STUDIES ON OPTIMAL CONDITIONS FOR IMMOBILIZTION OF ASPERGILLUS NIGER b-GLUCOSIDASE II AND PROPERTIES OF THE IMMOBILIZED ENZYME AND ITS APPILICATION

• Main Authors: Yu-ling Huang, 黃于玲
• Other Authors: Tsong-Rong Yan
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/74578643642433456491

碩士 === 大同大學 === 生物工程研究所 === 88 === The present research is mainly concerned with the oligosaccharides and their derivatives, for use in the food processing industry and particular in oenology. In this study, the optimal condition for immobilization of the extracellular b-glucosidase II of Aspergillus niger was studied by means of statistics and experimental designs. Besides, the characterized and the systhesis of oligosaccharides for immobilized b-glucosidase II was studied, also. Immobilization of the partially purified b-glucosidase II onto chitopearl beads, which had been activated by glutaraldehyde (1%, w/v), a maximum maintaining activity of 45 U/g-bead was obtained, when 12U/mL of enzyme was used. The immobilization yield was 37%. The pH value for maximum activity of immobilized enzyme was 5.0 and the temperature for maximum activity of immobilized enzyme was 4℃. The properties of the immobilized enzyme were compared to free enzyme. The optimal reaction temperature was promoted from 60℃ to 70℃. The optimal pH of the immobilized enzyme was slight shift to acidic side. The pH-stability range of the free enzyme at pH 4.0-5.5, when immobilized with chitopearl beads, the enzyme was stable in a pH range of pH 3.0-8.8. The half-life of enzyme stability at 55℃, 60℃ and 65℃ were calculates to be 62hr, 14hr and 12hr, comparing to 35hr, 2.3hr and 0.33hr of the free enzyme, respectively. The immobilized enzyme was recycle used about 23 times, the enzyme relative activity to decrease 50%. In the case of the synthesis of oligosaccharides (15% cellobiose as substrate), about 30% of cello-oligosaccharides (trisaccharide and gentiobiose) was obtained when reacted 10 hours.