Production of alpha-cyclodextrin glucosyltransferase by Bacillus stearothermophilus R2 strain isolated from a Bulgarian hot spring

A bacterial strain, R2, a producer of cyclodextrin glucosyltransferase, was isolated from a hot spring in Bulgaria and identified as Bacillus stearoth ermophilus. Starch, glucose and amylose at 0.5% were found to be the most s uitable carbon sources for strain cultivation and enzyme production. The CG T-ase yield increased twofold after the addition to the glucose-containing medium of 0.1% glutamic acidi Highest enzyme secretion occurred at 48 h of cultivation when the stationary phase was reached.