A Gram-stain-negative, yellow-pigmented, non-motile, rod-shaped, catalase-positive, strictly aerobic marine bacterium, designated XHP0103T, was isolated from seawater collected from the southern Yellow Sea, PR China (34° 45' 53″ N 119° 25' 30″ E). Strain XHP0103T grew optimally at 28 °C, pH 7.5 and in 1.0-3.0 % (w/v) sea salt. MK-6 was the major respiratory quinone. The major cellular fatty acids (>10%) were iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH. The polar lipid profile contained phosphatidylethanolamine, an unidentified aminolipid, an unidentified glycolipid and an unidentified lipid. Results of 16S rRNA gene sequence analysis indicated that strain XHP0103T displayed highest sequence similarity to Aestuariibaculum marinum IP7T (94.1 %). However, the phylogenetic trees based on 16S rRNA gene sequences suggested that strain XHP0103T clustered with Tamlana crocina HST1-43T (93.4 % sequence similarity) and Aestuariivivens insulae AH-MY3T (93.5 %). Genome sequencing revealed that strain XHP0103T comprised 3 134 388 bp with 2770 protein-coding genes, and the DNA G+C content was 35.5 %. The average nucleotide identity and digital DNA-DNA hybridization values between strain XHP0103T and T. crocina HST1-43T were 73.6 and 17.3 %, respectively. Based on phylogenetic, phenotypic, genomic and chemotaxonomic evidence, strain XHP0103T represents a novel genus in the family Flavobacteriaceae, for which the name Marixanthotalea marina gen. nov., sp. nov. is proposed. The type strain is XHP0103T (=MCCC 1K06060T=JCM 34682T).
Keywords: Flavobacteriaceae; Marixanthotalea gen. nov.; seawater; taxonomy.