MARIJANA

Abstract

Antimicrobal activity of the acetone, methanol and aqueous extracts of the lichens Lecanora atra, Lecanora muralis, Parmelia saxatilis, Parmelia sulcata and Parmeliopsis ambigua was explored In vitro against to 6 species of bacteria and 10 species of fungi by the disc-difusion method and determination of the minimal inhibitory concentration (MIC) by the Broth tube Dilution method. The acqueous extracts of the tested lichens didn't show any antimicrobal activity on any of the test organisms, whereas the acetone and methanol ones showed an activity related to the tested species. The bacteria were very sensitive related to the tested fungi. The strongest antimicrobal activity was found in the acetone extract of the lichen Parmelia sulcata where the least measured MIC value was 0.78 mg/ml. Generally, among the bacteria the most sensitive was the species Bacillus mycoides, and among the fungi Botrytis cinerea and Candida albicans. The bacterium Escerichia coli was resistant to all the extracts of the explored lichens. Generally, all the explored lichens had a relatively strong antimicrobal activity, which can be very important in making the food bad and in curing numerous diseases caused by these and similar microorganisms.