Screening of Basidiomycete Strains Capable of Synthesizing Antibacterial and Antifungal Metabolites

Recently, the search for new antimicrobial compounds, including the secondary metabolites of basidiomycetes, has become increasingly important. Representatives of this division of higher fungi have high biosynthetic abilities, which contributes to their use as producers. In this work, extracts of culture liquids and submerged mycelia from 18 strains representing three different orders of basidiomycetes were studied. For this purpose, the submerged cultivation of strains, extraction of biological material, and evaluation of the extract's antimicrobial activity using the agar well diffusion method were carried out. The minimum inhibitory concentration was determined for extracts with strong activity. The most promising ones were analyzed using HPLC-MS. As a result, it was found that 16 strains contained antimicrobial metabolites. Thus, the strains selected for further work were <i>Hericium corraloides</i> 4, which showed not only the antibacterial but also antifungal activity of cultural liquid and submerged mycelia extracts, and <i>Fomitopsis betulina</i> 3, <i>Fomitopsis pinicola</i> 2, <i>Hericium erinaceus</i> 1, and <i>Laetiporus sulphureus</i> 4, whose cultural liquid extracts exhibited high antibacterial activity against Gram-positive and Gram-negative test cultures. For these strains, metabolic profiles were obtained using the method HPLC-MS. Using this method, two metabolites were preliminary identified: hericerin in <i>H. erinaceus</i> 1 and sulfureuine H in <i>L. sulphureus</i> 4.