A critical analysis of the tax treatment of cryptocurrencies in a South African context
- Authors: Ho, Dau-Ming
- Date: 2022-10-14
- Subjects: Cryptocurrencies Taxation , Income tax Law and legislation South Africa , Income tax Law and legislation Australia , Financial services industry Security measures , South Africa. Income Tax Act, 1962
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/357504 , vital:64749
- Description: The aim of the present research was to investigate whether, as claimed by the South African Revenue Service in the media release issued in April 2018, the normal income tax provisions could apply to cryptocurrency transactions. To achieve this aim, a literature review was undertaken to describe the nature of cryptocurrencies and related crypto mining activities, providing definitions of cryptocurrencies, blockchains and crypto mining, as well as describing the functioning of the system. The research then proceeded to analyse the provisions of the definition of “gross income” in section 1 of the Income Tax Act, 58 of 1962, as amended, and the requirements of the “general deduction formula” in terms of the preamble to section 11, section 11(a) and section 23(g), as applying to cryptocurrency transactions. The application of other provisions in the Act to cryptocurrency transactions was analysed, including trading stock in terms of section 22, and capital allowances in terms of sections 11(e), 12C and 13quin of the Act, together with capital gains tax consequences in terms of the Eighth Schedule to the Income Tax Act. The regulation for income tax purposes of cryptocurrency transactions in Australia was discussed, with a view to making similar recommendations in South Africa. The research was situated in the interpretative paradigm, a doctrinal methodology was applied, together with a qualitative analysis of documentary data. The discussion was limited to the income tax consequences of cryptocurrencies as applying to individuals. The findings of the research were that, in general, the normal income tax provisions could apply to cryptocurrency transactions, but based on the analysis of the South African and Australian income tax acts as they apply to cryptocurrencies, it was recommended that a Comprehensive Guide on the income tax consequences of cryptocurrency transactions should be issued by the South African Revenue Service, together with amendments to section 25D and paragraph 43 of the Eighth Schedule to the Income Tax Act to deal with the conversion of cryptocurrencies to Rand values, and to section 9C of the Income Tax Act to include the deemed capital nature of the disposal of cryptocurrencies in the three-year rule presently applying to equity shares. , Thesis (MCom) -- Faculty of Commerce, Accounting, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Ho, Dau-Ming
- Date: 2022-10-14
- Subjects: Cryptocurrencies Taxation , Income tax Law and legislation South Africa , Income tax Law and legislation Australia , Financial services industry Security measures , South Africa. Income Tax Act, 1962
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/357504 , vital:64749
- Description: The aim of the present research was to investigate whether, as claimed by the South African Revenue Service in the media release issued in April 2018, the normal income tax provisions could apply to cryptocurrency transactions. To achieve this aim, a literature review was undertaken to describe the nature of cryptocurrencies and related crypto mining activities, providing definitions of cryptocurrencies, blockchains and crypto mining, as well as describing the functioning of the system. The research then proceeded to analyse the provisions of the definition of “gross income” in section 1 of the Income Tax Act, 58 of 1962, as amended, and the requirements of the “general deduction formula” in terms of the preamble to section 11, section 11(a) and section 23(g), as applying to cryptocurrency transactions. The application of other provisions in the Act to cryptocurrency transactions was analysed, including trading stock in terms of section 22, and capital allowances in terms of sections 11(e), 12C and 13quin of the Act, together with capital gains tax consequences in terms of the Eighth Schedule to the Income Tax Act. The regulation for income tax purposes of cryptocurrency transactions in Australia was discussed, with a view to making similar recommendations in South Africa. The research was situated in the interpretative paradigm, a doctrinal methodology was applied, together with a qualitative analysis of documentary data. The discussion was limited to the income tax consequences of cryptocurrencies as applying to individuals. The findings of the research were that, in general, the normal income tax provisions could apply to cryptocurrency transactions, but based on the analysis of the South African and Australian income tax acts as they apply to cryptocurrencies, it was recommended that a Comprehensive Guide on the income tax consequences of cryptocurrency transactions should be issued by the South African Revenue Service, together with amendments to section 25D and paragraph 43 of the Eighth Schedule to the Income Tax Act to deal with the conversion of cryptocurrencies to Rand values, and to section 9C of the Income Tax Act to include the deemed capital nature of the disposal of cryptocurrencies in the three-year rule presently applying to equity shares. , Thesis (MCom) -- Faculty of Commerce, Accounting, 2022
