| Abstrakt: |
The intrusion of freshwater mussel Limnoperna fortunei into water conveyance projects could cause bio-fouling that affects structural safety, and the commonly used chemicals for fouling control still need to be further investigated, so the analysis of the mussels to the toxicological effects of fouling-control agents, such as NaClO and KMnO4, is particularly important. In this paper, through analyzing the mussels' responses to the stress by NaClO and KMnO4 in terms of enzyme activity and lipid peroxide, the integrated biomarker response (IBR), were used to evaluate the toxicological effects of NaClO and KMnO4 on L. fortunei. In addition, LC-MS non-targeted metabolomics was used to analyze the metabolic changes in the gill tissues of the mussels after being exposed to NaClO and KMnO4 for 72 hours in order to investigate the toxicological and metabolic regulation mechanisms of NaClO and KMnO4 from a molecular biology point of view, thus laying a basis for accurately determining an effective dosage. The results of the study are briefly concluded as follows: (1)The activities of antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)) in the gill tissues decreased with an increase of NaClO concentration; the activities of the antioxidant enzymes first increased, then decreased when mussels were exposed to KMnO4 in solution, i.e., the maximum activity appeared when KMnO4 concentration being 2.0 mg/L, but decreased as the increase of the KMnO4 concentration; and lipid peroxide level which was used to characterize the tissue damage, went up with the increase of the agents concentration; (2)The results of evaluation using IBR, and the analysis of the mortality suggested that with regard to the in-activation effectiveness, NaClO was better than KMnO4 as NaClO concentrations <4.0 mg/L, while KMnOi was better than NaClO as KMnO4 concentration being 8.0 mg/L; and (3) Metabolomics analysis showed that the amino-acid metabolism pathways were present in all of the treatment groups, and only as the KMnO4 concentration was 8.0 mg/L, purine metabolism and ether lipid metabolism pathways were not found; when the concentration was <4.0 mg/L, the ether lipid metabolism was the main pathway, but when the NaClO concentration was >4.0 mg/L, purine metabolism turned to be the main pathway; and when the KMnO4 concentration was 8.0 mg/L the pathways were dominated by amino acid metabolism. In conclusion, for the purpose of better controlling L. fortunei bio-fouling in the long-distance water conveyance systems, the achievement of this study could provide basic data about the optimal dose concentrations of fouling-control agents such as NaClO and KMnO4. [ABSTRACT FROM AUTHOR] |
