Pseudomonas versuta sp. nov., isolated from Antarctic soil

Area of Science:

• Microbiology
• Bacterial Taxonomy
• Antarctic Microbiology

Background:

• Quorum-quenching bacteria play a role in microbial community regulation.
• Antarctic soils are a unique environment for discovering novel microorganisms.
• The genus Pseudomonas is known for its metabolic diversity and ecological importance.

Purpose of the Study:

• To characterize and classify three novel bacterial strains isolated from Antarctic soil.
• To determine the phylogenetic and taxonomic position of the isolates within the genus Pseudomonas.
• To propose a new species designation based on comprehensive data.

Main Methods:

• 16S rRNA gene sequencing for initial phylogenetic placement.
• Housekeeping gene sequence analysis (rpoB, rpoD, gyrB) for detailed phylogeny.
• Average Nucleotide Identity (ANI) calculations for species delineation.
• Phenotypic characterization including oxidase, catalase tests, and growth conditions.
• Chemotaxonomic analysis of respiratory quinones and fatty acids.

Main Results:

• The three strains (L10.10^T, A4R1.5, A4R1.12) showed 99.7% 16S rRNA gene similarity to Pseudomonas weihenstephanensis WS4993^T.
• Housekeeping gene similarities (84-95%) and ANI values (<86%) confirmed they belong to a distinct species within Pseudomonas.
• Physiological tests revealed oxidase and catalase positivity, with growth across a wide temperature (4-30°C) and pH (4.0-10) range.
• Major fatty acids and Q9 respiratory quinone were identified.
• DNA G+C content ranged from 58.2-58.3mol %.

Conclusions:

• The combined genotypic, phenotypic, and chemotaxonomic data strongly support the classification of the three strains as a novel species.
• The proposed name for the new species is Pseudomonas versuta sp. nov.
• The type strain designated for this new species is L10.10^T (LMG 29628^T, DSM 101070^T).