- Full Text:
- Date Issued: 2022-10-14
An exploratory study of King IV™: The effect of Principle Four and its practices in achieving good performance by selected JSE-listed companies
- Authors: Rohlandt, John
- Date: 2022-10-14
- Subjects: Corporate governance South Africa , Organizational performance , value creation , Business planning , Social responsibility of business South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/403047 , vital:69917
- Description: The research conducted for the dissertation entitled “An exploratory study of King IVTM: The effect of principle four and its practices in achieving good performance by selected JSE-listed companies”, aimed to determine whether principle four, namely the creation of value, and the application by an organisation of the recommended practices as set out in King IVTM, contribute to the achievement of good performance. The research outlined the background to the research by describing the history of the development of corporate governance internationally and in South Africa, dating back to 1932 and culminating with the King IV™ report. It described the problem statement, defined the aims and objectives of the study, and demonstrated that the significance of the study lies in its exploration of the relationship between the King IV™ practices and good performance. The research also provided a review of the related literature, describing the theoretical background for the research, which includes the conceptual framework and propositions of the research. The research was situated in the post-positivist paradigm, the methodology was qualitative, and the method adopted was a theory-based evaluation, based on a deductive thematic analysis with pattern matching. From a detailed reading of the integrated reports and the King IVTM compliance registers of the fifteen selected listed companies for the years 2017 to 2019, hits and misses in relation to the six capitals and the eight associated practices were recorded. From this, the resulting descriptive statistics were calculated and set out in the form of tables, and a regression analysis was used to support the findings. The research revealed, based on the descriptive statistics data that there is a moderate relationship between good performance and the application of the eight practices set out in King IVTM, that contribute to the achievement of good performance. It was, therefore, concluded that the adoption of corporate governance principles and practices has an effect on performance, although it may not be significant. It is also concluded that the application of the practices in terms of principle four as set out in King IVTM is achieving its intended outcome - the creation of value. The research also concluded that good performance constitutes more than just a company performing financially and that all companies need to comply with the requirements of King IVTM, as the Code is designed to guide organisations in achieving good corporate governance. Governance principles and practices should be adopted in a way that does not unduly constrain them and is appropriate to a company’s particular circumstances. Complying with corporate governance principles and implementing the recommended practices might not guarantee positive outcomes (good performance), but it will guide the board of directors in the pursuit of ethical and effective leadership, and that of sustainable development in order to meet the needs of all stakeholders. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Rohlandt, John
- Date: 2022-10-14
- Subjects: Corporate governance South Africa , Organizational performance , value creation , Business planning , Social responsibility of business South Africa
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/403047 , vital:69917
- Description: The research conducted for the dissertation entitled “An exploratory study of King IVTM: The effect of principle four and its practices in achieving good performance by selected JSE-listed companies”, aimed to determine whether principle four, namely the creation of value, and the application by an organisation of the recommended practices as set out in King IVTM, contribute to the achievement of good performance. The research outlined the background to the research by describing the history of the development of corporate governance internationally and in South Africa, dating back to 1932 and culminating with the King IV™ report. It described the problem statement, defined the aims and objectives of the study, and demonstrated that the significance of the study lies in its exploration of the relationship between the King IV™ practices and good performance. The research also provided a review of the related literature, describing the