低温纤维素降解菌的筛选及其产酶研究

Study on screening and cellulase production of cold-adaped bacterium

摘要: 从甘南州玛曲县高寒草甸土壤中筛选出一株低温纤维素降解菌M7。通过形态观察、生理生化及16SrRNA序列比对分析,发现菌株M7与Bacillus subtili strain XS6进化距离最近,初步鉴定为枯草芽孢杆菌（Bacillus subtili）。通过Box-Benhnken中心组合设计和响应面分析法（RSM）,对其生长和产羧甲基纤维素酶（CMCase）条件进行优化。结果表明:温度20℃,培养基初始pH5.0,转速175r/min,酵母膏2.5g/L和微晶纤维素2.5g/L,蛋白胨5g/L,菌株M7所产CMCase达到最大值。

Abstract: A strain M7 with cellulose degradation ability was screened from alpine meadow soil of Maqu county in Gansu province.It is identified as Bacillus subtilis by morphology, physiological and biochemical property and 16SrRNA sequence analysis.The initial study on its producing cellulase showed that the temperature was 20℃, initial pH5.0, revolving speed 175r/min, peptone 5g/L, yeast extract 2.5g/L and microcrystalline cellulose 2.5g/L.After the optimization of Box-Benhnken design and response surface methodology, the cellulase activity reached the maximum.