@article {ISI:000345702700014,
	title = {{Intracellular Oceanospirillales inhabit the gills of the hydrothermal vent snail Alviniconcha with chemosynthetic, gamma-Proteobacterial symbionts}},
	journal = {ENVIRONMENTAL MICROBIOLOGY REPORTS},
	volume = {6},
	number = {6},
	year = {2014},
	month = {dec},
	pages = {656{\textendash}664},
	type = {Article},
	abstract = {Associations between bacteria from the -Proteobacterial order Oceanospirillales and marine invertebrates are quite common. Members of the Oceanospirillales exhibit a diversity of interactions with their various hosts, ranging from the catabolism of complex compounds that benefit host growth to attacking and bursting host nuclei. Here, we describe the association between a novel Oceanospirillales phylotype and the hydrothermal vent snail Alviniconcha. Alviniconcha typically harbour chemoautotrophic - or epsilon-Proteobacterial symbionts inside their gill cells. Via fluorescence in situ hybridization and transmission electron microscopy, we observed an Oceanospirillales phylotype (named AOP for AlviniconchaOceanospirillales phylotype{\textquoteright}) in membrane-bound vacuoles that were separate from the known - or epsilon-Proteobacterial symbionts. Using quantitative polymerase chain reaction, we surveyed 181 Alviniconcha hosting -Proteobacterial symbionts and 102 hosting epsilon-Proteobacterial symbionts, and found that the population size of AOP was always minor relative to the canonical symbionts (median 0.53{\%} of the total quantified 16S rRNA genes). Additionally, we detected AOP more frequently in Alviniconcha hosting -Proteobacterial symbionts than in those hosting epsilon-Proteobacterial symbionts (96{\%} and 5{\%} of individuals respectively). The high incidence of AOP in -Proteobacteria hosting Alviniconcha implies that it could play a significant ecological role either as a host parasite or as an additional symbiont with unknown physiological capacities.},
	keywords = {ROV Jason (Remotely Operated Vehicle)},
	issn = {1758-2229},
	doi = {10.1111/1758-2229.12183},
	author = {Beinart, R A and Nyholm, S V and Dubilier, N and Girguis, P R}
}
@article {ISI:000322119600009,
	title = {{Metatranscriptomics reveal differences in in situ energy and nitrogen metabolism among hydrothermal vent snail symbionts}},
	journal = {ISME JOURNAL},
	volume = {7},
	number = {8},
	year = {2013},
	month = {aug},
	pages = {1556{\textendash}1567},
	type = {Article},
	abstract = {Despite the ubiquity of chemoautotrophic symbioses at hydrothermal vents, our understanding of the influence of environmental chemistry on symbiont metabolism is limited. Transcriptomic analyses are useful for linking physiological poise to environmental conditions, but recovering samples from the deep sea is challenging, as the long recovery times can change expression profiles before preservation. Here, we present a novel, in situ RNA sampling and preservation device, which we used to compare the symbiont metatranscriptomes associated with Alviniconcha, a genus of vent snail, in which specific host-symbiont combinations are predictably distributed across a regional geochemical gradient. Metatranscriptomes of these symbionts reveal key differences in energy and nitrogen metabolism relating to both environmental chemistry (that is, the relative expression of genes) and symbiont phylogeny (that is, the specific pathways employed). Unexpectedly, dramatic differences in expression of transposases and flagellar genes suggest that different symbiont types may also have distinct life histories. These data further our understanding of these symbionts{\textquoteright} metabolic capabilities and their expression in situ, and suggest an important role for symbionts in mediating their hosts{\textquoteright} interaction with regional-scale differences in geochemistry.},
	keywords = {ROV Jason (Remotely Operated Vehicle)},
	issn = {1751-7362},
	doi = {10.1038/ismej.2013.45},
	author = {Sanders, J G and Beinart, R A and Stewart, F J and Delong, E F and Girguis, P R}
}
@article {Beinart2012,
	title = {{Evidence for the role of endosymbionts in regional-scale habitat partitioning by hydrothermal vent symbioses}},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {109},
	number = {47},
	year = {2012},
	month = {nov},
	pages = {E3241{\textendash}E3250},
	abstract = {Deep-sea hydrothermal vents are populated by dense communities of animals that form symbiotic associations with chemolithoautotrophic bacteria. To date, our understanding of which factors govern the distribution of host/symbiont associations (or holobionts) in nature is limited, although host physiology often is invoked. In general, the role that symbionts play in habitat utilization by vent holobionts has not been thoroughly addressed. Here we present evidence for symbiont-influenced, regional-scale niche partitioning among symbiotic gastropods (genus Alviniconcha) in the Lau Basin. We extensively surveyed Alviniconcha holobionts from four vent fields using quantitative molecular approaches, coupled to characterization of high-temperature and diffuse vent-fluid composition using gastight samplers and in situ electrochemical