Pseudomonas floridensis sp. nov., a bacterial pathogen isolated from tomato

Area of Science:

• Microbiology
• Plant Pathology
• Bacterial Taxonomy

Background:

• Leaf spot symptoms on tomato plants, resembling bacterial speck, led to the isolation of an unusual fluorescent pseudomonad.
• The isolated strains displayed characteristics including oxidase- and arginine-dihydrolase-negativity, hypersensitive reaction on tobacco, and soft rot on potato slices.

Purpose of the Study:

• To characterize and classify a novel bacterial species isolated from diseased tomato plants.
• To determine the phylogenetic relationship of the novel strains within the genus Pseudomonas.

Main Methods:

• Multilocus sequence analysis (MLSA) using 16S rRNA, gap1, gltA, gyrB, and rpoD genes.
• Whole-genome comparisons including average nucleotide identity (ANI) and in silico DNA-DNA hybridization (dDDH).
• Biolog GEN III tests and fatty acid methyl ester (FAME) profiling.

Main Results:

• Phylogenetic analyses placed the strains as a distinct group within the genus Pseudomonas, closely related to Pseudomonas viridiflava.
• Genome-based comparisons showed ANI values below the species threshold (86.59%) and dDDH values (31.1%) indicating a new species.
• Distinct physiological and biochemical profiles differentiated the isolates from related species.

Conclusions:

• The isolated strains represent a novel species within the genus Pseudomonas, proposed as Pseudomonas floridensis sp. nov.
• Pseudomonas floridensis sp. nov. is proposed with GEV388T as the type strain, based on comprehensive genomic and phenotypic data.