| Co-Investigator(Kenkyū-buntansha) |
KUSANO Shuーichi Nikken Chemicals Co. Ltd., Ohmiya Research Laboratory, Research Chemist, 大宮研究所, 研究員
SHIRAISHI Takanori Nikken Chemicals Co. Ltd., Ohmiya Research Laboratory, Senior Research Chemist, 大宮研究所, 主任研究員
FUJIMOTO Daisaburo Tokyo University of Agriculture and Technology, Faculty of Agriculture, Professo, 農学部, 教授 (40004288)
KOGURE Yasuo Nikken Kasei Co. Ltd, General Affairs Division, Section Manager
白石 尊憲 日研化学(株), 大宮研究所, 主任研究員
小暮 靖夫 日研化学(株), 総務部, 研究員
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| Budget Amount *help |
¥4,500,000 (Direct Cost: ¥4,500,000)
Fiscal Year 1990: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1989: ¥3,800,000 (Direct Cost: ¥3,800,000)
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| Research Abstract |
The method of enzymic synthesis of branched cyclodextrins (BrーCDs) using the reverse reaction of Bacillus acidopullulyticus Pullulanase was established. More than 40 % of CDs were converted to Br-CDs from to the corresponding CDs used as substrates under the conditions as follows : the coubined concentration of CD and maltose, 70-75 % ; the molar ration of maltose to CD, 9-18 ; the amount of pullulanase, 100-200 units/g of CD ; pH and temperature, 4-4.5 and 60-70 ^ﾟC. The enzyme was immobilized easily on carriers (glass beads, ceramics, ionic exchanges, and chitosan beads, etc.) by physical adsorption, ionーbinding, and cross linkages, etc ; especially the enzyme was supported on SM 10 carrier (a kind of ceramic) with the highest activity in tested carriers. The column reactors (1.1-1.6 X 16-20 cm) were prepared with the immobilized enzyme preparations and the successive production of Br-CDs from CD and maltose were compared. SM 10 column reactor had remarkably high activity as well as stable ; the activity of this reactor hardly deceased after 1000 hr operation at 60 ^ﾟC. B. acidopullulyticus pullulanase was more stable than other pullulanases from Klebsiella pneumoniae and Bacillus sectorramus, etc. Moreover B. acidopullulyticus Pullulanase was remarkably stabilized under high concentration of sugar alcohols (maltitol, maltotriitol, maltotraitol, or maltopentaitol) and the thermal stability increased with the length of the sugar alcohols. This result indicates that this enzyme is particularly suitable for synthesis of BrーCDs. Generally the solubility of CD in water is not so high, 14.5 (alpha ーCD), 1.85(beta ーCD), and 23.2 (gamma -CD) g per 100g of water. The solubility of Br-CDs increased ; especially the solubility of Br- beta -CD was more than 100-fold of betaーCD. BrーCDs could stabilize labile compounds, emulsify oils, mask flavours of odors, increase solubility and convert viscous to oily compounds into powders similat to CDs.
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