Mucilaginibacter composti sp. nov., with ginsenoside converting activity, isolated from compost

Area of Science:

• Microbiology
• Bacterial Taxonomy
• Biochemistry

Background:

• Compost environments harbor diverse microbial communities.
• Bacterial isolates from compost require thorough taxonomic characterization.
• Understanding microbial metabolic capabilities is crucial for biotechnological applications.

Purpose of the Study:

• To isolate and taxonomically characterize a novel bacterial strain from compost.
• To investigate the biochemical properties of the isolate, including enzyme activity.
• To determine the phylogenetic placement of the novel strain within the Sphingobacteriaceae family.

Main Methods:

• Polyphasic taxonomic approach including phenotypic and genotypic analyses.
• 16S rRNA gene sequencing for phylogenetic analysis.
• Chemotaxonomic analysis (fatty acids, respiratory quinones) and enzyme activity assays (beta-glucosidase).

Main Results:

• Isolation of a Gram-negative, aerobic, non-motile, rod-shaped bacterial strain, TR6-03(T).
• Strain TR6-03(T) demonstrated beta-glucosidase activity, enabling the transformation of ginsenoside Re to Rg(2).
• Phylogenetic analysis based on 16S rRNA gene sequences placed the strain within the genus Mucilaginibacter, showing highest similarity to Mucilaginibacter lappiensis ANJLI2(T) (96.3%).
• Chemotaxonomic data (G+C content 45.6%, MK-7, specific fatty acids) supported its affiliation with the genus Mucilaginibacter.
• Phenotypic and genotypic differentiation confirmed TR6-03(T) as a distinct species within the genus.

Conclusions:

• The isolated strain TR6-03(T) represents a novel species, Mucilaginibacter composti sp. nov.
• The discovery of Mucilaginibacter composti expands the known diversity within the Mucilaginibacter genus.
• The beta-glucosidase activity of this novel bacterium suggests potential applications in ginseng metabolite biotransformation.