Evaluating Feruloyl Esterase—Xylanase Synergism for Hydroxycinnamic Acid and Xylo-Oligosaccharide Production from Untreated, Hydrothermally Pre-Treated and Dilute-Acid Pre-Treated Corn Cobs:
- Mkabayi, Lithalethu, Malgas, Samkelo, Wilhelmi, Brendan S, Pletschke, Brett I
- Authors: Mkabayi, Lithalethu , Malgas, Samkelo , Wilhelmi, Brendan S , Pletschke, Brett I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149240 , vital:38818 , https://doi.org/10.3390/agronomy10050688
- Description: Agricultural residues are considered the most promising option as a renewable feedstock for biofuel and high valued-added chemical production due to their availability and low cost. The efficient enzymatic hydrolysis of agricultural residues into value-added products such as sugars and hydroxycinnamic acids is a challenge because of the recalcitrant properties of the native biomass. Development of synergistic enzyme cocktails is required to overcome biomass residue recalcitrance, and achieve high yields of potential value-added products. In this study, the synergistic action of two termite metagenome-derived feruloyl esterases (FAE5 and FAE6), and an endo-xylanase (Xyn11) from Thermomyces lanuginosus, was optimized using 0.5% (w/v) insoluble wheat arabinoxylan (a model substrate) and then applied to 1% (w/v) corn cobs for the efficient production of xylo-oligosaccharides (XOS) and hydroxycinnamic acids.
- Full Text:
- Date Issued: 2020
- Authors: Mkabayi, Lithalethu , Malgas, Samkelo , Wilhelmi, Brendan S , Pletschke, Brett I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149240 , vital:38818 , https://doi.org/10.3390/agronomy10050688
- Description: Agricultural residues are considered the most promising option as a renewable feedstock for biofuel and high valued-added chemical production due to their availability and low cost. The efficient enzymatic hydrolysis of agricultural residues into value-added products such as sugars and hydroxycinnamic acids is a challenge because of the recalcitrant properties of the native biomass. Development of synergistic enzyme cocktails is required to overcome biomass residue recalcitrance, and achieve high yields of potential value-added products. In this study, the synergistic action of two termite metagenome-derived feruloyl esterases (FAE5 and FAE6), and an endo-xylanase (Xyn11) from Thermomyces lanuginosus, was optimized using 0.5% (w/v) insoluble wheat arabinoxylan (a model substrate) and then applied to 1% (w/v) corn cobs for the efficient production of xylo-oligosaccharides (XOS) and hydroxycinnamic acids.
- Full Text:
- Date Issued: 2020
Molecular cloning and expression of equine CYP1A2 in Escherichia coli
- Authors: Mkabayi, Lithalethu
- Date: 2017
- Subjects: Escherichia coli , Escherichia coli infections in animals , Cytochrome P-450 , Cytochromes , Horses -- Effect of drugs on
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4830 , vital:20734
- Description: Information regarding drug metabolism in veterinary species, especially horses, remains fragmented and incomplete. This information is essential for detection of metabolites of potential performance-enhancing substances in horseracing and for veterinary drug development. Equine liver microsomes have been used to study metabolism of a limited number of drugs, but these provide little information about individual drug metabolizing enzymes. Recombinant CYP enzyme systems are commonly used to determine contribution of individual CYP to metabolism of specific drugs. A limited number of recombinant equine CYPs have been expressed in insect cells and mammalian cell lines. However, there are no reports of recombinant equine CYP1A2 enzyme. In this study, equine CYP1A2 was identified, codon-optimized, cloned and expressed in E. coli BL21 cells. Multiple sequence alignments of equine CYP1A2 revealed an amino acid sequence identity of 83.69% to its human homolog which has previously been expressed in E. coli. The enzyme was expressed using both auto-induction and IPTG induction. Expressed equine CYP1A2 had a size of about 55 kDa, and was insoluble after cell lysis. Sarkosyl- solubilized CYP1A2 was purified using nickel affinity chromatography and gel filtration. For activity reconstitution, yeast NADPH-cytochrome P450 reductase was first expressed in E. coli BL21 cells and exhibited activity of 0.13 U/ml. Activity assay with Glo-P450 CYP1A2 assay kit indicated that CYP1A2 was inactive. Despite numerous attempts to obtain the activity, the CYP1A2 remained inactive. Although expression of equine CYP1A2 in E. coli produced non- catalytically active enzyme, this study could be used as the first step in an effort to fully develop a recombinant equine CYP1A2 system.
- Full Text:
- Date Issued: 2017
- Authors: Mkabayi, Lithalethu
- Date: 2017
- Subjects: Escherichia coli , Escherichia coli infections in animals , Cytochrome P-450 , Cytochromes , Horses -- Effect of drugs on
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4830 , vital:20734
- Description: Information regarding drug metabolism in veterinary species, especially horses, remains fragmented and incomplete. This information is essential for detection of metabolites of potential performance-enhancing substances in horseracing and for veterinary drug development. Equine liver microsomes have been used to study metabolism of a limited number of drugs, but these provide little information about individual drug metabolizing enzymes. Recombinant CYP enzyme systems are commonly used to determine contribution of individual CYP to metabolism of specific drugs. A limited number of recombinant equine CYPs have been expressed in insect cells and mammalian cell lines. However, there are no reports of recombinant equine CYP1A2 enzyme. In this study, equine CYP1A2 was identified, codon-optimized, cloned and expressed in E. coli BL21 cells. Multiple sequence alignments of equine CYP1A2 revealed an amino acid sequence identity of 83.69% to its human homolog which has previously been expressed in E. coli. The enzyme was expressed using both auto-induction and IPTG induction. Expressed equine CYP1A2 had a size of about 55 kDa, and was insoluble after cell lysis. Sarkosyl- solubilized CYP1A2 was purified using nickel affinity chromatography and gel filtration. For activity reconstitution, yeast NADPH-cytochrome P450 reductase was first expressed in E. coli BL21 cells and exhibited activity of 0.13 U/ml. Activity assay with Glo-P450 CYP1A2 assay kit indicated that CYP1A2 was inactive. Despite numerous attempts to obtain the activity, the CYP1A2 remained inactive. Although expression of equine CYP1A2 in E. coli produced non- catalytically active enzyme, this study could be used as the first step in an effort to fully develop a recombinant equine CYP1A2 system.
