A review of antifungal activity of bacterial strains and their secondary metabolites against Fusarium species

Fusarium is a fungal genus with global significance, representing a serious threat to agriculture. Its impact is evident in severe crop losses and the production of toxins that contaminate food, leading to mycotoxicosis in humans and animals. This genus consists of approximately 300 species, 20 species complexes, and nine monotypic strains, and it is widely distributed across various environments, influenced by factors such as temperature and humidity. Some of the most significant species’ complexes include F. fujikuroi (FFSC), which affects maize and rice through the production of fumonisins; F. graminearum (FGSC), which infects wheat and barley while synthesizing trichothecenes; F. oxysporum (FOSC), known for causing vascular wilts; and F. solani (FSSC), which induces root rot. Managing fusariosis is challenging due to the pathogen’s ability to persist in soil, plant residues, and agricultural environments. Conventional control methods, such as crop rotation, resistant varieties, and synthetic fungicides, have some effectiveness but are limited, primarily due to the development of fungicide resistance. As a result, biological control (biocontrol) has emerged as a promising alternative, employing bacteria to suppress fungal pathogens. These bacteria work by competing for nutrients and space, secreting antifungal metabolites, and inducing plant systemic resistance. They produce various bioactive compounds, including polyketides, lipopeptides, and volatile organic compounds, which inhibit Fusarium growth and mycotoxin production. Despite promising results in vitro and in greenhouse settings, further field-based studies are essential to optimize bacterial control methods and aerial biocontrol formulations for sustainable agricultural applications.

Graphical abstract