Abstract
A strain of Brevibacterium sp. No. 9605 was isolated from soil and produced cyclodextrin glucano transferase (CGTase, EC. 2.4.1.19). The CGTase produced mainly γ-cyclodextrin (γ-CD) from starch in the initial stage of reaction, but then the proportion of β-CD was increased and also produced a small amount of α-CD. CD formation was affected by the presence of calcium ions 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 γ-CD production from starch and the repression of γ-CD degradation by coupling reaction. Brevibacterium CGTase showed a broad acceptor specificity to various monosaccharides and phenolic compounds. When D-mannose, L-rhamnose, 1, 3-dihydroxybenzene, 1, 3, 5-trihydroxybenzene, 3-hydroxybenzyl alcohol and (+) -catechin were used as acceptors, Brevibacterium CGTase synthesized much greater amounts of transfer products than either Bacillus macerans and Bacillus stearothermophilus CGTases. 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.
