Roseomonas suffusca sp. nov., isolated from lagoon sediments

Three light-brown-coloured, Gram-stain-negative, small rod- to oval-shaped, motile bacteria were isolated from lagoon sediments collected from North Carolina, USA. The strains (S1T, AS3 and AS6) grew aerobically at 13-42 °C (optimum, 30-35 °C) and pH 6.5-9.1 (optimum, pH 7.0-7.5). All three strains were positive for catalase and oxidase activity, and no added NaCl was required for growth. C18 : 1ω6c/C18 : 1ω7c, C16 : 1ω6c/C16 : 1ω7c, C18 : 1ω7c 11-methyl and C16 : 0 were the predominant fatty acids (>5 %). Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and an unidentified glycolipid were the major polar lipids. The genomic DNA G+C content of strains S1T, AS3 and AS6 was 70.5, 70.1 and 70.8 mol%, respectively. Strain S1T showed 16S rRNA gene sequence similarity of 99.1 % with Roseomonas rubra S5T, 98.7 % with Roseomonas rhizosphaerae YW11T, 98.5 % with Roseomonas cervicalis E7107T, 97.8 % with Roseomonas aestuarii JC17T, 97.2 % with Roseomonas oryzae JC288T, 97.2 % with Roseomonas ludipueritiae 170/96Tand <97 % with other members of the genus Roseomonas. Strains AS3 and AS6 shared 99.9 % 16S rRNA gene sequence similarity with strain S1T. DNA-DNA hybridization values among strains S1T, AS3 and AS6 were >89 %, while all the three strains showed <56 % relatedness with the most closely related type strains. Distinct phenotypic, genotypic and phylogenetic differences from the previously described taxa support the classification of strain S1T as a representative of a novel species in the genus Roseomonas, for which the name Roseomonas suffusca sp. nov. is proposed. The type strain is S1T (=KEMB 563-465T=JCM 31176T). Strains AS3 and AS6 serve as additional strains of the newly proposed species.