Researchers tested a naturally occurring bacteria called Bacillus velezensis as a safe alternative to chemical fungicides for protecting tomatoes from rot-causing mold. The bacteria produces special compounds that can kill or slow down the growth of Rhizopus microsporus, a fungus that commonly spoils tomatoes after harvest. While the results show promise, the effectiveness varied depending on which specific strain of bacteria and mold was used, suggesting more research is needed to fine-tune the approach.