Pseudomonas canadensis sp. nov., a biological control agent isolated from a field plot under long-term mineral fertilization

The bacterial strain 2-92(T), isolated from a field plot under long-term (>40 years) mineral fertilization, exhibited in vitro antagonistic properties against fungal pathogens. A polyphasic approach was undertaken to verify its taxonomic status. Strain 2-92(T) was Gram-reaction-negative, aerobic, non-spore-forming, motile by one or more flagella, and oxidase-, catalase- and urease-positive. The optimal growth temperature of strain 2-92(T) was 30 °C. 16S rRNA gene sequence analysis demonstrated that the strain is related to species of the genus Pseudomonas. Phylogenetic analysis of six housekeeping genes (dnaA, gyrB, recA, recF, rpoB and rpoD) revealed that strain 2-92(T) clustered as a distinct and well separated lineage with Pseudomonassimiae as the most closely related species. Polar lipid and fatty acid compositions corroborated the taxonomic position of strain 2-92(T) in the genus Pseudomonas. Phenotypic characteristics from carbon utilization tests could be used to differentiate strain 2-92(T) from closely related species of the genus Pseudomonas. DNA–DNA hybridization values (wet laboratory and genome-based) and average nucleotide identity data confirmed that this strain represents a novel species. On the basis of phenotypic and genotypic characteristics, it is concluded that this strain represents a separate novel species for which the name Pseudomonas canadensis sp. nov. is proposed, with type strain 2-92(T) (=LMG 28499(T)=DOAB 798(T)). The DNA G+C content is 60.30 mol%.