. If lawyers or scientist can account for the razor properly, there is not really a problem of justification, at least not a philosophical one. Second, I consider the realist and theist positions, namely an argument of Aristotle’s in the Posterior Analytics and part of Aquinas’ On the Divine Simplicity. Further, I consider the work of Ockham as a nominalist. Lastly, I consider modern and contemporary philosophy, in the form of Hume, Quine and Sober (a modern writer on the razor). The aim here is to ‘stress test’ the philosophical resources of the various systems and analyse the results to see if they can produce a non-circular result. , Thesis (MA) -- Faculty of Humanities, Philosophy, 2022
- Full Text:
Regulation of Oct4 expression during cell stress
- Authors: Samson, William John
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365712 , vital:65778
- Description: Thesis embargoed. Expected release date early 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Authors: Samson, William John
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/365712 , vital:65778
- Description: Thesis embargoed. Expected release date early 2025. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
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Ubomi Sisilonda: Ingqokelela Yemibongo
- Authors: Manxiwa, Mzuvukile
- Date: 2021-10-29
- Subjects: Xhosa poetry 21st century , Xhosa poetry History and criticism , Buzani, Nompumezo Criticism and interpretation , Gwala, Mafika Pascal, 1946-2014 Criticism and interpretation , Xhosa language Rhythm , Xhosa language Rhyme , Creative writing (Higher education) South Africa
- Language: Xhosa
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192265 , vital:45210
- Description: Le thisisi igxila kwiintlobo ngeentlobo zokubhala imibongo. Iqamele kakhulu kwilinge lokubhodla isingqala isebenzisa isandi sengoma yesiNtu komameleyo, oko kukuthi isondele kwi-lyric poetry ngolwasemzini. Oku kufezwe ngokusebenzisa isingqisho, imfano-zandi, imvano-siqalo nemvano-siphelo, njalo njalo. Iinjongo zale thisisi kukongeza kuncwadi lwesiXhosa nakwinkcubeko yesiNtu, nokuhlab’ ikhwelo elikhuthaza uluntu ukuba lubuyele kwinkcubeko yesiNtu, ukuhlonipha imo-ntlalo yabo nokuxabisa abantu ababhinqileyo. Umbali ophum’ izandla kuncwadi lwesiXhosa, uNompumezo Buzani, umsebenzi wakhe ngakumbi kwenye yeencwadi zakhe ethi Imida, ube nefuthe elikhulu kulo msebenzi, ngakumbi indlela athe walusebenzisa ngayo ulwimi; ngesimbo seli xesha ukudlulisa umyalezo ngolwimi oluqhelekileyo, lungafihlakali kodwa lube namandla okudlwengula umxhelo kulowo ufundayo. Ndeyame nakwincwadi kaNgcwabe, uKhala Zome; undikhumbuzile ngemibongo yakhe eyayame kakhulu kwimo yentlalo yamandulo, kunye nemibongo kaMafika Gwala kuJolinkomo, efana nale: The Children of Nonti kunye noThe Shebeen Queen. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2021
- Full Text:
- Authors: Manxiwa, Mzuvukile
- Date: 2021-10-29
- Subjects: Xhosa poetry 21st century , Xhosa poetry History and criticism , Buzani, Nompumezo Criticism and interpretation , Gwala, Mafika Pascal, 1946-2014 Criticism and interpretation , Xhosa language Rhythm , Xhosa language Rhyme , Creative writing (Higher education) South Africa
- Language: Xhosa
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192265 , vital:45210
- Description: Le thisisi igxila kwiintlobo ngeentlobo zokubhala imibongo. Iqamele kakhulu kwilinge lokubhodla isingqala isebenzisa isandi sengoma yesiNtu komameleyo, oko kukuthi isondele kwi-lyric poetry ngolwasemzini. Oku kufezwe ngokusebenzisa isingqisho, imfano-zandi, imvano-siqalo nemvano-siphelo, njalo njalo. Iinjongo zale thisisi kukongeza kuncwadi lwesiXhosa nakwinkcubeko yesiNtu, nokuhlab’ ikhwelo elikhuthaza uluntu ukuba lubuyele kwinkcubeko yesiNtu, ukuhlonipha imo-ntlalo yabo nokuxabisa abantu ababhinqileyo. Umbali ophum’ izandla kuncwadi lwesiXhosa, uNompumezo Buzani, umsebenzi wakhe ngakumbi kwenye yeencwadi zakhe ethi Imida, ube nefuthe elikhulu kulo msebenzi, ngakumbi indlela athe walusebenzisa ngayo ulwimi; ngesimbo seli xesha ukudlulisa umyalezo ngolwimi oluqhelekileyo, lungafihlakali kodwa lube namandla okudlwengula umxhelo kulowo ufundayo. Ndeyame nakwincwadi kaNgcwabe, uKhala Zome; undikhumbuzile ngemibongo yakhe eyayame kakhulu kwimo yentlalo yamandulo, kunye nemibongo kaMafika Gwala kuJolinkomo, efana nale: The Children of Nonti kunye noThe Shebeen Queen. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2021
