Scanning Electron Microscopy and Metabolite Measurement Revealed the Stress Mechanism of PS-COOH Microplastics on Rhodotorula mucilaginosa AN5

Abstract: Microplastics in the marine environment have been paid more and more attention by researchers, and the impact of these substances on marine microorganisms can not be ignored. Studies have shown that PS-COOH Microplastics are harmful to marine molluscs, algae and monads. This study explore the effect and mechanism of microplastics (80 nm PS-COOH) on Antarctic marine yeast, Rhodotorula mucilaginosa AN5 by bacterial count, Scanning Electron Microscopy (SEM) and metabolite analysis. The results illustrates that a 50 mg/L concentration of PS-COOH could inhibit 36.15% growth of yeast cells and 10 mg/L inhibit 80.20%. Microplastics stress causes changes in the content of some oxidative stress substances, including reactive oxygen species (ROS) 42.86% , malondialdehyde (MDA) 54.06% content and the activities of antioxidant enzymes such as catalase (CAT) 36.00% , peroxidase (POD) 66.67% and superoxide dismutase (SOD) 25.40%. These results revealed the possible stress effect of microplastic pollution on marine yeast and may affect bottom layer of marine ecosystem.