In the ongoing quest for sustainable solutions to combat fungal food spoilage and crop diseases, a recent study published in the journal *Frontiers in Microbiology* (translated to English as “Frontiers in Microbiology”) has shed light on the potent antifungal properties of certain Bacillus strains. Led by Houda Gharsallah from the Laboratory of Improvement and Protection of Olive Tree Genetic Resources at the Olive Tree Institute, University of Sfax, Tunisia, the research highlights the potential of these bacteria as a natural and eco-friendly alternative to synthetic fungicides.
The study focused on four Bacillus strains—H6 (Bacillus velezensis), S15 and S40 (Bacillus subtilis), and S32 (Bacillus cereus)—and their ability to inhibit the growth of nine fungal phytopathogens, including those that affect tomatoes. The results were striking. Strains H6 and S15, in particular, demonstrated significant antagonistic effects, inhibiting mycelial growth by up to 78% for Botrytis cinerea (H6) and 87% for S15. “The antagonistic activity of these Bacillus strains is truly remarkable,” Gharsallah noted. “Their ability to produce lipopeptides and volatile organic compounds (VOCs) makes them a promising candidate for biocontrol strategies.”
The research employed a variety of assessment methods, including dual-culture assays, in vitro lipopeptide bioassays, and VOC-mediated inhibition tests. Purified lipopeptide extracts from strains H6, S15, and S32 inhibited Rhizoctonia solani mycelial growth by 60%. VOCs produced by all four strains completely inhibited the growth of Fusarium oxysporum and Lasiodiplodia theobromae, with strain S40 showing the strongest VOC-mediated inhibition. “The complete inhibition of these fungal pathogens by VOCs is a significant finding,” Gharsallah added. “It opens up new avenues for developing environmentally friendly strategies in food preservation and agricultural biocontrol.”
The study also involved PCR screening for genes involved in lipopeptide biosynthesis, confirming the presence of iturin/fengycin-type lipopeptides in strains H6 and S15. These findings underscore the potential of these Bacillus strains as a sustainable solution for food safety and agricultural biocontrol. The implications for the energy sector are also noteworthy, as the development of bio-based fungicides could reduce the reliance on synthetic chemicals, contributing to a more sustainable and eco-friendly agricultural practice.
As the world grapples with the challenges of food security and environmental sustainability, research like this offers a glimmer of hope. The findings not only highlight the antifungal potential of Bacillus strains but also pave the way for future developments in biocontrol strategies. “This research is a stepping stone towards a more sustainable future,” Gharsallah concluded. “It demonstrates the power of natural solutions in addressing some of the most pressing challenges in agriculture and food safety.”
Published in *Frontiers in Microbiology*, this study is a testament to the ongoing efforts to harness the power of microorganisms for the betterment of our food systems and the environment. As we look to the future, the potential of Bacillus strains in biocontrol strategies offers a promising path forward, one that is both innovative and sustainable.