| 摘要 |
PROBLEM TO BE SOLVED: To obtain a di-β-fructofuranose 1,2':2,1' dianhydride (β-DFA) having no calorie or approximately no calorie, excellent stability, high solubility in water, useful as a sweetener, an osmotic pressure regulating agent, etc., by treating inolobiose with a specific enzyme. SOLUTION: Inulobiose of formula I is treated with an enzyme capable of subjecting the inolobiose to intramolecular condensation to form β-DFA of formula II. The enzyme is obtained from a culture product of Bacillus circulans B1 strain (FERM P-16,343) and has the following enzymatic properties. (1) Hydrolyzing one β-1,2 fructofuranoside bond of β-DFA to form inolobiose and subjecting the inolobiose to intracellular condensation to form β-DFA. (2) Optimum pH 6.5.-7.0 and stable pH range of 5.0-7.0. (3) Optimum temperature 40 deg.C, retaining 100% activity by treatment at pH 7.0×1 hour at <=40 deg.C. (4) About 160,000 molecular weight (get filtration chromatography) or about 85,000 (SD gel electrophoresis). (5) 4.9 isoelectric point. |
