Oceanicaulis stylophorae sp. nov., isolated from the reef-building coral Stylophora pistillata

Abstract

A bacterial strain designated GISW-4(T) was isolated from the reef-building coral Stylophora pistillata, collected from seawater off the coast of southern Taiwan, and was characterized in this taxonomic study using a polyphasic approach. Strain GISW-4(T) was Gram-stain-negative, aerobic, beige, rod-shaped, and dimorphic, either non-motile with stalks (or prosthecae), or non-stalked and motile by means of a single polar flagellum. 16S rRNA gene sequence studies showed that the novel strain clustered with Oceanicaulis alexandrii C116-18(T) (98.9 % 16S rRNA gene sequence similarity). Strain GISW-4(T) exhibited optimal growth at 35-40 °C, 1-2 % (w/v) NaCl and at pH 7-9. The predominant cellular fatty acids (>10 %) were C(18 : 0), C(18 : 1)ω7c and C(18 : 1)ω7c 11-methyl. The predominant polar lipids were phosphatidylglycerol, sulfoquinovosyl diacylglycerol and two unknown phospholipids (PL1-2). The major respiratory quinones were ubiquinone Q-10 and Q-9, and the DNA G+C content was 61.6 mol%. The results of physiological and biochemical tests allowed clear phenotypic differentiation of strain GISW-4(T) from the type strain of O. alexandrii. It is evident from the genotypic, phenotypic and chemotaxonomic data that the isolate should be classified as a novel species of the genus Oceanicaulis. The name proposed for this taxon is Oceanicaulis stylophorae sp. nov., with the type strain GISW-4(T) (= LMG 25723(T) = BCRC 80207(T)).