厌氧菌群TC-5降解麦秸的动态协作机制解析及稳定共生多细胞体系构建

The anti-degradation of lignocellulosic biomass makes the hydrolysis process to be the rate-limiting step of microbial methane production. Multi-species consortium tends to have more abundant enzyme complements than pure cultures, which could be benificial for anaerobic digestion in lignocelulose degradation and biogas production.We have successfully enriched an anaerobic microbial consortium TC-5 with high lignocellulose-degradation capacity. Inoculation of TC-5 in digestion sludge resulted in a high methane yield of 311.8 ml/g-TS under thermophilic conditions, and remarkable enhancement of 36.6% were obtained, suggesting that TC-5 is a promising candidate for biogas production. However, the mechanism of the degradation of straw by the anaerobic bacteria TC-5 is still not clear, and the complex community interaction among species limits the stable application in the large-scale production process. Through the systematic study of the dynamic process of TC-5 during wheat straw degradation, the cooperation mechanism of core microorganisms in TC-5 is clarified to provide a theoretical basis for the construction of artificial multi-cell system. Based on the guidance of mathematical model, a variety of artificial multicellular systems will be constructed and the stability and straw degradation capacity will be evaluated. Finally, the optimal artificial symbiotic multi-cell system could be obtained to solve the bottleneck problem during the application of TC-5. The expected research results of this project can provide stable symbiotic microbial additives for enhancing methane production by anaerobic digestion using agriculture wastes. Besides, the degradation mechanism of TC-5 is helpful to the development of enzyme cocktails for the efficient conversion and utilization of agriculture wastes.

利用微生物菌群多酶协作的优势突破秸秆的抗降解屏障，促进秸秆原料厌氧发酵中甲烷的合成已成为研究热点。厌氧秸秆降解菌群可接种至甲烷发酵体系中促进秸秆水解，避免了分离式的预处理过程，有助于甲烷收率的提高。申请人筛选到一种高效降解秸秆的厌氧菌群TC-5，并显著提高了厌氧发酵中甲烷的合成效率和产率。然而，由于缺乏对TC-5秸秆降解机制和物种间复杂的群体关系的了解，限制了该菌群在实际生产过程中的稳定应用。本项目通过宏转录组、定量宏蛋白组测序等手段探明TC-5降解麦秸的多酶协作过程，解析TC-5菌群中核心微生物的动态协作机制；以Bottom-Up策略指导gLV模型构建多种稳定共生多细胞体系，采用绝对定量技术验证人工多细胞体系的群体关系，评价其降解麦秸和促进甲烷合成的能力，从而确定最优的人工多细胞体系组合。本项目的研究成果可为秸秆厌氧发酵产甲烷过程强化提供技术支撑，为生物质资源的转化与利用提供参考。

利用微生物菌群多酶协作的优势突破秸秆的抗降解屏障，促进秸秆原料厌氧发酵中甲烷的合成已成为研究热点。厌氧秸秆降解菌群可接种至甲烷发酵体系中促进秸秆水解，避免了分离式的预处理过程，有利于甲烷产率的进一步提高。本项目通过系统研究自主筛选的厌菌群TC-5降解秸秆的动态过程，阐明TC-5菌群中核心微生物的协作机制，构建了多个人工多细胞体系并获得最优的人工多细胞体系组合，解决TC-5菌群结构多变、群体关系复杂和不利于生产应用的瓶颈问题。具体结果如下：.1、本研究筛选到一株通过添加复合生化复苏因子筛选获得了高效降解秸秆的厌氧菌群TC-5，实现了秸秆生物质的高效降解，避免了传统预处理过程的高成本投入，同时中高温厌氧发酵过程甲烷产量分别提高了22.2%和36.6%。明确了初始氧气浓度对TC-5菌群降解麦秸过程的影响，为后续菌剂的生产提供了重要的技术支持。采用宏基因组测序技术探明了TC-5菌群中的核心微生物，阐明了在麦秸降解过程中起到重要作用的碳水化合物利用编码基因及其来源。.2、对厌氧菌群TC-5强化秸秆厌氧发酵产甲烷过程进行了系统的研究，优化了发酵温度，添加时间和添加量等重要参数，确定了基于厌氧菌TC-5的生物强化技术的可行性，为实现TC-5菌群在实际工况下的应用，本研究模拟了实际生产过程中的半连续进料发酵，并以猪粪和秸秆作为共消化底物，连续2个HRT发酵周期内甲烷产量提高15.9%。本研究开发了一种基于好氧菌与厌氧菌群联合培养的菌剂生产方法，实现了TC-5菌剂低成本、高活性的制备。研究成果可为秸秆厌氧发酵产甲烷过程强化提供技术支撑，为生物质资源的转化与利用提供参考。.3、本项目研究了厌菌群TC-5降解秸秆的动态酶学催化过程，阐明TC-5菌群中核心微生物的协作机制，为人工稳定共生多细胞体系的构建提供重要的理论依据。同时，本项目从群体互作关系的角度出发，构建并评价多种人工多细胞体系的群体关系和应用效果，获得最优的人工多细胞体系组合，解决TC-5菌群结构多变、群体关系复杂和不利于生产应用的瓶颈问题。