title: Identification of anaerobic arsenite-oxidizing and  arsenate-reducing bacteria associated with an alkaline  saline lake in Khovsgol, Mongolia.
abstract: Microbial arsenic transformation pathways associated with a saline lake located in northern Mongolia were examined using molecular biological and culturing approaches. Bacterial 16S rRNA gene sequences recovered from saline lake sediments and soils were affiliated with haloalkaliphiles, including Bacillus and Halomonas spp. Diverse sequences of arsenate respiratory reductase (arrA) and a new group of arsenite oxidase (arxA) genes were also identified. Pure cultures of arsenate-reducing Nitrincola strain and anaerobic arsenite-oxidizing Halomonas strain were isolated. The chemoorganotrophic Halomonas strain contains arxA gene similar to that of a chemoautotrophic arsenite-oxidizing Alkalilimnicola ehrlichii strain MLHE-1. These results revealed the diversity of arsenic transformation pathways associated with a geographically distinct saline system and the potential contribution of arx-dependent arsenite oxidation by heterotrophic bacteria.
authors: Natsuko
authors: N
authors: Hamamura
authors: Takaaki
authors: T
authors: Itai
authors: Yitai
authors: Y
authors: Liu
authors: Anna-Louise
authors: AL
authors: Reysenbach
authors: Narantuya
authors: N
authors: Damdinsuren
authors: William P
authors: WP
authors: Inskeep
mesh_terms: D001149:Arsenates / Q000378:metabolism*; D018053:Arsenites / Q000378:metabolism*; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D044822:Biodiversity; D006863:Hydrogen-Ion Concentration; D060106:Lakes / Q000737:chemistry / Q000382:microbiology*; D008969:Molecular Sequence Data; D008986:Mongolia; D010084:Oxidation-Reduction; D010802:Phylogeny
chemical_list: D001149:Arsenates; D018053:Arsenites; C015001:arsenite; C025657:arsenic acid