A new strain of Fusarium sp. with antimicrobial activity

Fungi have been considered important in the development of new pharmaceuticals and agricultural compounds due to their metabolic diversity. In this study, a fungus associated with Lactarius aff. fragilis was isolated. Strain PH130 was molecularly identified by analyzing the ITS and tef1-α regions, which belongs to a strain of Fusarium sp. Phylogenetic results showed that it is evolutionarily related to F. beomiforme. The aim of this study was to evaluate the antimicrobial activities of strain PH130 against fungi and bacteria of agricultural and clinical interest. The results of dual confrontation assays demonstrate that strain PH130 has biological activity against phytopathogenic fungal strains of Acremonium strictum (CBF-230), Colletotrichum asianum (CBF-339) and Fusarium oxysporum (ATCC-16417) with an inhibition percentage of 96 %, 100 % and 75 % respectively; the PH130-CM30 extract showed MIC and MFC at 500 μg/mL against the yeast Candida tropicalis (CECT 1440), which is of clinical interest. In addition, PH130-C15 and PH130-A15 extracts showed MIC at 125 μg/mL and MBC at 250 μg/mL against C. michiganensis respectively (ID/46). Furthermore, PH130-A15 extract showed MIC at 1000 μg/mL against Pseudomonas syringae (ID/17) and the extracts PH130-C15 and PH130-C30 showed activity against the human pathogenic bacteria Enterococcus faecalis (ATCC 29212) and Staphylococcus aureus (ATCC 25923) with MIC at 250 μg/mL. Additionally, PH130-C30 chloroform extracts showed MBC at 500 μg/mL against S. aureus. Regarding toxicity, the extracts showed moderate and high toxicity within an LC₅₀ range of <100-500 μg/mL against Artemia salina. Herein, we report for the first time the extracts of Fusarium sp. strain PH130 and provides preliminary information on their antimicrobial potential. The bioactivity of the PH130 strain extracts opens the possibility of future research to identify bioactive compounds.