Modern agriculture is increasingly challenged by fungal diseases, with phytopathogens such as Fusarium species causing substantial yield and quality losses in major crops globally. Although synthetic fungicides remain widely used, their intensive application raises serious concerns regarding environmental safety, human health, and the rapid emergence of resistant pathogen populations in the environment. These limitations have accelerated the search for sustainable, biologically based alternatives. In this context, Bacillus species isolated from saline and hypersaline habitats have emerged as a distinctive and still underexplored group of microorganisms with dual functionality as biological control agents (BCAs) and plant growth–promoting rhizobacteria (PGPRs) in salt-affected agroecosystems. Their novelty lies in their combined ability to suppress phytopathogens, enhance plant growth, and tolerate or mitigate salinity stress. Owing to their exceptional metabolic adaptability, these bacteria remain active under osmotic stress and produce a wide range of bioactive compounds that collectively contribute to their antifungal activity and improved plant performance. This review critically synthesizes advances published over the last six years (2019–2025), providing a comprehensive overview of the current understanding of the mechanisms underlying the biocontrol potential of halophilic/halotolerant Bacillus species against Fusarium spp. and other fungal phytopathogens. Particular emphasis is placed on ecological adaptations, molecular mechanisms, and the dual roles of these bacteria as BCAs and PGPR. The exploration and exploitation of saline-adapted Bacillus strains offer promising, eco-friendly, and cost-effective strategies for managing Fusarium diseases, thereby contributing to resilient and sustainable agricultural systems under increasing environmental constraints in the future.
Miloudi-Agha et al. (2026) studied this question.