Production and Purification of New Maltohexaose-forming Amylases from Alkalophilic Bacillus sp. H-167

Abstract

Three α-amylases that produce maltohexaose as the main product from starch were found in a culture filtrate of alkalophilic Bacillus sp. H-167, which was isolated from soil. The optimum culture conditions for enzyme production were determined: initial medium pH 9.4; temperature, 37°C; and 50 ~ 60 hr cultivation under aerobic conditions. The enzymes were separated completely and purified to be homogeneous on disc electrophoresis by using chromatographies on DEAE-Toyopearl 650M and DEAE-Sepharose CL-6B, followed by gel filtration on Sephadex G-100 or Ultrogel AcA-34. All the enzymes produced maltohexaose in the early stage of hydrolysis, the maximum yield being 25~30%.