Putridiphycobacter roseus gen. nov., sp. nov., isolated from Antarctic rotten seaweed.

A Gram-stain-negative, pink-pigmented, rod-shaped, non-flagellated, aerobic bacterium, designated strain SM1701T, was isolated from a rotten seaweed collected off Fildes Peninsula, King George Island, West Antarctica. The strain grew at 4-30 °C, pH 6.0-8.0 and with 0.5-5 % (w/v) NaCl. It hydrolysed gelatin and Tweens (40, 60 and 80), but did not reduce nitrates to nitrites. The major cellular fatty acids of strain SM1701T were iso-C15 : 0, iso-C15 : 1G, iso-C16 : 1G, C16 : 0 and iso-C17 : 0 3-OH. Polar lipids included phosphatidylethanolamine, one unidentified aminolipid, two unidentified glycolipids and one unidentified aminoglycolipid. The major respiratory quinone was MK-7. The genomic DNA G+C content of strain SM1701T was 34.1 mol%. It showed high 16S rRNA gene sequence similarities to Crocinitomix algicola (93.8 %) and Crocinitomix catalasitica (92.5 %) and less than 91 % sequence similarities to other known members in the family Crocinitomicaceae. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain SM1701T constituted a distinct lineage within the family Crocinitomicaceae. The phylogenetic trees based on concatenated 261 protein sequences from genome sequences showed that strain SM1701T occupied a branch separated from those of known genera in the family of Crocinitomicaceae, indicating it may belong to a new genus. On the basis of the polyphasic characterization of strain SM1701T in this study, it is considered to represent a novel species in a new genus in the family Crocinitomicaceae, for which the name Putridiphycobacter roseus gen. nov., sp. nov. is proposed. The type strain is SM1701T (=KCTC 62302T=NBRC 113201T=CGMCC 1.16510T).