analyses, respectively. Phylogenetic analyses exposed cryptic host and symbiont diversity, revealing three distinct host types and three different symbiont phylotypes (one $ε$-proteobacteria and two $\gamma$-proteobacteria) that formed specific associations with one another. Strikingly, we observed that holobionts with $ε$-proteobacterial symbionts were dominant at the northern fields, whereas holobionts with $\gamma$-proteobacterial symbionts were dominant in the southern fields. This pattern of distribution corresponds to differences in the vent geochemistry that result from deep subsurface geological and geothermal processes. We posit that the symbionts, likely through differences in chemolithoautotrophic metabolism, influence niche utilization among these holobionts. The data presented here represent evidence linking symbiont type to habitat partitioning among the chemosynthetic symbioses at hydrothermal vents and illustrate the coupling between subsurface geothermal processes and niche availability.},
	keywords = {ROV Jason (Remotely Operated Vehicle)},
	issn = {0027-8424},
	doi = {10.1073/pnas.1202690109},
	author = {Beinart, R A and Sanders, J G and Faure, B and Sylva, S P and Lee, R W and Becker, E L and Gartman, A and Luther, G W and Seewald, J S and Fisher, C R and Girguis, P R}
}
@article {Tivey2012,
	title = {{Links from Mantle to Microbe at the Lau Integrated Study Site:Insights from a Back-Arc Spreading Center}},
	journal = {Oceanography},
	volume = {25},
	number = {1},
	year = {2012},
	month = {mar},
	pages = {62{\textendash}77},
	abstract = {The Lau Integrated Study Site (ISS) has provided unique opportunities for study of ridge processes because of its back-arc setting in the southwestern Pacific. Its location allows study of a biogeographical province distinct from those of eastern Pacific and mid-Atlantic ridges, and crustal compositions along the ridge lie outside the range of mid-ocean ridge crustal compositions. The Lau ISS is located above a subduction zone, at an oblique angle. The underlying mantle receives water and other elements derived from the downgoing lithospheric slab, with an increase in slab influence from north to south. Water lowers the mantle melting temperature and leads to greater melt production where the water flux is greater, and to distinctive regional-scale gradients along the ridge. There are deeper faulted axial valleys with basaltic volcanism in the north and inflated axial highs with andesites in the south. Differences in igneous rock composition and release of magmatic volatiles affect compositions of vent fluids and deposits. Differences in vent fluid compositions and small-scale diffuse-flow regimes correlate with regional-scale patterns in microbial and megafaunal distributions. The interdisciplinary research effort at the Lau ISS has successfully identified linkages between subsurface processes and deep-sea biological communities, from mantle to microbe to megafauna.},
	keywords = {AUV ABE (Autonomous Benthic Explorer), ROV Jason (Remotely Operated Vehicle)},
	issn = {1042-8275},
	doi = {10.5670/oceanog.2012.04},
	author = {Tivey, M K and Becker, E and Beinart, R and Fisher, C R and Girguis, P R and Langmuir, C H and Michael, P J and Reysenbach, A -L}
}
@article {Gartman2011,
	title = {{Sulfide Oxidation across Diffuse Flow Zones of Hydrothermal Vents}},
	journal = {Aquatic Geochemistry},
	volume = {17},
	number = {4-5},
	year = {2011},
	month = {sep},
	pages = {583{\textendash}601},
	publisher = {SPRINGER},
	address = {NEW YORK; 233 SPRING ST, NEW YORK, NY 10013 USA},
	abstract = {The sulfide (H(2)S/HS(-)) that is emitted from hydrothermal vents begins to oxidize abiotically with oxygen upon contact with ambient bottom water, but the reaction kinetics are slow. Here, using in situ voltammetry, we report detection of the intermediate sulfur oxidation products polysulfides [S(x)(2-)] and thiosulfate [S(2)O(3)(2-)], along with contextual data on sulfide, oxygen, and temperature. At Lau Basin in 2006, thiosulfate was identified in less than one percent of approximately 10,500 scans and no polysulfides were detected. Only five percent of 11,000 voltammetric scans taken at four vent sites at Lau Basin in May 2009 show either thiosulfate or polysulfides. These in situ data indicate that abiotic sulfide oxidation does not readily occur as H(2)S contacts oxic bottom waters. Calculated abiotic potential sulfide oxidation rates are},
	keywords = {ROV Jason (Remotely Operated Vehicle)},
	issn = {1380-6165},
	doi = {10.1007/s10498-011-9136-1},
	author = {Gartman, A and Yucel, M and Madison, A S and Chu, D W and Ma, S and Janzen, C P and Becker, E L and Beinart, R A and Girguis, P R and Luther, G W}
}
@article {Luther2011,
	title = {{Thermodynamics and kinetics of sulfide oxidation by oxygen: a look at inorganically controlled reactions and biologically mediated processes in the environment}},
	journal = {Frontiers in Microbiology},
	volume = {2},
	year = {2011},
	pages = {62},
	publisher = {FRONTIERS RESEARCH FOUNDATION},
	address = {LAUSANNE; PO BOX 110, LAUSANNE, 1015, SWITZERLAND},
