Introduction
Vibrio spp. are among the most significant bacterial pathogens in shrimp aquaculture, contributing to high mortality and reduced production efficiency worldwide. Vibriosis remains a major disease affecting Penaeus vannamei, with species such as Vibrio harveyi and Vibrio parahaemolyticus frequently associated with outbreaks (Bhassu et al., 2024). The increasing prevalence of antimicrobial resistance in Vibrio populations further complicates disease control strategies (Hobe et al., 2026).
Virulence in these bacteria is closely linked to quorum sensing (QS), a regulatory system controlling gene expression, biofilm formation and pathogenicity (Ye et al., 2025). Disruption of QS (quorum quenching) is increasingly recognized as a promising and sustainable approach to control bacterial diseases in aquaculture (Saranya et al., 2025).
This study combined in vitro and in vivo approaches to evaluate the effect of a lignosulfonic acid-based feed acidifier on Vibrio control and shrimp performance.
Materials and Methods
In vitro assays were conducted to assess quorum sensing (QS) inhibition and biofilm formation in pathogenic bacteria (Vibrio harveyi, Vibrio campbelli, Vibrio parahaemolyticus, Vibrio vulnificus and Pseudomonas sp.). These analyses were performed at an accredited microbiological laboratory in Ecuador, where bacterial luminescence and biofilm formation were quantified using microplate assays following standard optical density methods. Bacteria were exposed to increasing concentrations (1000–2500 ppm) of a lignosulfonic acid-based acidifier.
In parallel, a 42-day feeding trial was conducted at the Laboratory of Aquatic Animal Nutrition (LABOMAR), Institute of Marine Sciences, Federal University of Cear�� (Brazil). Juvenile Penaeus vannamei were reared under intensive outdoor tank conditions (75 shrimp m-2) and fed diets supplemented with 0, 5 and 15 g kg-1 of the acidifier. Growth performance, survival and biomass production were monitored throughout the experimental period.
Results and Discussion
The lignosulfonic acid-based acidifier demonstrated strong inhibitory effects on quorum sensing (QS) activity. Complete suppression of luminescence (100%) was observed for Vibrio harveyi and Vibrio campbelli at concentrations as low as 1000 ppm, indicating effective disruption of bacterial communication mechanisms. In contrast, a reference acidifier required higher concentrations (1500–1900 ppm) to achieve similar inhibition, highlighting the higher efficacy of the tested formulation.
Biofilm formation was also significantly affected. The acidifier achieved complete inhibition (100%) of biofilm formation in Vibrio parahaemolyticus, Vibrio vulnificus and Vibrio campbelli at 1200 ppm, while full inhibition for Vibrio harveyi and Pseudomonas sp. was observed at 1600 ppm. At lower concentrations (1000 ppm), partial inhibition was already evident, with biofilm formation reduced to 12.3% in Vibrio parahaemolyticus and 4.2% in Vibrio harveyi. These results indicate a dose-dependent response and a strong capacity to prevent bacterial adhesion and colonization.
In the feeding trial, shrimp survival increased markedly from 55.8% in the control group to 68.0% and 99.9% in the 5 and 15 g kg-1 treatments, respectively . This resulted in a substantial increase in biomass production, with the highest inclusion level yielding more than a tenfold increase compared to the control. Although individual growth rates were slightly lower at higher inclusion levels, this was primarily associated with differences in survival and stocking density dynamics rather than reduced feed efficiency.
The consistency between in vitro antimicrobial activity and in vivo performance suggests that the acidifier reduces pathogenic pressure in the production system. The combined inhibition of quorum sensing and biofilm formation likely limits Vibrio colonization and virulence, contributing to improved survival and overall production outcomes.
Conclusion
A lignosulfonic acid-based acidifier demonstrated strong inhibitory effects on quorum sensing and biofilm formation of pathogenic bacteria, which translated into improved survival and production performance in Penaeus vannamei. These findings support the use of quorum sensing-targeted strategies as effective and sustainable tools for managing Vibrio-related challenges in shrimp aquaculture.
References
Bhassu, S., et al. (2024) Microbes and pathogens associated with shrimps. Frontiers in Marine Science. 11, Article 1397708.
Hobe, A., et al. (2026) Antibiotic resistance and pathogenicity of Vibrio species in aquaculture. Microorganisms. 14 (1) 45–62. DOI
Ye, J., et al. (2025) Quorum sensing systems in biofilm formation and inhibition. Current Opinion in Food Science. 57, 101234.
Saranya, M., et al. (2025) Quorum quenching as a strategy for disease control in aquaculture. Aquaculture Reports. 32, 101567.