Team Play: Determining Syntrophic Interactions in Hydrocarbon Biodegradation Processes

微生物在自然界存在混合社区的集体代谢大大有助于生物地球化学和/或营养循环现象,可以对全球健康产生深远的影响包括气候、水和土地资源。在缺氧环境中，由细菌和古细菌组成的混合微生物群落能够通过一种称为syntrophy的代谢过程将有机物转化为甲烷。Syntrophy热力学定义为相互依存(互惠)代谢在不同物种中混合厌氧社区必须合作执行一个给定的代谢反应,不能只由每个有机体异化。这种团队游戏的新陈代谢在热力学平衡附近运行，但在缺氧生态系统（如湿地、动物内脏、垃圾填埋场、稻田和废水处理系统）中对有机物到CH4和CO2的自然循环做出了重大贡献，并且在与缺氧碳氢化合物相关的生态系统（如天然油气渗漏、深层地下能量储层和浅层碳氢化合物污染的地下水系统）中是一个普遍的过程。然而，大多数有机化合物（包括碳氢化合物）的共生代谢的生态学原理仍有待充分探索。我的研究计划的首要、长期目标是确定与产甲烷烃生物降解过程相关的共生群落的相互作用。提出的两个主要的短期目标工作,将解决知识空白的在这一领域的研究(1)识别和潜在的相互作用知之甚少的角色syntrophic混合财团成员,包括那些不文明的类群(如Atribacteria的)和其他社区成员已确定在我们hydrocarbon-metabolizing产甲烷文化和在其他环境中,(2)通过实验评估产甲烷烃降解群落成员（如通过间接或直接的种间电子转移、介质或营养相互依赖）形成互利伙伴关系的机制。拟议的研究计划将为微生物群落成员如何集体相互作用以生物转化有机质提供见解，从而有助于更广泛地了解生物地球化学循环。对碳氢化合物降解系统的关注将有助于我们更好地理解如何最好地应用生物解决方案来修复加拿大和其他地方的碳氢化合物污染环境。

Microorganisms in the natural world exist as mixed communities whose collective metabolism substantially contributes to biogeochemical and/or nutrient cycling phenomena that can have profound impacts on global health including our climate, water, and land resources. In anoxic environments, mixed microbial communities comprised of Bacteria and Archaea are able to biotransform organic matter to methane through a metabolic process known as syntrophy. Syntrophy is defined as a thermodynamically interdependent (mutualistic) metabolism wherein different species within mixed anaerobic communities must cooperate to carry out a given metabolic reaction that cannot be catabolized by each organism alone. Such team play' metabolism operates near the thermodynamic equilibrium, yet contributes substantially to the natural cycling of organic matter to CH4 and CO2 in anoxic ecosystems such as wetlands, animal guts, landfills, rice paddies, and wastewater treatment systems, and is a prevalent process in anoxic hydrocarbon-associated ecosystems such as natural oil and gas seeps, deep subsurface energy reservoirs, and shallow hydrocarbon-contaminated groundwater systems. However, the ecological principles underlying the syntrophic metabolism of most organic compounds, including hydrocarbons, remain to be fully explored. The over-arching, long-term objective of my research program is to determine the interactions that govern syntrophic communities associated with methanogenic hydrocarbon biodegradation processes. The two major short-term objectives for the proposed work that will address gaps in knowledge in this field of study are to (1) identify the interactions and potential roles of poorly understood syntrophic members in mixed consortia, including those of uncultivated taxa (such as Atribacteria') and other community members that have been identified in our hydrocarbon-metabolizing methanogenic cultures and in other environments, and (2) to experimentally assess mechanisms used by methanogenic hydrocarbon-degrading community members (such as via indirect or direct interspecies electron transfer, mediators, or nutrient interdependencies) to form mutually beneficial partnerships with each other. The proposed research program will offer insights into how microbial community members collectively interact to biotransform organic matter thus contributing to a broader understanding of biogeochemical cycling. The focus on hydrocarbon-degrading systems undergoing such team play' will help to improve our understanding of how best to apply biological solutions to remediate hydrocarbon-contaminated environments in Canada and elsewhere.