COMPARISON IN PRODUCTION OF XTRACELLULAR GLUCOSYLTRANSFERASES FROM TWO STRAINS OF XANTHOPHYLLOMYCES DENDRORHOUS

• Main Authors: Cheng-Wei Lee, 李政衛
• Other Authors: Dey-Chyi Sheu
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/96086310327053907157

碩士 === 大同大學 === 生物工程學系(所) === 101 === Isomaltooligosaccharides (IMO) can stimulate the proliferation of bifidobacteria intestine and thus enhance human health. Among various functional oligosaccharides, IMO is acid resistant and can be added to acidic drinks. Generally, starch undergoes catalytic reactions of α- and β-amylases, yielding maltose syrup. In this project, we use two kinds of yeast Xanthophyllomyces dendrorhous to synthesize the enzyme which catalysis to produce glucose, panose, isomaltotetraose and isomaltopent- ose. More than generate α (1-6) bond, also produced the binding of α(1-2), and different from general commercial use only produce α-glucosidase transferase α(1-6) bond. Two yeast strains were incubated in the ferment- or for 48 hours. We use maltose as a substrate, controlling nitrogen sources adding, temperature, the aeration rate and agitation speed limiting, measuring pH and absorbance value of the broth, then analysis the saccharides and enzyme activity by HPLC. Centrifuged the fermentation broth after 48hours fermentation, the supernatants were collected after a molecular weight of 100 kDa hollowfiber module was filtered and then partially purified by isoelectric focusing electrophoresis step. After the process of purification we compare two extracellular enzyme activity and some characteristics of extracellular enzyme activity which affected by temperature and pH value. We know that 50 to 60 °C is more significant for transfer activity; SDS-PAGE electrophoresis determination of molecular weight is estimated to be 145.2 and 142 kDa. We can use the characteristics of the yeast secretion of α-glucosidase and use maltose to produce high purity isomalto-oligosaccharide. In the optimal pH value and temperature, the product of highest concentration of isomalto-oligosaccharide catalyzed by extracellular enzyme α-glucosidase can be achieved to 97 g/l. This experiment can understand purified extracellular enzyme α-glucosidase can catalyze maltose to produce high purity of isomalto-oligosaccharide, there is great potential for the production of isomalto-oligosaccharides.