The article describes some probiotic properties of fermented product made of natural association of Tibetan kefir grains cultivated in Ukrainian household (UTKG); also, the effect of UTKG microbiota on the growth of pathogenic microbiota and sensitivity to antibiotics was studied. It was found that the test-cultures of oppurtunistic pathogens (Staphylococcus aureus, Bacillus mesentericus, and Mycobacterium luteum) were sensitive; bacteriostatic zone of the test-culture ranged from 21 to 25 mm, and highly sensitive (Proteus vulgaris and Aspergillus niger) bacteriostatic zone exceeded 25 mm to probiotic bacteria of fermented product. UTKG microbiota is also moderately sensitive to multiple antibiotics that allows defining the obtained fermented milk product as functional with therapeutic properties. During the study of the influence of different NaCl and bile concentrations on acid-activity of UTKG it was found that active acid formation occurred at the concentrations up to 4% NaCl in cultivation medium (boiled milk) and at 20% bile and 0.45% phenol. It proves microbial association to be capable of withstanding adverse gastrointestinal conditions and continue developing.
Keywords: Fermented product; Probiotic bacteria; Tibetan kefir grains.