Community Composition of Bacterial Biofilms Formed on Simple Soil Based Bioelectrochemical Cell Anodes and Cathodes
Abstract
Microbial fuel cells (MFC), as bioelectrochemical systems, hold promise as a sustainable source of energy for use in novel environments and settings. Although electrode biofilms, both anode and cathode, are critical to the production of power in these systems, the taxonomies of the biofilms that form are not fully understood. The specific objectives of the current study were to classify the bacteria that enriched onto fuel cell electrodes, with three biogeochemically distinct surface soils serving as the inocula. Following 1000 hours of incubation under saturated soil conditions, the community composition of the anode and cathode bacterial biofilms was quantified by culture, fatty acid profile (FA), and terminal restriction fragment length polymorphisms (TRFLP). The three soils produced open circuit voltages of between 60 and 120 mV, but only one soil maintained voltage under resistance (60 mV at 10,000 omega). Fatty acid profiling identified differences among anode, cathode, and bulk soil microbial communities, specifically a greater relative abundance of terminally branched saturated FA in the bulk soils and a greater relative abundance of monounsaturated and cyclopropane FA on electrode surfaces. Bacteria cultured from both the anode and cathode biofilms included species of Actinobacteria; however,only the anode biofilms produced species of Firmicutes and Proteobacteria. Analysis of TRFLP profiles putatively identified a diversity of bacteria in the biofilms recovered from both electrode surfaces. The most predominant organisms detected were the alpha- and beta-Proteobacteria, specifically the Rhizobiales, Rhodobacterales, and Burkholderiales.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2012
- Accession Number
- ADA559329
Entities
People
- Charles M. Reynolds
- David B. Ringelberg
- Karen L. Foley
Organizations
- Engineer Research and Development Center