Fermentation optimization of cyclodextrin glycosyl transferase of bacillus macerans IFO 3490

Abstract

Cyclodextrins are cyclic, nonreducing oligosaccharides composed of six, seven of eight glucose units linked by α-1,4-bonds. The ability to form inclusion complexes with hydrophobic molecule is of potential industrial importance.Cyclodextrins are produced from starch by the action of an enzyme commonly known as cyclodextrin glycosyl transferase (E.C.2.4.19). Since the discovery fo cyclodextrin in 1891 by Viller, manymicroorganisms which produce CGTase were isolated from soil, but most of them are patented and their fermentational properties were not known well. For the efficient production of CGTase from Bacillus macerans, the study on optimization of culture medium was carried out and the composition of optimized culture medium were as follows; soluble starch 2.5%, yeast extract 0.5%, neopeptone 0.5%, $K_2HPO_4$ 0.15%, $MgSO_4$ 0.02%. The optimal culture temperature of Bacillus macerans IFO 3490 was 37℃. the pH of culture medium appeared important factor for the production of CGTase, and the optimum pH was 7. The C/N ratio was very important to CGTase production and its optimum value was 2.5:1(carbon source:organic nitrogen source). The effects of the rate of aeration and agitation on the production of CGTase were investigated. In highly aerated and agitated system(3vvm, 400rpm), the maximum production yield were obtained.