Roseomonas rubea sp. nov., isolated from rice paddy soil

Abstract

Three pale-red-pigmented, Gram-stain-negative, coccobacilli-shaped, motile and strictly aerobic bacteria, strains MO17T, MO41 and NPKOSM1, were isolated from rice paddy soil. Colonies were circular with entire edges, convex and pale red. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strains MO17T, MO41 and NPKOSM1 belonged to the genus Roseomonas and were closely related to Roseomonas sediminicola FW-3T (98.2 %), Roseomonas oryzicola YC6724T (98.0 %), Roseomonas soli 5N26T (98.0 %), Roseomonas eburnea BUT-5T (97.8 %), Roseomonas alkaliterrae YIM 78007T (97.7 %), Roseomonas lacus TH-G33T (97.6 %) and Roseomonas terrae DS-48T (96.8 %). The DNA–DNA hybridization values between strains MO17T, MO41 and NPKOSM1 were 84–92 %, and the values between the three strains and their close phylogenetic relatives were also below 70 %. The major cellular fatty acids were C18 : 1  ω7c, C16 : 0 and summed feature 3 (C16 : 1  ω7c and/or iso-C15 : 0 2OH). The predominant respiratory quinone was identified as Q-10. The polar lipids detected were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, one unidentified aminophospholipid and two unknown phospholipids. Based on their distinctive phenotypic, phylogenetic and chemotaxonomic characteristics, the three strains are considered to represent novel species of the genus Roseomonas for which the name Roseomonas rubea sp. nov. is proposed. The type strain is MO17T (=KACC 19933T=NBRC 114495T).