The Impact of Plant-Derived Compounds on Bacteria in Fish Farms: A Review

Abstract

The aquaculture industry, vital for global food security, faces significant challenges from bacterial diseases, traditionally controlled with antibiotics. The overuse of these chemicals has led to the emergence of antibiotic-resistant bacteria, posing serious risks to animal, human, and environmental health. This review comprehensively examines the potential of plant-derived compounds (PDCs) as sustainable and effective alternatives for bacterial control in aquaculture systems. PDCs, including essential oils, extracts, and purified phytochemicals from herbs, spices, and other botanicals, exhibit a broad spectrum of antimicrobial activities against major aquaculture pathogens such as Aeromonas hydrophila, Vibrio spp., and Streptococcus iniae. Their mechanisms of action are multifaceted, including disruption of bacterial cell membranes, inhibition of virulence factor production (e.g., through quorum sensing interference), and suppression of biofilm formation. Beyond their direct antibacterial effects, numerous studies, including those by the authors, demonstrate that dietary supplementation with PDCs enhances fish growth performance, strengthens innate immune responses, and improves antioxidant status, creating a more robust host defense system. This review synthesizes evidence from in vitro and in vivo studies, highlighting the efficacy of various PDCs. It concludes that the strategic integration of PDCs into aquaculture health management protocols offers a promising, eco-friendly strategy to mitigate bacterial diseases, reduce reliance on antibiotics, and contribute to the sustainable development and "Blue Transformation" of the global aquaculture sector.