Studies on alkalophilic CGTase-producing bacteria and effect of starch on cyclodextrin-glycosyltransferase activity

Abstract

The production of β- and γ-CD by CGTase from Bacillus firmus was studied, in regard to the effect of the source and concentration of starch on the yield of CD and CGTase activity. A cyclic activity of accumulation and consumption of β-CD and γ-CD occurred during the bacterial growth. CGTase was more active when citrate buffer, pH 5.5 was used. No differences were found for production of γ-CD with the use of commercial starch flour when compared with corn starch (p>0.05). The use of commercial starch flour resulted in decreased conversion of starch to β-CD (all the 4 starch sources were statistically different, p<0.05). The best results for β-CD production were obtained with the use of corn starch. The specific activity of CGTase was not affected by starch concentration, different source of starch nor by the presence of glutamic acid, a CD-complexing agent.