Cyclodextrin glycosyltransferase (CGTase) was produced by a 3-day cultivation of Bacillus macerans growing in a natural medium containing grated-potatoes. Besides CGTase the culture supernatant contained a mixture of serine proteinases with a predominant subtilisin-like activity. By fractionated precipitation with ammonium sulphate the CGTase (molecular mass approximately 70 kDa) was concentrated and largely separated from the proteinases (molecular mass approximately 28 kDa). Among the various immobilization methods and carrier materials tested the enriched CGTase was covalently bound preferably onto porous glass beads using glutardialdehyde as cross-linker. The discontinuous conversion of soluble starch into beta-cyclodextrin was carried out with native as well as immobilized CGTase over 24 h. The batch re-usability of the fixed enzyme proved to be at least 20 times with a residual CGTase activity of 65%.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.