Marinitoga hydrogenitolerans sp. nov., a novel member of the order Thermotogales isolated from a black smoker chimney on the Mid-Atlantic Ridge

Postec, Anne; Breton, Claire Le; Fardeau, Marie Laure; Lesongeur, Françoise; Pignet, Patricia; Quérellou, Joël; Ollivier, Bernard; Godfroy, Anne

doi:10.1099/ijs.0.63550-0

Cited by 39 publications

(29 citation statements)

References 31 publications

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“…The Aquificaceae, Hydrogenothermaceae, and Desulfurobacteriaceae families of the Aquificales are observed principally in hydrothermal deposits and fluids. Additionally, isolated Aquificae organisms, including Thermodesulfobacterium hydrogeniphilum (251), a heterotrophic sulfate-reducing bacterium, and Thermodesulfatator indicus (385), an autotrophic sulfate-reducing bacterium, both of the Thermodesulfobacteria class, as well as Marinitoga hydrogenitolerans (450), an anaerobic organotroph of the Thermotogae class, appear to be environmentally relevant in hydrothermal environments.…”

Section: Taxonomy Of Dark Ocean Prokaryotic Microbial Communitiesmentioning

confidence: 99%

Microbial Ecology of the Dark Ocean above, at, and below the Seafloor

Orcutt

Sylvan

Knab

et al. 2011

Microbiol Mol Biol Rev

590

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SUMMARY The majority of life on Earth—notably, microbial life—occurs in places that do not receive sunlight, with the habitats of the oceans being the largest of these reservoirs. Sunlight penetrates only a few tens to hundreds of meters into the ocean, resulting in large-scale microbial ecosystems that function in the dark. Our knowledge of microbial processes in the dark ocean—the aphotic pelagic ocean, sediments, oceanic crust, hydrothermal vents, etc.—has increased substantially in recent decades. Studies that try to decipher the activity of microorganisms in the dark ocean, where we cannot easily observe them, are yielding paradigm-shifting discoveries that are fundamentally changing our understanding of the role of the dark ocean in the global Earth system and its biogeochemical cycles. New generations of researchers and experimental tools have emerged, in the last decade in particular, owing to dedicated research programs to explore the dark ocean biosphere. This review focuses on our current understanding of microbiology in the dark ocean, outlining salient features of various habitats and discussing known and still unexplored types of microbial metabolism and their consequences in global biogeochemical cycling. We also focus on patterns of microbial diversity in the dark ocean and on processes and communities that are characteristic of the different habitats.

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Section: Taxonomy Of Dark Ocean Prokaryotic Microbial Communitiesmentioning

confidence: 99%

Microbial Ecology of the Dark Ocean above, at, and below the Seafloor

Orcutt

Sylvan

Knab

et al. 2011

Microbiol Mol Biol Rev

590

499

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“…The species of the genus Petrotoga represent slightly thermophilic members of the generally hyperthermophilic and deep-branching bacteria of the order Thermotogales (2,3,31). Organisms of this genus have all been isolated from hot oilfield water (21,25), and have an optimum temperature for growth of 55 to 60°C in medium containing NaCl in the range of 0.5 to 10% (16).…”

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confidence: 99%

Two Alternative Pathways for the Synthesis of the Rare Compatible Solute Mannosylglucosylglycerate inPetrotoga mobilis

et al. 2010

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The compatible solute mannosylglucosylglycerate (MGG), recently identified in Petrotoga miotherma, also accumulates in Petrotoga mobilis in response to hyperosmotic conditions and supraoptimal growth temperatures. Two functionally connected genes encoding a glucosyl-3-phosphoglycerate synthase (GpgS) and an unknown glycosyltransferase (gene Pmob_1143), which we functionally characterized as a mannosylglucosyl-3-phosphoglycerate synthase and designated MggA, were identified in the genome of Ptg. mobilis. This enzyme used the product of GpgS, glucosyl-3-phosphoglycerate (GPG), as well as GDP-mannose to produce mannosylglucosyl-3-phosphoglycerate (MGPG), the phosphorylated precursor of MGG. The MGPG dephosphorylation was determined in cell extracts, and the native enzyme was partially purified and characterized. Surprisingly, a gene encoding a putative glucosylglycerate synthase (Ggs) was also identified in the genome of Ptg. mobilis, and an active Ggs capable of producing glucosylglycerate (GG) from ADP-glucose and D-glycerate was detected in cell extracts and the recombinant enzyme was characterized, as well. Since GG has never been identified in this organism nor was it a substrate for the MggA, we anticipated the existence of a nonphosphorylating pathway for MGG synthesis. We putatively identified the corresponding gene, whose product had some sequence homology with MggA, but it was not possible to recombinantly express a functional enzyme from Ptg. mobilis, which we named mannosylglucosylglycerate synthase (MggS). In turn, a homologous gene from Thermotoga maritima was successfully expressed, and the synthesis of MGG was confirmed from GDP-mannose and GG. Based on the measurements of the relevant enzyme activities in cell extracts and on the functional characterization of the key enzymes, we propose two alternative pathways for the synthesis of the rare compatible solute MGG in Ptg. mobilis.Thermophilic and hyperthermophilic organisms, like the vast majority of other microorganisms, accumulate compatible solutes in response to water stress imposed by salt. In fact, many of the (hyper)thermophiles known were isolated from geothermal areas venting seawater (36). However, the compatible solutes of thermophilic and hyperthermophilic prokaryotes are generally different from those of their mesophilic counterparts and some, namely, di-myo-inositol-phosphate (DIP), mannosyl-di-myo-inositol-phosphate (MDIP), diglycerol phosphate, and mannosylglyceramide, are confined to organisms that grow at extremely high temperatures (19,22,34,38). Mannosylglycerate (2-␣-D-mannosylglycerate; MG), for example, is a common compatible solute of thermophiles and hyperhermophiles (23, 27, 38) but has also been found in mesophilic organisms, such as red algae, where it was first identified (6). It should also be noted that there is a growing awareness that compatible solutes are involved in other types of stress; trehalose, for example, plays a role in osmotic stress, heat stress, desiccation, and freezing (9). Some compatible solutes of ...

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“…The quantity and diversity of sequences of members of the Thermotogales that have been detected in oil reservoirs suggest that these organisms may play important roles in these environments (Grassia et al, 1996;Li et al, 2006Li et al, , 2007Magot et al, 2000). While numerous species of the Thermotogales have been shown to grow very slowly at relatively low temperatures (30-40 u C) (Davey et al, 1993;Huber et al, 1989;Miranda-Tello et al, 2004;Nunoura et al, 2007;Postec et al, 2005), robust growth at these temperatures has not been observed with isolated strains. There is evidence from metagenomic studies that species of the Thermotogales with low optimal growth temperatures exist in nature (Nesbø et al, 2006).…”

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confidence: 99%