RT Journal Article SR Electronic(1) A1 Roalkvam, Irene A1 Bredy, Florian A1 Baumberger, Tamara A1 Pedersen, Rolf-B. A1 Steen, Ida HeleneYR 2015 T1 Hypnocyclicus thermotrophus gen. nov., sp. nov. isolated from a microbial mat in a hydrothermal vent field JF International Journal of Systematic and Evolutionary Microbiology, VO 65 IS Pt_12 SP 4521 OP 4525 DO https://doi.org/10.1099/ijsem.0.000606 PB Microbiology Society, SN 1466-5034, AB The bacterial strain, IR-2T, was isolated from a microbial mat sampled near a hydrothermal vent in the Greenland Sea. Phylogenetic analysis, based on the 16S rRNA gene, showed that the closest relatives of IR-2T were Ilyobacter tartaricus, Ilyobacter insuetus, Propionigenium modestum and Fusobacterium varium (91 % 16S rRNA gene sequence similarity). The cells of the novel strain were Gram-stain-negative and pleomorphic; changing from long motile rods to non-motile ring structures during the growth cycle. Growth occurred at 20–55 °C (optimally at 48 °C), with 1–6 % (w/v) NaCl (optimally with 2 %), and at pH 5.3–8.0 (optimally at pH 6.0–8.0). The strain had obligate fermentative growth on various sugars and yeast extract. The DNA G+C content of strain IR-2T was 25.7 mol%. The cell sugars comprised mainly ribose, mannose and glucose, while the main polar lipids were glycolipids, phospholipids, phosphatidylglycerol and diphosphatidylglycerol. The fatty acid content of strain IR-2 was dominated by saturated and unsaturated iso-branched or anteiso-branched forms. Strain IR-2 represents a novel genus and species, for which the name Hypnocyclicus thermotrophus gen. nov., sp. nov. is proposed. The type strain is IR-2T ( = DSM 100055 = JCM 30901)., UL https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijsem.0.000606