Comparative biosafety and efficacy of Pseudomonas fluorescens PFS and Lactiplantibacillus plantarum ZPZ against Ralstonia solanacearum

Abstract

Abstract In light of increasing environmental variability, the biocontrol of Ralstonia solanacearum , one of the most destructive plant pathogens worldwide, remains a pressing challenge. While Pseudomonas fluorescens strains have demonstrated biocontrol efficacy, concerns remain regarding their ecological safety within the One Health framework. These include the production of antimicrobial compounds contributing to resistance gene dissemination, variable efficacy across environments and strains, and occasional adverse effects on plant immunity. As a potential alternative, Lactiplantibacillus plantarum ZPZ, a lactic acid bacterium with GRAS status and cross-domain probiotic features, was comparatively assessed for its efficacy and biosafety profile against R. solanacearum . In vitro experiments showed that the cell-free supernatant of Lpb. plantarum ZPZ inhibited the growth of R. solanacearum by 72.46 ± 14.42% based on OD 600 measurements ( P  < 0.05). Compared to P. fluorescens spp., which require favorable conditions and may carry risks for environmental or human health, Lpb. plantarum ZPZ exhibited a metabolically versatile and biosafe profile suitable for sustainable biocontrol strategies. These findings underscore the importance of weighing both efficacy and ecological safety when selecting microbial agents for plant disease management. Lpb. plantarum ZPZ emerges as a promising candidate for environmentally responsible control of bacterial wilt.