关键词: 芽孢杆菌, 纤维素酶, 响应面分析, 发酵优化

Abstract: One cellulose producing strains C-8 were isolated from Xinjiang turpan area soil samples. According to morphology, biochemical and physiological characterization, and 16S rRNA sequence analysis, C-8 was identified as Bacillus sp. The celluloses produced by C-8 could hydrolyze cellulose, the optimum pH and temperature were 4.0 and 40℃, also it has good thermal stability and pH stability. In order to improve the ability of cellulose producing strain C-8, the fermentation conditions were optimized using response surface method. It was to screen out the effects of the main effect of enzyme production condition factors using Plackett-Burman Design, the steepest ascent experiment approximation maximum response area, and optimize fermentation conditions by Response Surface Box-Behnken. The results showed that the initial pH, CMC-Na% and culture tempinduedrature was the main influencing factor. The response of three factors was, obtained, and the optimal conditions for the initiation of pH8.0, CMC-Na%2.5%, culture temperature 28℃. Under the optimum condition, the activity of cellulose was up to 193.89 U/mL, and the enzyme activity was increased by 2.35 times compare to previous optimization.

Key words: Bacillus sp. , Cellulose , Response surface analysis, Fermentation optimization