Leucobacter celer sp. nov., isolated from Korean fermented seafood.

Area of Science:

• Microbiology
• Bacteriology
• Food Science

Background:

• Traditional fermented foods are rich sources of microbial diversity.
• Gajami-sikhae, a Korean fermented flatfish seafood, harbors unique bacterial communities.
• Understanding the microbial composition of fermented foods is crucial for food safety and innovation.

Purpose of the Study:

• To isolate and characterize a novel bacterial strain from gajami-sikhae.
• To determine the taxonomic and phylogenetic placement of the novel isolate.
• To propose a new species within the genus Leucobacter.

Main Methods:

• Isolation and cultivation of bacterial strain NAL101(T) from gajami-sikhae.
• Physiological and biochemical characterization, including growth conditions and cell-wall composition.
• Molecular analyses, including 16S rRNA gene sequencing and DNA-DNA hybridization.
• Phylogenetic analysis to determine taxonomic relationships.

Main Results:

• Strain NAL101(T) is a Gram-positive, aerobic, rod-shaped, non-motile bacterium.
• It exhibits broad growth ranges for temperature, pH, and salinity, with optimal growth at 30-37 °C, pH 8, and low NaCl concentrations.
• 16S rRNA gene sequence analysis showed highest similarity (97.7%) to Leucobacter chironomi, but DNA-DNA hybridization values were low (<22%), confirming it as a distinct species.
• Chemotaxonomic data (cell-wall amino acids, fatty acids, menaquinone) supported its classification within the genus Leucobacter.

Conclusions:

• Strain NAL101(T) represents a novel species of the genus Leucobacter.
• The proposed name for this new species is Leucobacter celer sp. nov.
• This finding expands the known diversity of the genus Leucobacter and highlights the potential of fermented seafood as a source of novel microorganisms.