Curtobacterium salicis sp. nov., isolated from willow tree stems in Washington state.

Curtobacterium sp. strain WW7 is a Gram-positive, non-motile, orange rod-shaped bacterium isolated from branches of wild willow (Salix sitchensis) trees. The WW7 strain has optimum growth in the temperature range between 25 and 30 °C, a pH range of 6-7.7, and tolerates up to 5.5% (w/v) of NaCl. The genome sequencing of strain WW7 revealed a genome size of approximately 3.8 Mbp and a G + C content of 71.3 mol%. The phylogenomic analyses support the WW7 affiliation to a novel Curtobacterium lineage, with Curtobacterium herbarum being the closest type-strain. Chemotaxonomic analysis indicates that the carbon sources assimilation profile of strain WW7 was similar to the type strains, i.e. Curtobacterium luteum, Curtobacterium albidum, and Curtobacterium flaccumfaciens, while no assimilation of the organic acids succinate, alpha-ketobutyrate, mono methyl-succinate, and lactate was observed. Finally, fatty acid methyl ester analysis identifies anteiso-C and anteiso-C as major cellular fatty acids which is a common feature for members of the Curtobacterium genus. Based on the results of phylogenomic and chemotaxonomic analyses, strain WW7 represents a novel Curtobacterium lineage, for which the name Curtobacterium salicis sp. nov. is proposed. The type strain is WW7 (DSM 34805-NRRL B-68078).