theoretical background for the research, which includes the conceptual framework and propositions of the research. The research was situated in the post-positivist paradigm, the methodology was qualitative, and the method adopted was a theory-based evaluation, based on a deductive thematic analysis with pattern matching. From a detailed reading of the integrated reports and the King IVTM compliance registers of the fifteen selected listed companies for the years 2017 to 2019, hits and misses in relation to the six capitals and the eight associated practices were recorded. From this, the resulting descriptive statistics were calculated and set out in the form of tables, and a regression analysis was used to support the findings. The research revealed, based on the descriptive statistics data that there is a moderate relationship between good performance and the application of the eight practices set out in King IVTM, that contribute to the achievement of good performance. It was, therefore, concluded that the adoption of corporate governance principles and practices has an effect on performance, although it may not be significant. It is also concluded that the application of the practices in terms of principle four as set out in King IVTM is achieving its intended outcome - the creation of value. The research also concluded that good performance constitutes more than just a company performing financially and that all companies need to comply with the requirements of King IVTM, as the Code is designed to guide organisations in achieving good corporate governance. Governance principles and practices should be adopted in a way that does not unduly constrain them and is appropriate to a company’s particular circumstances. Complying with corporate governance principles and implementing the recommended practices might not guarantee positive outcomes (good performance), but it will guide the board of directors in the pursuit of ethical and effective leadership, and that of sustainable development in order to meet the needs of all stakeholders. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2022
- Full Text:
- Date Issued: 2022-10-14
Baseline assessments for foundation phase reading in isiXhosa: a case study
- Authors: Nesi, Nolubabalo Amanda
- Date: 2022-10-14
- Subjects: Test of Early Reading Ability , Xhosa language , Reading (Elementary) Ability testing , Reading (Elementary) Social aspects South Africa Makhanda , Dynamic assessment (Education)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406320 , vital:70258
- Description: The main objective of this study was to investigate the use of baseline assessments for reading in isiXhosa in Foundation Phase. It focused on how teachers conduct baseline assessments, the assessment tools they use, and their responsiveness to baseline assessments data in terms of curriculum planning and practice, given the lack of explicit guidelines and tools specifically developed for African languages. The lack of clarity may lead teachers to assume that the same assessment approaches and practices apply across all official languages despite their linguistic and sociolinguistic differences. Vygotsky’s socio-cultural theory of learning and Biggs’ concept on constructive alignment are used as the theoretical and conceptual framework for this study. The premise for this study was that it would be problematic to apply similar assessment approaches and use the same tools for all official South African languages. The socio-cultural approach emphasises the importance of language learning and learning generally according to the context within which language occurs. The main research sites are two Quintile 1 schools in a township in Makhanda District. These schools have been receiving external intervention which includes a baseline assessment for isiXhosa reading from Non-Governmental Organisations (NGOs). This study sought to provide some insights on whether previous assessments have informed subsequent teaching practices. The findings of the study revealed that the most prominent tool for assessing reading in isiXhosa is Early Grade Reading Assessment (EGRA) and the tools used by external literacy interventions in the two schools were adapted versions of EGRA. Additionally, the subtasks in the baseline assessment tools used were aligned to the linguistic features of isiXhosa besides the nonsense word component. Furthermore, teachers were assessing and teaching reading at lower levels than expected in the grades 2 and 3 in this study. This study recommends that teachers respond to the baseline assessment data appropriately to develop reading competencies. In addition, there is need for an alignment between the linguistic features, the curriculum and strategies of teaching reading. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Nesi, Nolubabalo Amanda
- Date: 2022-10-14
- Subjects: Test of Early Reading Ability , Xhosa language , Reading (Elementary) Ability testing , Reading (Elementary) Social aspects South Africa Makhanda , Dynamic assessment (Education)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/406320 , vital:70258
