Phenylobacterium montanum sp. nov., an oligotrophic, slightly acidophilic mesophile isolated from sandy soil.

A bacterial strain, designated S6 ^T , was isolated from the sandy soil on a rocky mountain in South China. Cells of S6 ^T were Gram-stain-negative, aerobic, non-spore-forming, non-motile and non-prosthecae-producing. 16S rRNA gene sequence analysis revealed the highest similarities to 12 uncultured bacteria, followed by Phenylobacterium sp. B6.10-61 (97.14 %). The closest related validly published strains are Caulobacter henricii ATCC 15253 ^T (96.15 %), Phenylobacterium conjunctum FWC 21 ^T (96.08 %) and Caulobacter mirabilis FWC 38 ^T (96.08 %). Phylogenetic analysis based on 16S rRNA gene, genome and proteome sequences demonstrated that S6 ^T formed a separated lineage in the genus Phenylobacterium . Strain S6 ^T contained Q-10 (97.5 %) as the major ubiquinone and C _18 : 1  ω7 c and C _16 : 0 as the major fatty acids. The polar lipid profile consisted of phosphatidylglycerol, an unknown phosphoglycolipid and three unknown glycolipids. The assembled genome comprises a chromosome with a length of 5.5 Mb and a plasmid of 96 014 bp. The G+C content was 67.6 mol%. The morphological, physiological, chemotaxonomic and phylogenetic analyses clearly distinguished this strain from its closest phylogenetic neighbours. Thus it is proposed that strain S6 ^T represents a novel species in the genus Phenylobacterium , for which the name Phenylobacterium montanum sp. nov. is proposed. The type strain is S6 ^T (=NBRC 115419 ^T =GCMCC 1.18594 ^T ).