| Abstract |
Two Gram-stain-negative, strictly aerobic, non-motile, rod-shaped bacteria, designated as strains S88T and W115T, exhibiting catalase- and oxidase-positive reactions, were isolated from marine red algae in South Korea. Strain S88T exhibited growth at 20-30 °C, pH 6.0-9.0 and 2.0-5.0% (w/v) NaCl, while strain W115T grew at 20-30 °C, pH 7.0-9.0 and 2.0-5.0% (w/v) NaCl. Strain S88T contained summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), C16 : 0 and C16 : 0 2-OH as major fatty acids (>5%), with major polar lipids being phosphatidylglycerol, phosphatidylcholine, an unidentified phospholipid, an unidentified aminolipid and two unidentified lipids. Strain W115T contained summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c) and C16 : 0 as major fatty acids (>5%), with major polar lipids including phosphatidylglycerol, phosphatidylcholine, an unidentified phospholipid, an unidentified aminolipid and unidentified lipids. Ubiquinone-10 was the sole respiratory quinone in both strains, and the genomic DNA G+C contents were 57.0% for strain S88T and 56.5% for strain W115T. Despite 99.86% 16S rRNA gene sequence similarity, strains S88T and W115T shared 88.8% average nucleotide identity (ANI) and 36.8% digital DNA-DNA hybridization (dDDH) value, indicating different species. Phylogenetic and phylogenomic analyses based on 16S rRNA gene and genome sequences, respectively, revealed that strains S88T and W115T formed a phylogenetic lineage within the genus Roseovarius. ANI and dDDH values of both strains with other type strains were less than 73.7 and 20.3%, respectively, confirming that they represent novel species. Based on phenotypic, chemotaxonomic and molecular characteristics, strains S88T and W115T represent two novel species of the genus Roseovarius, for which the names Roseovarius phycicola sp. nov. (S88T =KACC 23423T =JCM 36647T) and Roseovarius rhodophyticola sp. nov. (W115T =KACC 23690T =JCM 36651T) are proposed, respectively.
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