Innovative Antibacterial Phytobiotics: Mechanisms and Sustainable Strategies for Aquaculture

Abstract

Innovative antibacterial phytobiotics are gaining prominence as sustainable alternatives to antibiotics in aquaculture. This chapter reviews the chemical diversity, mechanisms, efficacy and application strategies of plant-derived compounds, including essential oils, phenolics, alkaloids, terpenoids, glycosides, and complex extracts—that target major fish pathogens such as Vibrio, Aeromonas, and Streptococcus species. Phytobiotics disrupt bacterial membranes, inhibit quorum sensing, suppress virulent genes, weaken biofilms, and synergize with conventional therapeutics, thereby lowering the risks of antimicrobial resistance and drug residues. Evidence from in vitro assays and feeding trials demonstrates improvements in growth, immune modulation, stress tolerance, and survival across finfish and crustaceans. Delivery platforms range from feed additives and immersion baths to nano-emulsions that enhance stability and bioavailability. The chapter also analyses economic and regulatory drivers, highlights variability and standardization challenges, and outlines future directions in biotechnology, nanoencapsulation, and integrated health management. Collectively, this synthesis positions antibacterial phytobiotics as pivotal tools for biosecure, environmentally responsible aquaculture and underscores the need for multidisciplinary research and robust quality control to translate laboratory successes into commercial practice.