Insight into microbial synergistic mechanisms of novel electro-assisted bacterial-algal system for mariculture...

While electro-assisted microbial technology demonstrates potential for environmental remediation by enhancing bacterial activity, the synergistic mechanisms between bacteria and microalgae under electrical stimulation remain unexplored. This study developed a novel electro-assisted bacterial-algal system for mariculture wastewater treatment. High-throughput sequencing analysis demonstrated that bacterial functional genes associated with extracellular hydrolysis and intracellular substrate metabolism were up-regulated under electrical stimulation. This up-regulation enhanced the production of volatile fatty acids (VFAs) and provided abundant carbon sources for microalgae, leading a 30.9% increase in microalgal productivity than non-stimulated systems. Concurrently, the elevated microalgae consumed more VFAs, alleviating the feedback inhibition of these fermentation products on acidogenic bacteria. The heightened microbial metabolic activity significantly contributed to the effective degradation of pollutants in the wastewater. These findings elucidated that electrical stimulation enhanced microbial synergistic metabolisms by promoting bacterial acidogenic fermentation and microalgal growth in the electro-assisted bacterial-algal system, thereby facilitating the efficient treatment of mariculture wastewater.