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.

Research on the stimulating effect of Tribulus terrestris on the oviparous activity of the queen bees

I. Hristakov

Abstract. All major processes in the bee colony are closely related to nectariferous vegetation in the area. Oviparous activity of queen bees is directly dependent on the flow of nectar and pollen in the bee colony. When it rises it leads to increase of the oviparous activity of queens, and thus increases the power of the colony. Stimulating feeding with sugar syrup in the absence of pollen flow has little effect on the laying activity of the queens, as the syrup with biologically active substances which are necessary for bees and queens. This paper presents a research on the addition of extract of Tribulus terrestris L. as invert sugar syrup, by which we import some of the biologically active substances needed by bees and bee stimulating oviparous activity of the queen bees.

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