- Full Text:
- Date Issued: 2017
'Becoming citizens': young people making sense of citizenship on a South African community radio station youth show
- Karamagi, Sharon Benna Kyakyo
- Authors: Karamagi, Sharon Benna Kyakyo
- Date: 2012
- Subjects: Citizenship -- Study and teaching -- South Africa Youth -- Social conditions Community radio -- South Africa -- Grahamstown Grahamstown (South Africa) -- Economic conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3444 , http://hdl.handle.net/10962/d1002898
- Description: This research set out to investigate the role that community radio can potentially play as a space in which young people engage with their own role as citizens and, in so doing, participate in discussions that seek to address social problems in a community divided by class, income, gender and race. The study examines how a local community radio station - Radio Grahamstown - developed a youth programme Y4Yin which the producers of the show and its audience came together to negotiate the meaning of citizenship. The study examines whether this interactive programme was able to function as something like a public sphere where in young people were able to develop a greater sense of agency, at least in the realm of citizenship. Using evidence gathered through focus group discussions with a group of young school-going leamers, interviews conducted with the producers of the show Y4Y, and drawing on Dahlgren's elaboration of a functional public sphere, the research concludes that the show provided a useful platform for Grahamstown high school students to develop their own notions of citizenship and to, at least partially and tentatively, build some 'bridges' across the vectors of socio-economic division in the town. However, the research also concludes that the Y4Y producers often failed to use a mode of address contemporary to the youth and often did not use production techniques congruent with young people's cultural tastes. This limited the programme's appeal and its potential as an enabler of discussion about notions of citizenship and as a platform for social bridging. In addition, because of the producers' control over the choice of topics put up for discussion, open interaction was more limited than could have been expected. In addition, the study also concludes that various limitations to the leamers' freedom of expression (including their fear that teachers might be listening in to the shows) inhibited the programme's role as a deliberative public sphere where issues could be aired, common ground found, and solutions discussed.
- Full Text:
- Date Issued: 2012
- Authors: Karamagi, Sharon Benna Kyakyo
- Date: 2012
- Subjects: Citizenship -- Study and teaching -- South Africa Youth -- Social conditions Community radio -- South Africa -- Grahamstown Grahamstown (South Africa) -- Economic conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3444 , http://hdl.handle.net/10962/d1002898
- Description: This research set out to investigate the role that community radio can potentially play as a space in which young people engage with their own role as citizens and, in so doing, participate in discussions that seek to address social problems in a community divided by class, income, gender and race. The study examines how a local community radio station - Radio Grahamstown - developed a youth programme Y4Yin which the producers of the show and its audience came together to negotiate the meaning of citizenship. The study examines whether this interactive programme was able to function as something like a public sphere where in young people were able to develop a greater sense of agency, at least in the realm of citizenship. Using evidence gathered through focus group discussions with a group of young school-going leamers, interviews conducted with the producers of the show Y4Y, and drawing on Dahlgren's elaboration of a functional public sphere, the research concludes that the show provided a useful platform for Grahamstown high school students to develop their own notions of citizenship and to, at least partially and tentatively, build some 'bridges' across the vectors of socio-economic division in the town. However, the research also concludes that the Y4Y producers often failed to use a mode of address contemporary to the youth and often did not use production techniques congruent with young people's cultural tastes. This limited the programme's appeal and its potential as an enabler of discussion about notions of citizenship and as a platform for social bridging. In addition, because of the producers' control over the choice of topics put up for discussion, open interaction was more limited than could have been expected. In addition, the study also concludes that various limitations to the leamers' freedom of expression (including their fear that teachers might be listening in to the shows) inhibited the programme's role as a deliberative public sphere where issues could be aired, common ground found, and solutions discussed.
