Isolation, purification and characterization of a novel CGTase from alkalophilic Bacillus lehensis SV1

摘要

A Cyclodextrin glycosyl transferase (CGTase) E.C. 2.4.1.19 enzyme is capable of converting starch and related substrates into ????, ???￠ and ???§ cyclodextrins in different ratio. They are currently seen as highly interesting industrial enzymes because of their broad substrate specificity.Apositive alkalophilic strain was isolated fromthe soil sample capable of producing CGTase as Bacillus lehensis SV1 and characterized by 16s rDNAstudies and Phylogenetic analysis. The CGTase activity was assayed by phenolphthalein method using starch as substrate. CGTase was purified by ion-exchange and gel filtration chromatography. The purified CGTase was a monomer showed a molecular mass of 40±1 kDa as estimated by SDS-PAGE and a 42.6-fold purificationwith a 29.03%yield. The optimum pH is at two pH range 5.0 and 8.0 and temperature 60?%C. The Km and Vmax was found to be 1.03mg/ml and 0.241mg/min respectively.Metal ions like MgSO4 and FeSO4 exhibited highest activity and MgSO4 and CaCl2 inhibited CGTase at higher concentrations. The isolated CGTase can be used in development of drug delivery agents and inclusion complexes.