genome Archives

Tengiliður

Viggó Marteinsson

Fagstjóri

viggo@matis.is

A novel bacterium, designated 19SA41, was isolated from the air of the Icelandic volcanic island Surtsey. Cells of strain 19SA41 are Gram-stain-negative, strictly aerobic, non-motile rods and form pale yellow-pigmented colonies. The strain grows at 4–30 °C (optimum, 22 °C), at pH 6–10 (optimum, pH 7.5) and with 0–4% NaCl (optimum, 0.5%). Phylogenetic analyses based on 16S rRNA gene sequences showed that 19SA41 belonged to the genus Flavobacterium and is most similar to Flavobacterium xinjiangense DSM 19743^T, with a sequence similarity of 96.52%. The new strain contained iso-C_15 : 0 (22%) and summed feature 3 (C_16∶1ω6c/C_16∶1ω7c) (20%) as the predominant fatty acids. The major respiratory quinone was menaquinone-6 (100%). The polar lipid profile consisted of phosphatidylethanolamine and several uncharacterized amino lipids, glycolipids and lipids. The genome of the new strain was 4.01 Mbp, and its G+C content was 33.2 mol%. Based on characterization and comparative results, using a polyphasic taxonomic approach, we propose that the new isolate represents a novel species of the genus Flavobacterium with the name Flavobacterium aerium sp. nov. The type strain is ISCaR-07695^T (=DSM 116640^T =UBOOC-M-3567^T).

Tengiliður

Pauline Vannier

Verkefnastjóri

pauline.vannier@matis.is

Novel thermophilic heterotrophic bacteria were isolated from the subsurface of the volcanic island Surtsey off the south coast of Iceland. The strains were isolated from tephra core and borehole fluid samples collected below 70 m depth. The Gram-negative bacteria were rod-shaped (0.3-0.4 µm wide, 1.5-7 µm long), aerobic, non-sporulating and non-motile. Optimal growth was observed at 70 °C, at pH 7-7.5 and with 1% NaCl. Phylogenetic analysis identified the strains as members of the genus Rhodothermus. The type strain, ISCAR-7401^T, was genetically distinct from its closest relatives Rhodothermus marinus DSM 4252^T and Rhodothermus profundi PRI 2902^T based on 16S rRNA gene sequence similarity (95.81 and 96.01%, respectively), genomic average nucleotide identity (73.73 and 72.61%, respectively) and digital DNA-DNA hybridization (17.6 and 16.9%, respectively). The major fatty acids of ISCAR-7401^T were iso-C_17:0, anteiso-C_15:0, anteiso-C_17:0 and iso-C_15:0 (>10 %). The major isoprenoid quinone was MK-7 while phosphatidylethanolamine, diphosphatidylglycerol, an unidentified aminophospholipid and a phospholipid were the predominant polar lipid components. Based on comparative chemotaxonomic, genomic and phylogenetic analyses, we propose that the isolated strain represents a novel species of the genus Rhodothermus with the name Rhodothermus bifroesti sp. nov. The type strain is ISCAR-7401^T(=DSM 112103^T=CIP 111906^T).