Isolated exopolysaccharide Streptococcus thermophilus. The conditions for the cultivation of bacteria for the maximum yield of the exopolysaccharide were selected. The bacterial culture of S. thermophilus was incubated for 48 hours in a liquid nutrient medium A. Welman at 38 °C, 180 rpm. on a thermostated shaker-incubator. As a source of carbon were used: sucrose, lactose and glucose. For the production of exopolysaccharide, the best source of carbon was sucrose. Isolation of the exopolysaccharide was carried out according to the J. Cerning method in our modification.