- Description: The main objective of this study was to investigate the use of baseline assessments for reading in isiXhosa in Foundation Phase. It focused on how teachers conduct baseline assessments, the assessment tools they use, and their responsiveness to baseline assessments data in terms of curriculum planning and practice, given the lack of explicit guidelines and tools specifically developed for African languages. The lack of clarity may lead teachers to assume that the same assessment approaches and practices apply across all official languages despite their linguistic and sociolinguistic differences. Vygotsky’s socio-cultural theory of learning and Biggs’ concept on constructive alignment are used as the theoretical and conceptual framework for this study. The premise for this study was that it would be problematic to apply similar assessment approaches and use the same tools for all official South African languages. The socio-cultural approach emphasises the importance of language learning and learning generally according to the context within which language occurs. The main research sites are two Quintile 1 schools in a township in Makhanda District. These schools have been receiving external intervention which includes a baseline assessment for isiXhosa reading from Non-Governmental Organisations (NGOs). This study sought to provide some insights on whether previous assessments have informed subsequent teaching practices. The findings of the study revealed that the most prominent tool for assessing reading in isiXhosa is Early Grade Reading Assessment (EGRA) and the tools used by external literacy interventions in the two schools were adapted versions of EGRA. Additionally, the subtasks in the baseline assessment tools used were aligned to the linguistic features of isiXhosa besides the nonsense word component. Furthermore, teachers were assessing and teaching reading at lower levels than expected in the grades 2 and 3 in this study. This study recommends that teachers respond to the baseline assessment data appropriately to develop reading competencies. In addition, there is need for an alignment between the linguistic features, the curriculum and strategies of teaching reading. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2022
- Full Text:
- Date Issued: 2022-10-14
Evolving IoT honeypots
- Authors: Genov, Todor Stanislavov
- Date: 2022-10-14
- Subjects: Internet of things , Malware (Computer software) , QEMU , Honeypot , Cowrie
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362819 , vital:65365
- Description: The Internet of Things (IoT) is the emerging world where arbitrary objects from our everyday lives gain basic computational and networking capabilities to become part of the Internet. Researchers are estimating between 25 and 35 billion devices will be part of Internet by 2022. Unlike conventional computers where one hardware platform (Intel x86) and three operating systems (Windows, Linux and OS X) dominate the market, the IoT landscape is far more heterogeneous. To meet the growth demand the number of The System-on-Chip (SoC) manufacturers has seen a corresponding exponential growth making embedded platforms based on ARM, MIPS or SH4 processors abundant. The pursuit for market share is further leading to a price war and cost-cutting ultimately resulting in cheap systems with limited hardware resources and capabilities. The frugality of IoT hardware has a domino effect. Due to resource constraints vendors are packaging devices with custom, stripped-down Linux-based firmwares optimized for performing the device’s primary function. Device management, monitoring and security features are by and far absent from IoT devices. This created an asymmetry favouring attackers and disadvantaging defenders. This research sets out to reduce the opacity and identify a viable strategy, tactics and tooling for gaining insight into the IoT threat landscape by leveraging honeypots to build and deploy an evolving world-wide Observatory, based on cloud platforms, to help with studying attacker behaviour and collecting IoT malware samples. The research produces useful tools and techniques for identifying behavioural differences between Medium-Interaction honeypots and real devices by replaying interactive attacker sessions collected from the Honeypot Network. The behavioural delta is used to evolve the Honeypot Network and improve its collection capabilities. Positive results are obtained with respect to effectiveness of the above technique. Findings by other researchers in the field are also replicated. The complete dataset and source code used for this research is made publicly available on the Open Science Framework website at https://osf.io/vkcrn/. , Thesis (MSc) -- Faculty of Science, Computer Science, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Genov, Todor Stanislavov
- Date: 2022-10-14
- Subjects: Internet of things , Malware (Computer software) , QEMU , Honeypot , Cowrie
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362819 , vital:65365
