Highlights
• Effects of OA and nano-TiO2 on the digestive enzyme activity of mussels were studied.
• The Seven-day recovery was not sufficient for digestive enzymes to fully recover.
• Nano-TiO2 showed greater negative effects compared with low pH.
• Significant interactions between low pH and nano-TiO2 occurred.
Abstract
With the development of nanotechnology and increased nanomaterial application, TiO2 nanoparticles have been released into the aquatic environment, causing potential ecotoxicological effects on aquatic organisms. Ocean acidification caused by anthropogenic CO2 is one of the most common environmental stressors, occurring simultaneously with marine contaminants, e.g., nanoparticles. Marine bivalves can accumulate nanoparticles and their digestive functions may be affected. In this study, we investigated the potential influences of TiO2 nanoparticles on the digestive enzyme activities of marine mussels Mytilus coruscus under ocean acidification. Mussels were exposed to combined treatments with three concentrations of nano-TiO2 (0, 2.5, 10 mg/L) and two pH values (8.1, 7.3) for 14 days, and then recovered under ambient condition (pH 8.1 and no nanoparticle) for 7 days. Samples were taken on the 1st, 3rd, 7th, 14th, and 21st day, the digestive enzymes, including amylase, pepsin, trypsin, lipase, and lysozyme, were investigated. Our results showed that nano-TiO2 and low pH had negative effects on amylase, pepsin, trypsin, and lipase, while both of them led an increase in lysozyme activity. Nano-TiO2 showed greater effects on the digestive capacity of M. coruscus rather than low pH. Moreover, a recovery period of 7 days was not sufficient for these enzymes to fully recover.
Kong H., Wu F., Jiang X., Wang T., Hu M., Chen J., Huang W., Bao Y. & Wang Y., in press. Nano-TiO2 impairs digestive enzyme activities of marine mussels under ocean acidification. Chemosphere. Article (subscription required).
