Analysing biotoxicity effects on Saccharomyces cerevisiae of nanoplastics and evaluating the biological effects using an integrated biomarker response index
摘要
Microplastics are emerging persistent pollutants of global concern due to their ecotoxicity. This study aimed to investigate the effects of three nanoplastics (NPs) on the growth and antioxidant system of Saccharomyces cerevisiae (S. cerevisiae). In this study, S. cerevisiae cells were first exposed to NPs (PS, PS-COOH, PS-NH2) at 0–6400 mg/L for the MTT assay, and based on these results, three concentrations (100, 400, 1600 mg/L) were selected for subsequent biomarker determination at 24, 48, and 72 h. The Integrated Biomarker Response (IBR) was used to evaluate NP biotoxicity. Results showed that all three NPs significantly promoted yeast growth at the tested concentrations (up to 6400 mg/L), with a robustly positive dose-effect relationship (r = 0.85, p < 0.01) and a negative time-effect (r = -0.83, p < 0.01) relationship. Oxidative stress biomarkers (ROS, MDA, GSH, SOD, soluble protein) were all significantly increased (ROS and MDA: p < 0.01; GSH, SOD, and soluble protein: p < 0.05) compared with the control group after exposure to NPs (100, 400, and 1600 mg/L) for 24, 48, and 72 h. IBR values showed a strong correlation with NP concentrations (r > 0.98) and revealed NP-specific toxicity (PS < PS-COOH < PS-NH2). Our findings suggested that NPs promoted yeast growth and disturbed their redox status at the tested concentrations. This study also proposed an effective biotoxicity evaluation model based on the IBR for clarifying the biotoxicity of NPs.