NSF Award
0918983
Ecosystem Research: Elucidating the Central Pathway of Microbial Electron Transport Systems in Complex Consortia<br/><br/>Intellectual Merit: <br/>Microbes perform fundamental energy transfer reactions that drive ecosystem changes such as the degradation of organic matter, and nutrient cycling in soils and sediments. Presently, little is known about what biological processes are facilitated and regulated within diverse microbial communities that perform energy transfer reactions. Microbial energy metabolism is dictated by electron transfer, i.e. the process of respiring or fermenting different chemical compounds. ?Extracellular? electron transfer (EET) is a strategy that microbes employ when they are respiring or deriving energy from a solid-phase compound, like iron(III)-oxides, which are extremely prevalent in most natural environments. Understanding the microbial EET reactions that drive many biological processes will contribute to the development of new methods for dealing with several environmental challenges including bioremediation of contaminated sites, treating wastewater, and reducing methane emissions from agricultural and industrial settings.<br/>Microbial fuel cell (MFC) electrodes can act as analogs to environmental solid-phase electron acceptors and are therefore ideal systems for isolating biofilms (bacterial communities attached to surfaces) that can perform EET; and for controlling EET reactions. This project will utilize MFC systems to isolate phylogenetically diverse, electrogenic, microbial consortia and will apply metagenomic and metatranscriptomic analyses to characterize gene expression in these biofilms. These data will be used to identify common genes associated with biofilms formed from different environments and under different MFC operating conditions. The resulting gene expression data will provide insights into the specific genes and pathways that are important for EET reactions in diverse microbial consortia. The research results will be applied toward creating new genetic markers that will enable the real-time investigation of EET reactions within natural environments. Ultimately, results from this project will generate fundamental knowledge about electron transfer processes and how they relate to ecosystem dynamics. <br/>Broader impacts: <br/>The research contributes to a broader impact by: 1) developing post-doctoral research programs in the interdisciplinary field of ?Electromicrobiology?; 2) providing opportunities for post-doctoral led sessions at scientific meetings; and 3) facilitating undergraduate education and laboratory experience via summer internship programs that will address topics ranging from advanced microbial cultivation techniques to comprehensive gene expression analyses. Post-doctoral appointees will have the opportunity to conduct interdisciplinary work in fields such as electrochemistry, microbial physiology and ecology, and metagenomic and metatranscriptomic analyses; and will emerge with unique expertise that can be applied in many research areas.
