Hypnocyclicus thermotrophus gen. nov., sp. nov. isolated from a microbial mat in a hydrothermal vent field.

Roalkvam I, Bredy F, Baumberger T, Pedersen RB, Steen IH (2015) Hypnocyclicus thermotrophus gen. nov., sp. nov. isolated from a microbial mat in a hydrothermal vent field. Int J Syst Evol Microbiol 65(12), 4521-4525.

Abstract

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).

Leibniz-HKI-Authors

Florian Bredy

Identifier

doi: 10.1099/ijsem.0.000606

PMID: 26373292