title: Shewanella sp. O23S as a Driving Agent of a System Utilizing Dissimilatory Arsenate-Reducing Bacteria Responsible for Self-Cleaning of Water Contaminated with Arsenic.
abstract: The purpose of this study was a detailed characterization of Shewanella sp. O23S, a strain involved in arsenic transformation in ancient gold mine waters contaminated with arsenic and other heavy metals. Physiological analysis of Shewanella sp. O23S showed that it is a facultative anaerobe, capable of growth using arsenate, thiosulfate, nitrate, iron or manganite as a terminal electron acceptor, and lactate or citrate as an electron donor. The strain can grow under anaerobic conditions and utilize arsenate in the respiratory process in a broad range of temperatures (10-37 °C), pH (4-8), salinity (0%-2%), and the presence of heavy metals (Cd, Co, Cr, Cu, Mn, Mo, Se, V and Zn). Under reductive conditions this strain can simultaneously use arsenate and thiosulfate as electron acceptors and produce yellow arsenic (III) sulfide (As2S3) precipitate. Simulation of As-removal from water containing arsenate (2.5 mM) and thiosulfate (5 mM) showed 82.5% efficiency after 21 days of incubation at room temperature. Based on the obtained results, we have proposed a model of a microbially mediated system for self-cleaning of mine waters contaminated with arsenic, in which Shewanella sp. O23S is the main driving agent.
authors.affiliation: Laboratory of Environmental Pollution Analysis, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland. ldrewniak@biol.uw.edu.pl.
authors.forename: Lukasz
authors.initials: L
authors.lastname: Drewniak
authors.affiliation: Laboratory of Environmental Pollution Analysis, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland. r.stasiuk@biol.uw.edu.pl.
authors.forename: Robert
authors.initials: R
authors.lastname: Stasiuk
authors.affiliation: Laboratory of Environmental Pollution Analysis, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland. w.uhrynowski@biol.uw.edu.pl.
authors.forename: Witold
authors.initials: W
authors.lastname: Uhrynowski
authors.affiliation: Laboratory of Environmental Pollution Analysis, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland. asklodowska@biol.uw.edu.pl.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Sklodowska
mesh_terms: D001149:Arsenates / Q000378:metabolism* / Q000633:toxicity; D019069:Cell Respiration; D008658:Inactivation, Metabolic; D010084:Oxidation-Reduction; D020592:Shewanella / Q000187:drug effects / Q000378:metabolism*; D018508:Water Purification / Q000379:methods*
chemical_list: D001149:Arsenates
keywords: Shewanella spp.; arsenic removal; dissimilatory arsenate reduction