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Yeast-baculovirus synergism: investigating mixed infections for improved management of the false codling moth, Thaumatotibia leucotreta
- Authors: Van der Merwe, Marcél
- Date: 2018
- Subjects: Cryptophlebia leucotreta , Baculoviruses , Yeast , Citrus Diseases and pests , Biological pest control agents , Pests Integrated control
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/62963 , vital:28347
- Description: Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) or otherwise commonly known as the false codling moth is an indigenous pest of the citrus industry in southern Africa. The pest is highly significant as it impacts negatively on the export of fresh citrus fruits from South Africa to international markets. To control T. leucotreta in South Africa, an integrated pest management (IPM) programme has been implemented. One component of this programme is the baculovirus Cryptophlebia leucotreta granulovirus (CrleGV-SA) which has been formulated into the products Cryptogran™ and Cryptex®. It has previously been reported that there is a mutualistic association between Cydia pomonella (L.) (Lepidoptera: Tortricidae) also known as codling moth, and epiphytic yeasts. Cydia pomonella larval feeding galleries were colonised by yeasts and this, in turn, reduced larval mortality and enhanced larval development. It has been demonstrated in laboratory assays and field trials that combining yeast and brown cane sugar with Cydia pomonella granulovirus (CpGV) significantly increased larval mortality and lowered the proportion of injured apple fruit. This suggests that yeasts can enhance the effectiveness of an insect virus in managing pest larvae. In this study, we proposed to determine which species of yeast occur naturally in the digestive tract, frass and on the epidermis of T. leucotreta larvae and to examine whether any of these yeasts, when combined with the CrleGV-SA, have a synergistic effect in increasing mortality of T. leucotreta larvae. Firstly, Navel oranges infested with T. leucotreta larvae were collected from orchards in Sundays River Valley in Eastern Cape of South Africa. Larvae were extracted and analysed for the presence of yeast on their surface, or in their gut and frass. Four yeasts were isolated from T. leucotreta larvae and identified down to species level via PCR amplification and sequencing of internal transcribed spacer (ITS) region and D1/D2 domain of the large subunit (LSU) of rDNA region. These yeasts were isolated from the frass, epidermis and digestive tract of T. leucotreta larvae. The yeast isolates were identified as Meyerozyma caribbica, Pichia kluyveri, Pichia kudriavzevii and Hanseniaspora opuntiae. A yeast preference assay was conducted on female T. leucotreta moths to examine whether any of the isolated yeast species affected their oviposition preference. Navel oranges were inoculated with the isolated yeast species at a concentration of 6 × 108 cells.ml-1. The assay also included a Brewer’s yeast and distilled water control. Pichia kudriavzevii was shown to be the preferred yeast species for oviposition, as significantly more eggs were deposited on Navel oranges inoculated with this yeast compared to the other treatments. Lastly, a detached fruit bioassay was performed to evaluate the efficacy of mixing P. kudriavzevii with CrleGV-SA to enhance T. leucotreta larvae mortality. Pichia kudriavzevii was selected as it was demonstrated as having an effect on the oviposition preference of female T. leucotreta moths. The concentration at which P. kudriavzevii was applied remained the same as in the preference assay while CrleGV-SA was applied at lethal concentration required to kill 50 % of the population (9.31 × 107 OBs.ml-1). Although an increase in larval mortality was observed between CrleGV-SA being applied alone and the yeast/virus mixture, this result was determined not to be statistically significant. The experiments performed in this study provide a platform for further research into the application of a yeast-virus combination as a novel control option for T. leucotreta in the field. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2018
