Antimicrobial effects of Leptogium saturninum, Ramalina peruviana and Punctelia borreri

Lichens produce high diversity of metabolites and they have different biological activities including antibacterial, antifungal, antiviral, anti-inflammatory and the cytotoxic effects. In this study, the impact of antimicrobial substances of lichens were studied. For this purpose, the lichens of northern forests around Babol city was collected and via the morphological and microscopic characteristics, biochemical and molecular methods were identified. Then, ethanol extracts of lichens were prepared. Antimicrobial effects of extracts was assayed using the diffusion agar method and the determination of minimum inhibitory concentration against five bacteria, Bacillus cereus, Xanthomonas campestris, Escherichia coli, Staphylococus aureus and Pseudomonas aeruginosa. The studies showed that the extract of Leptogium saturninum, Ramalina peruviana, Punctelia borreri were effective against X. campestris، S. aureus. However, in the case of Bacillus cereus and E.coli only the extract of R. peruviana was effective. Furthermore, measuring the diameter of zone inhibition and MIC against three clinical Candida albicans, Candida tropicalis, and Candida glabrat showed that the extracts of Leptogium saturninum, Ramalina peruviana were effective on all the strains. However the extract of Punktelia subrodecta was effective only on C.albicans. The substance of lichens, which assayed by biochemical tests showed that due to the presence of phenolic compounds, lichens show high antimicrobial properties. It should be carried out the antimicrobial experiments on a wide range of environmental and pathogenic microorganisms.