Roseomonas selenitidurans sp. nov., isolated from urban soil, and emended description of Roseomonas frigidaquae.

Abstract

An aerobic, non-motile, Gram-stain-negative, pink, convex, coccobacilli-shaped, mesophilic bacterium, designated strain BU-1T, was isolated from an urban soil sample from Zibo city, Shandong province, PR China. The strain grew at 20-37 °C (optimum, 30 °C), pH 5-10 (optimum, pH 7) and growth occurred with 0-2 % (w/v) NaCl (optimally with 0.5 %). The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that BU-1T was closely related to members of the genus Roseomonas and had highest 16S rRNA gene sequence similarities with Roseomonas frigidaquae JCM 15073T (97.8 %), Roseomonas tokyonensis JCM 14634T (96.9 %), Roseomonas stagni JCM 15034T (96.5 %), and Roseomonas riguiloci JCM 17520T (95.9 %). BU-1T also formed a subcluster with R. frigidaquae JCM 15073T and R. stagni JCM 15034T in phylogenetic trees based on genomic sequences. The genome size of BU-1T was 5.79 Mb and the DNA G+C content was 71.7 %. ANI, dDDH and AAI values between BU-1T and R. frigidaquae JCM 15073T were 84.0, 27.2 and 86.7 %, respectively. Furthermore, the genome of BU-1T contained 5446 predicted protein coding genes and 4945 (90.8%) of them had classifiable functions. BU-1T contained Q-10 as the main ubiquinone. The predominant fatty acids (>10 %) were summed feature 3, summed feature 8 and C16:0. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and five unidentified aminolipids. Combined data from phenotypic, phylogenetic and chemotaxonomic studies indicated that strain BU-1T is a representative of a novel species of the genus Roseomonas. Since strain BU-1T can reduce highly toxic selenite [Se(IV)] to low toxicity elemental selenium [Se(0)], the name Roseomonas selenitidurans sp. nov. is proposed. The type strain is BU-1T (=KACC 21750T =GDMCC 1.1776T).