@article {ISI:000371206300001,
	title = {{A distinct and active bacterial community in cold oxygenated fluids circulating beneath the western flank of the Mid-Atlantic ridge}},
	journal = {SCIENTIFIC REPORTS},
	volume = {6},
	year = {2016},
	month = {mar},
	type = {Article},
	abstract = {The rock-hosted, oceanic crustal aquifer is one of the largest ecosystems on Earth, yet little is known about its indigenous microorganisms. Here we provide the first phylogenetic and functional description of an active microbial community residing in the cold oxic crustal aquifer. Using subseafloor observatories, we recovered crustal fluids and found that the geochemical composition is similar to bottom seawater, as are cell abundances. However, based on relative abundances and functional potential of key bacterial groups, the crustal fluid microbial community is heterogeneous and markedly distinct from seawater. Potential rates of autotrophy and heterotrophy in the crust exceeded those of seawater, especially at elevated temperatures (25 degrees C) and deeper in the crust. Together, these results reveal an active, distinct, and diverse bacterial community engaged in both heterotrophy and autotrophy in the oxygenated crustal aquifer, providing key insight into the role of microbial communities in the ubiquitous cold dark subseafloor biosphere.},
	keywords = {ROV Jason (Remotely Operated Vehicle)},
	issn = {2045-2322},
	doi = {10.1038/srep22541},
	author = {Meyer, Julie L and Jaekel, Ulrike and Tully, Benjamin J and Glazer, Brian T and Wheat, C Geoffrey and Lin, Huei-Ting and Hsieh, Chih-Chiang and Cowen, James P and Hulme, Samuel M and Girguis, Peter R and Huber, Julie A}
}
@article {ISI:000380376700024,
	title = {{Subseafloor microbial communities in hydrogen-rich vent fluids from hydrothermal systems along the Mid-Cayman Rise}},
	journal = {ENVIRONMENTAL MICROBIOLOGY},
	volume = {18},
	number = {6, SI},
	year = {2016},
	month = {jun},
	pages = {1970{\textendash}1987},
	type = {Article},
	abstract = {Warm fluids emanating from hydrothermal vents can be used as windows into the rocky subseafloor habitat and its resident microbial community. Two new vent systems on the Mid-Cayman Rise each exhibits novel geologic settings and distinctively hydrogen-rich vent fluid compositions. We have determined and compared the chemistry, potential energy yielding reactions, abundance, community composition, diversity, and function of microbes in venting fluids from both sites: Piccard, the world{\textquoteright}s deepest vent site, hosted in mafic rocks; and Von Damm, an adjacent, ultramafic-influenced system. Von Damm hosted a wider diversity of lineages and metabolisms in comparison to Piccard, consistent with thermodynamic models that predict more numerous energy sources at ultramafic systems. There was little overlap in the phylotypes found at each site, although similar and dominant hydrogen-utilizing genera were present at both. Despite the differences in community structure, depth, geology, and fluid chemistry, energetic modelling and metagenomic analysis indicate near functional equivalence between Von Damm and Piccard, likely driven by the high hydrogen concentrations and elevated temperatures at both sites. Results are compared with hydrothermal sites worldwide to provide a global perspective on the distinctiveness of these newly discovered sites and the interplay among rocks, fluid composition and life in the subseafloor.},
	keywords = {ROV Jason (Remotely Operated Vehicle)},
	issn = {1462-2912},
	doi = {10.1111/1462-2920.13173},
	author = {Reveillaud, Julie and Reddington, Emily and McDermott, Jill and Algar, Christopher and Meyer, Julie L and Sylva, Sean and Seewald, Jeffrey and German, Christopher R and Huber, Julie A}
}
@article {ISI:000333189700012,
	title = {{Strain-level genomic variation in natural populations of Lebetimonas from an erupting deep-sea volcano}},
	journal = {ISME JOURNAL},
	volume = {8},
	number = {4},
	year = {2014},
	month = {apr},
	pages = {867{\textendash}880},
	type = {Article},
	abstract = {Chemolithoautotrophic Epsilonproteobacteria are ubiquitous in sulfidic, oxygen-poor habitats, including hydrothermal vents, marine oxygen minimum zones, marine sediments and sulfidic caves and have a significant role in cycling carbon, hydrogen, nitrogen and sulfur in these environments. The isolation of diverse strains of Epsilonproteobacteria and the sequencing of their genomes have revealed that this group has the metabolic potential to occupy a wide range of niches, particularly at dynamic deep-sea hydrothermal vents. We expand on this body of work by examining the population genomics of six strains of Lebetimonas, a vent-endemic, thermophilic, hydrogen-oxidizing Epsilonproteobacterium, from a single seamount in the Mariana Arc. Using Lebetimonas as a model for anaerobic, moderately thermophilic organisms in the warm, anoxic subseafloor environment, we show that genomic content is highly conserved and that recombination is limited between closely related strains. The Lebetimonas genomes are shaped by mobile genetic elements and gene loss as well as the acquisition of novel functional genes by horizontal gene transfer, which provide the potential for adaptation and microbial speciation in the deep sea. In addition, these Lebetimonas genomes contain two operons of nitrogenase genes with different evolutionary origins. Lebetimonas expressed nifH during growth with nitrogen gas as the sole nitrogen source, thus providing the first evidence of nitrogen fixation in any Epsilonproteobacteria from deep-sea hydrothermal vents. In this study, we provide a comparative overview of the genomic potential within the Nautiliaceae as well as among more distantly related hydrothermal vent Epsilonproteobacteria to broaden our understanding of microbial adaptation and diversity in the deep sea.},
