0000000000041126

AUTHOR

Wolfgang Ludwig

Thalassobacter stenotrophicus gen. nov., sp. nov., a novel marine alpha-proteobacterium isolated from Mediterranean sea water.

A Gram-negative, slightly halophilic, strictly aerobic, chemo-organotrophic bacterium was isolated from Mediterranean sea water near Valencia (Spain). 16S rRNA gene sequence comparisons showed that the isolate represented a separate branch within the α-3 subclass of the Proteobacteria, now included within the order ‘Rhodobacterales’. Jannaschia helgolandensis was the closest relative, but their low sequence similarity and other features indicated that they were not related at the genus level. Isolate 5SM22T produced bacteriochlorophyll a and grew on solid media as regular salmon-pink colonies. Cells are motile rods, with polar flagella. The DNA G+C content is 59·1 mol%. Morphological, physi…

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Vibrio pelagius: differences of the type strain deposited at various culture collections.

A critical evaluation of published and own taxonomic and phylogenetic studies on Vibrio pelagius showed substantial diversity of strains received as type strains from various Culture Collections. The comparison of data based upon 16S rRNA sequence analyses, earlier genomic DNA-DNA similarity studies as well as physiological investigations and the original description indicate that Vibrio pelagius strains CECT 4202T and ATCC 25916T really represent the originally described type species whereas strains NCIMB 1900T and CIP 102762T highly likely are representatives of Vibrio natriegens.

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ISLSCP II global river fluxes of carbon and sediments to the oceans.

International audience

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Worldwide distribution of continental rock lithology: Implications for the atmospheric/soil CO2uptake by continental weathering and alkalinity river transport to the oceans

[1] The silicate rock weathering followed by the formation of carbonate rocks in the ocean, transfers CO2 from the atmosphere to the lithosphere. This CO2 uptake plays a major role in the regulation of atmospheric CO2 concentrations at the geologic timescale and is mainly controlled by the chemical properties of rocks. This leads us to develop the first world lithological map with a grid resolution of 1° × 1°. This paper analyzes the spatial distribution of the six main rock types by latitude, continents, and ocean drainage basins and for 49 large river basins. Coupling our digital map with the GEM-CO2 model, we have also calculated the amount of atmospheric/soil CO2 consumed by rock weathe…

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Nereida ignava gen. nov., sp. nov., a novel aerobic marine alpha-proteobacterium that is closely related to uncultured Prionitis (alga) gall symbionts.

A Gram-negative, slightly halophilic, non-pigmented, strictly aerobic, chemo-organotrophic bacterium was isolated from Mediterranean sea water off the Spanish coast near Valencia. This strain was poorly reactive, being unable to grow in most carbon sources analysed in minimal medium. However, good growth was observed when more complex media and longer incubation times were used. Phylogenetic analysis based on an almost complete 16S rRNA gene sequence placed strain 2SM4T within the Roseobacter group, in the vicinity of uncultured bacteria described as gall symbionts of several species of the red alga Prionitis. Sequence similarity values between strain 2SM4T and the closest neighbouring spec…

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Sequencing orphan species initiative (SOS): Filling the gaps in the 16S rRNA gene sequence database for all species with validly published names

Yarza, Pablo et al.

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Vibrio agarivorans sp. nov., a novel agarolytic marine bacterium.

It is proposed that the new Vibrio species Vibrio agarivorans accommodates two agarolytic, halophilic, fermentative bacterial strains isolated from Mediterranean sea water. The cells were gram-negative, oxidase-positive, polarly flagellated bacilli that fermented glucose without gas production and that produced no decarboxylases. They used a wide range of compounds as sole carbon and energy sources. The DNA G+C content was 44.8 mol%. Phylogenetic analysis based on complete 16S and 23S rDNA sequences revealed that the strains belong to the gamma-Proteobacteria, and are specifically related to Vibrio species. Their nearest relatives were species of the Vibrio fischeri group, sharing 16S rDNA …

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Jannaschia rubra sp. nov., a red-pigmented bacterium isolated from sea water.

A Gram-negative, slightly halophilic, strictly aerobic, chemo-organotrophic bacterium was isolated from Mediterranean sea water near Valencia (Spain). Comparison of the almost complete 16S rRNA gene sequence showed that strain 4SM3T belonged to the Roseobacter group, with Jannaschia helgolandensis as its closest relative, with a similarity of 98·7 %. DNA–DNA hybridization analysis showed that the Mediterranean isolate had a level of relatedness of less than 42 % with J. helgolandensis and therefore that it represented a novel species of the genus Jannaschia. Phenotypic characteristics gave further evidence that the two organisms are not related at the species level. Isolate 4SM3T grows on s…

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