Marinicauda algicola sp. nov., isolated from a marine red alga Rhodosorus marinus.

An aerobic Gram-stain-negative prosthecate bacterium, designated RMAR8-3T, was isolated from a marine red alga Rhodosorus marinus in the Republic of Korea. Cells were dimorphic rods with a single polar prostheca (non-motile) or flagellum (motile) showing catalase- and oxidase-positive reactions. Growth of strain RMAR8-3T was observed at 15-45 °C (optimum, 40 °C), at pH 6.0-9.0 (optimum, pH 7.0) and in the presence of 0-10 % (w/v) NaCl (optimum, 2 %). Ubiquinone-10 was detected as the sole isoprenoid quinone and C18 : 0, summed feature 8 (comprising C18 : 1 ω7c and/or C18 : 1ω6c), C17 : 0, C12 : 0 3-OH and C16 : 0 were identified as the major cellular fatty acids. The major polar lipids were sulfo-quinovosyldiacylglycerol, glucuronopyranosyldiglyceride and monoglycosyldiglyceride. The G+C content of the genomic DNA was 66.3 mol%. Strain RMAR8-3T was most closely related to Marinicauda pacifica P-1 km-3T with a 97.6 % 16S rRNA gene sequence similarity. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain RMAR8-3T formed a tight phylogenic lineage with M. pacifica P-1 km-3T within the family Hyphomonadaceae. On the basis of phenotypic, chemotaxonomic and molecular features, strain RMAR8-3T clearly represents a novel species of the genus Marinicauda, for which the name Marinicauda algicola sp. nov. is proposed. The type strain is RMAR8-3T (=KACC 18990T=JCM 31718T).