Investigation of antimicrobial activity of some geophyte plants naturally distributed in Turkey

This study was to enlighten antimicrobial activities of the four plant species including Gagea dubia, Iris masia Dykes subsp. masia, Allium noeanum and Gladiolus italicus which belong to Liliaceae, Amaryllidaceae and Iridaceae families. Plant extracts were prepared in 80:20 ethanol:water solvent system. The extracts were tested using the following 18 bacterial species including Bacillus subtilis, Enterococcus durans, Enterobacter aerogenes, Enterococcus faecium, Enterococcus faecalis, Escherichia coli, Klebsiella pneumonia, Listeria monocytogenes, Pseudomonas aeruginosa, Pseudomonas fluorescens, Salmonella enteritidis, Salmonella infantis, Salmonella Kentucky, Salmonella typhimurium, Staphylococcus aureus, Staphylococcus epidermidis, Serratia marrescens and Listeria innocua along with the fungi Candida albicans. Antimicrobial activities of extracts for these 19 microbial species were evaluated using disc-diffusion (DD), minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) approaches. According to the findings, different plant extracts were shown active for different bacterial species. For example, extracts of Gladiolus italicus gave between 7.33 and 15 mm zone diameters for nine bacterial strains while extracts of Allium noeanum gave between 7 and 13 mm zone diameters for seven bacterial strains, and extracts of Gagea dubia gave between 7.66 and 15.66 mm zone diameters for five bacterial strains.