Evaluation of cellulase and xylanase production by two actinobacteria species belonging to the Micrococcus genus isolated from decaying lignocellulosic biomass
- Mmango-Kaseke, Ziyanda https://orcid.org/0000-0002-8936-1149
- Authors: Mmango-Kaseke, Ziyanda https://orcid.org/0000-0002-8936-1149
- Date: 2016-05
- Subjects: Lignocellulose , Biomass energy
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24197 , vital:62442
- Description: Bacteria were isolated from sawdust and screened for cellulase and xylanase production on carboxyl methyl cellulose (CMC) and birchwood xylan agar. The bacteria showing halo forms around the colony were selected for further analyses and those isolates with the highest cumulative halozone size (isolate PLY1 and MLY10) were chosen for detailed studies. Evaluation of cellulase and xylanase production by saw dust actinobacterial species whose 16S rDNA nucleotide sequences were deposited in GenBank as Micrococcus luteus strain SAMRC-UFH3 with accession number KU171371 and Micrococcus yunnanensis strain SAMRC-UFH4 with accession number KU171372. Optimum culture conditions for the production of cellulase for respective axenic culture include incubation period (96 h), incubation temperature (25oC), agitation speed (50 rpm), and pH 5. For xylanase production, the optimum culture conditions in the presence of 1percent (w/v) birchwood xylan include incubation period (84 h), incubation temperature (25oC), agitation speed (200 rpm), and pH 10. For Micrococcus yunnanensis strain SAMRC-UFH4 cellulase production was optimal under such conditions as, incubation temperature (30oC), agitation speed (0 rpm), and pH 5, while xylanase production was optimal at, incubation temperature (30oC), agitation speed (150 rpm), and pH 10. The high cellulase and xylanase activity obtained from these isolates suggest suitability of the organisms as important candidates for commercial application. , Thesis (MSc) -- Faculty of Science and Agriculture, 2016
- Full Text:
- Date Issued: 2016-05
- Authors: Mmango-Kaseke, Ziyanda https://orcid.org/0000-0002-8936-1149
- Date: 2016-05
- Subjects: Lignocellulose , Biomass energy
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24197 , vital:62442
- Description: Bacteria were isolated from sawdust and screened for cellulase and xylanase production on carboxyl methyl cellulose (CMC) and birchwood xylan agar. The bacteria showing halo forms around the colony were selected for further analyses and those isolates with the highest cumulative halozone size (isolate PLY1 and MLY10) were chosen for detailed studies. Evaluation of cellulase and xylanase production by saw dust actinobacterial species whose 16S rDNA nucleotide sequences were deposited in GenBank as Micrococcus luteus strain SAMRC-UFH3 with accession number KU171371 and Micrococcus yunnanensis strain SAMRC-UFH4 with accession number KU171372. Optimum culture conditions for the production of cellulase for respective axenic culture include incubation period (96 h), incubation temperature (25oC), agitation speed (50 rpm), and pH 5. For xylanase production, the optimum culture conditions in the presence of 1percent (w/v) birchwood xylan include incubation period (84 h), incubation temperature (25oC), agitation speed (200 rpm), and pH 10. For Micrococcus yunnanensis strain SAMRC-UFH4 cellulase production was optimal under such conditions as, incubation temperature (30oC), agitation speed (0 rpm), and pH 5, while xylanase production was optimal at, incubation temperature (30oC), agitation speed (150 rpm), and pH 10. The high cellulase and xylanase activity obtained from these isolates suggest suitability of the organisms as important candidates for commercial application. , Thesis (MSc) -- Faculty of Science and Agriculture, 2016
- Full Text:
- Date Issued: 2016-05
An investigation into the synergistic action of cellulose-degrading enzymes on complex substrates
- Authors: Thoresen, Mariska
- Date: 2015
- Subjects: Lignocellulose , Biomass energy , Cellulosic ethanol , Saccharomyces cerevisiae , Cellulase , Enzymes -- Biotechnology , Hydrolases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4154 , http://hdl.handle.net/10962/d1017915
- Full Text:
- Date Issued: 2015
- Authors: Thoresen, Mariska
- Date: 2015
- Subjects: Lignocellulose , Biomass energy , Cellulosic ethanol , Saccharomyces cerevisiae , Cellulase , Enzymes -- Biotechnology , Hydrolases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4154 , http://hdl.handle.net/10962/d1017915
- Full Text:
- Date Issued: 2015
The effect of GH family affiliations of mannanolytic enzymes on their synergistic associations during the hydrolysis of mannan-containing substrates
- Authors: Malgas, Samkelo
- Date: 2015
- Subjects: Lignocellulose , Biomass energy , Ethanol as fuel , Polysaccharides , Sugar -- Inversion , Glycosidases , Galactoglucomannans , Oligosaccharides
