Abstract

Strain PVT-9aT, a novel Gram-stain-negative, aerobic, non-spore-forming, motile-by-gliding and rod-shaped bacterium, was isolated from a skin lesion of Atlantic salmon (Salmo salar L.) during a tenacibaculosis outbreak that occurred in 2016 at a Chilean fish farm. Phylogenetic analysis based on 16S rRNA gene sequencing confirmed that strain PVT-9aT belonged to the genus Tenacibaculum , being related to the closest type strains Tenacibaculum haliotis KCTC 52419T (98.49 % sequence similarity), Tenacibaculum aestuariivivum JDTF-79(T) (97.36 %), Tenacibaculum insulae JDTF-31T (97.29 %) and Tenacibaculum ovolyticum IFO 15947(T) (97.15 %). The genome size of strain PVT-9a(T) was 2.73 Mb with a DNA G+C content 31.09 mol%. Average nucleotide identity analysis among 30 Tenacibaculum species rendered the most similar strains as follows: T. haliotis KCTC 52419(T) (87.91 %), T. ovolyticum IFO 15947(T )(82.47 %), Tenacibaculum dicentrarchi 35/09T (81.08 %), Tenacibaculum finnmarkense gv finnmarkense TNO006(T) (80.91 %) and T. finnmarkense gv ulcerans TNO010T (80.96 %). Menaquinone MK-6 was the predominant respiratory quinone. The predominant cell fatty acids (>10 %) were iso-C15 : 0, iso-C15 : 1 G and iso-C15 : 0 3-OH. Phenotypic, chemotaxonomic and genomic data supported the assignment of strain PVT-9a(T) (=DSM 115155(T)=RGM 3472(T)) as representing a novel species of Tenacibaculum , for which the name Tenacibaculum bernardetii sp. nov. is proposed.