Ponticoccus marisrubri sp. nov., a moderately halophilic marine bacterium of the family Rhodobacteraceae

Abstract

Strain SJ5A-1T, a Gram-stain-negative, coccus-shaped, non-motile, aerobic bacterium, was isolated from the brine–seawater interface of the Erba Deep in the Red Sea, Saudi Arabia. The colonies of strain SJ5A-1T have a beige to pale-brown pigmentation, are approximately 0.5–0.7μm in diameter, and are catalase and oxidase positive. Growth occurred optimally at 30–33 °C, pH 7.0–7.5, and in the presence of 9.0–12.0%NaCl (w/v). Phylogenetic analysis of the 16S rRNA gene indicates that strain SJ5A-1T is a member of the genus Ponticoccus within the family Rhodobacteraceae. Ponticoccus litoralis DSM 18986T is the most closely related described species based on 16S rRNA gene sequence identity (96.7%). The DNA–DNA hybridization value between strain SJ5A-1T and P. litoralis DSM 18986T was 36.7%. The major respiratory quinone of strain SJ5A-1T is Q-10; it predominantly uses the fatty acids C18: 1 (54.2%), C18: 0 (11.2%), C16: 0 (8.6%), 11-methyl C18: 1ω7c (7.7%), C19: 0cyclo ω8c (3.3%), and C12: 1 3-OH (3.5%), and its major polar lipids are phosphatidylethanolamine, phosphatidylglycerol, phosphocholine, an unknown aminolipid, an unknown phospholipid and two unknown lipids. The genome draft of strain SJ5A-1T as presented here is 4 562 830 bp in size and the DNA G+C content is 68.0 mol%. Based on phenotypic, phylogenetic and genotypic data, strain SJ5A-1T represents a novel species in the genus Ponticoccus, for which we propose the name Ponticoccus marisrubri sp. nov. The type strain of P. marisrubri is SJ5A-1T (=JCM 19520T=ACCC19863T).