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

Int J Syst Evol Microbiol. 2015 Dec;65(12):4521-4525. doi: 10.1099/ijsem.0.000606. Epub 2015 Sep 14.

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).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Typing Techniques
  • Base Composition
  • DNA, Bacterial / genetics
  • Fatty Acids / chemistry
  • Fusobacteria / classification*
  • Fusobacteria / genetics
  • Fusobacteria / isolation & purification
  • Glycolipids / chemistry
  • Hydrothermal Vents / microbiology*
  • Molecular Sequence Data
  • Phospholipids / chemistry
  • Phylogeny*
  • RNA, Ribosomal, 16S / genetics
  • Sequence Analysis, DNA

Substances

  • DNA, Bacterial
  • Fatty Acids
  • Glycolipids
  • Phospholipids
  • RNA, Ribosomal, 16S