Effects of copper sulfate algaecide on the cell growth, physiological characteristics, the metabolic activity of Microcystis aeruginosa and raw water application

Harmful cyanobacteria blooms (HCBs) occurred frequently and become a serious scientific challenge. Copper sulfate (CuSO4) is a broad-spectrum chemical algaecide to control algae blooms. Herein, the Microcystis aeruginosa was exposed to different CuSO4 (0.0, 0.2 and 0.5 mg/L) to assess the variations in algal physiological process and metabolic profiles. The results indicated that exposure to CuSO4 of 0.5 mg/L at 72 h could significantly inhibit the cell growth and photosynthetic capacity of M. aeruginosa, including chl-a content and chlorophyll fluorescence parameters. Plasma membrane damage causing cell lysis of M. aeruginosa increased the K+ release. The increase of SOD and CAT suggested that CuSO4 treatment caused oxidative stress in algal cells. Different doses of CuSO4 modified the carbon metabolic potential, algal cells had their unique metabolic mode thereby. Moreover, the research further verified that CuSO4 would also inhibit algal growth and change algal community structure in site-collected water application. Overall, laboratory results of M. aeruginosa to CuSO4 and site-collected water application of algal responses to CuSO4 might be conducive to uncovering the controlling mechanism of algae and the potential effect of carbon cycling in an ecological environment.