产纤维素酶枯草芽孢杆菌B29的鉴定与培养条件研究

Identification of the Cellulase-producing Bacteria and Optimization of Its Culture Conditions

从近海土壤中分离1株产纤维素酶的菌株,经形态和生理生化指标鉴定为枯草芽孢杆菌。对产酶菌株经碳源、氮源、金属元素、培养温度、pH和接种量进行优化,确定最佳培养组分和条件为:20 g/L葡萄糖,10 g/L胰蛋白胨,3 g/L K2HPO4,3 g/L NaH2PO4,2 g/L氯化铁,pH 6.5,培养温度32℃,接种量为2%(v/v)。优化后纤维素酶系中以羧甲基纤维素酶活性为最高,为72.37 U/mL,其次是β-糖苷酶和微晶纤维素酶。

Strain B29 with high-yield cellulase was screened from the coastal soil samples, and it was identified as Bacillus subtilis on the basis of biochemical properties and morphological characteristics. After these, medium compositions and culture conditions for the cellulase production were optimized. The optimal concentration for higher production of cellulase was as follows： 20 g/L glucose, 10 g/L tryptone, 3 g/L K：HPO4,3 g/L NaH2PQ ,2 g/L FeCl3, and the maximum activity of CMCase obtained was 72.37 U/mL at pH 6. 5, 32 ℃ and 2% （v/v） inoculum. At the same time, the activity of cellobiohydrolase and β-glucosidase were lower than endoglucanase activity.