- Full Text:
- Date Issued: 2012
An evaluation of synergistic interactions between feruloyl esterases and xylanases during the hydrolysis of various pre-treated agricultural residues
- Authors: Mkabayi, Lithalethu
- Date: 2021-04
- Subjects: Esterases , Xylanases , Hydrolysis , Agricultural wastes -- Recycling , Enzymes , Lignocellulose -- Biodegradation , Escherichia coli , Oligosaccharides , Hydroxycinnamic acids
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178224 , vital:42922 , 10.21504/10962/178224
- Description: Agricultural residues are readily available and inexpensive renewable resources that can be used as raw materials for the production of value-added chemicals. The application of enzymes to facilitate the degradation of agricultural residues has long been considered the most environmentally friendly strategy for converting this material into good quality value-added chemicals. However, agricultural residues are typically lignocellulosic in composition and recalcitrant to enzymatic hydrolysis. Due to this recalcitrant nature, the complete degradation of biomass residues requires the synergistic action of a broad range of enzymes. The development and optimisation of synergistic enzyme cocktails is an effective approach for achieving high hydrolysis efficiency of lignocellulosic biomass. The aim of the current study was to evaluate the synergistic interactions between two termite metagenome-derived feruloyl esterases (FAE6 and FAE5) and endo-xylanases for the production of hydroxycinnamic acids and xylo-oligosaccharides (XOS) from model substrates, and untreated and pre-treated agricultural residues. Firstly, the two fae genes were heterologously expressed in Escherichia coli, and the recombinant enzymes were purified to homogeneity. The biochemical properties of the purified recombinant FAEs and xylanases (XT6 and Xyn11) were then assessed to determine the factors which influenced their activities and to select suitable operating conditions for synergy studies. An optimal protein loading ratio of xylanases to FAEs required to maximise the release of both reducing sugar and ferulic acid (FA) was established using 0.5% (w/v) insoluble wheat arabinoxylan (a model substrate). The enzyme combination of 66% xylanase and 33% FAE (on a protein loading basis) produced the highest amounts of reducing sugars and FA. The enzyme combination of XT6 (GH10 xylanase) and FAE5 or FAE6 liberated the highest amount of FA while a combination of Xyn11 (GH11 xylanase) and FAE5 or FAE6 produced the highest reducing sugar content. The synergistic interactions which were established between the xylanases and FAEs were further investigated using agricultural residues (corn cobs, rice straw and sugarcane bagasse). The three substrates were subjected to hydrothermal and dilute acid pre-treatment prior to synergy studies. It is generally known that, during pre-treatment, many compounds can be produced which may influence enzymatic hydrolysis. The effects of these by-products were assessed and it was found that lignin and its degradation products were the most inhibitory to the FAEs. The optimised enzyme cocktail was then applied to 1% (w/v) of untreated and pre-treated substrates for the efficient production of XOS and hydroxycinnamic acids. A significant improvement in xylanase substrate degradation was observed, especially with the combination of 66% Xyn11 and 33% FAE6 which displayed an improvement in reducing sugars of approximately 1.9-fold and 3.4-fold for hydrothermal and acid pre-treated corn cobs (compared to when Xyn11 was used alone), respectively. The study demonstrated that pre-treatment substantially enhanced the enzymatic hydrolysis of corn cobs and rice straw. Analysis of the hydrolysate product profiles revealed that the optimised enzyme cocktail displayed great potential for releasing XOS with a low degree of polymerisation. In conclusion, this study provided significant insights into the mechanism of synergistic interactions between xylanases and metagenome-derived FAEs during the hydrolysis of various substrates. The study also demonstrated that optimised enzyme cocktails combined with low severity pre-treatment can facilitate the potential use of xylan-rich lignocellulosic biomass for the production of valuable products in the future. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Mkabayi, Lithalethu
- Date: 2021-04
- Subjects: Esterases , Xylanases , Hydrolysis , Agricultural wastes -- Recycling , Enzymes , Lignocellulose -- Biodegradation , Escherichia coli , Oligosaccharides , Hydroxycinnamic acids
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178224 , vital:42922 , 10.21504/10962/178224
- Description: Agricultural residues are readily available and inexpensive renewable resources that can be used as raw materials for the production of value-added chemicals. The application of enzymes to facilitate the degradation of agricultural residues has long been considered the most environmentally friendly strategy for converting this material into good quality value-added chemicals. However, agricultural residues are typically lignocellulosic in composition and recalcitrant to enzymatic hydrolysis. Due to this recalcitrant nature, the complete degradation of biomass residues requires the synergistic action of a broad range of enzymes. The development and optimisation of synergistic enzyme cocktails is an effective approach for achieving high hydrolysis efficiency of lignocellulosic biomass. The aim of the current study was to evaluate the synergistic interactions between two termite metagenome-derived feruloyl esterases (FAE6 and FAE5) and endo-xylanases for the production of hydroxycinnamic acids and xylo-oligosaccharides (XOS) from model substrates, and untreated and pre-treated agricultural residues. Firstly, the two fae genes were heterologously expressed in Escherichia coli, and the recombinant enzymes were purified to homogeneity. The biochemical properties of the purified recombinant FAEs and xylanases (XT6 and Xyn11) were then assessed to determine the factors which influenced their activities and to select suitable operating conditions for synergy studies. An optimal protein loading ratio of xylanases to FAEs required to maximise the release of both reducing sugar and ferulic acid (FA) was established using 0.5% (w/v) insoluble wheat arabinoxylan (a model substrate). The enzyme combination of 66% xylanase and 33% FAE (on a protein loading basis) produced the highest amounts of reducing sugars and FA. The enzyme combination of XT6 (GH10 xylanase) and FAE5 or FAE6 liberated the highest amount of FA while a combination of Xyn11 (GH11 xylanase) and FAE5 or FAE6 produced the highest reducing sugar content. The synergistic interactions which were established between the xylanases and FAEs were further investigated using agricultural residues (corn cobs, rice straw and sugarcane bagasse). The three substrates were subjected to hydrothermal and dilute acid pre-treatment prior to synergy studies. It is generally known that, during pre-treatment, many compounds can be produced which may influence enzymatic hydrolysis. The effects of