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4148 , http://hdl.handle.net/10962/d1017909
- Full Text:
- Date Issued: 2015
- Authors: Malgas, Samkelo
- Date: 2015
- Subjects: Lignocellulose , Biomass energy , Ethanol as fuel , Polysaccharides , Sugar -- Inversion , Glycosidases , Galactoglucomannans , Oligosaccharides
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4148 , http://hdl.handle.net/10962/d1017909
- Full Text:
- Date Issued: 2015
Ethanol production from lignocellulosic sugarcane leaves and tops
- Authors: Dodo, Charlie Marembu
- Date: 2014
- Subjects: Biomass energy , Ethanol as fuel , Lignocellulose
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11347 , http://hdl.handle.net/10353/d1019839 , Biomass energy , Ethanol as fuel , Lignocellulose
- Description: Various methods for the production of bioethanol using different feedstocks have been researched on. In most work on bioethanol synthesis from sugar cane, tops and leaves have been regarded as waste and generally removed and thrown away. In this work, lignocellulosic sugarcane leaves and tops were not discarded but instead used as biomass to evaluate their hydrolyzate content. The leaves and tops were hydrolysed using different methods, namely concentrated acid, dilute acid pre-treatment with subsequent enzyme hydrolysis and compared with a combination of oxidative alkali pretreatment and enzyme hydrolysis. Subsequent fermentation of the hydrolyzates into bioethanol was done using the yeast saccharomyces cerevisae. Acid hydrolysis has the problem of producing inhibitors, which have to be removed and this was done using overliming with calcium hydroxide and compared to sodium hydroxide neutralization. Oxidative alkali pre-treatment with enzyme hydrolysis gave the highest yields of fermentable sugars of 38% (g/g) using 7% (v/v) peroxide pre-treated biomass than 36% (g/g) for 5% (v/v) with the least inhibitors. Concentrated and dilute acid hydrolysis each gave yields of25% (g/g) and 22% (g/g) yields respectively although for acid a neutralization step was necessary and resulted in dilution. Alkaline neutralization of acid hydrolyzates using sodium hydroxide resulted in less dilution and loss of fermentable sugars as compared to overliming. Higher yields of bioethanol, 13.7 (g/l) were obtained from enzyme hydrolyzates than 6.9 (g/l) bioethanol from dilute acid hydrolyzates. There was more bioethanol yield 13.7 (g/l) after 72h of fermentation with the yeast than 7.0 (g/l) bioethanol after 24h. However, the longer fermentation period diminishes the value of the increase in yield by lowering the efficiency of the process.
- Full Text:
- Date Issued: 2014
- Authors: Dodo, Charlie Marembu
- Date: 2014
- Subjects: Biomass energy , Ethanol as fuel , Lignocellulose
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11347 , http://hdl.handle.net/10353/d1019839 , Biomass energy , Ethanol as fuel , Lignocellulose
- Description: Various methods for the production of bioethanol using different feedstocks have been researched on. In most work on bioethanol synthesis from sugar cane, tops and leaves have been regarded as waste and generally removed and thrown away. In this work, lignocellulosic sugarcane leaves and tops were not discarded but instead used as biomass to evaluate their hydrolyzate content. The leaves and tops were hydrolysed using different methods, namely concentrated acid, dilute acid pre-treatment with subsequent enzyme hydrolysis and compared with a combination of oxidative alkali pretreatment and enzyme hydrolysis. Subsequent fermentation of the hydrolyzates into bioethanol was done using the yeast saccharomyces cerevisae. Acid hydrolysis has the problem of producing inhibitors, which have to be removed and this was done using overliming with calcium hydroxide and compared to sodium hydroxide neutralization. Oxidative alkali pre-treatment with enzyme hydrolysis gave the highest yields of fermentable sugars of 38% (g/g) using 7% (v/v) peroxide pre-treated biomass than 36% (g/g) for 5% (v/v) with the least inhibitors. Concentrated and dilute acid hydrolysis each gave yields of25% (g/g) and 22% (g/g) yields respectively although for acid a neutralization step was necessary and resulted in dilution. Alkaline neutralization of acid hydrolyzates using sodium hydroxide resulted in less dilution and loss of fermentable sugars as compared to overliming. Higher yields of bioethanol, 13.7 (g/l) were obtained from enzyme hydrolyzates than 6.9 (g/l) bioethanol from dilute acid hydrolyzates. There was more bioethanol yield 13.7 (g/l) after 72h of fermentation with the yeast than 7.0 (g/l) bioethanol after 24h. However, the longer fermentation period diminishes the value of the increase in yield by lowering the efficiency of the process.
- Full Text:
- Date Issued: 2014
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