Carideicomes alvinocaridis gen. nov., sp. nov., a marine bacterium isolated from shrimp gill in a hydrothermal field of Okinawa Trough

Abstract

A Gram-stain-negative, strictly aerobic, oval-shaped, non-motile bacterium with no flagella, designated strain SCR17T, was isolated from a shrimp gill habitat in Tangyin hydrothermal field of Okinawa Trough. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SCR17T formed a lineage within the family ‘ Rhodobacteraceae ’, and shared 16S rRNA gene sequence similarity of 93.2–96.2 % to the related genera Aquicoccus and Roseivivax . Strain SCR17T was able to grow with 0–14 % (w/v) NaCl (optimum, 9–10 %). The sole respiratory quinone was ubiquinone-10. The major polar lipids of strain SCR17T comprised phosphatidylcholine (PC), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), an unidentified aminolipid (AL), an unidentified phospholipid (PL) and an unidentified lipid (L). The predominant fatty acids (more than 10 % of the total fatty acids) were C18 : 1ω7c or/and C18 : 1ω6c, anteiso-C15 : 0, C16 : 0 and C19 : 0 cyclo ω8c . The genomic DNA G+C content of strain SCR17T was 67.7 mol%. Based on polyphasic taxonomic analyses, strain SCR17T is considered to represent a novel species in a new genus of the family ‘ Rhodobacteraceae ’, for which the name Carideicomes alvinocaridis gen. nov., sp. nov. is proposed. The type strain of Carideicomes alvinocaridis is SCR17T (=JCM 33426T=MCCC 1K03732T). The discovery of a novel host-associated bacterium in hydrothermal fields provides an opportunity for the study of host–bacterial symbiosis in extreme environments.