降解水稻秸秆兼抑制水稻纹枯病菌多功能复合菌系的构建

Construction of a dual-functional microbial community with high capacity of rice straw degradation and sheath blight pathogen inhibition

目的针对稻草直接还田需要,构建能够高效降解水稻秸秆同时又能抑制水稻纹枯病菌的多功能复合菌系。方法通过将具有高效降解纤维素的天然复合菌群与具有抑制水稻纹枯病菌效果的菌株组合,构建多功能复合菌系;采用失重法检测该复合菌系对水稻秸杆的腐解作用,荧光定量PCR法检测其对水稻纹枯病菌的抑制效果。结果成功地构建了一组多功能复合菌系,腐解12 d后,水稻秸秆干物质总失重率为41.4%,其中半纤维素降解率为59.5%,纤维素降解率为52.5%,木质素降解率为15.3%,腐解过程中平均CMC酶活为8.1 IU/g。该复合菌系对水稻纹枯病菌的抑制效果明显,发酵40 d后对水稻纹枯病菌的抑制率为27.1%,对照组抑制率为2.7%。结论该复合菌系能高效降解水稻秸秆,同时又能较好地抑制水稻纹枯病菌,适宜在水稻秸秆直接还田过程中使用。

Objective To construct a dual-functional microbial community with high efficiency of rice straw degradation and sheath blight pathogen inhibition, according to the requirement by rice straw incorporation. Method The dualfunctional microbial community was constructed by combining selected natural microbial community having high capacity of cellulose degradation with selected strain having the function of Rice Sheath Blight pathogen inhibition. Rice straw degrada- tion capacity was investigated by weight-loss method and the Sheath Blight pathogen inhibition function was evaluated by Real-time PCR method. Result A dual-functional microbial community was constructed successfi.dly. After 12 days offermentation, the total rice straw weight reduced by 41.4%. The degradation rate of hemicellulose, cellulose and lignin were 59.5%, 52.5% and 15.3%, respectively. The average CMC enzyme activity during the process of degradation was 8.1 IU/g. The Rice Sheath Blight pathogen decreased by 25.2% after 40 days, and the control treatment decreased by 2.9%. Conclusion This dual-functional microbial community was both effective in rice straw degradation and sheath blight patho- gen inhibition. It can be used in rice straw incorporation.