title: Desulfohalophilus alkaliarsenatis gen. nov., sp. nov., an extremely halophilic sulfate- and arsenate-respiring bacterium from Searles Lake, California.
abstract: A haloalkaliphilic sulfate-respiring bacterium, strain SLSR-1, was isolated from a lactate-fed stable enrichment culture originally obtained from the extreme environment of Searles Lake, California. The isolate proved capable of growth via sulfate-reduction over a broad range of salinities (125-330 g/L), although growth was slowest at salt-saturation. Strain SLSR-1 was also capable of growth via dissimilatory arsenate-reduction and displayed an even broader range of salinity tolerance (50-330 g/L) when grown under these conditions. Strain SLSR-1 could also grow via dissimilatory nitrate reduction to ammonia. Growth experiments in the presence of high borate concentrations indicated a greater sensitivity of sulfate-reduction than arsenate-respiration to this naturally abundant anion in Searles Lake. Strain SLSR-1 contained genes involved in both sulfate-reduction (dsrAB) and arsenate respiration (arrA). Amplicons of 16S rRNA gene sequences obtained from DNA extracted from Searles Lake sediment revealed the presence of close relatives of strain SLSR-1 as part of the flora of this ecosystem despite the fact that sulfate-reduction activity could not be detected in situ. We conclude that strain SLSR-1 can only achieve growth via arsenate-reduction under the current chemical conditions prevalent at Searles Lake. Strain SLSR-1 is a deltaproteobacterium in the family Desulfohalobiacea of anaerobic, haloalkaliphilic bacteria, for which we propose the name Desulfohalophilus alkaliarsenatis gen. nov., sp. nov.
authors: US Geological Survey, Menlo Park, CA 94025, USA.
authors: Jodi Switzer
authors: JS
authors: Blum
authors: Thomas R
authors: TR
authors: Kulp
authors: Sukkyun
authors: S
authors: Han
authors: Brian
authors: B
authors: Lanoil
authors: Chad W
authors: CW
authors: Saltikov
authors: John F
authors: JF
authors: Stolz
authors: Laurence G
authors: LG
authors: Miller
authors: Ronald S
authors: RS
authors: Oremland
mesh_terms: D001149:Arsenates / Q000378:metabolism*; D002140:California; D020564:Deltaproteobacteria / Q000235:genetics / Q000378:metabolism; D017753:Ecosystem; D060106:Lakes / Q000382:microbiology; D010084:Oxidation-Reduction; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D054712:Salinity; D013431:Sulfates / Q000378:metabolism*; D014871:Water Microbiology
chemical_list: D001149:Arsenates; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D013431:Sulfates; C025657:arsenic acid