Diverse and highly active diazotrophic assemblages inhabit e

Details of Research

TitleDiverse and highly active diazotrophic assemblages inhabit ephemerally wetted soils of the Antarctic Dry ValleysAbstractEolian transport of biomass from ephemerally wetted soils, associated with summer glacial meltwater runoffs and lake edges, to low-productivity areas of the Antarctic Dry Valleys (DV) has been postulated to be an important source of organic matter (fixed nitrogen and fixed carbon) to the entire DV ecosystem. However, descriptions and identification of the microbial members responsible for N2 fixation within these wetted sites are limited. In this study, N2 fixers from wetted soils were identified by direct nifH gene sequencing and their in situ N2 fixation activities documented via acetylene reduction and RNA-based quantitative PCR assays. Shannon-index nifH diversity levels ranged between 1.8 and 2.6 and included the expected cyanobacterial signatures and a large number of phylotypes related to the gamma-, beta-, alpha-, and delta-proteobacteria. N2 fixation rates ranged between approximately 0.5 and 6 nmol N cm-3 h-1 with measurements indicating that approximately 50 percent of this activity was linked with sulfate reduction at some sites. Comparisons with proximal dry soils also suggested that these communities are not ubiquitously distributed, and conditions unrelated to moisture content may define the composition, diversity, or habitat suitability of the microbial communities within wetted soils of the DVs. Copyright 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd.AcknowledgementsWe would like to thank the staff at the United States Antarctic Program, as well as Antarctica New Zealand, and the Foundation for Research in Science and Technology, New Zealand, for logistical support while in the field. This research was supported by National Science Foundation Grants ANT 0739633 (to D.G.C.), ANT 0739640 (to E.J.C.), and ANT 0739648 and 0229836 (to S.C.C.).

Details

1st AuthorNiederberger, T.AuthorNiederberger, T.Sohm, J.Tirindelli, J.Gunderson, T.Capone, D.Carpenter, E.Cary, S.Year2012JournalFEMS Microbiology EcologyVolume82Number2Pages376-390DOI10.1111/j.1574-6941.2012.01390.xURLhttps://www.scopus.com/inward/recor.....0aba41cae477a21a0c81e1891Keywordsrank5

Other

TypeArticleCitationNiederberger, T., Sohm, J., Tirindelli, J., Gunderson, T., Capone, D., Carpenter, E. and Cary, S. (2012) Diverse and highly active diazotrophic assemblages inhabit ephemerally wetted soils of the {Antarctic Dry Valleys}. FEMS Microbiology Ecology, 82(2): 376-390 doi:10.1111/j.1574-6941.2012.01390.x IdentifierNiederberger2012Relevancerank5

Linked To

Author

Cary, S.