秸秆纤维素降解细菌的筛选及其产酶条件的研究

Selection and Fermentation Conditions of Bacillus licheniformis H-5 Producing Cellulases

用稀释平板法在羧甲基纤维素平板培养基和纤维素刚果红平板培养基上，从土壤中分离出1株纤维素酶活力较高的耐热细菌H-5，初步鉴定为地衣芽孢杆菌（Bacillus licheniformis）。对该菌株的液体发酵产纤维素酶的条件经行了研究，结果表明：菌株H-5产纤维素酶的最适培养温度为40℃，内切酶活力（CMCase）和滤纸酶活力（FPase）最高可达27．14U和22．17U，最佳培养时间为3d，内切酶活力（CMCase）和滤纸酶活力（Fpase）最高可达26．38U和20．14U，最适初始pH值为6～6．5．内切酶活力（CMCase）和滤纸酶活力（FPase）最高可达24．08U和21．96U，最适摇床转速为150r·min^-1，内切酶活力（CMCase）和滤纸酶活力（FPase）最高可达25-34U和20．67U。

Bacillus licheniformis H-5 with high cellulases activity and thermal stability was screened from the forest soil of Shenyang Agricultural University by dilution plate method, using CMC culture medium and cellulose congo red medium. Singlefactor experiments were adopted to optimize the fermentation conditions for H-5.The optimal fermentation temperature was 40℃ and the activity of the CMCase and FPase could reach 27.14U and 22.17U respectively. The optimal fermentation time was 3d and the activity of the CMCase and FPase could reach 26.38U and 20.14U respectively. The optimal original pH value was pH6-6.5 and the activity of the CMCase and FPase could reach 24.08U and 21.96U respectively. The optimal shaking speed was 150 r·min^-1 and the activity of the CMCase and FPase could reach 25.34U and 20.67U respectively.