高产纤维素酶菌的筛选及鉴定

Screening and identification of high-yielding strains of cellulase

为了获得高产纤维素酶的菌株,从纤维素含量丰富的地方进行取样,如稻秆堆积土壤、腐木堆积土壤等,以刚果红水解圈的大小作为判断标准,从12份样品中筛选出6株产酶能力强的菌株,并对其进行生理生化及16S r DNA鉴定,结果表明,2号为蜡状芽孢杆菌,5号为枯草芽孢杆菌,9号为巨大芽孢杆菌,10号为地衣芽孢杆菌,11号为微小杆菌,12号为绿色木霉。并把这些菌种用于固态发酵,选择麸皮和米糠两种不同的纤维质材料来进行发酵,用CMC法测量了发酵后的酶活力,发现地衣芽孢杆菌发酵后的活力最强,酶活值分别达到3 437 U/ml和8 541 U/ml,在生产上有潜在的应用前景。通过对地衣芽孢杆菌发酵温度、时间及含水量的初步优化,获得其固态发酵的最优化条件:培养温度30℃,培养时间60 h,初始水分含量40%。试验为进一步利用此菌株进行工业化生产奠定了基础。

To obtain strains with high cellulose enzyme, rich local sampling from cellulose content,such as straw accumulation of soil, rotting wood pile soil, were obtained. Hydrolyze with Congo red cir-cle as the judgment standard, the size of the selected 6 from 12 samples of enzyme production abilityof strain, and carry the physiological and biochemical and 16 S r DNA identification. The results showthat 2 is for the Bacillus cereus, 5 is for the Bacilus subtilis, 9 is for the Bacillus meqaterium, 10 isfor the Bacillus licheniformis, 11 is for the Exiguobacterium, 12 is for the Green trichoderma viride.And put these strains in solid state fermentation, select the bran and rice bran of the two different fi-ber materials for fermentation. CMC method was used to measure the enzymatic activity. The resultfound the Bacillus licheniformis after fermentation showed the strongest vitality and the enzyme activi-ty reached 3 437 U/ml and 8 541 U/ml. It is possible to make the Bacillus licheniformis in actual pro-duction application. By fermentation temperature, time and the initial moisture content optimization, getthe optimized conditions of solid state fermentation for Bacillus licheniformis: 30 ℃ to cultivate 48 h,quantity of initial moisture content of 40%. The trial was helpful for further utilization of this strain, ly-ing the foundation for the industrialized production.