Effect of the Extracts from Lichens and Lichenophilic Fungi on In Vitro Growth of Clinically Significant Microorganisms

Abstract

The activity of the ethanol extracts of lichens (LE), of the cultures of lichenophilic (endobiotic) fungi (LFE), and of ethanol extracts of these cultures was tested using the following test organisms: Escherichia coli, Salmonella typhimurium, Pseudomonas fluorescens, Staphylococcus aureus, Micrococcus luteus, Enterococcus faecium, Paenibacillus sp., and Candida parapsilosis. Selective activity of LE and LFE against yeasts and gram-positive and gram-negative bacteria was revealed. The extracts from Cladonia rangiferina exhibited no activity against any of the tested cultures. The previously reported locus effect on activity of metabolites of one lichen species was confirmed. Agar block technique was used to detect selective activity of 23 out of 61 analyzed fungal strains against gram-positive and gram-negative bacteria, and of 8 strains, against yeasts. Ethanol extracts of six cultures were shown to suppress the growth of St. aureus, M. luteus, Paenibacillus sp., and E. coli. Strain NM10F28209 from the lichen Stereocaulon paschale, which exhibited inhibitory activity against Ca. parapsilosis was selected for priority development of an antifungal preparation.