DefinePK

Abstract

Streptomyces cyaneogriseus capable of utilizing chitosan as sole carbon source was isolated from soil samples. Chitosanase enzyme produced in the culture filtrate of Streptomyces cyaneogriseus was purified to homogeneity through ammonium sulfate precipitation 80, ultrafiltration and Sephdex G-200 gel filtration. Molecular weight of the enzyme was 46 kDa. An optimum pH value was 5.0 and temperature was 50C, respectively. The enzyme was stable in absence of substrate at temperature range from 40 to 60C and at pH range from 3.0 to 8.0. The activity of chitosanase enzyme increased by the addition of 10 mM Mn2 and Co2. However, 10 mM Hg2 and Cd2 strongly inhibited the enzyme activity. Other metallic ions used Na, K, Ca2, Fe2, Mg2 and EDTA have little effect on chitosanase activity. The enzyme also showed activity for hydrolysis of crystalline and colloidal chitosan but did not hydrolyze chitin, colloidal chitin, cellulose and carboxymethyl cellulose.