- Full Text:
- Authors: Van der Merwe, Marcél
- Date: 2018
- Subjects: Cryptophlebia leucotreta , Baculoviruses , Yeast , Citrus Diseases and pests , Biological pest control agents , Pests Integrated control
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/62963 , vital:28347
- Description: Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) or otherwise commonly known as the false codling moth is an indigenous pest of the citrus industry in southern Africa. The pest is highly significant as it impacts negatively on the export of fresh citrus fruits from South Africa to international markets. To control T. leucotreta in South Africa, an integrated pest management (IPM) programme has been implemented. One component of this programme is the baculovirus Cryptophlebia leucotreta granulovirus (CrleGV-SA) which has been formulated into the products Cryptogran™ and Cryptex®. It has previously been reported that there is a mutualistic association between Cydia pomonella (L.) (Lepidoptera: Tortricidae) also known as codling moth, and epiphytic yeasts. Cydia pomonella larval feeding galleries were colonised by yeasts and this, in turn, reduced larval mortality and enhanced larval development. It has been demonstrated in laboratory assays and field trials that combining yeast and brown cane sugar with Cydia pomonella granulovirus (CpGV) significantly increased larval mortality and lowered the proportion of injured apple fruit. This suggests that yeasts can enhance the effectiveness of an insect virus in managing pest larvae. In this study, we proposed to determine which species of yeast occur naturally in the digestive tract, frass and on the epidermis of T. leucotreta larvae and to examine whether any of these yeasts, when combined with the CrleGV-SA, have a synergistic effect in increasing mortality of T. leucotreta larvae. Firstly, Navel oranges infested with T. leucotreta larvae were collected from orchards in Sundays River Valley in Eastern Cape of South Africa. Larvae were extracted and analysed for the presence of yeast on their surface, or in their gut and frass. Four yeasts were isolated from T. leucotreta larvae and identified down to species level via PCR amplification and sequencing of internal transcribed spacer (ITS) region and D1/D2 domain of the large subunit (LSU) of rDNA region. These yeasts were isolated from the frass, epidermis and digestive tract of T. leucotreta larvae. The yeast isolates were identified as Meyerozyma caribbica, Pichia kluyveri, Pichia kudriavzevii and Hanseniaspora opuntiae. A yeast preference assay was conducted on female T. leucotreta moths to examine whether any of the isolated yeast species affected their oviposition preference. Navel oranges were inoculated with the isolated yeast species at a concentration of 6 × 108 cells.ml-1. The assay also included a Brewer’s yeast and distilled water control. Pichia kudriavzevii was shown to be the preferred yeast species for oviposition, as significantly more eggs were deposited on Navel oranges inoculated with this yeast compared to the other treatments. Lastly, a detached fruit bioassay was performed to evaluate the efficacy of mixing P. kudriavzevii with CrleGV-SA to enhance T. leucotreta larvae mortality. Pichia kudriavzevii was selected as it was demonstrated as having an effect on the oviposition preference of female T. leucotreta moths. The concentration at which P. kudriavzevii was applied remained the same as in the preference assay while CrleGV-SA was applied at lethal concentration required to kill 50 % of the population (9.31 × 107 OBs.ml-1). Although an increase in larval mortality was observed between CrleGV-SA being applied alone and the yeast/virus mixture, this result was determined not to be statistically significant. The experiments performed in this study provide a platform for further research into the application of a yeast-virus combination as a novel control option for T. leucotreta in the field. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2018
- Full Text:
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