Flavivirga rizhaonensis sp. nov., a marine bacterium isolated from intertidal sand

A bacterial strain designated RZ03^T was isolated from an intertidal sand sample from the Yellow Sea in China and characterised using a polyphasic taxonomic approach. Cells of strain RZ03^T were observed to be Gram-stain negative, aerobic, and oxidase and catalase positive rods showing gliding motility and forming yellow colonies. Growth was found to occur at 7-30 °C (optimum, 25 °C), at pH 5.5-9.5 (optimum, pH 6.5-7.0) and with 0.5-5% NaCl (optimum, 1.5-2%). Phylogenetic analysis based on 16S rRNA gene sequences indicates that strain RZ03^T clusters within members of the genus Flavivirga of the family Flavobacteriaceae and is closely related to the type strains Flavivirga amylovorans JCM 17112^T and Flavivirga jejuensis JCM 17113^T (97.9% and 97.5% similarity, respectively). The predominant cellular fatty acids are iso-C_15:0, iso-C_15:1 G, iso-C_17:0 3-OH and iso-C_15:0 3-OH and the major respiratory quinone is MK-6. Polar lipids include phosphatidylethanolamine, three unidentified aminolipids, an unidentified phospholipid and four unidentified lipids. The genome of strain RZ03^T is 4.88 Mbp with a G+C content of 32.2 mol%. A total of 4152 genes are predicted, with 4052 protein-coding genes, 51 RNA genes and 49 pseudogenes. This polyphasic study suggests that strain RZ03^T represents a novel species in the genus Flavivirga, for which the name Flavivirga rizhaonensis is proposed. The type strain is RZ03^T(= KCTC 62833^T = MCCC 1K03615^T).