Production of xylanase from Aspergillus strain and its impact on enzymatic sugar recovery from paddy straw
KrishiKosh
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Title |
Production of xylanase from Aspergillus strain and its impact on enzymatic sugar recovery from paddy straw
M.Sc. |
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Creator |
JAIRAM CHOUDHARY
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Contributor |
Anju Arora
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Subject |
enzymes, fungi, fermentation, polysaccharides, cellulose, crop residues, productivity, rice, sugar, biomass
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Description |
Lignocellulosic biomass is most abundant source for production of greener energy & replacement for starchy material, consist of mainly cellulose, hemicellulose & lignin. Lignin makes these polysaccharides unaccessible to hydrolytic enzymes and generates the urgency of different pretreatment strategies to remove lignin and unlock the substrate. Existing technologies do not allow complete saccharification of plant polymers as there are many technological gaps hindering the action of currently available standard cellulases. Commercial cellulases are not efficient in utilization of complete substrate as they are subjected to tight induction & regulation systems and inhibited by end products. To overcome these limitations and make the process economically feasible, supplementation of cellulases with accessory enzymes (xylanase, xylosidase, β-glucosidase and cofactors) is required. Aspergillus strains were found efficient in xylanase production. Five Aspergillus strains were screened both qualitatively and quantitatively for xylanolytic and cellulolytic activities and hyperxylanolytic strains A. awamori F 18 and A. foetidus MTCC 508 were selected on the basis of high specific activity (IU/mg protein) of xylanase under submerged and solid state fermentation. Xylanase was produced by these two strains under solid state fermentation using corn cob, paddy straw and mixture of paddy straw and wheat bran (1:1 ratio). A. awamori F 18 was most efficient in producing xylanase with specific activity 456.19 IU/mg protein, under solid state fermentation. Xylanase produced by A. awamori F 18 was concentrated (11.5 fold) by acetone precipitation method. Xylanase had optimum pH 6.0 and temperature, 45°C. Steam pretreated paddy straw was used as substrate to study the effect of this xylanase supplementation on sugar yields. Supplementation of xylanase to standard cellulases yielded significantly higher amount of sugars than standard cellulases alone. These sugars can be fermented by fermenting organism like yeast to produce bioethanol. The study confirmed role of accessory enzyme xylanase in enhancing sugar yields from biomass by standard cellulases. This strategy can be utilized in biorefinery to produce greener energy more economically. |
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Date |
2016-03-14T16:16:42Z
2016-03-14T16:16:42Z 2013 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/65129
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Language |
en_US
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Format |
application/pdf
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Publisher |
IARI, DIVISION OF MICROBIOLOGY, NEW DELHI
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