The antibacterial activity of culture filtrates and mycelia of selected strains of macromycetes from the genus Hericium

The aim of the study was to investigate the antibacterial activity of selected strains of the genus Hericium, belonging to basidiomycetes, from the IBK Mushroom Culture Collection of the M.G. Kholodny Institute of Botany of the National Academy of Sciences of Ukraine. A total of 14 strains including H. abietis, H. cirrhatum, H. coralloides, and H. erinaceus were investigated. The strains were cultivated on a liquid glucose-peptone-yeast medium. Both the homogenised mycelium and filtrate of these fungi were evaluated against gram-positive (Bacillus subtilis, Micrococcus luteus, and Staphylococcus aureus) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria by the disk diffusion and cylinder methods. The activity of the strains varied significantly. Depending on the techniques assay, species, strain, and stage of fungal development, the inhibition zone of the tested bacteria ranged from 5.3 mm to 20.0 mm. In general, the antibacterial potential of the culture filtrates of the investigated species was significantly higher than their mycelia activity. The homogenised mycelium showed potentially good results only against E. coli. The antibacterial activities of the H. abietis and H. cirrhatum species were observed for the first time. To the best of our knowledge, the ability of H. coralloides to inhibit the growth of P. aeruginosa and S. aureus has not been previously reported. The obtained results indicate the ability of the studied Hericium species to produce antibacterial metabolites with a wide and narrow spectrum of action which might have potential health benefits and could be recommended for the further analysis, isolation and identification of potentially promising antibacterial compounds in pharmacology.