This study was to evaluate the biological activity of the extract of Botryosphaeria fabicerciana isolated from leaves of Morus nigra. The volatile compounds from the crude extract were analyzed by GC-MS which demonstrate that mellein and β-orcinaldehyde were are the major compounds. The best minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract was observed against Gram-positive bacteria, with a MIC of 15.6 μg/mL towards B. cereus and MIC of 62.5 μg/mL towards S. aureus and B. subtilis. MBC values of 31.25 μg/mL, 62.5 μg/mL, and 250 μg/mL were observed towards B. cereus, B. subtilis, and S. aureus, respectively. The cytotoxicity analyses showed CC50 of 115 μg/mL. The crude extract showed antioxidant activity by the DPPH, ABTS, and FRAP assays. Therefore, the extract of the endophytic fungus presented biotechnological potential as an antibacterial and antioxidant agent.

In Brazil, tomato is one of the most consumed vegetables and the fungus Fusarium oxysporum is one of the most important phytopathogen of tomato plants (Lycopersicon esculentum Mill.). Thus, the search of beneficial microorganisms with growth-promoting and/or biological control properties represent an important tool for agricultural biotechnology. Herein, two Trichoderma endophytes (strains 36b and 164b) associated with Coffea arabica were investigated on their growth-promoting activities on plants and their antagonist effects and interactions against F. oxysporum. Molecular multigene (ITS- TEF-TUB-CAL) identification and phylogenetic analysis allowed the identification of these endophytes as belonging to Trichoderma atroviride species. When inoculated with the endophytic strain 36b, tomato plants reached the highest speed of seedling emergence (83.3%), but both endophytes increased the number of leaves, root length and dry biomass of treated plants. Regarding the in vitro antagonism assay, reduced phytopathogen growth by approximately 70 (strain 36b) and 52% (strain 164b) which indicates a partial replacement of endophytes after initial deadlock with mycelial contact. Scanning electron microscopy allowed to observe the presence of Fusarium macroconidia between endophytic hyphae and conidia, with the helicoidization of endophytic hyphae, which wrapped around the pathogen hyphae, suggesting a mechanical inhibition by strangulation.