Sp. Nov., a Plant-pathogenic Bacterium Isolated from Pepper Leaf in Georgia, USA

Three phytopathogenic bacterial strains (Pc19-1, Pc19-2 and Pc19-3) were isolated from seedlings displaying water-soaked, dark brown-to-black, necrotic lesions on pepper () leaves in Georgia, USA. Upon isolation on King's medium B, light cream-coloured colonies were observed and a diffusible fluorescent pigment was visible under ultraviolet light. Analysis of their 16S rRNA gene sequences showed that they belonged to the genus , with the highest similarity to ATCC 10857 (99.7 %). The fatty acid analysis revealed that the majority of the fatty acids were summed feature 3 (C ω7/C ω6), C and summed feature 8 (C ω7/C ω6). Phylogenomic analyses based on whole genome sequences demonstrated that the pepper strains belonged to the complex with as their closest neighbour, and formed a separate monophyletic clade from other species. Between the pepper strains and , the average nucleotide identity values were 91.3 %. Furthermore, the digital DNA-DNA hybridization values of the pepper strains when compared to their closest relatives, including , were 45.2 % or less. In addition, biochemical and physiological features were examined in this study and the results indicate that the pepper strains represent a novel species. Therefore, we propose a new species sp. nov., with Pc19-1 (=CFBP 8884=LMG 32209) as the type strain. The DNA G+C content of the strain Pc19-1 is 58.4 mol%.