Cellulose is one of the most common biopolymer in nature. It is an unbranched glucose polymer composed of ?-D-glucose units linked by a ?-1,4-D-glucosidic bond. Cellulolytic enzyme degrade cellulose by cleaving the glycosidic bonds. The cellulase enzyme complex consists of three types of enzymes that act synergistically in cellulose hydrolysis. Endoglucanases randomly attack cellulose chains and release cello-oligosaccharides, exoglucanases cleave cellobiose units from the end of cellulose chains and ?-glucosidases convert the resulting cellobiose to glucose. Cellulases have diverse application in textile, paper, food and feed industry. These enzymes are increasingly used in the production of biofuel and single cell protein. Cellulases are relatively costly enzymes, and a significant reduction in cost will be important for their commercial use in different industry. Extensive research were done for economical production of cellulases. Simple way is to find hypercellulytic microorganisms. Although, several microorganisms use cellulose as a carbon source, few of them have been screened for their cellulase production potential. Among these, microorganism live in rumen of herbivorous animals are remarkable. In this research cellulytic fungi isolated from sheep rumen, molecular identified and enzymatic activity of secreted Endoglucanase of this isolate was done. Molecular identification revealed that, the isolate is belonged to Trichoderma longibrachiatum . Optimum temperature for growth of fungus was 37 0 C. Optimum protein content, substrate concentration, pH, temperature and incubation time was 700µg, 1.25% (w/v), 6, 50 0 C and 60 minute, respectively. When carboxymethyl cellulose was used as substrate, K m and V max values of 3.32 (g/l) and 4.4 µmol glucose ml -1 h -1 for Endoglucanase were obtained additionally specific activity was 1.1 µmol glucose ml -1 h -1. CMC zymogram result show that molecular weight of this enzyme was 118 kDa and didn’t show any isozyme.
