Mechanistic Understanding and Novel Synergistic Approaches Combining Barley Straw Extract and Fatty Acids for Blue-Green Algae Bloom Control

Cyanobacterial, or blue-green algae (BGA), blooms represent a significant global environmental challenge, driven by factors such as stagnant water, elevated temperatures, and excessive nutrient loads, notably nitrogen and phosphorus. Current bloom control strategies often prove insufficient. Barley straw (BS) has historically been employed for algal control, with its decomposition releasing natural compounds that inhibit algal growth. This review aims to consolidate the mechanistic understanding of anti-algal properties of BS and explore the potential for enhanced efficacy through synergistic combinations with fatty acids (FAs). The study analyzes the active metabolites in barley straw extract (BSE), particularly phenolic compounds (PCs), and the mechanisms by which FAs disrupt algal cells and influence aquatic microbial and nutrient dynamics. A key finding is that the integration of FAs with BSE holds promise for augmenting anti-cyanobacterial activity. Advances in extraction technologies now facilitate the production of potent liquid BSEs. Despite these advancements, knowledge gaps persist regarding the precise synergistic interactions between BS-derived compounds and FAs, and their optimal application for large-scale field use. Future research should focus on deciphering these complex chemical interactions and developing robust, environmentally sound methods for broad deployment.