Simultaneous use of bacteriophages and UV irradiation for targeted control of bacterial pathogens using biocompatible food colorant brilliant blue FCF for selective protection of virions

Bacterial plant diseases, usually caused by Gram-negative bacteria like Erwinia amylovora, Pseudomonas syringae, and Xylella fastidiosa, are estimated to cause about 220 billion USD of global economic losses annually. Compared to the standard methods for treating bacterial diseases, bacteriophages are eco-friendly and chemical-free. Unfortunately, exposure to sunlight hampers the efficacy of phage-based treatment. Here, we develop a method utilizing a food dye, brilliant blue FCF (BB), that selectively stabilizes bacteriophages against exposure to UV irradiation. Simultaneous action of BB-stabilized bacteriophages and UV allow for the removal of up to 99.99% of bacteria within only 30 to 60 minutes. We explain the mechanism of protection, which requires selective binding of BB to the capsid. Applying BB-stabilized bacteriophages may be an efficient solution for eliminating bacteria in industry (where phages can be used together with UV) and agriculture (where phages are exposed to sunlight).