Antibacterial activity of ethanol extracts of fifteen Bulgarian plants

A. Solak, S. Dyankova

Institute of Cryobiology and Food Technologies, 53 Cherni Vrah Str., 1407 Sofia, Bulgaria

(Manuscript received 1 September 2018; accepted for publication 16 January 2019)

Abstract. Analyses were performed of the antimicrobial activity of 15 herbs and spices (lemongrass, sour cherry, horseradish, ginger, St. John’s wort, common centaury, fig, clove, rose geranium, dill, rosemary, oregano, savory, smoketree and wild thyme) widely spread and used in Bulgaria and of some combinations thereof by the agar disk diffusion method. Total phenol content was the highest in the smoketree extract (43.80±1.50 GAE/ml), followed by rosemary (27.80±1.20 GAE/ml), clove (25.17±0.26 GAE/ml), wild thyme (24.83±1.20 GAE/ml), and oregano (23.50±2.00 GAE/ml) extracts. It was established that ethanol extracts of many tested plants showed inhibitory action against S. aureus and E. coli. The most potent effect was observed with extracts of St. John’s wort, smoketree and clove. With combination of plant extracts, very good results were demonstrated in mixtures of St. John’s wort with wild thyme, with savory and with clove. The said extracts may be used as active constituents in biopolymer matrices for development of functional antimicrobial films needed for food and pharmaceutical industries.