THE EFFECT OF BACTERIOCIN ENTEROCOCCUS ITALICUS ONU 547 AND ESSENTIAL OILS ON THE GROWTH OF OPPORTUNISTIC MICROORGANISMS

Abstract

Purpose. To evaluate the effectiveness of bacteriocin of Enterococcus italicusONU 547 and essential oils individually and in combination against indicatorstrains of opportunistic pathogens. Methods. The antagonistic activity of essential oils and bacteriocin was determined by the optical density of the bacterial suspension of test strains (Salmonella enterica NCTC 6017, Escherichia coli АТСС 25922, Pseudomonas aeruginosa АТСС 27853, Pseudomonas putida KT 2440, Enterococcus faecalis АТСС 29212, Klebsiella pneumoniae АТСС 10031,Staphylococcus aureus АТСС 25923). The index of fractional inhibitory activity(FIC) was calculated by adding the FIC values of bacteriocin E. italicus ONU 547and the studied essential oils. The results. The maximum antimicrobial effect was caused by the essential oils of Anisum officinalis and Melissa officinalis, which suppressed the growth of test strains more than 50.0%. When using bacteriocin of E. italicus ONU 547 suppression of viability of indicator strains did not exceed 30.0%. Experimental combinations of essential oils and bacteriocin caused 4 types of consequences: synergy effect; additive effect; antagonistic effect; interactiveeffect (no interaction effect). In most cases, the combined action of bacteriocinand essential oils caused an additive effect. Conclusions. This study demonstrated the potential of using different combinations of natural antimicrobial compounds. The obtained results provide grounds for further development and optimization ofcombinations of essential oils and probiotic strains of microorganisms for use in food and pharmaceutical biotechnology.