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，微生物呼吸三价铁，即铁锈中铁的形式。在产甲烷过程中，微生物产生甲烷，这是天然气的主要成分，也是一种有效的温室气体。一些铁还原剂和产甲烷菌（驱动反应的微生物）可以通过种间电子转移（IET）共享能源来相互合作。然而，大多数预测模型假设由于能源竞争，产甲烷菌和铁还原剂并不共存，并且只允许在铁矿物耗尽的情况下产生甲烷。如果不考虑 IET 和竞争，可能会在基于过程的甲烷产量估计中引入错误。此外，IET 的环境驱动因素尚未确定，这限制了模型预测甲烷通量如何随环境变化而变化的能力。这项研究将创建一个将竞争与合作相互作用联系起来的产甲烷新模型。该模型将提高预测甲烷产生量和管理自然和工程系统（包括土壤、含水层、垃圾填埋场和废水处理系统）碳预算的能力。该研究还将为本科生和研究生提供培训，并通过参加堪萨斯路易斯斯托克斯少数族裔参与联盟夏季研究计划和针对中学生的夏季外展活动，增加代表性不足的群体对科学的参与。这项研究的研究目标是：1) 确定推动产甲烷菌和铁还原剂在竞争和 IET 之间相互作用的环境驱动因素，2) 确定产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) 评估耦合酶特性和环境化学在确定相互作用的性质中的作用。为了实现这些目标，该研究将生物反应器实验的结果与动态酶模型相结合。生物反应器实验将研究相互作用和甲烷产量如何随关键生物地球化学因素而变化，包括pH值、三价铁来源以及电子供体和二价铁的可用性。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基础。在实验和模拟中，产甲烷菌和铁还原剂之间的竞争和互养都将成为可能，从而使研究能够解决相互作用和甲烷生成如何随环境化学而演变。此外，研究结果将创建一个路线图，通过定义这种相互作用的环境背景来评估铁还原剂和产甲烷菌之间 IET 的环境意义。在此过程中，研究结果将提供所需的工具，以增进我们对全球甲烷循环生态基础的理解。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值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

Influence of pH on the balance between methanogenesis and iron reduction

pH对产甲烷和铁还原平衡的影响

• DOI: 10.1111/gbi.12320
• 发表时间: 2018-11-01
• 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
• 通讯作者: M. Kirk

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

用于量化厌氧有机物分解温度敏感性的 Q10 系数的局限性：基于建模的评估

• DOI: 10.1029/2021jg006264
• 发表时间: 2021-08-01
• 期刊: Journal of Geophysical Research: Biogeosciences
• 作者: Qiong Wu;R. Ye;S. Bridgham;Q. Jin
• 通讯作者: Q. Jin

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

• 发表时间: 2022-04
• 期刊: Frontiers in ecology and evolution
• 作者: Wu, Qiong;Guthrie, Megan J.;Jin, Qusheng
• 通讯作者: Jin, Qusheng

LimitedMechanisticLinkBetweentheMonodEquationand MethanogenGrowth:aPerspectivefromMetabolicModeling

莫诺方程与产甲烷菌生长之间的有限机制联系：代谢模型的视角

• 发表时间: 2022-03
• 期刊: Microbiology spectrum
• 影响因子: 3.7
• 作者: Jin, Qusheng;Wu, Qiong;Shapiro, Benjamin M.;McKernan, Shannon E.
• 通讯作者: McKernan, Shannon E.

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: 2021-07
• 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.