- Description: The Internet of Things (IoT) is the emerging world where arbitrary objects from our everyday lives gain basic computational and networking capabilities to become part of the Internet. Researchers are estimating between 25 and 35 billion devices will be part of Internet by 2022. Unlike conventional computers where one hardware platform (Intel x86) and three operating systems (Windows, Linux and OS X) dominate the market, the IoT landscape is far more heterogeneous. To meet the growth demand the number of The System-on-Chip (SoC) manufacturers has seen a corresponding exponential growth making embedded platforms based on ARM, MIPS or SH4 processors abundant. The pursuit for market share is further leading to a price war and cost-cutting ultimately resulting in cheap systems with limited hardware resources and capabilities. The frugality of IoT hardware has a domino effect. Due to resource constraints vendors are packaging devices with custom, stripped-down Linux-based firmwares optimized for performing the device’s primary function. Device management, monitoring and security features are by and far absent from IoT devices. This created an asymmetry favouring attackers and disadvantaging defenders. This research sets out to reduce the opacity and identify a viable strategy, tactics and tooling for gaining insight into the IoT threat landscape by leveraging honeypots to build and deploy an evolving world-wide Observatory, based on cloud platforms, to help with studying attacker behaviour and collecting IoT malware samples. The research produces useful tools and techniques for identifying behavioural differences between Medium-Interaction honeypots and real devices by replaying interactive attacker sessions collected from the Honeypot Network. The behavioural delta is used to evolve the Honeypot Network and improve its collection capabilities. Positive results are obtained with respect to effectiveness of the above technique. Findings by other researchers in the field are also replicated. The complete dataset and source code used for this research is made publicly available on the Open Science Framework website at https://osf.io/vkcrn/. , Thesis (MSc) -- Faculty of Science, Computer Science, 2022
- Full Text:
- Date Issued: 2022-10-14
Igniting a revolution at point zero? Exploring the barriers to early learning access in South Africa and the possibility of the social economy : a comparative analysis and study of Smartstart
- Authors: McCann, Claire Mary
- Date: 2022-10-14
- Subjects: Early childhood education South Africa , Social economy South Africa , Smart Start , Education and state South Africa , Social democracy , Dual economy South Africa , South Africa Economic conditions 1991-
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/403080 , vital:69920
- Description: Economic theory suggests that the greatest return to education investment is in the earliest years; early learning and childcare may enhance skill accumulation and mothers’ labour market choices. These services may be catalytic, igniting a revolution at point zero that transforms family outcomes and aids development. In South Africa, however, early learning deficits persist. This thesis explores barriers to quality early learning access and the possibility social economy initiatives offer, focusing on social franchises like SmartStart. Document analysis, comparative analysis, and interviews with SmartStart leaders suggest two key barriers. Firstly, where private firms are dominant and ability to pay for services is limited, low-income areas are under-served. For this reason, Polanyi claims that markets should be embedded in institutions. A post-Polanyian approach emphasises the role of social investment states, which focus spending on education and where social protection scaffolds markets, in this regard. The South African state seems to embrace this approach as ECD policy frames early learning as a public good and social investment. However, a second barrier is that an insulated state enables technocratic over democratic embeddedness, with powerful rights-based discourse but poor implementation. In particular, it seems that the state lacks a framework to progressively realise the right to quality early learning. Attempts to enforce high standards are not accompanied by sufficient resources, capacity or collaboration, resulting in sub-standard services and barriers to entry. Even in better resourced contexts (e.g., Basic Education), top-down, technocratic models (re)produce failing systems, where those with means exit in favour of market alternatives. An exploration of other developing countries suggests that this failure, with variations, prevails, but also that possibility exists. In these contexts, states seem more coordinated and responsive when partnering with civil society. In South Africa, the SmartStart model is based on partnership. SmartStart frames itself as a delivery platform, building relationships with local NGOs to simultaneously scale and deepen early learning. Partnerships with communities are crucial, to build demand in a sector whose association with social reproduction means that its economic significance may be overlooked. In addition, SmartStart puts forward a child-centred approach based on a prefigurative vision but also responsive to the realities of under-resourced contexts, aiming to progressively realise rights. Though with some limitations, SmartStart’s least-cost innovation for scale provides lessons for the state. As the state’s ECD mandate shifts to Basic Education, these findings serve to inform a more effective implementation model, leveraging resources that already exist. , Thesis (MEcon) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: McCann, Claire Mary
