Characterization and chillproofing activity of two enzymes from Streptomyces species

Two enzymes, amylase and protease of Streptomyces species were purified by a combination of ion exchange chromatography and gel filtration and characterized. The amylase had an exoaction on starch yielding maltose as a major end product and was identified as beta-amylase. The purified amylase had a molecular weight of 48,000 and was maximally active at 35 degrees C and at pH 6.0. On the other hand, protease had a molecular weight of 21,000 and was most active at pH 10.0 and at a temperature of 30 degrees C. The K-m or MICHAELIS constant of amylase for maize starch was 0.333 mg/ml while that of protease for casein was 2.5 mg/ml. The feasibility of using the purified protease for various industrial application especially in the chillproofing of beer is discussed.