@article {ISI:000368893500001,
	title = {{Microbial Communities in Methane- and Short Chain Alkane-Rich Hydrothermal Sediments of Guaymas Basin}},
	journal = {FRONTIERS IN MICROBIOLOGY},
	volume = {7},
	year = {2016},
	month = {jan},
	type = {Article},
	abstract = {The hydrothermal sediments of Guaymas Basin, an active spreading center in the Gulf of California (Mexico), are rich in porewater methane, short-chain alkanes, sulfate and sulfide, and provide a model system to explore habitat preferences of microorganisms, including sulfate-dependent, methane- and short chain alkane-oxidizing microbial communities. In this study, hot sediments (above 60 degrees C) covered with sulfur-oxidizing microbial mats surrounding a hydrothermal mound (termed {\textquoteleft}{\textquoteleft}Mat Mound{\{}{\textquoteright}{\textquoteright}{\}}) were characterized by porewater geochemistry of methane, C-2-C-6 short-chain alkanes, sulfate, sulfide, sulfate reduction rate measurements, in situ temperature gradients, bacterial and archaeal 16S rRNA gene clone libraries and V6 tag pyrosequencing. The most abundantly detected groups in the Mat mound sediments include anaerobic methane-oxidizing archaea of the ANME-1 lineage and its sister Glade ANME-1Guaymas, the uncultured bacterial groups SEEP-SRB2 within the Deltaproteobacteria and the separately branching HotSeep-1 Group; these uncultured bacteria are candidates for sulfate-reducing alkane oxidation and for sulfate-reducing syntrophy with ANME archaea. The archaeal dataset indicates distinct habitat preferences for ANME-1, ANME-1-Guaymas, and ANME-2 archaea in Guaymas Basin hydrothermal sediments. The bacterial groups SEEP-SRB2 and HotSeep-1 co-occur with ANME-1 and ANME-1Guaymas in hydrothermally active sediments underneath microbial mats in Guaymas Basin. We propose the working hypothesis that this mixed bacterial and archaeal community catalyzes the oxidation of both methane and short-chain alkanes, and constitutes a microbial community signature that is characteristic for hydrothermal and/or cold seep sediments containing both substrates.},
	keywords = {HOV Alvin (Human Occupied Vehicle)},
	issn = {1664-302X},
	doi = {10.3389/fmicb.2016.00017},
	author = {Dowell, Frederick and Cardman, Zena and Dasarathy, Srishti and Kellermann, Matthias Y and Lipp, Julius S and Ruff, S Emil and Biddle, Jennifer F and McKay, Luke J and MacGregor, Barbara J and Lloyd, Karen G and Albert, Daniel B and Mendlovitz, Howard and Hinrichs, Kai-Uwe and Teske, Andreas}
}
@article {ISI:000372952900002,
	title = {{Tracing the production and fate of individual archaeal intact polar lipids using stable isotope probing}},
	journal = {ORGANIC GEOCHEMISTRY},
	volume = {95},
	year = {2016},
	month = {may},
	pages = {13{\textendash}20},
	type = {Article},
	abstract = {Analysis of cellular membrane lipids has been widely applied to describe the microbial community composition in natural systems. When combined with stable isotope probing (SIP) experiments, deuterium label (D2O) uptake into lipids enables assessment of microbial biomass production. We performed SIP on methane-rich, hydrothermally-heated sediments to examine the de novo production of individual archaeal intact polar lipids (IPLs) by mesophilic anaerobic methane oxidizing group-1 archaea (ANME-1). The greatest extent of label uptake was by phosphatidyl glycerol archaeol (PG-AR), reaching 50{\%} of the medium{\textquoteright}s label concentration in only 10 days. This indicates PG-AR as an important cell membrane lipid during the active growth phase of mesophilic ANME-1. Much less label uptake was into intact polar glycerol dibiphytanyl glycerol tetraethers (GDGTs), especially for those bound to diglycosidic head groups. The low production of these GDGTs contrasts with their predominance in ANME-1-dominated natural samples. We attribute the differential label uptake among individual IPLs to the ANME-1 tetraether biosynthetic pathway. This mechanism likely involves head-to-head condensation of two molecules of PG-AR and progressive substitution of PG by glycosidic head groups. The observation that ANME-1 invest in the synthesis of diethers during optimum growth suggests intact ARs and/or phosphate-bearing tetraethers as important biomarkers for actively growing populations in natural environments, while the diglycosidic GDGTs appear to signal stationary ANME-1 communities. (C) 2016 Elsevier Ltd. All rights reserved.},
	keywords = {HOV Alvin (Human Occupied Vehicle)},
	issn = {0146-6380},
	doi = {10.1016/j.orggeochem.2016.02.004},
	author = {Kellermann, Matthias Y and Yoshinaga, Marcos Y and Wegener, Gunter and Krukenberg, Viola and Hinrichs, Kai-Uwe}
}
@article {ISI:000299052400011,
	title = {{Thermophilic anaerobic oxidation of methane by marine microbial consortia}},
	journal = {ISME JOURNAL},
	volume = {5},
	number = {12},
	year = {2011},
	month = {dec},
	pages = {1946{\textendash}1956},
	type = {Article},
	abstract = {The anaerobic oxidation of methane (AOM) with sulfate controls the emission of the greenhouse gas methane from the ocean floor. AOM is performed by microbial consortia of archaea (ANME) associated with partners related to sulfate-reducing bacteria. In vitro enrichments of AOM were so far only successful at temperatures {\textless}= 25 degrees C; however, energy gain for growth by AOM with sulfate is in principle also possible at higher temperatures. Sequences of 16S rRNA genes and core lipids characteristic for ANME as well as hints of in situ AOM activity were indeed reported for geothermally heated marine environments, yet no direct evidence for thermophilic growth of marine ANME consortia was obtained to date. To study possible thermophilic AOM, we investigated hydrothermally influenced sediment from the Guaymas Basin. In vitro incubations showed activity of sulfate-dependent methane oxidation between 5 and 70 degrees C with an apparent optimum between 45 and 60 degrees C. AOM was absent at temperatures {\textgreater}= 75 degrees C. Long-term enrichment of AOM was fastest at 50 degrees C, yielding a 13-fold increase of methane-dependent sulfate reduction within 250 days, equivalent to an apparent doubling time of 68 days. The enrichments were dominated by novel ANME-1 consortia, mostly associated with bacterial partners of the deltaproteobacterial HotSeep-1 cluster, a deeply branching phylogenetic group previously found in a butane-amended 60 degrees C-enrichment culture of Guaymas sediments. The closest relatives (Desulfurella spp.; Hippea maritima) are moderately thermophilic sulfur reducers. Results indicate that AOM and ANME archaea could be of biogeochemical relevance not only in cold to moderate but also in hot marine habitats. The ISME Journal (2011) 5, 1946-1956; doi: 10.1038/ismej.2011.77; published online 23 June 2011},
	keywords = {HOV Alvin (Human Occupied Vehicle)},
	issn = {1751-7362},
	doi = {10.1038/ismej.2011.77},
	author = {Holler, Thomas and Widdel, Friedrich and Knittel, Katrin and Amann, Rudolf and Kellermann, Matthias Y and Hinrichs, Kai-Uwe and Teske, Andreas and Boetius, Antje and Wegener, Gunter}
}
