Pseudomonas solani sp. nov. isolated from the rhizosphere of eggplant in Japan

The search for bacteria that can be used as biocontrol agents to control crop diseases yielded a promising candidate, Sm006 T , which was isolated from the rhizosphere of eggplant ( Solanum melongena ) growing in a field in Aichi Prefecture, Japan, in 2006. The cells were Gram-stain-negative, aerobic, non-spore-forming, rod-shaped and motile with one polar flagellum. The results of homology searches and phylogenetic analyses based on the 16S rRNA gene sequence indicated that Sm006 T represents a member of the genus Pseudomonas . The genomic DNA G+C content was 66.3 mol% and the major cellular fatty acids (more than 5 % of the total fatty acids) were summed feature 8 (C 18 : 1 ω7 c and/or C 18 : 1 ω6 c ), summed feature 3 (C 16 : 1 ω7 c and/or C 16 : 1 ω6 c ), C 16 : 0 and C 12 : 0 . Phylogenetic analyses using the rpoD gene sequence and phylogenomic analysis of the whole genome sequence revealed that Sm006 T represents a member of the Pseudomonas resinovorans group; however, its phylogenetic position does not match that of any known species of the genus Pseudomonas . The average nucleotide identity and digital DNA–DNA hybridisation values between the strain and closely related species were lower than the thresholds for prokaryotic species delineation (95–96 and 70 %, respectively), with the highest values observed for Pseudomonas tohonis TUM18999 T (92.05 and 46.3 %, respectively). Phenotypic characteristics, cellular fatty acid composition and possession of 2,4-diacetylphloroglucinol biosynthetic gene cluster could be used to differentiate the strain from its closest relatives. The phenotypic, chemotaxonomic and genotypic data obtained during this study indicated that Sm006 T represents a novel species of the genus Pseudomonas , for which we propose the name Pseudomonas solani sp. nov., with Sm006 T (= MAFF 212523 T = ICMP 24689 T ) as the type strain.