title: Isolation and characterization of a novel As(V)-reducing bacterium: implications for arsenic mobilization and the genus Desulfitobacterium.
abstract: Dissimilatory arsenate-reducing bacteria have been implicated in the mobilization of arsenic from arsenic-enriched sediments. An As(V)-reducing bacterium, designated strain GBFH, was isolated from arsenic-contaminated sediments of Lake Coeur d'Alene, Idaho. Strain GBFH couples the oxidation of formate to the reduction of As(V) when formate is supplied as the sole carbon source and electron donor. Additionally, strain GBFH is capable of reducing As(V), Fe(III), Se(VI), Mn(IV) and a variety of oxidized sulfur species. 16S ribosomal DNA sequence comparisons reveal that strain GBFH is closely related to Desulfitobacterium hafniense DCB-2(T) and Desulfitobacterium frappieri PCP-1(T). Comparative physiology demonstrates that D. hafniense and D. frappieri, known for reductively dechlorinating chlorophenols, are also capable of toxic metal or metalloid respiration. DNA-DNA hybridization and comparative physiological studies suggest that D. hafniense, D. frappieri, and strain GBFH should be united into one species. The isolation of an Fe(III)- and As(V)-reducing bacterium from Lake Coeur d'Alene suggests a mechanism for arsenic mobilization in these contaminated sediments while the discovery of metal or metalloid respiration in the genus Desulfitobacterium has implications for environments cocontaminated with arsenious and chlorophenolic compounds.
authors.affiliation: Program in Environmental Science, University of Idaho, Moscow, Idaho 83844, USA.
authors.forename: A
authors.initials: A
authors.lastname: Niggemyer
authors.forename: S
authors.initials: S
authors.lastname: Spring
authors.forename: E
authors.initials: E
authors.lastname: Stackebrandt
authors.forename: R F
authors.initials: RF
authors.lastname: Rosenzweig
mesh_terms: D001149:Arsenates / Q000378:metabolism*; D001151:Arsenic / Q000378:metabolism; D003470:Culture Media; D004275:DNA, Ribosomal / Q000032:analysis; D005561:Formates / Q000378:metabolism; D005618:Fresh Water / Q000382:microbiology*; D016987:Gram-Positive Rods / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D014877:Water Pollution, Chemical
chemical_list: D001149:Arsenates; D003470:Culture Media; D004275:DNA, Ribosomal; D005561:Formates; D012336:RNA, Ribosomal, 16S; C030544:formic acid; D001151:Arsenic; C025657:arsenic acid