title: Electron acceptor dependence of electron shuttle secretion and extracellular electron transfer by Shewanella oneidensis MR-1.
abstract: Shewanella oneidensis MR-1 is an extensively studied dissimilatory metal-reducing bacterium with a great potential for bioremediation and electricity generation. It secretes flavins as electron shuttles which play an important role in extracellular electron transfer. However, the influence of various environmental factors on the secretion of flavins is largely unknown. Here, the effects of electron acceptors, including fumarate, ferrihydrite, Fe(III)-nitrilotriacetic acid (NTA), nitrate and trimethylamine oxide (TMAO), on the secretion of flavins were investigated. The level of riboflavin and riboflavin-5'-phosphate (FMN) secreted by S. oneidensis MR-1 varied considerably with different electron acceptors. While nitrate and ferrihydrite suppressed the secretion of flavins in relative to fumarate, Fe(III)-NTA and TMAO promoted such a secretion and greatly enhanced ferrihydrite reduction and electricity generation. This work clearly demonstrates that electron acceptors could considerably affect the secretion of flavins and consequent microbial EET. Such impacts of electron acceptors in the environment deserve more attention.
authors.affiliation: Department of Chemistry, University of Science & Technology of China, Hefei 230026, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wu
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Cheng
authors.forename: Bing-Bing
authors.initials: BB
authors.lastname: Li
authors.forename: Wen-Wei
authors.initials: WW
authors.lastname: Li
authors.forename: Dao-Bo
authors.initials: DB
authors.lastname: Li
authors.forename: Han-Qing
authors.initials: HQ
authors.lastname: Yu
mesh_terms: D055664:Electrochemical Techniques; D004566:Electrodes; D004579:Electron Transport / Q000187:drug effects; D004583:Electrons; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism*; D005290:Ferric Compounds / Q000378:metabolism; D005486:Flavin Mononucleotide / Q000378:metabolism*; D008744:Methylamines / Q000494:pharmacology; D010084:Oxidation-Reduction / Q000187:drug effects; D012256:Riboflavin / Q000378:metabolism*; D020592:Shewanella / Q000187:drug effects / Q000378:metabolism*
chemical_list: D005290:Ferric Compounds; D008744:Methylamines; D005486:Flavin Mononucleotide; C092844:ferric oxyhydroxide; C005855:trimethyloxamine; D012256:Riboflavin