title: Selenite reduction by Shewanella oneidensis MR-1 is mediated by fumarate reductase in periplasm.
abstract: In situ reduction of selenite to elemental selenium (Se(0)), by microorganisms in sediments and soils is an important process and greatly affects the environmental distribution and the biological effects of selenium. However, the mechanism behind such a biological process remains unrevealed yet. Here we use Shewanella oneidensis MR-1, a widely-distributed dissimilatory metal-reducing bacterium with a powerful and diverse respiration capability, to evaluate the involvement of anaerobic respiration system in the microbial selenite reduction. With mutants analysis, we identify fumarate reductase FccA as the terminal reductase of selenite in periplasm. Moreover, we find that such a reduction is dependent on central respiration c-type cytochrome CymA. In contrast, nitrate reductase, nitrite reductase, and the Mtr electron transfer pathway do not work as selenite reductases. These findings reveal a previously unrecognized role of anaerobic respiration reductases of S. oneidensis MR-1 in selenite reduction and geochemical cycles of selenium in sediments and soils.
authors.affiliation: 1] School of Earth and Space Sciences [2] Department of Chemistry [3].
authors.forename: Dao-Bo
authors.initials: DB
authors.lastname: Li
authors.affiliation: 1] Department of Chemistry [2].
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Cheng
authors.affiliation: Department of Chemistry.
authors.forename: Chao
authors.initials: C
authors.lastname: Wu
authors.affiliation: Department of Chemistry.
authors.forename: Wen-Wei
authors.initials: WW
authors.lastname: Li
authors.affiliation: Department of Chemistry.
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.affiliation: School of Life Sciences, University of Science & Technology of China, Hefei, 230026, China.
authors.forename: Zong-Chuang
authors.initials: ZC
authors.lastname: Yang
authors.affiliation: Department of Chemistry.
authors.forename: Zhong-Hua
authors.initials: ZH
authors.lastname: Tong
authors.affiliation: Department of Chemistry.
authors.forename: Han-Qing
authors.initials: HQ
authors.lastname: Yu
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D004579:Electron Transport; D005110:Extracellular Space / Q000378:metabolism; D053858:Metabolic Networks and Pathways; D009154:Mutation; D019897:Periplasm / Q000378:metabolism*; D020887:Selenious Acid / Q000378:metabolism*; D020592:Shewanella / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013385:Succinate Dehydrogenase / Q000378:metabolism*
chemical_list: D013385:Succinate Dehydrogenase; D020887:Selenious Acid