Kyrpidia spormannii sp. nov., a thermophilic, hydrogen-oxidizing, facultative autotroph, isolated from hydrothermal systems at São Miguel Island, and emended description of the genus Kyrpidia.

Abstract

A Gram-stain-positive, rod-shaped, non-motile, spore-forming bacterium, strain EA-1T, was isolated from hydrothermal sediment samples from the Azores (São Miguel, Portugal). 16S rRNA gene sequence analysis of the isolated bacterium revealed a phylogenetic affiliation with the genus Kyrpidia. The sequence similarity of the five 16S rRNA gene copies to its closest relative, Kyrpidia tusciae, ranged from 97.79 to 97.85 %. The in silico estimate of DNA-DNA hybridization was 56.0 %. The dominant fatty acids of the novel isolate were anteiso-C17 : 0 (49.9 %), iso-C17 : 0 (23.0 %) and iso-C16 : 0 (13.3 %), while the quinone detected was menaquinone MK-7. Analysis of polar lipids identified phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and additional unidentified compounds comprising two glycolipids, two phospholipids and two lipids. The presence of meso-diaminopimelic acid in the peptidoglycan and mannose, arabinose and ribose in the cell wall of strain EA-1T were detected. The strain was able to grow heterotrophically as well as autotrophically with carbon dioxide as the sole carbon source and with hydrogen and oxygen as electron donor and acceptor, respectively. Based on its chemotaxonomic, physiological and genomic characteristics, the new strain is considered to represent a novel species within the genus Kyrpidia, for which the name Kyrpidiaspormannii sp. nov. is proposed. The type strain is strain EA-1T (=DSM 106492T=CCOS1194T).