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

Abstract

Abstract Curtobacterium sp. strain WW7 is a Gram-positive, non-motile, orange rod-shaped bacterium isolated from branches of wild willow (Salix sitchensis) trees on nitrogen-free media. The WW7 strain shows growth in the temperature range between 4 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 C. herbarum being the closest type-strain. Chemotaxonomic analysis indicates that WW7 capacity to assimilate carbohydrates was similar to the type strains, i.e. C. luteum, C. albidum, and C. flaccumfaciens, while no assimilation of the organic acids succinate, alpha-Ketobutyrate, mono methyl-succinate, and lactate was observed. Finally, fatty acid methyl ester (FAME) analysis identifies anteiso-C15:0 and anteiso-C17:0 major cellular fatty acids (FAs) 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 WW7PP(DSM 34805PP - NRRL B-68078PP).