Abstract

Since the discovery of its anti-tumor properties, L-glutaminases have been in prime focus and microbial sources of the enzyme are sought. In the present study L-glutaminase from Streptomyces avermitilis was optimized and the results revealed that the optimum pH, temperature, inoculum size, incubation period and NaCl concentration  for enzyme production were pH 8, 28°C, 5 ml/100 ml media v/v, 5 days and 3% NaCl respectively. Glucose and sodium nitrate proved to be the best carbon and nitrogen sources respectively. The enzyme was purified 8.02 fold and the apparent molecular weight of the enzyme was found to be 50 kDa. The optima pH and temperature for the enzyme were (7.0 and 8.0) and 30°C respectively. The enzyme was more stable at 4% NaCl and its activity increased when NaCl and MgSO₄ were added as metal salts. The enzyme also showed high stability in the presence of different oxidizing agents.

Key words:  L-Glutaminase, Streptomyces avermitilis, anti-tumor, purification.