Perlucidibaca aquatica sp. nov., isolated from fresh water

Area of Science:

• Microbiology
• Bacteriology
• Environmental Microbiology

Background:

• Microbial diversity in aquatic ecosystems remains incompletely characterized.
• Limestone cave environments harbor unique microbial communities.
• The genus Perlucidibaca comprises bacteria with specific ecological niches.

Purpose of the Study:

• To isolate and characterize a novel bacterial strain from stream water in a Korean limestone cave.
• To determine the taxonomic placement of the novel isolate using polyphasic characterization.
• To propose a new species within the genus Perlucidibaca.

Main Methods:

• Isolation and cultivation of bacteria from stream water.
• Gram staining, motility, pigmentation, and aerobic growth tests.
• Phylogenetic analysis based on 16S rRNA gene sequencing.
• Average nucleotide identity (ANI) and genome-to-genome distance (GDD) calculations.
• Determination of DNA G+C content, major fatty acids, and isoprenoid quinones.

Main Results:

• A novel Gram-staining-negative, aerobic, rod-shaped bacterium, strain BK296T, was isolated.
• Phylogenetic analysis placed strain BK296T within the genus Perlucidibaca, closely related to Perlucidibaca piscinae.
• ANI (79.8%) and GDD (17.5%) values indicated a distinct species.
• Chemotaxonomic data (fatty acids, quinones) and G+C content (55.7%) supported its unique identity.

Conclusions:

• Strain BK296T represents a novel species of the genus Perlucidibaca.
• The proposed name for this new species is Perlucidibaca aquatica sp. nov.
• This discovery expands the known diversity of the Perlucidibaca genus in aquatic environments.