Influence of culture conditions of Streptomyces sp. [strain S242] on chitinase production

The purpose of this study was to determine the influence of growth conditions and medium composition on the production of chitinase by Strtptomyces sp. (strain S₂₄₂,). Production of chitinase by strain S₂₄₂ was detected on colloidal chitin agar (CCA) medium after 8 days of incubation at 28°C resulting in a clear zone 10 mm around the colony. Chitinase activity was assayed as the amount of N-acetylglucosamine released in pmol/ml/min using the dinitrosalicylic acid assay method. The crude enzyme had maximum activity (0.162 U ml/l) after 4 days of incubation at pH 7 and 30°C when the broth medium was supplemented with 1.6% of colloidal chitin. However, enzyme activity was strongly decreased at 40°C and extreme acidic and alkaline pH values. SDS-PAGE and zymogram analysis revealed six distinctive bands that range from 39 to 97 kDa with chitinolytic activity. The findings of this investigation create a possibility for the use of the organism in the commercial production of chitinase. In addition, it can be a source of DNA for cloning the chitinase gene(s) to generate phytopathogen resistant transgenic plants.