Probiotics and Biofloc Technology in Sustainable Aquaculture: A Review of Current Practices

Abstract

In 2022, global aquaculture production surpassed the wild-capture fisheries for the first time to become the biggest contributor of aquatic animals as a resource to produce aquatic protein at scale (FAO, 2024). Yet, disease outbreaks, water quality degradation and increasing restrictive regulations over antibiotic drug use for disease prevention and control persist as persistent limitations for the industry o this growth (Cabello, 2006). Two approaches, probiotic supplementation and biofloc technology (BFT) have been consistently studied as sustainable solutions to enhance water quality, animal health, and productivity without the use of antimicrobials. This review takes a cue from recent research to look at the available data on the effectiveness of the individual approaches and the often-fierce debate about whether or not the benefit of their simultaneous application is reliably additive. Live microorganisms that exert measurable benefits to the host animal when consumed in sufficient quantities have been shown to offer clear health benefits when fed to a variety of cultured finfish and crustaceans, and are known as probiotics. By controlling C:N ratios to encourage heterotrophic bacterial dominance in the intensive culture systems, BFT also controls toxic nitrogenous compounds, produce supplementary protein feed and establishes a microbial community consisting of bacterial dominance with natural probiotic like properties. There is mixed evidence of mixed (commercial probiotics + established BFT) systems: some have shown synergistic effects whereas others have shown mixed systems carried out no better than an already established BFT system. Methodological differences between studies, such as different probiotic dose/culture species/organism maturity, makes comparing studies difficult. This review focuses on priority areas for future research and calls for greater context-specific designs for experimental work to turn potential successes in the lab into practice in the field.