基于功能基因组学揭示自凝集产氢细菌代谢调控机制

Ethanol type fermentation as an acidogenic fermentation with highly efficent hydrogen production has wide application prospects in the fileds of organic wastewater treatment and energy recovery. Ethanoligenens harbinense as a typical ethanologenic hydrogen-producing bacterium will become a promosing microbe in engineering appliaction due to it's capabilities of hydrogen production, autoaggregation and acid-tolerant growing. Therfore, to understand physiological metabolism and autoaggregation of this species has important significance in theoretical studies and pricatice application. The aim of this proposal is to analyze the transcriptome and proteome of Ethanoligenens harbinense under interuption conditions, including the expression levels of genes related to center metabolic pathway and hydrogenase based on complete genome sequence analysis, to elucidate the mechanism of molecular regulations of efficient hydrogen production metabolism, to test hydrogen production and autoaggregation ability under different ecological conditions, and to determine the optimum ecological conditions and strategies of operation regulation baded on gene expressions. in order to reveal the regulation mechanism of key gene expression and the mechanism of autoaggregation, co-expressed genes with hydrogenase gene will be analyzed. The study aims to conduct the genetically modification of Ethanoligenens harbinense, realize the bioaugmentaiton of hydrogen production, and lay the foundation of biohydrogen production in a full scale.

乙醇型发酵作为一种具有较高产氢能力的产酸发酵类型，在有机废水处理与能源化方面有着广阔的工程应用前景。产乙醇杆菌是乙醇型产氢发酵的代表细菌，具有良好的产氢、自凝集和耐酸生长等特性，开展该属模式菌株的生理代谢及其自凝集机制研究具有重要的理论和现实意义。本课题研究目的是基于已获得的全基因组序列分析产乙醇杆菌的转录组和蛋白质组、特别是氢化酶基和中心代谢途径相关基因表达水平，解析高效产氢代谢的分子调控机制。分析不同生态条件干扰下的产氢效能和自凝集能力，通过基因表达水平确定最佳生态条件及其调控对策，同时分析与氢化酶高效共表达的相关基因，进一步揭示环境胁迫下关键基因表达调控和自凝集生长机制。为进行产乙醇杆菌的遗传改良和利用此菌实现制氢系统生物强化，以期尽快合理应用于生物制氢规模化生产奠定基础。

乙醇型发酵是厌氧发酵主要类型之一，由于该发酵类型利用碳水化合物产生乙醇和乙酸同时产生氢气，乙醇易于转化成可被产甲烷菌利用的乙酸，因此研究乙醇型发酵对于揭示厌氧发酵调控机理具有重要意义。哈尔滨产乙醇杆菌（Ethanoligenens harbinense YUAN-3）是乙醇型发酵的典型种，具有高产氢能力和自聚集生长。通过研究该种的产氢代谢条例机制具有重要的科学价值和实际意义。本课题利用基因组学、转录组学和定量蛋白质组学在分子水平系统的研究了Ethanoligenens harbinense的代谢调控。完成了产氢细菌的基因组完成图及比较基因组学研究，确定了Ethanoligenens harbinense的进化分类地位和种类不同菌种的差异。确定了影响产乙醇杆菌产氢产乙醇代谢相关的重要功能基因。通过多组学技术分析了不同培养时期和初始pH对产氢效能、生长特性、基因表达和蛋白表达的影响，发现生态因子干扰下存在大量差异表达基因和蛋白；氢化酶蛋白质修饰和铁氧化还原蛋白上调表达是产氢代谢调控的关键。通过定量蛋白质组学揭示产氢细菌对乙醇和乙酸的耐受机制。阐明了产氢产乙醇代谢途径与调控机制，为高效自凝集产氢细菌的改造和应用提供重要的依据。将产氢细菌E. harbinense YUAN-3与兼性好氧细菌Pseudomonas aeruginosa进行复配，基于呼吸互作机制实现了好氧条件产氢，并形成自凝聚厌氧颗粒工程菌种。发现了纳米磁性颗粒可以促进产氢细菌产氢代谢。这些研究为放大化生物制氢的启动、运行调控提供了理论依据。在Biosensors and Bioelectronics，Biotechnology for Biofuels，Frontiers in Microbiolog，Chemical Engineering Journal，Science of the Total Environment等期刊发表SCI论文6篇，EI论文1篇，获得2017年教育部青年科学奖，授权发明专利3项，申请美国专利1项。