稻秆纤维素降解菌的分离筛选和降解性能研究

Isolation,Screening and Capability of Cellulose-Degrading Strains for Rice Straw

从种稻红壤中分离微生物菌株,经紫外诱变后得到了3株高效的稻秆纤维素降解菌株,分别为细菌YB20、真菌F9和YF15.经鉴定,菌株YB20为枯草芽孢杆菌(Bacillus subtilis sp.),菌株F9和YF15均为绿色木霉(Trichoderma viride sp.).对3株纤维素降解菌株产酶特性进行了初步研究,确定了菌株的最佳产酶条件,菌株YB20、F9和YF15的胞外羧甲基纤维素(CMC)酶活性高达2.67、2.78和3.56(mg/mL).30 min.产酶稳定性试验表明,菌株YB20、F9、YF15的CMC酶活性均具有较好的稳定性.纤维素降解菌剂培养试验结果表明,3株菌混合培养对秸秆腐解具有较好的协同效应,稻秆腐解率可达到35.02%,比对照提高了4.43倍.大田应用试验显示,与不施用菌剂的对照相比,施用纤维素降解菌剂在一定程度上提高了晚稻产量.

Three high-efficient cellulose-degrading strains were isolated and screened from the red soil of paddy field with the ultraviolet-induced mutation, including one bacterial strain named as YB20 and two fungal strains F9 and YF15. The strain of YB20 was characterized as a Bacillus subtilis sp, the strain F9 and YF15 were both characterized as Trichoderma viride sp. The optimum conditions for cellulase production by three strains were investigated, in which the highest carboxylmethyl cellulose （CMC） enzyme activities of the strain YB20, the strain F9 and YF15 were 2. 67, 2. 78 and 3.56 （mg/mL） · 30 min, respectively. The stability of CMC enzyme activities of three strains remained at a high level. There was obviously synergistic effect for straw decay, approximately 35.02% when three strains mixed together in the incubated experiment, with 5.43 times higher than the control. The application of cellulose-degrading microbial agents to the red soil of paddy field could to some extent improve rice yield compared with the control in a field plot experiment.