sp. nov., a novel symbiotic bacterial species associated with entomopathogenic nematodes.

One motile, Gram-negative, non-spore-forming and rod-shaped symbiotic bacterium, strain UCH-936, was isolated from nematodes. Results of biochemical, physiological, molecular and genomic analyses suggest that it represents a new species, which we propose to name sp. nov. Digital DNA-DNA hybridization shows that strain UCH-936 is more closely related to DSM 23513, but shares solely 50.5 % similarity, which is below the 70% cut-off value that delimits species boundaries in bacteria. Phylogenetic reconstructions using whole-genome sequences show that strain UCH-936 forms a unique clade, suggesting its novel and distinct taxonomic status again. Similarly, comparative genomic analyses shows that the virulence factor flagella-related gene , the type IV pili-related gene and the vibriobactin-related gene are present in the genome of strain UCH-936 but absent in the genomes of its closest relatives. Biochemically and physiologically, UCH-936 differs also from all closely related species. Therefore, sp. nov. is proposed as a new species with the type strain UCH-936 (CCCT 21.06=CCM 9188=CCOS 1991).