NEW CYCLODEXTRIN GLUCANOTRANSFERASE, METHOD FOR PRODUCING THE SAME AND METHOD FOR PRODUCING CYCLODEXTRIN USING THE ENZYME

摘要

PROBLEM TO BE SOLVED: To provide γ-cyclodextrin glucanotransferase(CGTase) capable of dominantly forming γ-CD, a microorganism having the ability of producing γ-CGTase, and a method for producing ϕ-CD using γ-CGTase. SOLUTION: The CGTase has the following enzyme-chemical properties: (1) action and substrate specificity: It acts on starch dextrin, amylopectin or amylose to mainly form γ-CD, and less β- and α-CD. (2) It has an optimal pH at 10.5-11.0. (3) It has an optimal temperature around 60 deg.C. (4) It is stable at pH6-11. (5) temperature stability: It keeps 90% activity or higher when treated at 50 deg.C for 15 min. The method for producing CGTase comprises the steps of culturing a microorganism (e.g. FERM BP-7156) that belongs to Bacillus clarkii and has an ability of producing CGTase, making the microorganism produce CGTase in the medium, and collecting the CGTase formed. The method for mainly producing γ-CD comprises reacting CGTase produced by B. clarkii. with a solution containing starch or the like.