Pullulanibacillus camelliae sp. nov., isolated from Pu'er tea

Area of Science:

• Microbiology
• Bacterial Taxonomy
• Fermentation Science

Background:

• The genus Pullulanibacillus comprises spore-forming bacteria with industrial and environmental relevance.
• Characterization of novel bacterial species is crucial for understanding microbial diversity and potential applications.
• Pu'er tea fermentation involves complex microbial communities, offering a source for novel microorganisms.

Purpose of the Study:

• To isolate and characterize a novel bacterial strain from ripened Pu'er tea.
• To determine the taxonomic position of the novel strain using phylogenetic and chemotaxonomic analyses.
• To propose a new species within the genus Pullulanibacillus based on comprehensive data.

Main Methods:

• Isolation and cultivation of bacterial strain 7578-24T from Pu'er tea.
• 16S rRNA gene sequencing for phylogenetic analysis.
• DNA-DNA hybridization, cell-wall analysis, fatty acid profiling, and polar lipid analysis for chemotaxonomic characterization.
• Determination of DNA G+C content.

Main Results:

• A novel Gram-positive, aerobic, endospore-forming rod, strain 7578-24T, was isolated.
• Phylogenetic analysis placed strain 7578-24T within the genus Pullulanibacillus, closely related to Pullulanibacillus pueri.
• Distinct genotypic and phenotypic characteristics, including low DNA-DNA relatedness (35%) with P. pueri, supported its classification as a new species.
• Key chemotaxonomic features included meso-diaminopimelic acid in peptidoglycan, menaquinone 7, and specific predominant fatty acids.

Conclusions:

• Strain 7578-24T represents a novel species, proposed as Pullulanibacillus camelliae sp. nov.
• This finding contributes to the taxonomy of the genus Pullulanibacillus and highlights the microbial richness of fermented tea ecosystems.
• The detailed characterization provides a basis for future studies on the properties and potential roles of this new bacterium.