title: ¹³C Pathway Analysis for the Role of Formate in Electricity Generation by Shewanella Oneidensis MR-1 Using Lactate in Microbial Fuel Cells.
abstract: Microbial fuel cell (MFC) is a promising technology for direct electricity generation from organics by microorganisms. The type of electron donors fed into MFCs affects the electrical performance, and mechanistic understanding of such effects is important to optimize the MFC performance. In this study, we used a model organism in MFCs, Shewanella oneidensis MR-1, and (13)C pathway analysis to investigate the role of formate in electricity generation and the related microbial metabolism. Our results indicated a synergistic effect of formate and lactate on electricity generation, and extra formate addition on the original lactate resulted in more electrical output than using formate or lactate as a sole electron donor. Based on the (13)C tracer analysis, we discovered decoupled cell growth and electricity generation in S. oneidensis MR-1 during co-utilization of lactate and formate (i.e., while the lactate was mainly metabolized to support the cell growth, the formate was oxidized to release electrons for higher electricity generation). To our best knowledge, this is the first time that (13)C tracer analysis was applied to study microbial metabolism in MFCs and it was demonstrated to be a valuable tool to understand the metabolic pathways affected by electron donors in the selected electrochemically-active microorganisms.
authors: Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
authors: Shuai
authors: S
authors: Luo
authors: Department of Biological Systems Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
authors: Weihua
authors: W
authors: Guo
authors: Department of Earth Sciences, University of Southern California, Los Angeles, CA 90089, USA.
authors: Kenneth H
authors: KH
authors: Nealson
authors: Department of Biological Systems Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
authors: Xueyang
authors: X
authors: Feng
authors: Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
authors: Zhen
authors: Z
authors: He
mesh_terms: D001674:Bioelectric Energy Sources / Q000382:microbiology*; D002247:Carbon Isotopes; D004560:Electricity; D004583:Electrons; D005561:Formates / Q000378:metabolism*; D019344:Lactic Acid / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D020592:Shewanella / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D005561:Formates; C030544:formic acid; D019344:Lactic Acid