Flavobacterium ichthyis sp. nov., isolated from a fish pond

Area of Science:

• Microbiology
• Bacteriology
• Taxonomy

Background:

• The genus Flavobacterium comprises diverse bacteria, some of which are associated with aquatic environments and fish.
• Accurate classification of bacterial species is crucial for understanding microbial ecology and potential impacts.

Purpose of the Study:

• To characterize a novel bacterial isolate, strain NST-5T, from a fish pond in Taiwan.
• To determine the taxonomic placement of strain NST-5T within the genus Flavobacterium.

Main Methods:

• Polyphasic taxonomy approach, including 16S rRNA gene sequencing and whole-genome-based phylogenetic analyses.
• Phenotypic characterization, including cellular morphology, growth conditions, and biochemical analyses.
• Analysis of fatty acid profiles, polar lipids, polyamines, and isoprenoid quinones.

Main Results:

• Phylogenetic analyses placed strain NST-5T within the genus Flavobacterium, distinct from known species.
• Average nucleotide identity (94.9%) and digital DNA-DNA hybridization (19.1-23.7%) values confirmed its novelty.
• Strain NST-5T is a Gram-negative, aerobic, motile, rod-shaped bacterium forming yellow colonies, with optimal growth at 30°C, pH 7, and 0.5% NaCl.

Conclusions:

• Strain NST-5T represents a novel species within the genus Flavobacterium.
• The proposed name for this new species is Flavobacterium ichthyis sp. nov., with strain NST-5T as the type strain.