Microbial community structure of hydrothermal deposits from geochemically different vent fields along the Mid-Atlantic Ridge

Environmental Microbiology
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Abstract

To evaluate the effects of local fluid geochemistry on microbial communities associated with active hydrothermal vent deposits, we examined the archaeal and bacterial communities of 12 samples collected from two very different vent fields: the basalt-hosted Lucky Strike (37°17'N, 32°16.3'W, depth 1600-1750m) and the ultramafic-hosted Rainbow (36°13'N, 33°54.1'W, depth 2270-2330m) vent fields along the Mid-Atlantic Ridge (MAR). Using multiplexed barcoded pyrosequencing of the variable region 4 (V4) of the 16S rRNA genes, we show statistically significant differences between the archaeal and bacterial communities associated with the different vent fields. Quantitative polymerase chain reaction (qPCR) assays of the functional gene diagnostic for methanogenesis (mcrA), as well as geochemical modelling to predict pore fluid chemistries within the deposits, support the pyrosequencing observations. Collectively, these results show that the less reduced, hydrogen-poor fluids at Lucky Strike limit colonization by strict anaerobes such as methanogens, and allow for hyperthermophilic microaerophiles, like Aeropyrum. In contrast, the hydrogen-rich reducing vent fluids at the ultramafic-influenced Rainbow vent field support the prevalence of methanogens and other hydrogen-oxidizing thermophiles at this site. These results demonstrate that biogeographical patterns of hydrothermal vent microorganisms are shaped in part by large scale geological and geochemical processes.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Microbial community structure of hydrothermal deposits from geochemically different vent fields along the Mid-Atlantic Ridge
Series title Environmental Microbiology
DOI 10.1111/j.1462-2920.2011.02463.x
Volume 13
Issue 8
Year Published 2011
Language English
Publisher Wiley
Publisher location Hoboken, NJ
Contributing office(s) Branch of Regional Research-Eastern Region
Description 14 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Environmental Microbiology
First page 2158
Last page 2171