生物质废弃物发酵过程中菌群多样性及秸秆降解菌的筛选

Microbial diversity and screening of straw-degrading bacteria in different fermentation processes of biomass waste

利用16s rRNA高通量测序技术研究了生物质废弃物玉米秸秆、畜禽粪便、活性污泥混合物在不同氧含量条件下发酵过程中微生物的群落特征变化,同时采用选择培养基筛选对秸秆具有降解能力的菌株,以寻找能在秸秆还田中具有较大应用潜力的菌种资源。高通量测序结果表明:在秸秆、畜禽粪便、污泥共发酵体系中,厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidetes)和变形菌门(Proteobacteria)占据绝对优势,不同氧含量堆肥条件下发酵体系营养结构、微生物群落结构不同,氧含量较低的条件更有利于秸秆的降解。通过纯培养方式得到的目的菌株对玉米秸秆降解效率最高可达28.9%,初步被确定为厚壁菌门中芽孢杆菌属(Bacillus),进一步证明结合高通量测序结果快速选择生物质废弃物发酵体系中秸秆降解菌具有可行性。

The 16s rRNA high-throughput sequencing technology was used to study the characteristics of microbial communities during the co-fermentation of corn straw,livestock manure and sludge under different oxygen conditions.In order to find the strains with great potential in the return of straw to the field a selection medium was used to quickly screen the strains which could degrade straw.The results of high-throughput sequencing showed that Firmicutes,Bacteroidetes and Proteobacteria occupied absolute advantages in the co-fermentation system of straw,livestock manure and sludge.The nutrient structure and microbial community structure in fermentation system were different under different compositing conditions,and the condition of low oxygen content was more conducive to the degradation of straw.The highest degradation efficiency of target strain obtained by pure culture method was 28.9%,and the strain could be initially identified as Bacillus in the Firmicutes phylum.These results proved that it was feasible to select straw-degrading bacteria in co-fermentation system by combining high-throughput sequencing results.