Construction and composition analysis of the complex microbial system css-1 of high decomposition efficiency for corn stalks

【目的】选育在常温(22℃)下对玉米秸秆具有高效稳定腐解功能的微生物复合菌系,明确其菌群组成,以促进选育的复合菌系在中国北方原位还田玉米秸秆中的应用。【方法】采用限制性培养与温度梯度诱导相结合的方法,以山西、山东、北京等省(市)玉米秸秆连续多年还田的土壤样品为菌源,以秸秆失重率、C/N及CMC酶活为筛选指标,获得高效稳定的玉米秸秆腐解复合菌系CSS-1;比较复合菌系不同继代腐解秸秆的失重率、CMC酶活、木聚糖酶活和PCR-DGGE的菌群监测动态变化,评价CSS-1的功能及其组成稳定性;采用克隆文库法,解析复合菌系CSS-1的主要菌群组成。【结果】CSS-1处理玉米秸秆的CMC平均酶活和最高酶活,比目前广泛应用的秸秆腐解菌剂A分别提高了82%和79%;CSS-1处理的秸秆失重率比菌剂A和空白对照分别提高了62.62%和173.65%;CSS-1不同继代腐解秸秆功能及其菌系组成监测表明该复合菌系的稳定性;克隆文库方法显示CSS-1优势菌群由多种具有纤维素与半纤维素降解功能的细菌和真菌构成,其细菌菌群分别归属Enterobacter、Cellulomonas、Streptomyces、Bacillaceae、Pantoe、Cellvibrio 6个属,真菌菌群归属Trichoderma、Gibberella 2个属。【结论】获得了在中国北方地区常温条件下高效稳定腐解玉米秸秆的复合菌系CSS-,可研发利用该菌系促进田间原位还田玉米秸秆的快速腐解。 【Objective】 In order to accelerate decay of cornstalks returned to fields in Northern China, the complex microbial system CSS-1 with high efficiency and stable degrading ability for corn stalks was constructed and its microbial composition was analyzed. 【Method】 The CSS-1 was domesticated from the soils which had been treated with cornstalks for a long time in Shanxi, Shandong and Beijing us