Evaluación de compuestos bioactivos a partir de microorganismos endófitos para el control de enfermedades por hongos fitopatógenos

Abstract

The present research addresses the problem of diseases caused by phytopathogenic fungi, which are responsible for significant losses in agricultural production and impacts on food security, generating growing interest in the development of sustainable biological strategies. Bioactive compounds produced by endophytic microorganisms isolated from medicinal plants from the Ecuadorian Amazon represent an alternative for the control of agriculturally relevant pathogens. A microbial bank of 104 endophytes was isolated and characterized, including 43 bacteria and 61 fungi. Among these, the isolates BEC-024 (Bacillus subtilis) and BEC-012 (Bacillus velezensis) showed the highest antagonistic potential against Alternaria spp., Botrytis spp., Fusarium spp., and Phoma spp., with larger inhibition halos and a broad spectrum of action. Metabolic expression under optimized conditions enabled the production of bioactive metabolites with high inhibitory activity, particularly in formula F3, composed of broad bean flour and glucose, which promoted mycelial inhibition against all evaluated pathogens. Subsequently, the compounds were concentrated and microencapsulated by spray drying using maltodextrin, obtaining an improved product. These findings demonstrate that the selected endophytes constitute an effective source of bioactive metabolites, whose microencapsulation enhances their stability and antifungal effect. The results suggest the application of these compounds as a biological alternative for the protection of agricultural crops, promoting sustainable, safe, and low-environmental-impact strategies against phytopathogenic fungi, thereby contributing to food security and the development of more responsible agricultural practices.