The effect of low temperatures and osmotic stress on the growth of lactic acid bacteria

Background. To date, the use of lactic acid bacteria has not found wide industrial application in the production of fish products. At the same time, the scientific direction associated with the development and use of bacterial cultures for the processing of fish products is highly relevant. Technological processes of fish processing often involve the use of high concentrations of NaCl and low positive temperatures; these factors inhibit the growth and development of most microorganisms. Therefore, the development of bacterial cultures to produce fish products should include the study of tolerance of probiotic strains to these stress factors. Latilactobacillus sakei species have great prospects for the use as bacterial cultures for fish products processing due to high biochemical activity and potential probiotic properties. Purpose. The aim of the study was to study the resistance of Latilactobacillus sakei strains to high sodium chloride concentrations and low temperatures. The objects of the study were four strains of Latilactobacillus sakei. Materials and methods. Cultivation of lactic acid bacteria was carried out on MRS medium at a temperature of 37 °C. The ability of bacteria to grow in the presence of sodium chloride was determined on MRS medium containing 12% NaCl, and the tolerance of bacteria to low positive temperatures was studied by strains cultivation at 8 °C. Results. As a result of the studies, it was proven that the strains Llb. sakei LSK-45, Llb. sakei LSK-104, Llb. sakei LSK-103 can grow in the medium with a high concentration of NaCl (12%) and at low positive temperatures. Conclusion. Thus, the use of Llb. sakei LSK-45, Llb. sakei LSK-104, Llb. sakei LSK-103 strains in the fish processing industry is of great scientific interest.