The aim of the study is to examine the anti-microbial effect of those plant species, which, based on our previous results, significantly inhibit the growth of microorganisms. The cultivars of the chosen sea buckthorn and sour cherry species, originated in Hungarian growing regions, and they are rich in polyphenolic and anthocyanin compounds. The antioxidant capacity was determined by FRAP (Ferric Reducing Ability of Plasma), total polyphenol content (TPC) and TEAC (Trolox Equivalent Antioxidant Capacity) assays. In this study, antimicrobial effect was tested on the strains of two bacteria (E. coli, S. aureus). The degree of inhibition was measured by rapid methods: impedance technique (RABIT, Don Whitley Scientific Ltd., UK). The antimicrobial effect was compared with analytical results. The results of our measurement show that due to the high antioxidant capacity of sea buckthorn; have higher antimicrobial effect against chosen bacteria. Anti-microbial efficiency of sour cherry was significantly less than effect of sea buckthorn, but it reached greatly inhibition of microorganisms. Further researches these fruits can serve as a raw material for new, natural origin, and effective antimicrobial agents in a food industry which can use as bio-preservatives