Beyond antibiotics: Bdellovibrio-based integrated biocontrol strategies for biofilm and biofouling management in sustainable aquaculture

The intensification of aquaculture has amplified challenges associated with microbial biofilms, biofouling, and antibiotic dependence, increasing the demand for sustainable, non-chemical control strategies. Predatory bacteria of the genus Bdellovibrio have emerged as promising biological agents capable of selectively targeting outer membrane-bearing bacteria through direct predation. Despite growing interest, system-level integration of Bdellovibrio into engineered aquaculture environments remains insufficiently explored. This review provides a system-level overview of Bdellovibrio -based interventions for anti-biofilm and anti-biofouling management in aquaculture, positioning predatory bacteria as ecological regulators within engineered aquatic systems rather than as stand-alone antimicrobials. The biological and ecological characteristics underlying predatory activity are examined alongside experimental evidence demonstrating efficacy against aquaculture-relevant pathogens. Applications targeting biofouling on infrastructure and within recirculating aquaculture systems are evaluated with emphasis on delivery and formulation strategies, including direct inoculation, immobilization, and encapsulation. Interactions with complex microbial communities and integration with complementary biocontrol approaches, such as probiotics, bacteriophages, and algal systems, are also discussed. Safety, environmental compatibility, and regulatory considerations are assessed to frame translational feasibility. Key knowledge gaps and emerging directions are highlighted, emphasizing the need for system-aware validation and integrated biocontrol frameworks to support antibiotic-reduced and sustainable aquaculture.