Production, purification and characterization of ß-glucosidase from Paecilomyces variotii
Shodhganga@INFLIBNET
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Title |
Production, purification and characterization of ß-glucosidase from Paecilomyces variotii
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Contributor |
Jaychandran, K
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Subject |
Glucose resistant
Paecilomyces variotii ß-glucosidase Plackett-Burman Design Box- Behnken Design Solid state fermentation Biochemistry |
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Description |
A fungal strain Paecilomyces variotii MG3 capable of producing and#946;-glucosidase was selected from twelve isolates screened for the production of and#946;-glucosidase. The various process parameters influencing the production of the enzyme through submerged fermentation as well as solid state fermentation were optimized. Optimization of parameters for solid state fermentation was carried out by a two step statistical design of experiment approach. The influencing parameters were identified using Plackett-Burman Design and the identified factors were further optimized using Box-Behnken Design. The modeling was done using the DesignExpert software. The optimum levels of the most influencing parameters obtained were peptone concentration of 2g/L, inoculums concentration of 1.2 X 106 spores /ml and incubation period of 96h. Purification of the enzyme using ammonium sulphate fractionation, gel filtration and anion exchange chromatography established the presence of two isozymes. Isozymes I and II were monomeric proteins with molecular weights of approximately 40kDa and 90kDa respectively. The optimum pH of isozyme I was 6 and that of isozyme II was 5 with broad pH stability range of 3 to 7. Vmax and Km were determined using non linear regression curve fitting function of the GraphpadPrism software. Vmax values of isozyme I and II were 0.2497U/ml and 0.3519 U/ml respectively with pNPG as substrate. The Km value of isozyme I was 0.08839mM and that of the other isozyme was 0.2710 mM. Isozyme II was highly sensitive to glucose concentrations higher than 0.5M and isozyme I was resistant to glucose concentrations as high as 2M. The Ki values of isozyme I and II were found to be 901.6 mM and 22.65 mM respectively. The glucose resistant isozyme I was found to be capable of acting on cellulose in combination with cellulase and the crude enzyme was found to enhance the release of vanillin from vanilla beans.
Bibliography p.149-190,Appendix 191p. |
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Date |
2013-11-22T11:50:34Z
2013-11-22T11:50:34Z 2013-11-22 n.d. 2010 n.d. |
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Type |
Ph.D.
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Identifier |
http://hdl.handle.net/10603/13171
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Language |
English
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Relation |
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Rights |
university
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Format |
191p.
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Coverage |
Biochemistry
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Publisher |
Kottayam
Mahatma Gandhi University School of Bio Sciences |
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Source |
INFLIBNET
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