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URN etd-0725113-120758 Statistics This thesis had been viewed 1512 times. Download 0 times. Author Yu-hsing Chen Author's Email Address No Public. Department Bioengineering Year 2012 Semester 2 Degree Master Type of Document Master's Thesis Language zh-TW.Big5 Chinese Page Count 75 Title Comparative biochemical characterization of microbial transglutaminases from two streptomyces sp. Keyword Streptomyces transglutaminase transglutaminase Streptomyces Abstract Transglutaminase (TGase, EC 18.104.22.168) is an enzyme that catalyzes acyl-transfer reaction, forming inter- and intra-molecular covalent bonds, and thus leads to the formation of high molecular weight proteins. TGase is widely distributed in mammalian tissues and organs (such as liver, follicle, and blood), fishes, plants and microorganisms. In food processing, it was widely applied to modify solubility, water holding capacity, rheological characteristics, emulsifying properties and heat stability of proteins. The aim of this work was to screen the best species among six Streptomyces sp. having TGase activities. From shake flask cultures, two strains─Streptoverticillium mobaraensis and S. cinnamoneum─were selected, because they had higher TGase activities than others. Then the two strains were cultured in a 5-L fermenter for the mass production of TGase. Supernatants of the cultures were treated by using hollow fiber module with the pore sizes of 10 and 100 kDa. Two fractions of proteins with MW in the range of 10-100 kDa and >100kDa were collected and the biochemical characteristics were determined. The TGase from Streptoverticillium mobaraensis BCRC 12165 exhibited optimum activity at pH 6.6 and 50 oC. This enzyme was stable at the pH ranged from 5.0 to 9.0 and the temperature ranged from 4 to 40 oC. The TGase from S. cinnamoneum BCRC 12169 demonstrated optimum activity at pH 6.2 and 50 oC. The enzyme was stable in the pH range of 5.0-8.0 and temperature range of 4-40 oC. The TGase from commercial source indicated optimum activity at pH 6.6 and 50 oC and was stable at pH 5.0-7.0 and 4-40 oC. The TGase activity was assayed using N-carboxybenzoyl-L-glutaminyl-glycine as the substrate and the product hydroxamate was quantitatively determined by spectrophotomer. Advisor Committee Dey-Chyi Sheu - advisor
Files Date of Defense 2013-07-22 Date of Submission 2013-08-07