- Date: 2022-10-14
- Subjects: Early childhood education South Africa , Social economy South Africa , Smart Start , Education and state South Africa , Social democracy , Dual economy South Africa , South Africa Economic conditions 1991-
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/403080 , vital:69920
- Description: Economic theory suggests that the greatest return to education investment is in the earliest years; early learning and childcare may enhance skill accumulation and mothers’ labour market choices. These services may be catalytic, igniting a revolution at point zero that transforms family outcomes and aids development. In South Africa, however, early learning deficits persist. This thesis explores barriers to quality early learning access and the possibility social economy initiatives offer, focusing on social franchises like SmartStart. Document analysis, comparative analysis, and interviews with SmartStart leaders suggest two key barriers. Firstly, where private firms are dominant and ability to pay for services is limited, low-income areas are under-served. For this reason, Polanyi claims that markets should be embedded in institutions. A post-Polanyian approach emphasises the role of social investment states, which focus spending on education and where social protection scaffolds markets, in this regard. The South African state seems to embrace this approach as ECD policy frames early learning as a public good and social investment. However, a second barrier is that an insulated state enables technocratic over democratic embeddedness, with powerful rights-based discourse but poor implementation. In particular, it seems that the state lacks a framework to progressively realise the right to quality early learning. Attempts to enforce high standards are not accompanied by sufficient resources, capacity or collaboration, resulting in sub-standard services and barriers to entry. Even in better resourced contexts (e.g., Basic Education), top-down, technocratic models (re)produce failing systems, where those with means exit in favour of market alternatives. An exploration of other developing countries suggests that this failure, with variations, prevails, but also that possibility exists. In these contexts, states seem more coordinated and responsive when partnering with civil society. In South Africa, the SmartStart model is based on partnership. SmartStart frames itself as a delivery platform, building relationships with local NGOs to simultaneously scale and deepen early learning. Partnerships with communities are crucial, to build demand in a sector whose association with social reproduction means that its economic significance may be overlooked. In addition, SmartStart puts forward a child-centred approach based on a prefigurative vision but also responsive to the realities of under-resourced contexts, aiming to progressively realise rights. Though with some limitations, SmartStart’s least-cost innovation for scale provides lessons for the state. As the state’s ECD mandate shifts to Basic Education, these findings serve to inform a more effective implementation model, leveraging resources that already exist. , Thesis (MEcon) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-10-14
Production of mannooligosaccharides from pineapple pulp and pine sawdust using Aspergillus niger derived Man26A and determination of their prebiotic effect
- Authors: Hlalukana, Nosipho Pretty
- Date: 2022-10-14
- Subjects: Oligosaccharides , Prebiotics , Lignocellulose , Mannans
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362853 , vital:65368
- Description: Lignocellulosic biomass is the most abundant source of renewable biomass on earth. Lignocellulosic biomass consists of cellulose, hemicelluloses and lignin. These can be used as a source of renewable fuel as well as other value-added products . Mannans are part of the hemicellulose fraction of lignocellulosic biomass and are the major hemicellulosic polysaccharide fraction in softwoods, where they are found as galactoglucomannans and as glucomannans. Mannans are also found in hardwoods in the form of glucomannans. Mannans can be enzymatically hydrolysed using endo-mannanases to produce of short chain mannooligosaccharides (MOS). MOS have received significant attention for their prebiotic properties, as they promote the growth of probiotic bacteria, which have positively affects on gut health. This study focused on the production of prebiotic MOS from lignocellulosic biomass waste (LBW) and an evaluation of the prebiotic potential of the produced MOS. An