Format

Send to

Choose Destination
Appl Environ Microbiol. 2010 Feb;76(3):757-68. doi: 10.1128/AEM.02409-09. Epub 2009 Nov 30.

Archaeal and bacterial communities respond differently to environmental gradients in anoxic sediments of a California hypersaline lake, the Salton Sea.

Author information

1
Department of Earth Science and Marine Science Institute, University of California, Santa Barbara, CA 93106-9630, USA. valentine@geol.ucsb.edu

Abstract

Sulfidic, anoxic sediments of the moderately hypersaline Salton Sea contain gradients in salinity and carbon that potentially structure the sedimentary microbial community. We investigated the abundance, community structure, and diversity of Bacteria and Archaea along these gradients to further distinguish the ecologies of these domains outside their established physiological range. Quantitative PCR was used to enumerate 16S rRNA gene abundances of Bacteria, Archaea, and Crenarchaeota. Community structure and diversity were evaluated by terminal restriction fragment length polymorphism (T-RFLP), quantitative analysis of gene (16S rRNA) frequencies of dominant microorganisms, and cloning and sequencing of 16S rRNA. Archaea were numerically dominant at all depths and exhibited a lesser response to environmental gradients than that of Bacteria. The relative abundance of Crenarchaeota was low (0.4 to 22%) at all depths but increased with decreased carbon content and increased salinity. Salinity structured the bacterial community but exerted no significant control on archaeal community structure, which was weakly correlated with total carbon. Partial sequencing of archaeal 16S rRNA genes retrieved from three sediment depths revealed diverse communities of Euryarchaeota and Crenarchaeota, many of which were affiliated with groups previously described from marine sediments. The abundance of these groups across all depths suggests that many putative marine archaeal groups can tolerate elevated salinity (5.0 to 11.8% [wt/vol]) and persist under the anaerobic conditions present in Salton Sea sediments. The differential response of archaeal and bacterial communities to salinity and carbon patterns is consistent with the hypothesis that adaptations to energy stress and availability distinguish the ecologies of these domains.

PMID:
19948847
PMCID:
PMC2812989
DOI:
10.1128/AEM.02409-09
[Indexed for MEDLINE]
Free PMC Article

Publication type, MeSH terms, Substances, Secondary source ID

Publication type

MeSH terms

Substances

Secondary source ID

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center