Antimicrobial potential of lactic acid bacteria Lactobacillus rhamnosus lysate

Антимікробний потенціал лізату молочнокислих бактерій Lactobacillus rhamnosus V / Д. Остапченко та ін. Вісник Київського національного університету імені Тараса Шевченка. Біологія. 2022. Вип. 4(91). С. 19-23.

According to World Health Organization, antibiotic resistance is rising to dangerously high levels in all parts of the world. New resistance mechanisms are emerging and spreading globally, threatening our ability to treat common infectious diseases. Therefore, searching for new antimicrobial agents of natural origin is an extraordinary global problem. The work aimed to determine the antimicrobial activity of lyophilized enzymatic lysate of cells of the Lactobacillus rhamnosus V strain of lactic acid bacteria. The object of the study was the drug Del-Imun V®, which hasanti-allergican dimmuno stimulating activity. The researchers' efforts aimed to fully reveal the drug's potential, particularlyitsanti microbialaction. Antimicrobial activity was determined by the minimum inhibitory concentration (MIC). Determination of MIC was carried out by the method of twotime serial dilutions in meat-peptone broth (MPB) for bacteria and liquid wort for yeast. Gram-negative (Escherichia coli IEM-1, Proteus vulgaris PA-12, Pseudomonas sp. MI-2) and Gram-positive (Bacillus subtilis BТ-2, Staphylococcus aureus BМС-1) bacteria, as well as yeast (Candida albicans D-6, Candida tropicalis PE-2, Candida utilis BVS-65). It was shown that MIC valuesof the native preparation for the bacterial test cultures (EscherichiacoliIEM-1, Bacillussubtilis BT-2, Staphylococcusaureus BMS-1, Proteusvulgaris PA-12, Pseudomonassp. MI-2) were 8 time slower, than those of the thermally in activated preparation, forthe yeasts (Candidaalbicans D-6, Candidatropicalis PE-2, Candidautilis BVS-65) – 4-8 time slower. As a result of the conducted research, the antibacterial and antifungal activity of the drugDel-Imun V® was established. The spectrum of antimicrobial activity concerned gram-positiveand gram-negative bacteria and yeast-like fungi of the genus Candida. The minimum inhibitory concentrations were quite low: from 1.0 to 4.0 μg/ml for bacterial cultures and from 62.5 to 125 μg/ml for yeast. The culture of B. subtilis BT-2 was the least sensitive to the drug's action (MIC – 12.5 μg/ml). There fore, it can be concluded that the lysate of Lactobacillus rhamnosus V lacticacid bacteriahasanti bacteria landanti fungal properties.