these by-products were assessed and it was found that lignin and its degradation products were the most inhibitory to the FAEs. The optimised enzyme cocktail was then applied to 1% (w/v) of untreated and pre-treated substrates for the efficient production of XOS and hydroxycinnamic acids. A significant improvement in xylanase substrate degradation was observed, especially with the combination of 66% Xyn11 and 33% FAE6 which displayed an improvement in reducing sugars of approximately 1.9-fold and 3.4-fold for hydrothermal and acid pre-treated corn cobs (compared to when Xyn11 was used alone), respectively. The study demonstrated that pre-treatment substantially enhanced the enzymatic hydrolysis of corn cobs and rice straw. Analysis of the hydrolysate product profiles revealed that the optimised enzyme cocktail displayed great potential for releasing XOS with a low degree of polymerisation. In conclusion, this study provided significant insights into the mechanism of synergistic interactions between xylanases and metagenome-derived FAEs during the hydrolysis of various substrates. The study also demonstrated that optimised enzyme cocktails combined with low severity pre-treatment can facilitate the potential use of xylan-rich lignocellulosic biomass for the production of valuable products in the future. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-04
Cloning, expression, partial characterisation and application of a recombinant GH10 xylanase, XT6, from Geobacillus stearothermophilus T6 as an additive to chicken feeds
- Authors: Sithole, Tariro
- Date: 2022-04-06
- Subjects: Chicken feed industry , Chickens Feeding and feeds , Bacillus (Bacteria) , Xylanases , Polysaccharides , Geobacillus stearothermophilus
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/292693 , vital:57007
- Description: Monogastric animal farming has largely been sustained by feeding animals with grain feedstocks containing non-starch polysaccharides (NSPs) and anti-nutritive factors, which cause adverse effects, such as increased digesta viscosity and entrapment of nutrients, which leads to the inaccessibility of nutrients. These effects have been linked to a reduction in nutrient digestion and absorption, which results in a decreased feed conversion ratio, energy metabolism and animal growth. Monogastric animals do not produce enzymes that can hydrolyse these NSPs. The application of exogenous enzymes as supplements to animal feeds has been implemented to reduce viscosity and increase nutrient absorption in poultry and pigs over the past few decades. The aim of this study was to clone, express, partially characterise and apply a glycoside hydrolase (GH) family 10 xylanase (XT6), derived from Geobacillus stearothermophilus T6, as an additive to locally produced chicken feeds. The xt6 gene (1,236 bp) was subcloned and expressed in Escherichia coli DH5α and BL21(DE3) cells, respectively. Upon expression, XT6 had a molecular weight of 42 kDa and was partially purified by Ni-NTA chromatography and ultrafiltration. The purification step resulted in a yield of 66.7% with a 16.8-fold increase in purification. XT6 exhibited maximal activity when incubated at a pH and temperature of pH 6.0 and 70°C, respectively, with a high thermostability over a broad range of pH (2–9) and temperature (30–90 °C). The specific activities of XT6 on extracted soluble and insoluble wheat flour arabinoxylans were 110.9 U/mg and 63.98 U/mg, respectively. Kinetic data showed that XT6 displayed a higher catalytic activity and affinity (Vmax = 231.60 μmol/min/mg and KM = 2.759 mg/ml) for soluble wheat arabinoxylan, compared to insoluble wheat arabinoxylan (Vmax = 99.02 μmol/min/mg and KM = 5.058 mg/ml). High-performance liquid chromatography (HPLC) analysis showed that the enzyme hydrolysed wheat flour, arabinoxylan and chicken feeds, producing a range of xylooligosaccharides (XOS), with xylotetraose and xylopentaose being the predominant XOS species. Hydrolysis of both soluble and insoluble wheat flour arabinoxylans by XT6 led to a significant reduction in substrate viscosity. The effects of simulated gastrointestinal fluid contents, such as proteases, bile salts and mucins, on XT6 stability were also studied. Exposure of XT6 to pepsin did not significantly reduce its activity; however, the inhibitory effect of trypsin and mucin on XT6 was much greater. The presence of gut-derived bile salts had no iii | P a g e significant effect on XT6 activity. Finally, it was shown that the XOS produced from the hydrolysis of chicken feeds (starter and grower feeds) by XT6 significantly enhanced the growth of the probiotic bacteria B. subtilis, while there was no significant improvement in the growth of S. thermophilus and L. bulgaricus. In conclusion, the recombinantly produced XT6 demonstrated efficient hydrolysis of starter and grower feeds, and produced XOS that showed prebiotic activity on selected probiotic bacteria. In addition, the pH, temperature and simulated gastric juice content stability of XT6 renders it an attractive candidate as an additive for chicken feeds. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Sithole, Tariro
- Date: 2022-04-06
- Subjects: Chicken feed industry , Chickens Feeding and feeds , Bacillus (Bacteria) , Xylanases , Polysaccharides , Geobacillus stearothermophilus
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/292693 , vital:57007
- Description: Monogastric animal farming has largely been sustained by feeding animals with grain feedstocks containing non-starch polysaccharides (NSPs) and anti-nutritive factors, which cause adverse effects, such as increased digesta viscosity and entrapment of nutrients, which leads to the inaccessibility of nutrients. These effects have been linked to a reduction in nutrient digestion and absorption, which results in a decreased feed conversion ratio, energy metabolism and animal growth. Monogastric animals do not produce enzymes that can hydrolyse these NSPs. The application of exogenous enzymes as supplements to animal feeds has been implemented to reduce viscosity and increase nutrient absorption in poultry and pigs over the past few decades. The aim of this study was to clone, express, partially characterise and apply a glycoside hydrolase (GH) family 10 xylanase (XT6), derived from Geobacillus stearothermophilus T6, as an additive to locally produced chicken feeds. The xt6 gene (1,236 bp) was subcloned and expressed in Escherichia coli DH5α and BL21(DE3) cells, respectively. Upon expression, XT6 had a molecular weight of 42 kDa and was partially purified by Ni-NTA chromatography and ultrafiltration. The purification step resulted in a yield of 66.7% with a 16.8-fold increase in purification. XT6 exhibited maximal activity when incubated at a pH and temperature of pH 6.0 and 70°C, respectively, with a high thermostability over a broad range of pH (2–9) and temperature (30–90 °C). The specific activities of XT6 on extracted soluble and insoluble wheat flour arabinoxylans were 110.9 U/mg and 63.98 U/mg, respectively. Kinetic data showed that XT6 displayed a higher catalytic activity and affinity (Vmax = 231.60 μmol/min/mg and KM = 2.759 mg/ml) for soluble wheat arabinoxylan, compared to insoluble wheat arabinoxylan (Vmax = 99.02 μmol/min/mg and KM = 5.058 mg/ml). High-performance liquid chromatography (HPLC) analysis showed that the enzyme hydrolysed wheat flour, arabinoxylan and chicken feeds, producing a range of xylooligosaccharides (XOS), with xylotetraose and xylopentaose being the predominant XOS species. Hydrolysis of both soluble and insoluble wheat flour arabinoxylans by XT6 led to a significant reduction in substrate viscosity. The effects of simulated gastrointestinal fluid contents, such as proteases, bile salts and mucins, on XT6 stability were also studied. Exposure of XT6 to pepsin did not significantly reduce its activity; however, the inhibitory effect of trypsin and mucin on XT6 was much greater. The presence of gut-derived bile salts had no iii | P a g e significant effect on XT6 activity. Finally, it was shown that the XOS produced from the hydrolysis of chicken feeds (starter and grower feeds) by XT6 significantly enhanced the growth of the probiotic bacteria B. subtilis, while there was no significant improvement in the growth of S. thermophilus and L. bulgaricus. In conclusion, the recombinantly produced XT6 demonstrated efficient hydrolysis of starter and grower feeds, and produced XOS that showed prebiotic activity on selected probiotic bacteria. In addition, the pH, temperature and simulated gastric juice content stability of XT6 renders it an attractive candidate as an additive for chicken feeds. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-04-06
Application of web design techniques and best practices in implementing web development, maintenance and enhancement of RUBi websites and web application systems
- Authors: Tshabalalala, Thulani
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424688 , vital:72175
- Description: The popularity of the web has seen various fields, such as the sciences taking advantage of this resource to further their scientific endeavours. This has seen science groups moving into developing websites and web applications, and such a group is the Research Unit in Bioinformative (RUBi). With the use of the web, the development and maintenance of whatever web-related tools become inevitable, given the continuous changes in the web space. This continuous evolution of web development and maintenance will come with techniques, principles and standards which will not only enable faster development of web entities but also ensure that modern hardware, fulfilment of the requirements to use such hardware and modern concepts are incorporated into forming web tools that enable such progression. Furthermore, introducing the previously mentioned progress of the web becomes an essential part of its development and maintenance. This paper did implement the processes of progressing the web using the technique of documentation and version control systems. The web development for the COVIDRUG website was done for the Covidrug-Africa Consortium (COVIDRUG) using the Django webdevelopment framework. The RUBi website and the MDM-Task we band the Job Management System (JMS) web applications were maintained for the maintenance aspect. Archives brought value regarding the traceability it provides of the various web-related aspects. The development showed a website’s potential value, particularly for research groups. The maintenance carried out showed how different techniques and approaches could be used in different maintenance prospects to achieve set objectives. The development and maintenance resulted in websites and web applications that have the features stated in their respective maintenance plans. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Tshabalalala, Thulani
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424688 , vital:72175
- Description: The popularity of the web has seen various fields, such as the sciences taking advantage of this resource to further their scientific endeavours. This has seen science groups moving into developing websites and web applications, and such a group is the Research Unit in Bioinformative (RUBi). With the use of the web, the development and maintenance of whatever web-related tools become inevitable, given the continuous changes in the web space. This continuous evolution of web development and maintenance will come with techniques, principles and standards which will not only enable faster development of web entities but also ensure that modern hardware, fulfilment of the requirements to use such hardware and modern concepts are incorporated into forming web tools that enable such progression. Furthermore, introducing the previously mentioned progress of the web becomes an essential part of its development and maintenance. This paper did implement the processes of progressing the web using the technique of documentation and version control systems. The web development for the COVIDRUG website was done for the Covidrug-Africa Consortium (COVIDRUG) using the Django webdevelopment framework. The RUBi website and the MDM-Task we band the Job Management System (JMS) web applications were maintained for the maintenance aspect. Archives brought value regarding the traceability it provides of the various web-related aspects. The development showed a website’s potential value, particularly for research groups. The maintenance carried out showed how different techniques and approaches could be used in different maintenance prospects to achieve set objectives. The development and maintenance resulted in websites and web applications that have the features stated in their respective maintenance plans. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2023-10-13
Impact of social media on the brand image of a higher education institution
- Authors: Visser, Ilze
- Date: 2012
- Subjects: Branding (Marketing) , Social media
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9292 , http://hdl.handle.net/10948/d1011274 , Branding (Marketing) , Social media
- Description: Social media is an unexplored and new area, for both businesses and academia. Many institutions are not confident on how to improve their business through the use of social media, neither for internal or external purposes. Social media is nevertheless immense among private persons (Wikström & Wigmo 2010:1) and to ignore this would be a critical mistake by marketing communicators, regardless of the economic sector in which they operate. Therefore, this study intended to expand on the current limited knowledge and information available relating to the use of social media by Higher Education Institutions (HEIs) to improve their brand image. The primary objective of this research was to evaluate and empirically test the impact of selected Brand identity variables (Brand reputation, Brand relevance, Brand personality, Brand performance and Brand relationship) on the Brand image of a HEI, through the use of social media. The focus was on the impact of social media (Facebook) on the brand image of a Higher Education Institution (HEI), namely the Nelson Mandela Metropolitan University (NMMU), which was used as the sample for this study.
