Collaborative Research: Biogeochemical drivers of interspecies electron transfer from iron reducers to methanogens

合作研究：从铁还原剂到产甲烷菌的种间电子转移的生物地球化学驱动因素

• 批准号: 1753436
• 负责人: Matthew Kirk
• 金额: $ 19.63万
• 依托单位: Kansas State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1753436&HistoricalAwards=false
• 关键词: Collaborative; Research; Biogeochemical; drivers; interspecies

Iron reduction and methanogenesis are two of the most common microbial reactions in nature. During iron reduction, microorganisms respire ferric iron, the form of iron in rust. During methanogenesis, microorganisms make methane, the primary component of natural gas and a potent greenhouse gas. Some iron reducers and methanogens, the microbes that drive the reactions, can cooperate with one another by sharing energy resources through interspecies electron transfer (IET). However, most predictive models assume that methanogens and iron reducers do not coexist, due to competition for energy sources, and only allow methane generation where ferric minerals have been depleted. Failure to account for both IET and competition may introduce error in process-based estimates of methane production. Moreover, environmental drivers of IET have not been identified, limiting the ability of models to predict how methane fluxes vary with environmental change. This study will create a new model for methanogenesis that links competitive and cooperative interactions. The model will improve the ability to predict methane generation and manage carbon budgets in natural and engineered systems including soils, aquifers, landfills, and wastewater treatment systems. The study will also provide training to undergraduate and graduate students and increase involvement of underrepresented groups in science through participation in the Kansas Louis Stokes Alliance for Minority Participation summer research program and summer outreach events for middle-school girls.Research goals of this study are to: 1) identify environmental drivers that push interactions of methanogens and iron reducers between competition and IET, 2) determine how changes in interactions between methanogens and iron reducers affect methane generation, and 3) evaluate the coupled role of enzyme properties and environmental chemistry in determining the nature of interactions. To achieve these goals, the study will integrate the results of bioreactor experiments with dynamic enzyme modeling. The bioreactor experiments will examine how interactions and methane production vary with key biogeochemical factors, including pH, ferric iron source, and the availability of electron donors and ferrous iron. The modeling analysis will consider enzyme kinetics and reaction energetics to simulate reactions at a subcellular/enzymatic level, with experiment results providing a basis for validation. Both competition and syntrophy between methanogens and iron reducers will be possible in the experiments and simulations, allowing the study to resolve how interactions and methane generation evolve with environmental chemistry. Moreover, study findings will create a roadmap for evaluating the environmental significance of IET between iron reducers and methanogens by defining an environmental context for this interaction. In doing so, study results will provide the tools needed to advance our understanding of ecological underpinnings of the global methane cycle.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

铁还原和产甲烷是自然界中最常见的两种微生物反应。在铁还原过程中，微生物呼吸铁，这是铁锈中的铁的形式。在甲烷生成过程中，微生物会产生甲烷，甲烷是天然气的主要成分，也是一种强有力的温室气体。一些铁还原剂和产甲烷菌是推动反应的微生物，它们可以通过物种间电子转移(IET)共享能量资源，从而相互合作。然而，大多数预测模型假设，由于对能源的竞争，产甲烷菌和铁还原剂不会共存，只允许在含铁矿物耗尽的地方产生甲烷。如果不能同时考虑IET和竞争，可能会在基于流程的甲烷产量估计中带来误差。此外，还没有确定IET的环境驱动因素，限制了模型预测甲烷通量如何随着环境变化而变化的能力。这项研究将创建一种将竞争和合作相互作用联系起来的产甲烷新模型。该模型将提高在包括土壤、含水层、垃圾填埋场和废水处理系统在内的自然和工程系统中预测甲烷生成和管理碳收支的能力。这项研究还将为本科生和研究生提供培训，并通过参与堪萨斯州路易斯·斯托克斯少数民族参与联盟暑期研究计划和中学女生暑期外展活动，增加未被充分代表的群体对科学的参与。本研究的研究目标是：1)确定推动甲烷菌和铁还原剂在竞赛和IET之间相互作用的环境驱动因素；2)确定甲烷菌和铁还原剂之间相互作用的变化如何影响甲烷生成；以及3)评估酶特性和环境化学在确定相互作用性质方面的耦合作用。为了实现这些目标，这项研究将把生物反应器实验的结果与动态酶建模结合起来。生物反应器实验将研究相互作用和甲烷产量如何随着关键生物地球化学因素的变化而变化，这些因素包括pH、铁源以及电子供体和亚铁的可用性。建模分析将考虑酶动力学和反应能量学来模拟亚细胞/酶水平的反应，实验结果为验证提供了基础。在实验和模拟中，产甲烷菌和铁还原剂之间的竞争和合成都是可能的，这使得这项研究能够解决相互作用和甲烷生成是如何随着环境化学的演变而演变的。此外，研究结果将通过定义铁还原剂和产甲烷菌之间的环境背景，为评估铁还原剂和产甲烷菌之间的IET的环境意义创建路线图。通过这样做，研究结果将提供所需的工具，以促进我们对全球甲烷循环的生态基础的理解。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Limitations of the Q10 Coefficient for Quantifying Temperature Sensitivity of Anaerobic Organic Matter Decomposition: A Modeling Based Assessment

• DOI: 10.1029/2021jg006264
• 发表时间: 2021-08
• 期刊: Journal of Geophysical Research: Biogeosciences
• 作者: Qiong Wu;R. Ye;S. Bridgham;Q. Jin

Influence of pH on the balance between methanogenesis and iron reduction

• DOI: 10.1111/gbi.12320
• 发表时间: 2018-11
• 期刊: Geobiology
• 影响因子: 3.7
• 作者: K. A. Marquart;Ben R. Haller;Janet M. Paper;T. Flynn;M. Boyanov;Ganiyat Shodunke;Colleen M. Gura;Q. Jin;M. Kirk

Physiological Acclimation Extrapolates the Kinetics and Thermodynamics of Methanogenesis From Laboratory Experiments to Natural Environments

生理适应将产甲烷的动力学和热力学从实验室实验推断到自然环境

• DOI: 10.3389/fevo.2022.838487
• 发表时间: 2022
• 期刊: Frontiers in Ecology and Evolution
• 影响因子: 3
• 作者: Wu, Qiong;Guthrie, Megan J.;Jin, Qusheng
• 通讯作者: Jin, Qusheng

Limited Mechanistic Link Between the Monod Equation and Methanogen Growth: a Perspective from Metabolic Modeling.

• DOI: 10.1128/spectrum.02259-21
• 发表时间: 2022-04-27
• 期刊: Microbiology spectrum
• 影响因子: 3.7

Influences of pH and substrate supply on the ratio of iron to sulfate reduction

pH 值和底物供应对铁与硫酸盐还原比例的影响

• DOI: 10.1111/gbi.12444
• 发表时间: 2021
• 期刊: Geobiology
• 影响因子: 3.7
• 作者: Paper, Janet M.;Flynn, Theodore M.;Boyanov, Maxim I.;Kemner, Kenneth M.;Haller, Ben R.;Crank, Kathleen;Lower, AnneMarie;Jin, Qusheng;Kirk, Matthew F.
• 通讯作者: Kirk, Matthew F.