Pseudomonas moraviensis sp. nov. and Pseudomonas vranovensis sp. nov., soil bacteria isolated on nitroaromatic compounds, and emended description of Pseudomonas asplenii

This study describes two novel Pseudomonas species isolated from Czech soil using selective enrichment with nitroaromatic compounds. Strains 1B4T and 2B2T were characterized using polyphasic taxonomy, including 16S rRNA gene sequencing, DNA–DNA hybridization, biochemical testing, fatty acid analysis, and ribotyping. Strain 1B4T showed highest 16S rRNA similarity to P. koreensis (99.5%) and P. jessenii (99.3%), while strain 2B2T was closest to P. asplenii (98.9%). DNA–DNA hybridization values ranged from 12–46%, all below the 70% threshold for species demarcation. Phenotypic differentiation included variations in enzyme production, carbohydrate assimilation, and biochemical profiles. The two isolates are proposed as Pseudomonas moraviensis sp. nov. (1B4T) and Pseudomonas vranovensis sp. nov. (2B2T). Additionally, an emended description of P. asplenii was provided based on detailed characterization of the type strain. Both novel species are Gram-negative, aerobic rods with polar flagella, capable of degrading various organic compounds.

Key findings

• Two novel Pseudomonas species isolated from nitroaromatic-enriched soil: P. moraviensis sp. nov. and P. vranovensis sp. nov.
• DNA–DNA hybridization values (12–46%) clearly below the 70% species threshold despite high 16S rRNA similarity (>98%), supporting species differentiation
• Phenotypic differentiation achieved through enzyme production, carbohydrate assimilation patterns, and biochemical profiles distinct from closely related species
• Emended description of P. asplenii provided with additional phenotypic and biochemical characterization data