- Full Text:
- Date Issued: 2012
- Authors: Visser, Ilze
- Date: 2012
- Subjects: Branding (Marketing) , Social media
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9292 , http://hdl.handle.net/10948/d1011274 , Branding (Marketing) , Social media
- Description: Social media is an unexplored and new area, for both businesses and academia. Many institutions are not confident on how to improve their business through the use of social media, neither for internal or external purposes. Social media is nevertheless immense among private persons (Wikström & Wigmo 2010:1) and to ignore this would be a critical mistake by marketing communicators, regardless of the economic sector in which they operate. Therefore, this study intended to expand on the current limited knowledge and information available relating to the use of social media by Higher Education Institutions (HEIs) to improve their brand image. The primary objective of this research was to evaluate and empirically test the impact of selected Brand identity variables (Brand reputation, Brand relevance, Brand personality, Brand performance and Brand relationship) on the Brand image of a HEI, through the use of social media. The focus was on the impact of social media (Facebook) on the brand image of a Higher Education Institution (HEI), namely the Nelson Mandela Metropolitan University (NMMU), which was used as the sample for this study.
- Full Text:
- Date Issued: 2012
Between"culture" and "Cruelty"narratives of widows on land dispossession in Gqadu administrative area, Mbashe Municipality , Eastern Cape
- Authors: Baleka, Zola
- Date: 2016
- Subjects: Widows -- South Africa -- Eastern Cape Land tenure -- South Africa -- Eastern Cape Right of property -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , Degree
- Identifier: http://hdl.handle.net/10353/5083 , vital:29057
- Description: This study highlights the cultural underpinnings of specific indulgences pertaining to land ownership with reference to widowhood in the rural Eastern Cape. The study does this by examining the narratives of widows about their experiences of land dispossession in Nqadu Administrative Area. Nqadu Administrative Area is a rural community in Mbhashe Local Municipality in the Eastern Cape Province of South Africa. The study focuses on widows’ experiences relating to the cultural practices of the community regarding land ownership. A qualitative, case study design was adopted. To uncover the widows’ narratives, the study utilised in-depth interviews and focus group discussions, with a sample of 50 widows. Further empirical data were obtained from four members of the municipal Land Committees, two Ward Councillors, four Traditional Leaders and two officials from the Eastern Cape Department of Rural Development and Agrarian Reform, using in-depth and key informant interviews. The study found that widows were vulnerable to land ownership violations and dispossessions, and that these violations were perpetrated by community members, particularly relatives of deceased husbands. Low levels of education and fear of antagonising clan relatives played a vital role in preventing widows from fighting for their legal rights. The failure of widows to fight for their rights increased their chances of being heavily exposed to dispossession of their land rights. Cultural practices within the communities catalysed abusive practices against widows, particularly against those whose marriage was not ‘recognised’ due to various stated reasons. The study also revealed that widows who had married as second wives and those who did not bear children experienced egregious abuses. Another finding was that men from Nqadu Administrative Area were given priority during the allocation of land, based on cultural and traditional practices, and were given land of their own choice depending on availability. The study thus highlights the impact of cultural practices and the ways in which these became instruments of gender abuse, despite the existence of laws designed to prevent specific social cruelties.
- Full Text:
- Date Issued: 2016
- Authors: Baleka, Zola
- Date: 2016
- Subjects: Widows -- South Africa -- Eastern Cape Land tenure -- South Africa -- Eastern Cape Right of property -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , Degree
- Identifier: http://hdl.handle.net/10353/5083 , vital:29057
- Description: This study highlights the cultural underpinnings of specific indulgences pertaining to land ownership with reference to widowhood in the rural Eastern Cape. The study does this by examining the narratives of widows about their experiences of land dispossession in Nqadu Administrative Area. Nqadu Administrative Area is a rural community in Mbhashe Local Municipality in the Eastern Cape Province of South Africa. The study focuses on widows’ experiences relating to the cultural practices of the community regarding land ownership. A qualitative, case study design was adopted. To uncover the widows’ narratives, the study utilised in-depth interviews and focus group discussions, with a sample of 50 widows. Further empirical data were obtained from four members of the municipal Land Committees, two Ward Councillors, four Traditional Leaders and two officials from the Eastern Cape Department of Rural Development and Agrarian Reform, using in-depth and key informant interviews. The study found that widows were vulnerable to land ownership violations and dispossessions, and that these violations were perpetrated by community members, particularly relatives of deceased husbands. Low levels of education and fear of antagonising clan relatives played a vital role in preventing widows from fighting for their legal rights. The failure of widows to fight for their rights increased their chances of being heavily exposed to dispossession of their land rights. Cultural practices within the communities catalysed abusive practices against widows, particularly against those whose marriage was not ‘recognised’ due to various stated reasons. The study also revealed that widows who had married as second wives and those who did not bear children experienced egregious abuses. Another finding was that men from Nqadu Administrative Area were given priority during the allocation of land, based on cultural and traditional practices, and were given land of their own choice depending on availability. The study thus highlights the impact of cultural practices and the ways in which these became instruments of gender abuse, despite the existence of laws designed to prevent specific social cruelties.
