Marinomonas algae sp. nov. and Marinomonas phycocola sp. nov., two novel bacteria isolated from marine algae

Two novel bacterial strains, designated as 2405UD66-6 T and 2405UD68-3 T , were isolated from marine algae collected in the Republic of Korea. Both strains were Gram-stain-negative, strictly aerobic, motile, rod-shaped and oxidase-positive. Optimal growth occurred at 28 °C and pH 7.0, with NaCl concentrations of 3.0–4.0% (w/v) for strain 2405UD66-6 T and 2.0–3.0% (w/v) for strain 2405UD68-3 T . Phylogenetic analysis based on 16S rRNA gene sequences and phylogenomic analysis based on draft genome sequences revealed that strains 2405UD66-6ᵀ and 2405UD68-3ᵀ belong to the genus Marinomonas . Phylogenomic analysis revealed that strain 2405UD66-6 T was most closely related to Marinomonas colpomeniae SM2066 T , while strain 2405UD68-3 T was most closely related to Marinomonas phaeophyticola 15G1-11 T . Average nucleotide identity and digital DNA–DNA hybridization values between strain 2405UD66-6 T and its closest relative were 77.4 and 20.6%, respectively, whereas those between strain 2405UD68-3 T and its closest relative were 75.8 and 19.7%, respectively. These values are well below the accepted species delineation thresholds, indicating that both strains represent novel species within the genus Marinomonas . The genomic G+C contents for strains 2405UD66-6 T and 2405UD68-3 T were 42.5 and 40.5 mol%, respectively. The major polar lipids of both strains were phosphatidylglycerol and phosphatidylethanolamine, and the sole respiratory quinone was ubiquinone-8. The predominant fatty acids (>10.0%) in both strains were C 16 : 0 , summed feature 3 (C 16 : 1 ω6 c and/or C 16 : 1 ω7 c) and summed feature 8 (C 18 : 1 ω7 c and/or C 18 : 1 ω6 c). Based on a polyphasic taxonomic approach, the names Marinomonas algae sp. nov. and Marinomonas phycocola sp. nov. are proposed, respectively. The type strain is 2405UD66-6 T (KACC 24016 T =MCCC 1K09776 T ) for M. algae and 2405UD68-3 T (KACC 24017 T =MCCC 1K09819 T ) for M. phycocola .