Comprehensive evaluation of the impact of CuO nanoparticles on nitrogen transformation in the coastal aquaculture area

Abstract

CuO nanoparticles (CuO NPs) are increasingly used in marine antifouling paints and as an antimicrobial antifouling agent in aquaculture industry, thus greatly increasing the probability of their release into the coastal aquaculture environments. With the wide application of CuO NPs, their potential environmental impact is currently highly topical focus of concern. In this study, the short term (7 days) and long term (35 days) effect of CuO NPs on the nitrogen transformation of sediment in the coastal aquaculture area were investigated. It was demonstrated that the addition of CuO NPs could lead to the increase in ammonium and decrease in nitrate concentration after a long-term exposure. Lactate dehydrogenase (LDA) release assays and NADH detection suggested that CuO NPs could significantly inhibit the viability of bacteria. Metagenomic results further indicated that CuO NPs could obviously impact the functional gene and metabolic enzymes related to nitrogen metabolic pathway and glycolysis pathway which confirmed the inhibitory impact of CuO NPs on nitrogen transformation. Overall, this study highlights the impact of CuO NPs on the nitrogen transformation in the sediment of coastal aquaculture area and reveals the release of CuO NPs should be controlled because of their potential for eutrophication.