- Full Text:
- Date Issued: 2016
The oversight role of governing bodies in selected schools in the Upper Xolobe administrative area, Tsomo Magisterial district
- Authors: Yotsi, Bafo Synford
- Date: 20XX
- Subjects: School boards -- South Africa -- Eastern Cape School management and organization -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: http://hdl.handle.net/10948/11320 , vital:26910
- Description: The primary aim of this study is to investigate the role of school governing bodies in their oversight role of the implementation of education departmental policies by school principals in selected schools in the Upper Xolobe Administrative Area. According to Clarke (2009: 14), there is no doubt that a school improves when a school’s governors exert their governance oversight authority in a way that promotes the effective use of resources and establishes a climate which encourages teaching and learning. South African schools, especially in rural areas, are still grappling with the challenges of electing effective people into school governing bodies (National Guidelines for School Governing Body Elections, 2012: 6). The Upper Xolobe Administrative Area is a rural traditional authority area under the traditional leadership of a headman who is appointed in line with traditional chieftainship under the supervision of a chief. There is also a democratically elected ward councillor as a political leader. In the area, there are seven General Education and Training (GET) band schools and one Further Education and Training (FET) band school or senior secondary school which offers tuition for grades 10 to 12. There are, therefore eight (8) governing bodies for the eight institutions. The majority of SGB members are not adequately educated. According to Clarke (2009: 1), schools are effective when there is an institutional environment that is conducive to teaching and learning. There is significant research identifying the characteristics of schools where good teaching and learning are evident, where there is a good work ethic and where children are provided with opportunities to develop to their full potential (Clarke, 2009: 1). The challenge for school governors is to see that they perform their governance functions in a way that will create a school environment where these characteristics are evident. The perceptible indications are that against the background of the challenge of the level of education of the majority of the parent members of SGBs, their mandatory term of office which is only three years and a myriad of other environmental challenges, the eight SGBs of the eight institutions in the Upper Xolobe Administrative Area are to grapple with, creating a school environment where the characteristics mentioned might be challenging. Two important principles of the South African Schools’ Act are concerned with inclusivity and decentralisation. Inclusivity means the participation of parents, educators, non-teaching staff, learners, and other people who are willing and able to make contribution to the school. Bringing decision-making closer to the people is desirable, but this in itself will not solve all the problems and challenges faced by school governing bodies. Research has shown that school governing bodies face many problems despite the fact that decisions are made by people closest to the situation (Ramadiro & Vally, 2005: 1). This study intends to investigate the combined effect of the various components constituting the school governing body members of eight schools in the Upper Xolobe Administrative Area in their oversight role of policy implementation by school principals or school managers.
- Full Text:
- Date Issued: 20XX
- Authors: Yotsi, Bafo Synford
- Date: 20XX
- Subjects: School boards -- South Africa -- Eastern Cape School management and organization -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: http://hdl.handle.net/10948/11320 , vital:26910
- Description: The primary aim of this study is to investigate the role of school governing bodies in their oversight role of the implementation of education departmental policies by school principals in selected schools in the Upper Xolobe Administrative Area. According to Clarke (2009: 14), there is no doubt that a school improves when a school’s governors exert their governance oversight authority in a way that promotes the effective use of resources and establishes a climate which encourages teaching and learning. South African schools, especially in rural areas, are still grappling with the challenges of electing effective people into school governing bodies (National Guidelines for School Governing Body Elections, 2012: 6). The Upper Xolobe Administrative Area is a rural traditional authority area under the traditional leadership of a headman who is appointed in line with traditional chieftainship under the supervision of a chief. There is also a democratically elected ward councillor as a political leader. In the area, there are seven General Education and Training (GET) band schools and one Further Education and Training (FET) band school or senior secondary school which offers tuition for grades 10 to 12. There are, therefore eight (8) governing bodies for the eight institutions. The majority of SGB members are not adequately educated. According to Clarke (2009: 1), schools are effective when there is an institutional environment that is conducive to teaching and learning. There is significant research identifying the characteristics of schools where good teaching and learning are evident, where there is a good work ethic and where children are provided with opportunities to develop to their full potential (Clarke, 2009: 1). The challenge for school governors is to see that they perform their governance functions in a way that will create a school environment where these characteristics are evident. The perceptible indications are that against the background of the challenge of the level of education of the majority of the parent members of SGBs, their mandatory term of office which is only three years and a myriad of other environmental challenges, the eight SGBs of the eight institutions in the Upper Xolobe Administrative Area are to grapple with, creating a school environment where the characteristics mentioned might be challenging. Two important principles of the South African Schools’ Act are concerned with inclusivity and decentralisation. Inclusivity means the participation of parents, educators, non-teaching staff, learners, and other people who are willing and able to make contribution to the school. Bringing decision-making closer to the people is desirable, but this in itself will not solve all the problems and challenges faced by school governing bodies. Research has shown that school governing bodies face many problems despite the fact that decisions are made by people closest to the situation (Ramadiro & Vally, 2005: 1). This study intends to investigate the combined effect of the various components constituting the school governing body members of eight schools in the Upper Xolobe Administrative Area in their oversight role of policy implementation by school principals or school managers.
