Lactobacillus cerevisiae sp. nov., isolated from a spoiled brewery sample

Area of Science:

• Microbiology
• Bacteriology
• Food Science

Background:

• Spoiled beer can harbor various microorganisms impacting quality.
• Accurate identification and classification of bacterial contaminants are crucial for food safety and quality control.

Purpose of the Study:

• To isolate and characterize a novel bacterial strain from spoiled beer.
• To determine the taxonomic position of the isolate using polyphasic methods.
• To propose a new species within the Lactobacillus genus.

Main Methods:

• Isolation and cultivation of bacteria from spoiled beer.
• Gram staining, motility, spore formation, catalase activity, and anaerobic growth tests.
• 16S rRNA, pheS, and rpoA gene sequencing for phylogenetic analysis.
• DNA-DNA hybridization for genetic relatedness assessment.
• Fatty acid profiling for chemotaxonomic characterization.

Main Results:

• A Gram-positive, non-motile, rod-shaped, facultatively anaerobic bacterium (TUM BP 140423000-2250T) was isolated.
• Phylogenetic analysis based on 16S rRNA, pheS, and rpoA genes indicated its placement within the Lactobacillus genus, with closest relatives Lactobacillus koreensis and Lactobacillus yonginensis.
• DNA-DNA relatedness values confirmed its distinctness from known species.
• DNA G+C content was 50.0 mol%, and major fatty acids included C18:1ω9c, summed feature 7, and C16:0.

Conclusions:

• The isolate TUM BP 140423000-2250T represents a novel species within the Lactobacillus genus.
• The proposed name for the new species is Lactobacillus cerevisiae sp. nov.
• The type strain TUM BP 140423000-2250T is available for further research.