Characterization of a New Thermostable Maltooligosaccharide-forming Amylase

Recently, we isolated about 250 strains of thermophiles from hot springs in South China and screened for enzymes useful for industrial processes. A strain HY-1 was found to produce a special extracellular maltooligosaccharide-forming amylase. Strain HY-1 has been determined to be a Bacillus sp.; it is a strictly aerobic, gram-positive, and endospore-forming bacterium. The optimal growth temperature is 65 degree C. The enzyme was purified by ammonium sulfate fractionation and twice by DEAE-cellulose column chromatography. The purified enzyme was homogeneous on polyacrylamide gel electrophoresis. Some physicochemical and enzymatic properties of the enzyme were determined.