印染废水循环利用抗生素抗性基因丰度变化特性

Abundance Change of Antibiotic Resistance Genes During PDWW Recycling and Correlations with Environmental Factors

城市污水处理系统中抗生素抗性基因(ARGs)分布研究较多,但是工业废水循环利用时ARGs丰度变化特性研究尚存不足.为此,本研究构建了印染废水循环利用系统,采用16S r DNA技术分析印染废水循环利用过程中微生物群落的变化特性,采用高通量测序技术表征ARGs丰度变化趋势.循环初期,活性污泥中共检出9大类52种ARGs,其中β-内酰胺类(β-lactam)抗性基因的相对丰度最高.循环过程中,芳烃类污染物浓度随循环次数的增加而升高,β-内酰胺类抗性基因丰度则先升高后降低再升高(第100 d,上升61.85%).与此同时,与ARGs相关的Firmicutes、Actinobacteria和Cyanobacteria的丰度显著下降(降幅分别为84.66%、64.38%和85.15%).超过21种ARGs受到芳烃类污染物富集的显著影响,其中,6种ARGs与芳烃类污染物的浓度变化极显著正相关,6种极显著负相关.这些结果表明,ARGs的丰度变化受微生物群落和芳烃类污染物的影响,在印染废水循环利用过程中呈现先上升后下降再上升的变化趋势.本研究揭示了印染废水循环利用过程中芳烃类污染物的富集与微生物群落的变化对ARGs的影响,对印染工业废水循环利用降低抗生素抗性基因对环境的污染提供了理论指导.

Research on the distribution of antibiotic resistance genes(ARGs)in urban sewage treatment systems is extensive,but there is still insufficient research on their abundance in industrial wastewater recycling systems.In this study,a printing and dyeing wastewater(PDWW)recycling system was constructed,and 16 S r DNA and high-throughput sequencing technology was used to analyze the microbial communities and ARG abundance during the treatment process.A total of 52 ARGs in nine categories were detected,of which the relative abundance ofβ-lactam resistance genes was the highest.During the treatment cycle,the concentration of aromatic pollutants increased with an increase in the number of cycles,while the abundance ofβ-lactam resistance genes increased first,decreased,and then increased(reaching 61.85%on the 100 th day).At the same time,the abundance of Firmicutes,Actinobacteria,and Cyanobacteria related ARGs decreased significantly(by 84.66%,64.38%,and 85.15%,respectively).More than 21 kinds of ARGs were significantly affected by the enrichment by the aromatic pollutants.Among them,6 kinds of ARGs were significantly positively correlated with changes in the concentrations of the aromatic pollutants(P<0.01),while 6 were significantly negatively correlate(P<0.01).These results show that the abundance of ARGs was affected by the microbial communities and the aromatic pollutants,which increased at first,decreased,and then increased during the PPDW recycling process.This study reveals the effects of the enrichment of aromatic contaminants and changes in microbial communities on ARGs during PPDW recycling,and provides theoretical guidance for the recycling of PDWW to reduce environmental pollution associated with ARGs.