The bactericidal effect of extracts from Humulus lupulus l marynka variety on selected bacteria

The aim of the research was to obtain extracts of Humulus lupulus L hop cones of the Marynka variety and to evaluate their antibacterial properties against three strains of gram-negative bacteria (Escherichia coli ATCC 10536, E. coli IPS and Pseudomonas aeruginosa ATCC 27853) and against two strains of gram-positive bacteria (Enterococcus hirae ATCC 10541 and Bacillus cereus ATCC 12826). The research material consisted of dried Marynka variety hop cones, from which extracts in the form essential oil (EO), infusion and decoction were obtained. EO was obtained in the process of hydrodistillation. The antibacterial activity of the extracts was evaluated by the plate-cylinder diffusion method against the tested gram-negative and gram-positive bacteria. Diverse antibacterial activity of water extracts of H. lupulus L hop cones of the Marynka variety (essential oil, infusion and decoction) on the tested bacteria was demonstrated, with higher sensitivity of gram-positive than gram-negative bacteria. The highest resistance to hop extracts was demonstrated by P. aeruginosa ATCC 27853. The best antibacterial properties were demonstrated by the essential oil at a concentration of 2.0 %. In the group of gram-positive bacteria, E. hirae ATCC 10541 was more sensitive to EO, and E. coli IPS in the group of gram-negative bacteria. In the case of B. cereus ATCC 12826, the sensitivity to infusions and decoctions of hop cones requires further investigation, as the obtained large zones of growth inhibition were unstable.