The purpose of the research work was to select the optimal conditions for the cultivation of microorganisms. As a result of the conducted research work, the modes of growing a nitrogen-fixing culture and a microorganism with high enzymatic activity were selected and worked out. At the same time, the optimal conditions for the cultivation of Azotobacter sp were determined – the temperature optimum for cell accumulation was 30°C, for increased polysaccharide production 20 °C, aeration within 5-10 l/l/min, agitator speed-150 rpm, pH value within 6.0±0.2 units, which allowed to achieve a cell titer of at least 1.0×109 CFU/ml. A cost-effective nutrient medium was selected for growing Pseudomonas sp. molasses-autolysate medium and optimal conditions for growing the culture: cultivation temperature 30-32 °C, aeration 1.0-1.5 l/l/ min, agitator speed 150-200 rpm, pH 6.8-7.2 units, sub-titration 5.0 % KOH, defoaming with adecanol, cultivation time-72 hours, which allowed to achieve a cell titer of at least 1.0×109 CFU/ml.