[Keratinolytic activity of Streptomyces sp. 1382]

Abstract

Research in the growth dynamics of Streptomyces sp. 1382--a producer of keratinolytic enzyme--has shown that maximum of its biosynthesis in the culture medium is achieved on the 5th day, that correlates with maximum of biomass accumulation. The enzyme complex, obtained from culture liquid, is active in the wide range of pH (4-11) and temperature (10-70 degrees C). Under such conditions it is stable and does not lose its activity during several hours. The preparation possesses different pH-optima of keratinase and total proteolytic activities: in neutral (pH 7.0) and weakly alkali (pH 8.0) regions, as well as different thermal optima at 37-40 and 50-60 degrees C, respectively. Four types of colonies whose level of keratinase activity was considerably different have been found, when analyzing heterogeneity of the strain-producer population. Study of the effect of various sources of carbon and nitrogen on proteases synthesis by the culture has found the activating effect of arabinose, maltose, peptone and yeast autolysate. Under such conditions synthesis of keratinolytic enzyme increased 6-7 time, only the sheep wool and chicken feather being added as the only source of carbon and nitrogen. The induction with substrate is discussed as a possible mechanism of keratinase synthesis regulation.