STUDY OF THE MICROBIOLOGICAL COMPOSITION OF DAIRY PRODUCTS AND MAYONNAISE USING DNA BARCODING AND METABARCODING

Abstract

Prokaryotic and eukaryotic microorganisms cause spoilage of produced dairy and fat-and-oil products. In addition, these products can be contaminated with pathogenic microorganisms. The standard practice of detecting bacterial pathogens is based on the cultivation of microorganisms due to which the analysis lasts from 5 to 7 days. Molecular genetic methods can reduce the analysis time to 1-2 days. In this paper, the ready-made commercial products of the dairy and fat-and-oil industry have been analyzed for the microbiological composition using classical DNA barcoding and DNA metabarcoding. During the study, representatives of the genera Pseudomonas , Bacillus , Lactococcus , Kocuria , Staphylococcus , Moraxella , Paucisalibacillus, Acinetobacter , Klebsiella , Paenibacillus , Lysinibacillus , Enterobacter, Acetobacter and Massilia have been defined . When analyzing the quantitative ratio of microorganisms, it was revealed that dairy and fat-and-oil products are most often seeded with Bacillus sp., among which Bacillus licheniformis (16.67% of colonies) and Bacillus subtilis (11.4% of colonies) can be distinguished . Among Pseudomonas sp. , Pseudomonas fluorescens (19.3% of colonies) are the most numerous . Lactococcus lactis , Acetobacter indonesiensis and Moraxella osloensis bacteria also significantly contaminate dairy and fat-and-oil products . Mayonnaise is contaminated with yeast of the Pichia genus. The analysis revealed opportunistic pathogenic species: Staphylococcus warneri , Staphylococcus epidermidis, Klebsiella pneumonia , Bacillus cereus, Vibrio sp . The presented method for detecting microbial contamination using an Ion torrent PGM platform seems promising for the rapid testing of the produced dairy and fat-and-oil products.

Keywords

• Bacteria
• eukaryotic microorganisms
• food products
• seeding
• spoilage
• DNA barcoding
• DNA metabarcoding