MATHEMATICAL ANALYSIS AND OPTIMIZATION OF THE CULTURE MEDIUM FOR STRAIN LACTOBACILLUS PLANTARUM ONU 87

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Ai m. The aim of this work was to optimize the composition of the nutrient medium for cultivation the strain L. plantarum ONU87 of lactic acid bacteria while studying the impact of various components of culture media on the growth characteristics and antagonistic activity of these bacteria. Methods. The antagonistic activity of the strain L. plantarum ONU87 relatively to Rhizobium radiobacter C58 in vitro was determined by the double agar layer. The titer was determined by method of serial delutions of Rhizobium radiobacter C58 followed by plating on solid medium MRS. Methodological basis for the work were well-known methods, which allowed determine the quantitative values of the index CFU/ml and antagonistic activity. Assess the impact of each factor of the growth media on verifiable indicators was performed using the partial regression model. Optimization of culture medium was performed using the central composite orthogonal design. The indicator of bacterial concentration served as a parameter optimization. Results. The studies show that the accumulation of bacteria and their antagonistic activity depends on the components of culture media and their relationship, which was proved by mathematical models. The final result of the research was the new culture medium – OLB (glucose – 22.5 g/l, peptone – 8.5 g/l, yeast extract – 4.5 g/l, K2HPO4 – 6.0 g/l, Na citrate – 2.0 g/l, CH3COONa ½ 3H2O – 25.0 g/l, MgSO4 – 0.2 g/l, MnSO4 – 0.2 g/l FeSO4 – 0.05 g/l) by using it the concentration of lactic acid bacteria in the stationary phase of growth increased to 3.51±0.10½1010 CFU/ml. Conclusion. It has been shown that the mathematical design of the experiments, allows with little change in the quantitative composition of the culture medium, significantly increase the accumulation of biomass.