Serinicoccus hydrothermalis sp. nov., isolated from shallow-sea hydrothermal systems off Kueishantao Island.

Abstract

A Gram-stain-positive, non-flagellated, non-gliding, coccoid bacterial strain, designated JLT9T, was isolated from the shallow-sea hydrothermal system off Kueishantao Island, Taiwan, ROC. Strain JLT9T was aerobic, chemoheterotrophic and grew optimally at 35 °C, at pH 6.0 and in the presence of 2.5 % (w/v) NaCl. Strain JLT9T exhibited highest 16S rRNA gene sequence similarity to Serinicoccus marinus DSM 15273T (98.83 %). Phylogenetic trees based on 16S rRNA gene sequences revealed that strain JLT9T belonged to the genus Serinicoccus, clustering with Serinicoccus marinus JC1078T, Serinicoccus profundi MCCC 1A05965T, Serinicoccus sediminis GP-T3-3T and Serinicoccus chungangensis CAU9536T. The digital DNA-DNA genome hybridization values between strain JLT9T and the closest related strain S. marinus DSM 15273T was 34.30 %. The DNA G+C content was 72.43 mol%. The dominant fatty acids were identified as iso-C15 : 0 (41.4 %) and iso-C16 : 0 (24.7 %). The polar lipids of strain JLT9T comprised diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, three unidentified glycolipid and an unidentified phospholipid. The predominant isoprenoid quinone was MK-8 (H4). The cell wall contained ornithine and serine, and no diaminopimelic acid. On the basis of phylogenetic data and several distinct phenotypic characteristics, strain JLT9T represents a novel species of the genus Serinicoccus, for which the name Serinicoccus hydrothermalis sp. nov. is proposed. The type strain is JLT9T (=CGMCC 1.15779T=JCM 31502T).