A taxonomic study was carried out on a Gram-stain negative, rod-shaped, non-flagellated, and facultatively anaerobic bacterial strain designated as strain SF-16T, which was isolated from an unidentified starfish in Sanya, China. Strain SF-16T was found to be 5.0-7.0 μm long, and oxidase and catalase positive. Cell growth was observed at pH 6.0-8.5 (optimum, 7.0-8.0), temperatures of 10-41 °C (optimum, 25-30 °C), and salinities of 0-12 % (optimum, 3.0-6.0 %). The predominant fatty acids (>20 %) were found to be C18:1 ω7c and/or C18:1 ω6c (summed feature 8). Ubiquinone 10 was identified as the predominant quinone for strain SF-16T. The polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, two unidentified aminolipids, two unidentified lipids, and three unidentified phospholipids. The DNA G+C content of the genomic DNA of strain SF-16T was determined to be 63.0 mol%. Phylogenetic analysis based on the 16S rRNA gene showed that strain SF-16T belongs to the genus Pseudoruegeria and is closely related to Pseudoruegeria sabulilitoris GJMS-35T (98.42 % similarity). The ANI value between strain SF-16T and P. sabulilitoris GJMS-35T was found to be 74.98 %, and DNA-DNA hybridization value was 21.1 ± 2.3 % in silico and 57 % in vitro. Based on the low level of the genetic relatedness, phylogenetic and phenotypic data, a novel species Pseudoruegeria marinistellae sp. nov. is proposed. The type strain is SF-16T (=MCCC 1K01155T = KCTC 42910T).
Keywords: Polyphasic approach; Proteobacteria; Pseudoruegeria marinistellae sp. nov.; Starfish.