Chitin-binding domain based immobilization of γ-PGA depolymerase
碩士 === 元智大學 === 生物科技與工程研究所 === 100 === Poly-?-glutamic acid (?-PGA) is a biopolymer produced by microorganism in which D- and L- glutamate is polymerized via??-amide linkages. A large range of its applications has been suggested due to its characteristics, such as biodegradable, edible, nontoxic tow...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
2012
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| Online Access: | http://ndltd.ncl.edu.tw/handle/28880467034327963218 |
| Summary: | 碩士 === 元智大學 === 生物科技與工程研究所 === 100 === Poly-?-glutamic acid (?-PGA) is a biopolymer produced by microorganism in which D- and L- glutamate is polymerized via??-amide linkages. A large range of its applications has been suggested due to its characteristics, such as biodegradable, edible, nontoxic toward human or the environment. The molecular weight of ?-PGA plays an important role which effects its application. The objective of this study is to expand the application of??-PGA and increase the utilization of ??-PGA depolymerase in the industry by enhancing the enzyme activity and stability. We used recombinant E. coli to express fusion protein (chitin binding domain and γ-PGA depolymerase) and then direct adsorption on chitin beads as the immobilized enzyme.
It was found that one gram of chitin beads could adsorb 12.4 mg of enzyme for 4h. The Immobilized??-PGA depolymerase exhibited higher temperature and pH value tolerance than the free one. The results indicated that the best condition for r-PGA hydrolysis was pH 7 and 30oC. Furthermore, the immobilized enzyme could store under 30 oC for 48h and maintain over 50% of its activity. The storage time of the immobilized ?-PGA depolymerase is 9 day. And the immobilized enzyme could be reused for 6 times. Those results indicated that the immobilized ?-PGA depolymerase could be applied in the industry.
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