Aspergillus niger derived endo-mannanase, Man26A, was fractionated and biochemically analysed. Purified Man26A had a fold purification of 1.25 and a yield of 41.1%. SDS-PAGE analysis of the enzyme revealed that it had a molecular weight of 46 kDa. The pH and temperature optima of Man26A were determined and the pH optimum was found to be pH 4.0 (but the enzyme displayed high activity over a broad acidic pH range, with up to 90% of the activity retained between pH 3.0 and 7.0). The temperature optimum was 50℃. The enzyme was shown to have the highest specific activity on locust bean gum (52.27 U/mg) and ivory nut mannan (57.25 U/mg), compared to guar gum (29.07 U/mg), which indicated that it was affected by the substitution pattern of the mannans. Man26A produced MOS of different diversity on model mannan substrates, where the MOS produced were mannobiose, mannotriose, and mannotetraose for ivory nut mannan, mannobiose, mannotriose, mannotetraose, and mannopentaose and MOS with a higher degree of polymerisation for locust bean gum, and mannobiose, mannotriose, mannotetraose, mannopentaose, and mannohexose and MOS with a higher degree of polymerisation for guar gum, as determined by thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Pretreatment and characterisation of pineapple pulp (PP) and pine sawdust (PSD) was conducted, and the impact of the pretreatment procedures was analysed using Megazyme sugar kits, thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), and microscopic analysis using scanning electron microscopy (SEM) and light microscopy. Compositional analysis of the carbohydrates present in both substrates revealed that they had a glucan content of 36.41 and 50.47% for untreated PP and PSD, respectively. Their respective mannan content was 6.74 and 11.59% and was deemed sufficient for the production of MOS via enzymatic hydrolysis. TGA analysis revealed that untreated and sodium chlorite-acetic acid delignified samples decomposed at approximately the same time, and had a negligible ash content at 600℃, while delignified plus phosphoric acid swollen substrates decomposed at a faster rate, but had a residual ash content at 600℃. FTIR analysis of the substrates revealed slight changes in the structures of untreated and pretreated samples. SEM analysis of PP and PSD showed a change in the morphology of the substrates with subsequent pretreatment steps. Histochemical analysis for lignin for PP and PSD showed successful delignification upon pretreatment. Untreated and sodium chlorite delignified PP and PSD released low amounts of reducing sugars compared to delignified + phosphoric acid swollen substrates. The delignified + phosphoric acid swollen substrates were used for further experiments. MOS produced from delignified and phosphoric acid swollen (Del + PAS) PP and PSD at 0.1 mg/ml enzyme loading and 80 mg/ml (8% (w/v)) substrate concentration, ran between mannose and mannobiose and between mannobiose and manotriose on TLC, with low concentrations of MOS running between mannotetraose and mannopentaose. HPLC analysis of the MOS revealed that Del + PAS PP produced mannose to mannohexose, while Del + PAS PSD produced mannose, mannobiose, and mannotetraose. The MOS were analysed using FTIR, to determine whether the MOS produced contained any acetyl groups, which were present for Del + PAS PSD at 1706 cm-1. The MOS were stable at different pHs, and at temperatures below 200℃. The MOS were also found to be stable in a simulated gastrointestinal environment, in the presence of bile salts and digestive enzymes. The prebiotic effect of the MOS derived from Del + PAS PP and PSD was evaluated. MOS had a proliferative effect on probiotic bacteria (Lactobacillus bulgaricus, Bacillus subtilis and Streptococcus thermophilus). The production of short chain fatty acids (SCFAs) was evaluated on TLC, where no SCFAs were observed on the plate. The effect of MOS on the adhesion ability of bacteria revealed that they do not positively influence the adhesion of probiotic bacteria. The antioxidant activities of 1 mg/ml MOS produced from both substrates were determined to be approximately 15% using the ABTS radical scavenging assay, compared to a radical scavenging activity of 45% for the 0.02 mg/ml gallic acid standard. This study demonstrated that biomass waste could be used to produce prebiotic MOS, which play a positive role in gut ecology and provide health benefits. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Hlalukana, Nosipho Pretty
- Date: 2022-10-14
- Subjects: Oligosaccharides , Prebiotics , Lignocellulose , Mannans
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362853 , vital:65368
