Studies on Cyclodextrin Glucanotransferase from Brevibacterium sp. No. 9605

Abstract

A strain of Brevibacterium sp. No. 9605 was isolated from soil and produced cyclodextrin glucanotransferase (CGTase, EC. 2.4.1.19). The CGTase produced mainly γ-cyclodextrin (γ-CD) from sarch in the initial stage of reaction, but then, the proportion of β-CD was increased and also produced a small amount of α-CD. The CDs formation was affected by the presence of calcium ion and ethanol . In the presence of ethanol, the yield of γ-CD from soluble starch was increased . It was thought to be due to the repression of β-CD production from starch and the repression of γ-CD degradation by coupling reaction. Brevibacterium CGTase showed a broad acceptor specificity to various monosaccha rides and phenolic compounds and produced more transfer products of D-mannose, L-rhamnose, 1, 3-dihydroxybenzene, 1, 3, 5-trihydroxybenzene, 3-hydroxybenzyl alcohol, and (+) -catechin using as acceptors than Bacillus macerans and Bacillus stearothermophilus CGTases did. The transfer products of D-mannose and kojic acid were 4-O-α-D-glucosyl-D-mannose and kojic acid 7-O-α-D-glucoside, respectively.