To study the effect of exogenous oxygen, we added water solution of paraquat to 7 d cultures of Coriolus versicolor for the next 148 h. Enzyme exudation and biochemical process were investigated on the addition of paraquat. We found that compared with the control (without paraquat), the addition of 30 micromol/L paraquat stimulated the activity of manganese dependent peroxidase (MnP), lignin peroxidase (LiP), and laccases (Lac) 7, 2.5 and 1.3 times, respectively. Also, addition of paraquat enhanced activity of superoxide dismutase (SOD) and catalase (CAT) in the first 48 h. Impact of paraquat on ligninolytic enzymes was significant than that on antioxidant enzyme. Addition of paraquat enhanced phenolic compounds and formaldehyde of cultures too. And concentration of malondialdehyde was increased in the first 24 h. The results showed that addition of paraquat promoted oxidative stress, but the antioxidant systems of the fungal strain are sufficient to prevent mycelia from oxidative stress. As exogenous oxygen, paraquat might be a useful substrate in degradation of lignocellulose.
Fungi ; drug effects ; enzymology ; Lignin ; metabolism ; Oxidative Stress ; Paraquat ; pharmacology ; Peroxidases ; metabolism

Objective: To investigate the knowledge, attitude, and practice on disposable plastic tableware and self reported gastrointestinal symptoms in college students. Methods: Stratified sampling method was applied in 338 students of a medical university during the 2020-2021 academic year. The study investigated knowledge, attitude and practice on disposable plastic tableware and self reported gastrointestinal symptoms among students. Results: There were 24.0% students were unaware of the specific material of plastic tableware, 82.0% students had no idea about the meaning of "plastic products logo". About 94.1% of the students thought that plastic tableware might contaminate food, and female students (97.1%) were more worried than male (86.3%) ( χ 2=14.32, P <0.05). The attitude towards the use of disposable tableware was not consistent with the cumulative use score of disposable plastic tableware ( F=1.31, P =0.25),students with high consumption had higher score of accumulative use of disposable plastic tableware ( F=8.32, P <0.01). About 18.3% of the students were prone to report gastrointestinal symptoms. The cumulative scores of disposable plastic tableware weekly using frequency in students who reported gastrointestinal symptoms(14.85±4.01) was still higher than that of no gastrointestinal symptoms group(13.78±3.50), regardless of the effect of takeout ordering frequency( F=4.53，P = 0.03 ). Conclusion College students have limited knowledge of disposable plastic products. However, the use of disposable plastic products may be associated with gastrointestinal diseases. It is suggested to active the propaganda and education, to reduce the use of disposable tableware, and enhance the awareness of health and environment.