一株产纤维素酶菌株的鉴定及其产酶条件优化

Identification for a Strain of Produce Cellulase and Enzyme Production Conditions Optimization

从土壤中筛选出一株产纤维素酶的细菌,编号为X-2。该菌株为革兰氏阳性菌,好氧,可生成芽孢。根据其菌体形态、菌落形态、生理生化特征作为初步分类依据,并通过16S rDNA分子生物学鉴定的技术手段,鉴定为苏云金芽孢杆菌(Bacillus thuringiensis)。液体发酵试验表明,其产酶的最适条件为:发酵时间为72 h,培养温度35°C,转速130 rpm、接种量6%以及初始pH 7.2,在该条件下其羟甲基纤维素酶(CMCase)活性可达10.89 U/mL。

This paper screened a strain of cellulose-producing bacteria No.X-2from the soil.It was an aerobic Gram-positivebacteria and able to generate spore.It had been identified as Bacillus thuringiensis in laboratory according to thallusmorphology,Colony morphology,physiological and biochemical characteristics and16S rDNA molecular biologyidentification.Liquid fermentation test showed that Optimum fermentation conditions of X-2were72h fermentation time,incubation temperature at35°C,130rpm of revolving speed,6%of inoculum size and pH7.2of the initial value.The activityof hydroxymethyl cellulase(CMCase)under this condition reached10.89U/mL.