Study On Cellulase Production By Alkalophilic Strain Bacillus Sp.AC-2

Cellulase production using an alkalophilic strain Bacillus sp. AC-2, the enzymatic characteristics and the applications in pulp deinking & textile biofinishing were studied in the thesis.Fermentation conditions for the cellulase producing were studied in shaking flasks by Bacillus sp. AC-2, including inoculum age, inoculum volume, initial pH value, fermentation temperature, carbon sources, ratio of C/N, nitrogen sources and surface active agent, etc. Under the optimal conditions, the CMCase activities at pH7.0 and pH9.5 reached 111.25 U/mL and 76.04 u/ml respectively in 44 hours.The cellulase production was carried out in a 3.7L fermentor. It was found that the optimal fermentation conditions were 0.2vvm and 200rpm. A high cellulase activity was obtained (136.77 U/mL at pH 7.0 and 93.48U/mL at pH9.5).The studies on the enzymatic characteristic showed that Bacillus sp. AC-2 cellulase mainly had CMCase activity with a little activity of amylase and FPA. The enzyme was stable under pH 6.0-10.0 and below 70℃; The optimum temperature and pH value were 60℃ and 7.0, but it also showed a high activity at pH9.5. Metal ions had different effects to the enzymatic activity.The cellulase from Bacillus sp. AC-2 showed a good application potential in waste paper deinldng and detergent industry. The research work in this dissertation was meaningful both in theoretical research and practical application.