title: Thermal and geochemical influences on microbial biogeography in the hydrothermal sediments of Guaymas Basin, Gulf of California.
abstract: Extreme thermal gradients and compressed metabolic zones limit the depth range of microbial colonization in hydrothermally active sediments at Guaymas Basin. We investigated the physicochemical characteristics of this ecosystem and their influence on microbial community structure. Temperature-related trends of δ(13)C values of methane and dissolved inorganic carbon from 36 sediment cores suggest in situ thermal limits for microbial anaerobic methane oxidation and organic carbon re-mineralization near 80°C and 100°C respectively. Temperature logging probes deposited in hydrothermal sediments for 8 days demonstrate substantial thermal fluctuations of up to 25°C. Putative anaerobic methanotroph (ANME) populations dominate the archaeal community, transitioning from ANME-1 archaea in warm surficial sediments towards ANME-1 Guaymas archaea as temperatures increase downcore. Since ANME archaea performing anaerobic oxidation of methane double on longer time scales (months) compared with relatively rapid in situ temperature fluctuations (hours to days), we conclude that ANME archaea possess a high tolerance for short-term shifts in the thermal regime.
authors.affiliation: Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3300, USA.|Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, 59717, USA.|Center for Biofilm Engineering, Montana State University, Bozeman, MT, 59717, USA.
authors.forename: Luke
authors.initials: L
authors.lastname: McKay
authors.affiliation: Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3300, USA.|Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands.
authors.forename: Vincent W
authors.initials: VW
authors.lastname: Klokman
authors.affiliation: Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3300, USA.
authors.forename: Howard P
authors.initials: HP
authors.lastname: Mendlovitz
authors.affiliation: Department of Earth Sciences, University of Southern California, Los Angeles, CA, 90089, USA.
authors.forename: Douglas E
authors.initials: DE
authors.lastname: LaRowe
authors.affiliation: Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3300, USA.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Hoer
authors.affiliation: Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3300, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Albert
authors.affiliation: Department of Earth Sciences, University of Southern California, Los Angeles, CA, 90089, USA.|Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA.
authors.forename: Jan P
authors.initials: JP
authors.lastname: Amend
authors.affiliation: Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-3300, USA.
authors.forename: Andreas
authors.initials: A
authors.lastname: Teske
mesh_terms: D000693:Anaerobiosis; D001105:Archaea / Q000145:classification* / Q000235:genetics; D058448:Biota; D002140:California; D002244:Carbon / Q000032:analysis; D019015:Geologic Sediments / Q000737:chemistry* / Q000382:microbiology*; D060086:Hydrothermal Vents / Q000382:microbiology*; D008697:Methane / Q000032:analysis; D058974:Phylogeography; D013696:Temperature
chemical_list: D002244:Carbon; D008697:Methane