- Description: Lignocellulosic biomass is the most abundant source of renewable biomass on earth. Lignocellulosic biomass consists of cellulose, hemicelluloses and lignin. These can be used as a source of renewable fuel as well as other value-added products . Mannans are part of the hemicellulose fraction of lignocellulosic biomass and are the major hemicellulosic polysaccharide fraction in softwoods, where they are found as galactoglucomannans and as glucomannans. Mannans are also found in hardwoods in the form of glucomannans. Mannans can be enzymatically hydrolysed using endo-mannanases to produce of short chain mannooligosaccharides (MOS). MOS have received significant attention for their prebiotic properties, as they promote the growth of probiotic bacteria, which have positively affects on gut health. This study focused on the production of prebiotic MOS from lignocellulosic biomass waste (LBW) and an evaluation of the prebiotic potential of the produced MOS. An Aspergillus niger derived endo-mannanase, Man26A, was fractionated and biochemically analysed. Purified Man26A had a fold purification of 1.25 and a yield of 41.1%. SDS-PAGE analysis of the enzyme revealed that it had a molecular weight of 46 kDa. The pH and temperature optima of Man26A were determined and the pH optimum was found to be pH 4.0 (but the enzyme displayed high activity over a broad acidic pH range, with up to 90% of the activity retained between pH 3.0 and 7.0). The temperature optimum was 50℃. The enzyme was shown to have the highest specific activity on locust bean gum (52.27 U/mg) and ivory nut mannan (57.25 U/mg), compared to guar gum (29.07 U/mg), which indicated that it was affected by the substitution pattern of the mannans. Man26A produced MOS of different diversity on model mannan substrates, where the MOS produced were mannobiose, mannotriose, and mannotetraose for ivory nut mannan, mannobiose, mannotriose, mannotetraose, and mannopentaose and MOS with a higher degree of polymerisation for locust bean gum, and mannobiose, mannotriose, mannotetraose, mannopentaose, and mannohexose and MOS with a higher degree of polymerisation for guar gum, as determined by thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Pretreatment and characterisation of pineapple pulp (PP) and pine sawdust (PSD) was conducted, and the impact of the pretreatment procedures was analysed using Megazyme sugar kits, thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), and microscopic analysis using scanning electron microscopy (SEM) and light microscopy. Compositional analysis of the carbohydrates present in both substrates revealed that they had a glucan content of 36.41 and 50.47% for untreated PP and PSD, respectively. Their respective mannan content was 6.74 and 11.59% and was deemed sufficient for the production of MOS via enzymatic hydrolysis. TGA analysis revealed that untreated and sodium chlorite-acetic acid delignified samples decomposed at approximately the same time, and had a negligible ash content at 600℃, while delignified plus phosphoric acid swollen substrates decomposed at a faster rate, but had a residual ash content at 600℃. FTIR analysis of the substrates revealed slight changes in the structures of untreated and pretreated samples. SEM analysis of PP and PSD showed a change in the morphology of the substrates with subsequent pretreatment steps. Histochemical analysis for lignin for PP and PSD showed successful delignification upon pretreatment. Untreated and sodium chlorite delignified PP and PSD released low amounts of reducing sugars compared to delignified + phosphoric acid swollen substrates. The delignified + phosphoric acid swollen substrates were used for further experiments. MOS produced from delignified and phosphoric acid swollen (Del + PAS) PP and PSD at 0.1 mg/ml enzyme loading and 80 mg/ml (8% (w/v)) substrate concentration, ran between mannose and mannobiose and between mannobiose and manotriose on TLC, with low concentrations of MOS running between mannotetraose and mannopentaose. HPLC analysis of the MOS revealed that Del + PAS PP produced mannose to mannohexose, while Del + PAS PSD produced mannose, mannobiose, and mannotetraose. The MOS were analysed using FTIR, to determine whether the MOS produced contained any acetyl groups, which were present for Del + PAS PSD at 1706 cm-1. The MOS were stable at different pHs, and at temperatures below 200℃. The MOS were also found to be stable in a simulated gastrointestinal environment, in the presence of bile salts and digestive enzymes. The prebiotic effect of the MOS derived from Del + PAS PP and PSD was evaluated. MOS had a proliferative effect on probiotic bacteria (Lactobacillus bulgaricus, Bacillus subtilis and Streptococcus thermophilus). The production of short chain fatty acids (SCFAs) was evaluated on TLC, where no SCFAs were observed on the plate. The effect of MOS on the adhesion ability of bacteria revealed that they do not positively influence the adhesion of probiotic bacteria. The antioxidant activities of 1 mg/ml MOS produced from both substrates were determined to be approximately 15% using the ABTS radical scavenging assay, compared to a radical scavenging activity of 45% for the 0.02 mg/ml gallic acid standard. This study demonstrated that biomass waste could be used to produce prebiotic MOS, which play a positive role in gut ecology and provide health benefits. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
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- Date Issued: 2022-10-14
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