	abstract = {The thermodynamics for the first electron transfer step for sulfide and oxygen indicates that the reaction is unfavorable as unstable superoxide and bisulfide radical ions would need to be produced. However, a two-electron transfer is favorable as stable S(0) and peroxide would be formed, but the partially filled orbitals in oxygen that accept electrons prevent rapid kinetics. Abiotic sulfide oxidation kinetics improve when reduced iron and/or manganese are oxidized by oxygen to form oxidized metals which in turn oxidize sulfide. Biological sulfur oxidation relies on enzymes that have evolved to overcome these kinetic constraints to affect rapid sulfide oxidation. Here we review the available thermodynamic and kinetic data for H2S and HS center dot as well as O-2, reactive oxygen species, nitrate, nitrite, and NOx species. We also present new kinetic data for abiotic sulfide oxidation with oxygen in trace metal clean solutions that constrain abiotic rates of sulfide oxidation in metal free solution and agree with the kinetic and thermodynamic calculations. Moreover, we present experimental data that give insight on rates of chemolithotrophic and photolithotrophic sulfide oxidation in the environment. We demonstrate that both anaerobic photolithotrophic and aerobic chemolithotrophic sulfide oxidation rates are three or more orders of magnitude higher than abiotic rates suggesting that in most environments biotic sulfide oxidation rates will far exceed abiotic rates due to the thermodynamic and kinetic constraints discussed in the first section of the paper. Such data reshape our thinking about the biotic and abiotic contributions to sulfide oxidation in the environment.},
	keywords = {ROV Jason (Remotely Operated Vehicle)},
	issn = {1664-302X},
	doi = {10.3389/fmicb.2011.00062},
	author = {Luther, G W and Findlay, A J and MacDonald, D J and Owings, S M and Hanson, T E and Beinart, R A and Girguis, P R}
}
@article {Wankel2010,
	title = {{New constraints on methane fluxes and rates of anaerobic methane oxidation in a Gulf of Mexico brine pool via in situ mass spectrometry}},
	journal = {Deep-Sea Research. Part II: Topical Studies in Oceanography},
	volume = {57},
	number = {21-23},
	year = {2010},
	pages = {2022{\textendash}2029},
	abstract = {Deep-sea biogeochemical cycles are, in general, poorly understood owing to the difficulties of making measurements in situ, recovering samples with minimal perturbation, and, in many cases, coping with high spatial and temporal heterogeneity. In particular, biogeochemical fluxes of volatiles such as methane remain largely unconstrained because of the difficulties with accurate quantification in situ and the patchiness of point sources such as seeps and brine pools. To better constrain biogeochemical fluxes and cycling, we have developed a deep-sea in situ mass spectrometer (ISMS) to enable high-resolution quantification of volatiles in situ. Here we report direct measurements of methane concentrations made in a Gulf of Mexico brine pool located at a depth of over 2300 m. Concentrations of up to 33 mM methane were observed within the brine pool, whereas concentrations in the water directly above were three orders of magnitude lower. These direct measurements enabled us to make the first accurate estimates of the diffusive flux from a brine pool, calculated to be 1.1{\textpm}0.2 mol m-2 yr-1. Integrated rate measurements of aerobic methane oxidation in the water column overlying the brine pool were \~{}320 $μ$mol m-2 yr-1, accounting at most for just 0.03{\%} of the diffusive methane flux from the brine pool. Calculated rates of anaerobic methane oxidation were 600{\textendash}1200 $μ$M yr-1, one to two orders of magnitude higher than previously published values of AOM in anoxic fluids. These findings suggest that brine pools are enormous point sources of methane in the deep sea, and may, in aggregate, have a pronounced impact on the global marine methane cycle.},
	keywords = {HOV Alvin (Human Occupied Vehicle), ROV Jason (Remotely Operated Vehicle)},
	issn = {0967-0645},
	doi = {10.1016/j.dsr2.2010.05.009},
	url = {http://dx.doi.org/10.1016/j.dsr2.2010.05.009},
	author = {Wankel, S D and Joye, S B and Samarkin, V A and Shah, S R and Friederich, G and Melas-Kyriazi, J and Girguis, P R}
}
@article {Girguis2006,
	title = {{Metabolite uptake, stoichiometry and chemoautotrophic function of the hydrothermal vent tubeworm Riftia pachyptila: responses to environmental variations in substrate concentrations and temperature}},
	journal = {Journal of Experimental Biology},
	volume = {209},
	number = {18},
	year = {2006},
	pages = {3516{\textendash}3528},
	keywords = {HOV Alvin (Human Occupied Vehicle)},
	issn = {0022-0949},
	doi = {10.1242/jeb.02404},
	url = {http://dx.doi.org/10.1242/jeb.02404},
	author = {Girguis, P R and Childress, J J}
}
@inbook {Childress2004,
	title = {{On the edge of a deep biosphere: Real animals in extreme environments}},
	booktitle = {Subseafloor Biosphere at Mid-Ocean Ridges},
	year = {2004},
	pages = {41{\textendash}49},
	publisher = {AGU},
	organization = {AGU},
	doi = {10.1029/144GM04},
	author = {Childress, J J and Fisher, C R and Felbeck, H and Girguis, P and Girguis, P R}
}
