Halomonas nigrificans sp. nov., isolated from cheese

Area of Science:

• Microbiology
• Bacteriology
• Food Science

Background:

• The genus Halomonas comprises diverse bacteria found in various environments, including fermented foods.
• Characterization of novel bacterial species is crucial for understanding microbial diversity and potential applications.

Purpose of the Study:

• To isolate and characterize a novel bacterial strain from acid curd cheese (Quargel).
• To determine the taxonomic position of the novel isolate within the Halomonas genus.

Main Methods:

• Isolation and cultivation of bacteria from Quargel cheese.
• Gram staining, motility tests, and flagella observation.
• 16S rRNA gene sequencing for phylogenetic analysis.
• Comparative sequence analysis of housekeeping genes (secA, gyrB).
• Physiological and biochemical characterization.

Main Results:

• A Gram-negative, rod-shaped, motile bacterium (MBT G8648^T) was isolated.
• Phylogenetic analysis based on 16S rRNA gene sequences placed the strain within the genus Halomonas, with Halomonas titanicae BH1^T as the closest relative (98.42% similarity).
• Comparative gene sequencing and phenotypic analyses confirmed that MBT G8648^T represents a distinct taxon, well-separated from known Halomonas species.

Conclusions:

• The isolated strain MBT G8648^T represents a new species within the genus Halomonas.
• The proposed name for this new species is Halomonas nigrificans sp. nov.
• The type strain is MBT G8648^T (=LMG 29097^T =DSM 105749^T).