Screening of Cellulolytic Bacteria from Giant Panda and Optimization of Enzyme-producing Fermentation Conditions

Through collecting the fresh faeces of giant panda in Kunming Wild Animal Park, after preliminary screening of using with carboxymethylcellulose sodium(CMC-Na) and Congo red staining method to selective culture, and then determining of cellulase activity by DNS method for rescreening, the target strain was identified by morphology and 16SrDNA homology, and the strain with high cellulase production was optimized by single factor fermentation optimization. The results showed that 2 strains of celluloytic bacterium were identified as Bacillus subtilis ZD1 and MZ3 from fresh faeces of giant panda, the activity of cellulase in ZD1 and MZ3 is 277.58 U/mL and 255.22 U/mL after the fermentation optimization, the maximal activity of cellulase in ZD1 and MZ3 is up to 339.48 U/mL and 293.65 U/mL respectively, which is 22.30 % and 15.06 % higher than that before the optimization. The selected strains were very active as follow: using medium of CMC-Na + P, culture temperature 37 ℃, PH value of 6.8 to 7.2, culture time 36 hours to 48 hours.