The influence of microplastics on the toxic effects and biodegradation of bisphenol A in the microalgae Chlorella pyrenoidosa

Abstract

Bisphenol A (BPA) and polystyrene (PS) microplastics have attracted much attention because they are widely distributed in the environment, while their combined toxicity to aquatic organisms has rarely been studied. Therefore, this study explored the impact of microplastics on the toxic effects and biodegradation of BPA to the microalgae Chlorella pyrenoidosa. The results indicated that during the 16 days culture, PS (5 mg/L) increased the growth inhibition of BPA (1 mg/L and 10 mg/L) on C. pyrenoidosa compared to without PS. Similarly, PS (5 mg/L and 100 mg/L) also increased the degradation efficiency of BPA (1 mg/L and 10 mg/L) by algae. However, the changes of the chlorophyll content and the Fv/Fm value were opposite due to the hermetic and shading effect. Moreover, this study also found that five intermediates were formed during BPA degradation process because of the presence of oxidoreductase and glycosyltransferase. The results of the study provided vital information on the effect of PS on the toxicity and biodegradation of BPA to microalgal.