畜禽粪便厌氧发酵连续产氢产甲烷过程中微生物群落特征及其调控机理研究

During the hydrogen or methane fermentation from waste biomass, there are many problem, including nature microflora instability, low conversion efficiency of raw materials, low gas production rate, little understand on the structure, function and succession law of microflora population. So, it is difficult to effectively regulate the fermentation process. In this project, a continuous hydrogen and methane production by anaerobic dark fermentation was constructed using animal manure as the substrate. Through dynamic monitoring the activity and structural changes of microbial community, the community succession and metabolism characteristics of hydrogen-producing and methanogenic microflora population will be revealed under different operational phase and operating conditions, and continuous bio-hydrogen production process will be strengthen. We expect to clarify the regulation mechanism of hydrogen-methane fermentation, and to establish a feasible and effective fermentation control strategy.This research can provide a theoretical and technical support for the clean energy conversion and harmless biological treatment of animal manure, and can lay the foundations for realization the large-scale continuous hydrogen-methane production from animal manure.

在利用废弃生物质发酵产氢或产甲烷的过程中普遍存在菌源不稳定、原料转化效率较低、产气速率低、对产氢产甲烷微生物菌群的结构、功能及演替规律了解甚少，很难有效调控发酵过程等问题。基于此，本课题拟采用畜禽粪便为底物构建厌氧发酵连续产氢产甲烷系统，通过动态监测微生物群落活性和结构的变化，揭示不同运行阶段和运行状态下产氢产甲烷微生物菌群的功能、演替规律和代谢特征，并实现对连续产氢系统的生物强化，期待能阐明产氢产甲烷发酵调控机理，并建立有效可行的发酵调控策略。本课题的研究为畜禽粪便的高效清洁能源转化和无害化生物处理提供理论和技术支持，为最终实现畜禽粪便厌氧发酵连续产氢-产甲烷的规模化生产奠定基础。

氢气和甲烷是公认的可再生清洁能源，在废弃生物质资源利用、减少对化石燃料的依赖及环境保护诸方面具有重要意义。本课题以牛粪为底物构建了厌氧发酵产氢产甲烷体系，对河底污泥进行长期驯化使其能适应牛粪发酵高效产氢，运用单因素试验和响应面分析方法系统研究了牛粪发酵产氢的影响因素，并通过高通量测序、PCR-DGGE等方法检测微生物群落结构，阐明了不同运行阶段和运行状态下产氢产甲烷微生物菌群的结构和代谢特征；通过以微晶纤维素为底物富集高效产氢混合菌，对产氢系统进行了生物强化，并分离得到一株能直接利用纤维素物质产氢的Clostridium sp. FZ11菌株，并对该菌种的生理生化特性和和产氢特性进行了系统研究。研究发现牛粪厌氧发酵产氢的优势菌种主要集中Lactobacillales、Bacillales、Clostridiales和Coriobacteriales，产氢量和产氢速率急剧升高时，优势菌梭菌目和Coriobacteriales数量相应提高。产甲烷发酵液优势菌主要为Proteiniphilum、Petrimonas、Clostridium、Sedimentibacter和未分类菌属,调节菌群降低厚壁菌门含量、提高拟杆菌门含量时有利于实现产氢至产甲烷的转换。在本研究中牛粪发酵产氢潜能和甲烷生成量分别达到59.85ml H2/g-TVS和447.3ml CH4/g-TVS，该结果在国内外同类研究中处于较好水平。该研究结果对实现畜禽粪便的高效清洁能源转化和无害化生物处理具有普遍的指导和借鉴价值。