FIELD: biotechnology.
SUBSTANCE: method for determining the biocompatibility level of strains of bifidobacteria and/or lactobacilli is proposed. Method involves separately growing strains in a liquid medium and co-incubating their supernatants separately with a suspension of cells of the Bifidobacterium lognum MC-42 test strain. Washed cells of the test strain are cultured in nutrient broth, the supernatant is separated, and the previously co-incubated strain is then cultured, pre-grown on a dense nutrient medium, determine its growth properties, anti-lysozyme activity, biofilm formation. Calculate the level of biocompatibility of strains – B, (%) according to the formula: 
, where GPo and GPk are growth properties of the strains in experience and control, unit OP450; BFFo and BFFk – biofilm formation, units OP630; ALAo and ALAe – anti-lysozyme activity, mcg/ml*OP450. With a value of B equal to or more than 50 %, the biocompatibility of strains of bifidobacteria and/or lactobacilli is considered high.
EFFECT: method allows to determine the level of biocompatibility of strains in a consortium of probiotic bacteria.
1 cl, 4 tbl, 3 ex