	keywords = {ROV Jason (Remotely Operated Vehicle)},
	issn = {1751-7362},
	doi = {10.1038/ismej.2013.206},
	author = {Meyer, Julie L and Huber, Julie A}
}
@article {ISI:000325142700005,
	title = {{Growth kinetics and energetics of a deep-sea hyperthermophilic methanogen under varying environmental conditions}},
	journal = {ENVIRONMENTAL MICROBIOLOGY REPORTS},
	volume = {5},
	number = {5},
	year = {2013},
	month = {oct},
	pages = {665{\textendash}671},
	type = {Article},
	abstract = {{A hyperthermophilic deep-sea methanogen, Methanocaldococcus strain JH146, was isolated from 26 degrees C hydrothermal fluid at Axial Volcano to model high temperature methanogenesis in the subseafloor. Emphasis was placed on defining growth kinetics, cell yields and growth energy demand (GE) across a range of conditions. The organism uses H-2 and CO2 as its sole carbon and energy sources. At various temperatures, pHs, and chlorinities, its growth rates and cell yields co-varied while GE remained uniform at 1.69x10(-11) J cell(-1)s(-1)+/- 0.68x10(-11) J cell(-1)s(-1) (s.d.},
	keywords = {HOV Alvin (Human Occupied Vehicle)},
	issn = {1758-2229},
	doi = {10.1111/1758-2229.12065},
	author = {Eecke, Helene C Ver and Akerman, Nancy H and Huber, Julie A and Butterfield, David A and Holden, James F}
}
@article {ISI:000331246100002,
	title = {{Phylogenetic diversity and functional gene patterns of sulfur-oxidizing subseafloor Epsilonproteobacteria in diffuse hydrothermal vent fluids}},
	journal = {FRONTIERS IN MICROBIOLOGY},
	volume = {4},
	year = {2013},
	month = {jul},
	type = {Article},
	abstract = {Microorganisms throughout the dark ocean use reduced sulfur compounds for chemolithoautotrophy. In many deep-sea hydrothermal vents, sulfide oxidation is quantitatively the most important chemical energy source for microbial metabolism both at and beneath the seafloor. In this study, the presence and activity of vent endemic Epsilonproteobacteria was examined in six low-temperature diffuse vents over a range of geochemical gradients from Axial Seamount, a deep-sea volcano in the Northeast Pacific. PCR primers were developed and applied to target the sulfur oxidation soxB gene of Epsilonproteobacteria. soxB genes belonging to the genera Sulfurimonas and Sulfurovum are both present and expressed at most diffuse vent sites, but not in background seawater. Although Sulfurovum-like sox8 genes were detected in all fluid samples, the RNA profiles were nearly identical among the vents and suggest that Sulfurirnonas-like species are the primary Epsilonproteobacteria responsible for actively oxidizing sulfur via the Sox pathway at each vent. Community patterns of subseafloor Epsdonproteobactena 16S rRNA genes were best matched to methane concentrations in vent fluids, as well as individual vent locations, indicating that both geochemistry and geographical isolation play a role in structuring subseafloor microbial populations. The data show that in the subseafloor at Axial Seamount, Epsilonproteobacteria are expressing the soxB gene and that microbial patterns in community distribution are linked to both vent location and chemistry.},
	keywords = {ROV Jason (Remotely Operated Vehicle)},
	issn = {1664-302X},
	doi = {10.3389/fmicb.2013.00185},
	author = {Akerman, Nancy H and Butterfield, David A and Huber, Julie A}
}
@article {ISI:000280633000011,
	title = {{Isolated communities of Epsilonproteobacteria in hydrothermal vent fluids of the Mariana Arc seamounts}},
	journal = {FEMS MICROBIOLOGY ECOLOGY},
	volume = {73},
	number = {3},
	year = {2010},
	month = {sep},
	pages = {538{\textendash}549},
	type = {Article},
	abstract = {Low-temperature hydrothermal vent fluids represent access points to diverse microbial communities living in oceanic crust. This study examined the distribution, relative abundance, and diversity of Epsilonproteobacteria in 14 low-temperature vent fluids from five volcanically active seamounts of the Mariana Arc using a 454 tag sequencing approach. Most vent fluids were enriched in cell concentrations compared with background seawater, and quantitative PCR results indicated that all fluids were dominated by bacteria. Operational taxonomic unit-based statistical tools applied to 454 data show that all vents from the northern end of the Mariana Arc grouped together, to the exclusion of southern arc seamounts, which were as distinct from one another as they were from northern seamounts. Statistical analysis also showed a significant relationship between seamount and individual vent groupings, suggesting that community membership may be linked to geographical isolation and not geochemical parameters. However, while there may be large-scale geographic differences, distance is not the distinguishing factor in the microbial community composition. At the local scale, most vents host a distinct population of Epsilonproteobacteria, regardless of seamount location. This suggests that there may be barriers to exchange and dispersal for these vent endemic microorganisms at hydrothermal seamounts of the Mariana Arc.},
	keywords = {ROV Jason (Remotely Operated Vehicle)},
	issn = {0168-6496},
	doi = {10.1111/j.1574-6941.2010.00910.x},
	author = {Huber, Julie A and Cantin, Holly V and Huse, Susan M and Welch, David B Mark and Sogin, Mitchell L and Butterfield, David A}
}
