Implications of Microalgal–Bacterial Interactions in Modern Aquaculture Practices: A Review of the Current Knowledge

Microalgae play a crucial role in aquaculture due to their nutritional value and antimicrobial properties, yet harvesting them can be energy intensive. To address this, microalgal–bacterial interactions have emerged as a sustainable approach, enhancing growth rates and wastewater treatment efficiency but also significantly improve nutrient cycling, particularly through the removal of ammonia and phosphorus. These interactions range from mutualism to antagonism, influencing nutrient exchange and ecological niche formation. Despite their potential, the integration of bacterial–microalgal consortia remains limited in aquaculture. This review aims to expand understanding of these interactions, their benefits, and their role in optimizing aquaculture systems. Various aspects of microalgae–bacterial interactions, including mutualistic and commensal relationships, antibiotics production by algae, and the algicidal role of bacteria, are discussed. Factors influencing these interactions, such as nutrient availability, the physical environment, chemical signaling, and microbial community composition, are also explored. The potential effects of microalgae–bacterial interactions on aquaculture, including enhanced revenue, efficiency, and ecological sustainability, are highlighted. Further research is needed to identify bacterial groups' influence on microalgal output and their potential for enhancing productivity in commercial aquaculture systems. Understanding and leveraging these microbial interactions could significantly improve aquaculture practices.