Study of the antagonistic properties of C. utilis in relation to the resident microflora of the animal organism

Abstract C. utilis yeast is widely used in industry for the production of fodder protein, amino acids, vitamins, and enzymes. We have studied the antimicrobial activity of C. utilis CY 302 against such collection strains as E. coli 3912/41, S. flexneri 1a 8516, S. enterica serovar Typhimurium 79, S. epidermidis ATCC 14990, S. aureus ATCC 25923, Proteus vulgaris HX 19 222, L. casei subsp. Rhamnosus ATCC 7469, B. breve ATCC 15701, C. albicans ATCC 10231 by using the agar blocks method and by measuring the inhibition growth zone (IGZ, mm) accompanied by the target cells death zone. The yeast strain was grown on Sabouraud’s medium at 28±1 °C for 3 days, and the test cultures were grown on differential diagnostic media for each bacterial species (HiMedia Laboratories Pvt. Ltd, India) at 35±2 °C overnight. The analyses were done separately for each culture. A weak antimicrobial effect was observed with respect to L. casei and B. breve, the IGZ was 5.0 and 4.0 mm, respectively. The halos of inhibition against pathogenic bacteria were 7 mm for E. coli, 5 mm for S. typhimurium, 5 mm for P. vulgaris, 6 mm for S. fiexneri, 6 mm for S. aureus, and 5 mm for S. epidermidis. After incubation there was noted the absence of DZZR in the wild C. utilis CY 302 strain in relation to the C. albicans ATCC 10231 strain from the collection. As a result of the studies the antagonistic potential of the yeast isolate C. utilis CY 302 was revealed. The work was supported by the Ministry of Science and Higher Education of Russia.