Abstract: Optimal culture conditions for production of cellulases using two bacterial strains (Bacillus sp. X18 and X10-1-2) were investigated. The highest level of cellulase activity was induced in the medium containing wheat bran, and their optimal mass concentration for Bacillus sp.X18 and X10-1-2 were 2.5% and 3%, respectively. Bean cake was the best nitrogen source, and their optimal mass concentration for Bacillus sp.X18 and X10-1-2 were 4% and 1%, respectively. Optimal culture temperature of cellulase production of Bacillus sp.X18 and X10-1-2 was 30℃. Optimal cultural pH values of cellulase production of Bacillus sp.X18 and X10-1-2 were 6-8 and 5, respectively. Optimal times of cellulase production of Bacillus sp.X18 and X10-1-2 were 20 and 60 h, respectively.

Key words: Bacillus, cellulase