Methane and hydrogen in East Pacific Rise hydrothermal fluids

Welhan, J. A.; Craig, H.

doi:10.1029/gl006i011p00829

Cited by 228 publications

(93 citation statements)

References 12 publications

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“…H 2 concentrations of up to 3 mM measured in GB endmember hydrothermal fluids are the result of the reaction of seawater with mantle-derived basalt in the oceanic crust at high temperature and pressure (34)(35)(36). Unfortunately, to our knowledge, no direct measurements of H 2 concentration have been made on GB plumes.…”

Section: Thermodynamic Model For Estimation Of Plume Chemistry Andmentioning

confidence: 98%

Evidence for hydrogen oxidation and metabolic plasticity in widespread deep-sea sulfur-oxidizing bacteria

Anantharaman¹,

Breier

Sheik³

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

174

224

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Hydrothermal vents are a well-known source of energy that powers chemosynthesis in the deep sea. Recent work suggests that microbial chemosynthesis is also surprisingly pervasive throughout the dark oceans, serving as a significant CO 2 sink even at sites far removed from vents. Ammonia and sulfur have been identified as potential electron donors for this chemosynthesis, but they do not fully account for measured rates of dark primary production in the pelagic water column. Here we use metagenomic and metatranscriptomic analyses to show that deep-sea populations of the SUP05 group of uncultured sulfur-oxidizing Gammaproteobacteria, which are abundant in widespread and diverse marine environments, contain and highly express genes encoding group 1 Ni, Fe hydrogenase enzymes for H 2 oxidation. Reconstruction of near-complete genomes of two cooccurring SUP05 populations in hydrothermal plumes and deep waters of the Gulf of California enabled detailed population-specific metatranscriptomic analyses, revealing dynamic patterns of gene content and transcript abundance. SUP05 transcripts for genes involved in H 2 and sulfur oxidation are most abundant in hydrothermal plumes where these electron donors are enriched. In contrast, a second hydrogenase has more abundant transcripts in background deep-sea samples. Coupled with results from a bioenergetic model that suggest that H 2 oxidation can contribute significantly to the SUP05 energy budget, these findings reveal the potential importance of H 2 as a key energy source in the deep ocean. This study also highlights the genomic plasticity of SUP05, which enables this widely distributed group to optimize its energy metabolism (electron donor and acceptor) to local geochemical conditions. Guaymas | oxygen minimum zone D eep-sea hydrothermal vent ecosystems depend on microorganisms that use reduced chemicals such as sulfur, methane, ammonium, and H 2 as electron donors for chemosynthesis (1-5). Recent work suggests that microbial chemosynthesis is also far more prevalent in the broader deep oceans than previously recognized, extending throughout the water column of the dark open ocean, where it serves as a significant source of organic carbon (6, 7). The fuels for this pelagic primary production remain unknown, but recent studies show that ammonium (3) and sulfur (8, 9) are potential electron donors in the water column. H 2 , long known as an energy source for free-living bacteria in seafloor hydrothermal systems, was also recently identified as an electron donor in hydrothermal vent animal symbioses (4). Although microbial communities at seafloor hydrothermal vent sites have attracted much attention, hydrothermal vent plumes remain poorly characterized despite their importance as habitats for free-living chemolithoautotrophs (10). These plume microorganisms mediate the hydrothermal transfer of elements from the lithosphere to the oceans (11, 12) and contribute significantly to organic carbon in the deep oceans via carbon fixation (1, 13-15).We investigated hydrothermal vent ...

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Section: Thermodynamic Model For Estimation Of Plume Chemistry Andmentioning

confidence: 98%

Evidence for hydrogen oxidation and metabolic plasticity in widespread deep-sea sulfur-oxidizing bacteria

Anantharaman¹,

Breier

Sheik³

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

174

224

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“…Endmember gas concentrations and isotope compositions from high-temperature black smoker vents (Bio9, TWP) and proximal low-temperature diffuse flow vents (Bio9R, Y) from the BIOGEOTRANSECT study area near 9°50'N along the EPR are presented in Table 2 LILLEY et al, 1983;MERLIVAT et al, 1987;WELHAN and CRAIG, 1979;WELHAN and CRAIG, 1983), the MidAtlantic Ridge (MAR) at MARK, TAG and Broken Spur (CHARLOU et al, 1996;JAMES et al, 1995;JEAN-BAPTISTE et al, 1991), and the Juan de Fuca Ridge at South Cleft and Axial Volcano (BUTTERFIELD et al, 2004;EVANS et al, 1988).…”

Section: Endmember Gas Concentrationsmentioning

confidence: 99%

Stable isotopic evidence in support of active microbial methane cycling in low-temperature diffuse flow vents at 9°50′N East Pacific Rise

Proskurowski

Lilley

Olson

2008

Geochimica et Cosmochimica Acta

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“…Such a definition is necessary to assess the impact of methane production on the Archean atmosphere prior to the establishment of biological methanogenic pathways. In presentday Earth, there are three main sources of abiotic methane: water-rock interactions at mid-ocean ridges (0.1 -9 Mt y À1 ) [Welhan and Craig, 1979;Sorokhtin et al, 2001;Kasting and Catling, 2003]; volcanic activity (0.34-6.2 Mt y À1 ) [Cadle, 1980;Kvenvolden and Rogers, 2005]; and geothermal systems (0.9 -6.3 Mt y…”

Section: Introductionmentioning

confidence: 99%

Implications of present‐day abiogenic methane fluxes for the early Archean atmosphere

Emmanuel

Ague

2007

Geophysical Research Letters

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[1] During Earth's early history, greenhouse warming by atmospheric methane helped to maintain elevated surface temperatures. Here, we estimate the present-day abiogenic CH 4 flux generated by mineral alteration (serpentinization) at midocean ridges, volcanic emissions, and geothermal sources; in addition, we assess the impact that abiogenic methane may have had on greenhouse warming during the early prebiotic Archean. Based on estimates of the rate of seafloor spreading and the degree of serpentinization within the oceanic crust, the flux of methane generated by serpentinized lithosphere is calculated to be $1.35 Mt CH 4 y À1

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Methane and hydrogen in East Pacific Rise hydrothermal fluids

Cited by 228 publications

References 12 publications

Evidence for hydrogen oxidation and metabolic plasticity in widespread deep-sea sulfur-oxidizing bacteria

Evidence for hydrogen oxidation and metabolic plasticity in widespread deep-sea sulfur-oxidizing bacteria

Stable isotopic evidence in support of active microbial methane cycling in low-temperature diffuse flow vents at 9°50′N East Pacific Rise

Implications of present‐day abiogenic methane fluxes for the early Archean atmosphere

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