EFFECTS OF CULTURAL AND NUTRITIONAL CONDITIONS FOR CARBOXYLMETHYLCELLULASE (CMCase) PRODUCTION BY CELLULOSE DEGRADING BACTERIA

Abstract

      The aim of the present study is to identify cellulose degrading bacteria and the effects of cultural and nutritional conditions for their cellulase activity. Among the tested bacterial strains, the GT1 strain had the highest cellulase production yields. This strain was further characterized by biochemical and morphological tests and identified as Bacillus subtilis, therefore, we primarily concluded that GT1 was Bacillus sp., denoted as Bacillus sp. GT1. Different parameters: temperature, pH, nitrogen and carbon sources, and metal ions were optimized. The optimal pH and temperature for the activity of crude enzymes were 7 and 35°C, respectively. Supplementation of peptone and corn starch to the culture medium is favored for enzyme secretion. The metal profile of the enzymes indicated that the enzymes were stimulated by Mn²⁺, Mg²⁺, and Ca²⁺, while Fe²⁺, Zn²⁺, and Cu²⁺ reduced activity of cellulase from the cellulolytic bacterial strain Bacillus sp. GT1. These results open up the broad application of GT1 in many fields.