Of 450 strains isolated from the soil microbes collected in various locations in Korea, a strain had a strong inhibitory activity against bacterial ¥á-amylase and was named strain DMC-72 of the genus Streptomyces. The amylase inhibitory metabolite produced by this strain was purified by means of acetone precipitation, adsorption on Amberlite IRC-50 and SP-Sephadex C-25. The inhibitor was found to be a derivative of oligosaccharides by spectral and chemical data. The inhibitor was stable at the pH range of 1¡13 and at 100¡É for half an hour, also inhibited other amylases such as salivary ¥á-amylase, pancreatic ¥á-amylase, fungal ¥á-amylase and glucoamylase. However, it showed no inhibitory activity against ¥á-glucosidase, ¥â-glucosidase, dextranase, and ¥â-amylase. The kinetic studies of the inhibitor showed that its inhibitory effects on starch hydrolysis by ¥á-amylase were noncompetitive.
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