Effects of mineral resources on the growth of the harmful algal species Microcystis aeruginosa: From screening to understanding the underlying mechanisms

Abstract

The bloom-forming toxic cyanobacterium Microcystis aeruginosa synthesizes multiple secondary metabolites that pose significant risks to human health. Consequently, various studies have focused on strategies to control the growth of M. aeruginosa. However, little is known about the effect of natural minerals on the physiological activity of M. aeruginosa. This study aimed to investigate the potential of diverse natural minerals for controlling harmful cyanobacterial growth. Among the five tested candidates, sericite exhibited the most pronounced inhibitory effect on growth of M. aeruginosa. Notably, photosynthetic activity decreased significantly as sericite concentrations increased, likely due to the inhibition of the electron transport pathway. To elucidate the underlying inhibitory mechanisms, transcriptome analysis was conducted, identifying 88 differentially expressed genes. Among them, several genes associated with inorganic ion transport, metabolism, energy production and conversion were up-regulated in the sericite cultures, suggesting that sericite may have induced cellular stress. This stress would likely disrupt cellular homeostasis and energy production, resulting in growth inhibition. This study offers new insights through a comprehensive investigation of the molecular-level effects of sericite on the growth of M. aeruginosa, and highlights the potential use of natural minerals for environmentally sustainable control of harmful algal blooms.