- Full Text:
- Date Issued: 20XX
Rhodes University Graduation Ceremony 2014
- Authors: Rhodes University
- Date: 2014
- Language: English
- Type: text
- Identifier: vital:8148 , http://hdl.handle.net/10962/d1009493
- Description: Rhodes University Graduation Ceremonies [at] 1820 Settlers National Monument Thursday, 10 April at 10.00 & 17:00 [and] Friday, 11 April at 10:00; 14:30 & 18:00 [and] Saturday, 12 April at 10:00 , Rhodes University Awards, Scholarships,Bursaries and Prizes 2014
- Full Text:
- Date Issued: 2014
- Authors: Rhodes University
- Date: 2014
- Language: English
- Type: text
- Identifier: vital:8148 , http://hdl.handle.net/10962/d1009493
- Description: Rhodes University Graduation Ceremonies [at] 1820 Settlers National Monument Thursday, 10 April at 10.00 & 17:00 [and] Friday, 11 April at 10:00; 14:30 & 18:00 [and] Saturday, 12 April at 10:00 , Rhodes University Awards, Scholarships,Bursaries and Prizes 2014
- Full Text:
- Date Issued: 2014
Rhodes University Graduation Ceremony 2013
- Authors: Rhodes University
- Date: 2013
- Language: English
- Type: text
- Identifier: vital:8134 , http://hdl.handle.net/10962/d1007241
- Description: Rhodes University 2013 Installation of Lex Mpati as 7th Chancellor of Rhodes University and Graduation Ceremony [at] 1820 Settlers National Monument Thursday, 4 April 2013 at 18.00 , Rhodes University Graduation Ceremony [at] 1820 Settlers National Monument Friday, 5 April at 10.00; 14:30 & 18:00 [and] Saturday, 6 April at 10:00 , Rhodes University Awards, Scholarships, Bursaries and Prizes 2013
- Full Text:
- Date Issued: 2013
- Authors: Rhodes University
- Date: 2013
- Language: English
- Type: text
- Identifier: vital:8134 , http://hdl.handle.net/10962/d1007241
- Description: Rhodes University 2013 Installation of Lex Mpati as 7th Chancellor of Rhodes University and Graduation Ceremony [at] 1820 Settlers National Monument Thursday, 4 April 2013 at 18.00 , Rhodes University Graduation Ceremony [at] 1820 Settlers National Monument Friday, 5 April at 10.00; 14:30 & 18:00 [and] Saturday, 6 April at 10:00 , Rhodes University Awards, Scholarships, Bursaries and Prizes 2013
- Full Text:
- Date Issued: 2013
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
- Full Text:
- Date Issued: 2022-10-14
Rhodeo, Vol. 22, No. 16
- Date: 1968-08-22
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14590 , http://hdl.handle.net/10962/d1019462
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Date Issued: 1968-08-22
- Date: 1968-08-22
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14590 , http://hdl.handle.net/10962/d1019462
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Date Issued: 1968-08-22
Rhodes University Graduation Ceremony 2017
- Authors: Rhodes University
- Date: 2017
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/58067 , vital:27061
- Description: 2017 Graduation Ceremony, Umsitho Wothweso-Zidanga, Gradeplegtigheid [at] 1820 Settlers National Monument, Thursday, 20 April until Saturday, 22 April 2017.
- Full Text:
- Date Issued: 2017
- Authors: Rhodes University
- Date: 2017
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/58067 , vital:27061
- Description: 2017 Graduation Ceremony, Umsitho Wothweso-Zidanga, Gradeplegtigheid [at] 1820 Settlers National Monument, Thursday, 20 April until Saturday, 22 April 2017.
- Full Text:
- Date Issued: 2017
Rhodeo, Vol. 22, No. 17
- Date: 1968-08-29
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14591 , http://hdl.handle.net/10962/d1019463
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Date Issued: 1968-08-29
- Date: 1968-08-29
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14591 , http://hdl.handle.net/10962/d1019463
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Date Issued: 1968-08-29
Rhodeo, Vol. 22, No. 8
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14583 , http://hdl.handle.net/10962/d1019455
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14583 , http://hdl.handle.net/10962/d1019455
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
Rhodeo, Vol. 22, No. 13
- Date: 1968-06-13
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14587 , http://hdl.handle.net/10962/d1019459
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Date Issued: 1968-06-13
- Date: 1968-06-13
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14587 , http://hdl.handle.net/10962/d1019459
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Date Issued: 1968-06-13
Grahamstown : average number of rooms per dwelling
- Authors: Watts, Hilstan Lett, 1929-
- Date: 1957
- Subjects: f-sa , 2 cm = 2000 yards 30.5595° S, 22.9375° E , Grahamstown (South Africa) Maps , Grahamstown (South Africa) Street maps , South Africa History 1909-1961 , South Africa History 1836-1909
- Language: English
- Type: maps , digital maps , cartographic
- Identifier: http://hdl.handle.net/10962/121281 , vital:34995 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa , T654_22
- Description: Map 22 in the map album accompanying the thesis by Hilstan Lett Watts, "Grahamstown : a socio-ecological study of a small South African town", Rhodes University thesis, 1957. Map signed 1955. The data are based on mean values calculated for each street, using survey sample data for the number of rooms per dwelling.
- Full Text: false
- Date Issued: 1957
- Authors: Watts, Hilstan Lett, 1929-
- Date: 1957
- Subjects: f-sa , 2 cm = 2000 yards 30.5595° S, 22.9375° E , Grahamstown (South Africa) Maps , Grahamstown (South Africa) Street maps , South Africa History 1909-1961 , South Africa History 1836-1909
- Language: English
- Type: maps , digital maps , cartographic
- Identifier: http://hdl.handle.net/10962/121281 , vital:34995 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa , T654_22
- Description: Map 22 in the map album accompanying the thesis by Hilstan Lett Watts, "Grahamstown : a socio-ecological study of a small South African town", Rhodes University thesis, 1957. Map signed 1955. The data are based on mean values calculated for each street, using survey sample data for the number of rooms per dwelling.
- Full Text: false
- Date Issued: 1957
- Authors: Andrew
- Identifier: http://hdl.handle.net/10962/226990 , vital:49397
- Full Text: false
Rhodeo, Vol. 16, No. 10
- Date: 1962-08-22
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14470 , http://hdl.handle.net/10962/d1019342
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Date Issued: 1962-08-22
- Date: 1962-08-22
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14470 , http://hdl.handle.net/10962/d1019342
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Date Issued: 1962-08-22