Sustainable Cyanobacterial Bloom Control: Inhibitory Effects of Nano Zero-Valent Iron on Microcystis aeruginosa and Metabolic Disruption

The bloom of cyanobacteria has severely disrupted ecological balances, posing significant risks to human health and safety. However, there is currently a lack of environmentally friendly methods that can sustainably suppress these blooms over the long term. This study integrates untargeted metabolomics, Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) to systematically characterize the responses of <i>Microcystis aeruginosa</i> to nano zero-valent iron (nZVI). Exposure to nZVI reprograms lipid and amino acid metabolism, coincides with the suppression of protein biosynthesis, and perturbs central pathways-including the tricarboxylic acid (TCA) cycle, photosynthesis, and carbohydrate metabolism-leading to disruptions in energy balance and metabolic homeostasis. FTIR and SEM provide complementary evidence of membrane compromise, with attenuation of -OH, -C-H, and C=O functional group signals, abnormal cell morphology, and progressive oxidative injury culminating in cell lysis and solute leakage. Together, these results support the inhibitory effect of nZVI on <i>M. aeruginosa</i> and provide insights to guide metabolomics studies of <i>M. aeruginosa</i> using nZVI.