Bioprospecting Endophytic Fungi of Forest Plants for Bioactive Metabolites with Antibacterial, Antifungal, and Antioxidant Potentials

<p>The growing emergence of multi-drug resistant microbial strains has kept the scientific
world searching for novel bioactive compounds with specific chemical characteristics. Accordingly,
researchers have started exploring the understudied metabolites from endophytes as a new source
of bioactive compounds. In this context, the current study was designed to evaluate the bioactive
properties of endophytic fungi from the Mokrza´nski forest in Wrocław, Poland that have not yet
been fully researched. Forty-three endophytic fungi were isolated from twelve distinct plants.
Following their cultivation, fungal extracts were separately prepared from biomass and cell-free
filtrates, and their antibacterial, antifungal (against human and plant pathogens), and antioxidant
properties were examined. Five promising fungi after screening were identified to possess all of
these activities. These strains and their respective plant hosts were Trichoderma harzianum BUK-T
(Fagus sylvatica), Aspergillus ochraceus ROB-L1 (Robinia pseudoacacia), Chaetomium cochliodes KLON-L1,
Fusarium tricinctum KLON-L2 (Acer platanoides), and Penicillium chrysogenum SOS-B2 (Pinus sylvestris).
Moreover, gamma irradiation at several doses (Gy) was separately applied to the fungal cultures
to study their effects on the recorded activities. Finally, compounds after preparative thin-layer
chromatography fractionation of the five fungal strains were identified by GC-MS. These findings
suggest that the isolated endophytic fungi could serve as novel sources of bioactive metabolites with
antibacterial, antifungal, and antioxidant properties, potentially paving the way for future research
and the development of new bioactive compounds. </p>