| Summary: | 碩士 === 大同大學 === 生物工程學系(所) === 93 === Cyclodextrins (CDs) are cyclic oligosaccharides composed of 6-8 glucose with α-1, 4-linkages. CDs have been used in food, pharmaceutics, cosmetics industries. CDs are produced by enzymatic catalyzation of cyclodextrin glucanotransferase (CGTase) from starch. In this study, CGTase is produced using starch or starch hydrolyzates as carbon sources from a Bacillus sp. BCRC 10094. The maximum CGTase activity was about 1400 unit/ml in a shaking culture using 2％（v/w）corn starch, cassava starch, soluble starch (Kanto Chemical Co. Ltd) at 33℃and 160 rpm. The carbon sources using DE10, DE20 soluble starch (Taiwan Fructose Co.,Ltd) and maltose in the medium produced less CGTase activity. The CGTase of this study and commercial CGTase (NOVO) were employed to produce CDs from 15 % (w/v) starch. CDs were produced from corn starch catalyzed by CGTase (NOVO, 250 unit/g-starch) at 75 C for 24 hrs. The yield of CDs from starch was 33 %. However, it was 1000 ~ 2000 unit needed per gram of starch for the CGTase cultured from Bacillus sp. BCRC 10094 in this study. The yield of CDs from starch was 18 ~23 % using our enzyme. The results indicated that CGTase from NOVO had better thermal stability.
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