Influence of anode pretreatment on its microbial colonization

• Published in: Journal of applied microbiology 2007, Vol.102 (1), p.177-183
• Main Authors: Liu, J.L, Lowy, D.A, Baumann, R.G, Tender, L.M
• Format: Article
• Language: English
• Subjects: 16S rRNA; Alphaproteobacteria - isolation & purification; anode pretreatment; Biodiversity; Bioelectric Energy Sources - microbiology; biofilm; Biofilms; biofuel cell; Biological and medical sciences; Deltaproteobacteria - isolation & purification; Deltaproteobacteria - metabolism; Electrochemistry; Electrodes; Fundamental and applied biological sciences. Psychology; Gammaproteobacteria - isolation & purification; Gammaproteobacteria - metabolism; Geologic Sediments - microbiology; marine sediment; microbial colonization; Microbiology; Oxidation-Reduction; phylotypes; Proteobacteria - isolation & purification; Proteobacteria - metabolism; RNA, Bacterial; RNA, Ribosomal, 16S; Seawater - microbiology; Sulfates - metabolism; Sulfur - metabolism; Water Microbiology
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/j.1365-2672.2006.03051.x

To assess the influence of chemical treatment of the anode of a marine sediment biofuel cell (MSBFC) on the microbial diversity of the anode biofilm. A MSBFC was equipped with two graphite plate anodes, one pretreated by electrochemical oxidation in sulfuric acid and the other untreated. After 6 weeks of operation, 16S rRNA clone libraries were constructed from each anode biofilm. The pretreated anode exhibited a fourfold depletion in γ-proteobacteria, a fourfold enrichment in δ-proteobacteria, a sixfold increase in sulfate reducers, a fivefold enrichment in unclassified micro-organisms, and 6% of the colonies were sulfur oxidizers while none were detected on the untreated anode. Anode pretreatment significantly affects the anode-colonized microbial communities of MSBFCs. The MSBFC is one of a new class of microbial fuel cells in which the anode is spontaneously colonized by a subset of micro-organisms indigenous to a complex anaerobic mixture (such as sewage and food processing effluents). These micro-organisms utilize the anode as an oxidant, catalysing power generation by oxidizing fuel in the mixture and reducing the anode. This study reveals that pretreatment of the anode can greatly affect the composition of the microbial colony of such fuel cells.