Determination of Antagonistic Activity and Antibiotic Resistance of Bacteria and Yeast for Starter Cultures: An Experimental Study to Increase the Production of Fermented Milk Drinks in Kazakhstan

Abstract

The interest in the study of lactic acid bacteria is due not only to the fact that they play a large and versatile role in human life. Researchers pay special attention to their biological properties, such as adhesiveness, antagonistic, immunoregulatory, antitumor, cytoprotective, and cholesterol-neutralizing activity, phage resistance, and bacteriocinogenity. This entails the need to constantly isolate new species of lactic acid bacteria and their phages, study their characteristics and systematic position in modern classification, and expand the ways of their practical application in the food industry. The purpose of the paper is to present the results of the antagonistic activity and antibiotic resistance of lactic acid bacteria and lactic acid bacteria yeast, which form the basis of priority starter cultures in the production of fermented milk drinks. To conduct the study, we obtained 56 strains of lactic acid bacteria newly isolated from products whose production was located in three geographically distributed regions of Kazakhstan. The media for maintaining isolated cultures of lactic acid bacteria and yeast were De Man–Rogosa–Sharpe (MRS) agar, milk hydrolysate (MH) (according to Bogdanov), MH with agar, generally accepted diagnostic media, and wort agar. The optimal environment for the manifestation of antagonistic properties is the MRS agar. The studied strains are sensitive mainly to ampicillin, levomycetin, and streptomycin, and to the rest of the antibiotics, they are slightly sensitive or not sensitive at all.