Bacillus macerans cyclodextrin glucanotransferase(EC 2.4.1.19: 1, 4-a-D-Glucan 4 a D(1, 4-a-glucano)-trans ferase, CGTase) was purified by the technique of starch adsorption and DEAE-cellulose column chromatography. The molecular weight of the enzyme was 67,000, consisting of a subunit. The enzyme converted starch into a-, j9-, and y-CD in the relative amounts of 1:1.68:0.3;respectively. In the early reaction period, maltohexose was formed mainly by the coupling reaction of a-CD with D-glucose and then other oligosaccharides. Maltotetrose was formed mainly from a--CD in the initial stage of hydrolysis of the enzyme and then small amount of other oligosaccharides. Maltotriose was a good sub
´ strate for the enzyme and maltosyl or D-glucopyranosyl group can be transfered from this sugar. In this work, D-glucosyl transfer was prefered.
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