黄河三角洲耐高渗碱性纤维素酶产生细菌YRD-19的诱变育种和产酶条件优化

Study on the screening and fermentation of osmophilic of alkaline cellulase higher production strain Bacillus sp. YRD-19

用紫外线对1株产耐盐碱纤维素酶的枯草芽孢杆菌YRD-19进行诱变育种,获得产酶能力是出发菌株5.97倍,并且产酶性能稳定的菌株YRD-19-35。进一步对其发酵条件进行研究,优化了培养基和培养条件。实验结果表明,优化培养基为:1.5%乳糖,1.5%蛋白胨,NaCl∶KH2PO4=5∶1,添加量为0.55%;优化培养条件为:接种量为2%,发酵温度为37℃,培养基初始pH为8.0,种子活化时间为24h,发酵时间为48h,装液量为50mL,摇床转速为200r/min时菌株YRD-19-35产酶的酶活力达到最高。在上述条件下,纤维素酶活力可达182.705U/g。

The original strain Bacillus sp. YRD-19 was mutated by UV, and its enzyme productivity was 5.97 fold higher than that of parent strain.The continuous 6 generations test showed that the mutant YRD-19-35 was stable in the alkaline cellulase（CMCase） production.The effects of compositions of culture medium and cultural conditions on cellulose production were investigated. The optimal culture media were： lactose 1.5%, peptone 1.5%, NaCl：KH2PO4 =5：1 （0.55%）.The optimum enzyme-producing conditions were pH 7.2 at 37%, and the enzyme activity reached 182.705U/g after 48h of culture.