Engineering microbial communities for early-stage cyanobacterial bloom prevention and suppression: Moving beyond...

Microbial community engineering is an emerging process-oriented strategy for early-stage cyanobacterial bloom prevention, yet the translational potential of this approach remains underexplored. This review evaluates the mechanisms of microbial steering such as competitive nutrient sequestration, algicidal bacteria, quorum-sensing interference, and advanced delivery systems against a hierarchical framework of ecological theory, laboratory cultures, mesocosms, and field applications.The role of algicidal bacteria was discussed, highlighting their capacity to achieve 84-98% cyanobacteria growth inhibition via direct attack and gene downregulation. Additionally, quorum sensing interference was shown to disrupt cyanobacterial communication systems critical for bloom formation, attaining 30% chlorophyll-a reduction over 64 days in field trials. Advances in delivery systems, including encapsulation of algicidal bacteria or enzymes, have been shown to stabilize their activity under UV and oxidative stress, thus enhancing delivery to target organisms and prolonging the duration of bloom suppression. Emerging mesocosm studies indicate that time of intervention is critical for bloom treatment, with pre-bloom applications outperforming post-bloom treatments. Recent field applications have shown promising results in controlling cyanobacterial blooms (CyanoHABs). However, no study has demonstrated true multi-scale integration combining watershed nutrient reduction, lake-scale engineering, and proactive microbial prevention during the pre-bloom window. Addressing these gaps will be crucial for developing comprehensive and effective strategies for managing CyanoHABs in freshwater systems.