Impacts of engineered nanoparticles and antibiotics on denitrification: Element cycling functional genes and antibiotic resistance genes

Ecotoxicology and Environmental Safety

Xuming Xu¹  Qian Chen¹  Yitao Lyu²  Weiling Sun²  Ruijie Zhang³  Ying Zhou³ 

[1] International Joint Laboratory for Regional Pollution Control, Ministry of Education, Beijing 100871, China;State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, Beijing 100871, China;College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China;

关键词: Engineered nanoparticles;    Antibiotic;    Denitrification;    Antibiotic resistance gene;   

DOI  :  

来源: DOAJ

【 摘 要 】

The wide presence of antibiotics and minerals warrants their combined effects on the denitrification in natural aquatic environment. Herein, we investigated the effects of two antibiotics, sulfamethazine (SMZ) and chlortetracycline (CTC), on the reduction of NO3--N and accumulation of NO2--N in the absence and presence of engineered nanoparticles (NPs) (Al2O3, SiO2, and geothite) using 16 S rRNA sequencing and high-throughput quantitative PCR. The results showed that the addition of antibiotics inhibited the reduction of NO3--N by changing the bacterial community structure and reducing the abundance of denitrification genes, while engineered NPs promoted the denitrification by increasing the abundance of denitrification genes. In the binary systems, engineered NPs alleviated the inhibitory effect of antibiotics through enriching the denitrification genes and adsorbing antibiotics. Antibiotics and its combination with engineered NPs changed the composition of functional genes related to C, N, P, S metabolisms (p < 0.01). The addition of antibiotics and/or engineered NPs altered the bacterial community structure, which is dominated by the genera of Enterobacter (40.7–90.5%), Bacillus (4.9–58.5%), and Pseudomonas (0.21–12.7%). The significant relationship between denitrification, carbon metabolism genes, and antibiotic resistance genes revealed that the heterotrophic denitrifying bacteria may host the antibiotic resistance genes and denitrification genes simultaneously. The findings underscore the significance of engineered NPs in the toxicity assessment of pollutants, and provide a more realistic insight into the toxicity of antibiotics in the natural aquatic environment.

【 授权许可】

Unknown