title: Molecular and Phenetic Characterization of the Bacterial Assemblage of Hot Lake, WA, an Environment with High Concentrations of Magnesium Sulfate, and Its Relevance to Mars.
abstract: Hot Lake (Oroville, WA) is an athalassohaline epsomite lake that can have precipitating concentrations of MgSO4salts, mainly epsomite. Little biotic study has been done on epsomite lakes and it was unclear whether microbes isolated from epsomite lakes and their margins would fall within recognized halotolerant genera, common soil genera, or novel phyla. Our initial study cultivated and characterized epsotolerant bacteria from the lake and its margins. Approximately 100 aerobic heterotrophic microbial isolates were obtained by repetitive streak-plating in high-salt media including either 10% NaCl or 2 M MgSO4. The collected isolates were all bacteria, nearly evenly divided between Gram-positive and Gram-negative clades, the most abundant genera beingHalomonas,Idiomarina, Marinobacter, Marinococcus,Nesterenkonia, Nocardiopsis,andPlanococcus. Bacillus, Corynebacterium, Exiguobacterium, Kocuria, andStaphylococcusalso were cultured. This initial study included culture-independent community analysis of direct DNA extracts of lake margin soil using PCR-based clone libraries and 16S rRNA gene phylogeny. Clones assigned Gram-positive bacterial clades (70% of total clones) were dominated by sequences related to uncultured actinobacteria. There were abundantDeltaproteobacteriaclones related to bacterial sulfur metabolisms and clones ofLegionellaandCoxiella. These epsomite lake microbial communities seem to be divided between bacteria primarily associated with hyperhaline environments rich in NaCl and salinotolerant relatives of common soil organisms. Archaea appear to be in low abundance and none were isolated, despite near-saturated salinities. Growth of microbes at very high concentrations of magnesium and other sulfates has relevance to planetary protection and life-detection missions to Mars, where scant liquid water may form as deliquescent brines and appear as eutectic liquids.
authors.affiliation: Department of Biological Sciences, Wichita State University, Wichita, KS.
authors.forename: Brian R
authors.initials: BR
authors.lastname: Kilmer
authors.affiliation: Department of Biological Sciences, Wichita State University, Wichita, KS.
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Eberl
authors.affiliation: USDI-Bureau of Land Management, Wenatchee, WA.
authors.forename: Brent
authors.initials: B
authors.lastname: Cunderla
authors.affiliation: Planetary Protection Group, Jet Propulsion Laboratory, NASA, Pasadena, CA.
authors.forename: Fei
authors.initials: F
authors.lastname: Chen
authors.affiliation: Space Science Institute, Boulder, CO.
authors.forename: Benton C
authors.initials: BC
authors.lastname: Clark
authors.affiliation: Department of Biological Sciences, Wichita State University, Wichita, KS.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Schneegurt
references.citation: Int J Syst Evol Microbiol. 2003 Jan;53(Pt 1):165-172
references.pmid: 12656168
references.citation: Microb Ecol. 2009 Oct;58(3):519-28
references.pmid: 19306116
references.citation: Appl Environ Microbiol. 2010 May;76(9):2837-45
references.pmid: 20228115
references.citation: J Microbiol Methods. 2001 May;45(1):7-20
references.pmid: 11295193
references.citation: Astrobiology. 2003 Winter;3(4):785-811
references.pmid: 14987483
references.citation: Nucleic Acids Res. 1989 Oct 11;17(19):7843-53
references.pmid: 2798131
references.citation: J Basic Microbiol. 2012 Feb;52(1):16-26
references.pmid: 21953014
references.citation: Bioinformatics. 2004 Sep 22;20(14):2317-9
references.pmid: 15073015
references.citation: Environ Microbiol. 2003 Oct;5(10):977-85
references.pmid: 14510851
references.citation: Adv Space Res. 1996;18(1-2):311-6
references.pmid: 11538978
references.citation: Appl Environ Microbiol. 2011 Aug;77(15):5438-44
references.pmid: 21652744
references.citation: Microb Ecol. 2004 Feb;47(2):159-63
references.pmid: 14502417
references.citation: Nature. 2011 Jun 22;474(7353):620-2
references.pmid: 21697830
references.citation: Appl Environ Microbiol. 2009 Dec;75(23):7537-41
references.pmid: 19801464
references.citation: Microb Ecol. 2007 Nov;54(4):598-617
references.pmid: 17450395
references.citation: Res Microbiol. 2006 Dec;157(10):928-37
references.pmid: 17070674
references.citation: Astrobiology. 2012 Feb;12(2):98-106
references.pmid: 22248384
references.citation: J Microbiol Methods. 2003 Mar;52(3):367-77
references.pmid: 12531506
references.citation: Astrobiology. 2005 Jun;5(3):391-405
references.pmid: 15941382
references.citation: J Bacteriol. 1961 Sep;82:436-41
references.pmid: 13766927
references.citation: Appl Environ Microbiol. 2009 Oct;75(20):6559-67
references.pmid: 19700540
references.citation: Arch Microbiol. 1975 Aug 28;104(3):207-14
references.pmid: 1190944
references.citation: ISME J. 2008 Jan;2(1):115-9
references.pmid: 18180750
references.citation: Appl Environ Microbiol. 2009 Jun;75(11):3484-91
references.pmid: 19363082
references.citation: Appl Environ Microbiol. 1977 Feb;33(2):379-84
references.pmid: 848957
references.citation: Environ Biol Med. 1971 May;1(1):27-36
references.pmid: 4951037
references.citation: J Bacteriol. 1962 Mar;83:483-9
references.pmid: 14470034
references.citation: Appl Microbiol. 1975 Oct;30(4):546-50
references.pmid: 1190759
references.citation: Can J Microbiol. 1983 Oct;29(10):1424-9
references.pmid: 6661704
references.citation: Syst Appl Microbiol. 2001 Jul;24(2):311-20
references.pmid: 11518337
references.citation: Science. 2011 Aug 5;333(6043):740-3
references.pmid: 21817049
references.citation: Extremophiles. 2009 Jul;13(4):609-21
references.pmid: 19387766
references.citation: Nucleic Acids Res. 1994 Nov 11;22(22):4673-80
references.pmid: 7984417
references.citation: Astrobiology. 2013 Apr;13(4):334-53
references.pmid: 23560417
references.citation: Saline Syst. 2005 Nov 18;1:10
references.pmid: 16297237
references.citation: Science. 2008 May 30;320(5880):1204-7
references.pmid: 18511686
references.citation: J Mol Biol. 1990 Oct 5;215(3):403-10
references.pmid: 2231712
references.citation: Appl Microbiol. 1968 Mar;16(3):480-6
references.pmid: 5649862