RRC ID 35232
著者 Newton GJ, Mori S, Nakamura R, Hashimoto K, Watanabe K.
タイトル Analyses of current-generating mechanisms of Shewanella loihica PV-4 and Shewanella oneidensis MR-1 in microbial fuel cells.
ジャーナル Appl Environ Microbiol
Abstract Although members of the genus Shewanella have common features (e.g., the presence of decaheme c-type cytochromes [c-cyts]), they are widely variable in genetic and physiological features. The present study compared the current-generating ability of S. loihica PV-4 in microbial fuel cells (MFCs) with that of well-characterized S. oneidensis MR-1 and examined the roles of c-cyts in extracellular electron transfer. We found that strains PV-4 and MR-1 exhibited notable differences in current-generating mechanisms. While the MR-1 MFCs maintained a constant current density over time, the PV-4 MFCs continued to increase in current density and finally surpassed the MR-1 MFCs. Coulombic efficiencies reached 26% in the PV-4 MFC but 16% in the MR-1 MFCs. Although both organisms produced quinone-like compounds, anode exchange experiments showed that anode-attached cells of PV-4 produced sevenfold more current than planktonic cells in the same chamber, while planktonic cells of MR-1 produced twice the current of the anode-attached cells. Examination of the genome sequence indicated that PV-4 has more c-cyt genes in the metal reductase-containing locus than MR-1. Mutational analysis revealed that PV-4 relied predominantly on a homologue of the decaheme c-cyt MtrC in MR-1 for current generation, even though it also possesses two homologues of the decaheme c-cyt OmcA in MR-1. These results suggest that current generation in a PV-4 MFC is in large part accomplished by anode-attached cells, in which the MtrC homologue constitutes the main path of electrons toward the anode.
巻・号 75(24)
ページ 7674-81
公開日 2009-12-1
DOI 10.1128/AEM.01142-09
PII AEM.01142-09
PMID 19837834
PMC PMC2794086
MeSH Bioelectric Energy Sources* Cytochrome c Group / genetics Cytochrome c Group / metabolism Electricity Electron Transport / genetics Oxidation-Reduction Shewanella / classification Shewanella / genetics Shewanella / physiology*
IF 4.016
引用数 96
WOS 分野 BIOTECHNOLOGY & APPLIED MICROBIOLOGY MICROBIOLOGY
リソース情報
原核生物(大腸菌) CV-43(JM109(Lambdapir))