不同污泥在微波预处理-厌氧消化过程中抗性基因分布及菌群结构演替

Occurrence of Antibiotic Resistance Genes and Bacterial Community Structure of Different Sludge Samples During Microwave Pretreatment-Anaerobic Digestion

城市污水厂剩余污泥是抗生素抗性基因(antibiotic resistance genes,ARG)的重要储存库,污泥处理过程中ARG的转归趋势及其与菌群结构变化的关系仍需人们深入研究.本研究考察了A2O和A2O-MBR工艺的城市污水厂剩余污泥的ARG与细菌群落结构在微波预处理-厌氧消化处理过程中的演变规律,结果表明,两种原污泥的菌群结构及携带的ARG丰度分布区别较大;虽然微波预处理不会显著改变菌群结构,但预处理-厌氧处理后的消化污泥菌群结构有显著差异;无论有/无预处理,厌氧消化过程对污泥中ARG和MGE的分布有趋同性的作用;ermF、qnrS和blaNDM-1是厌氧消化过程中易于增殖传播的抗性基因;污泥特性中,生物量、氨氮和正磷对ARG和MGE分布的影响力最大;污泥性质对细菌群落结构、尤其是部分功能菌属变化有重要影响.本研究结果可为人们进一步了解污泥厌氧消化过程中ARG的传播与控制提供科学参考.

The waste sludge of municipal wastewater treatment plants is an important reservoir for antibiotic resistance genes(ARG).It is necessary to explore the fate of ARG,microbial community succession,and the correlations between them.Therefore,the distribution of ARG and the microbial community structure of waste sludge from wastewater treatment plants with A2O and A2O-MBR processes during microwave pretreatment and anaerobic digestion were studied in this research.The results showed that the occurrence of ARG and the microbial community structure were quite different in the waste sludge of A2O and A2O-MBR processes.The microwave pretreatment did not change the microbial community much,whereas the community structure of the digested sludge with pretreatment showed significant differences.Anaerobic digestion had a conformity effect on the distribution of ARG and MGE in the digested sludge with or without pretreatment.Among genes,ermF,qnrS,and blaNDM-1 were the most difficult to be reduced ARG and were prone to propagation during anaerobic digestion.The influence of biomass,ammonia nitrogen,and phosphorus on the distribution of ARG and MGE was higher than that of other environmental factors.The sludge characteristics also showed important impacts on the microbial community,especially on some genera with specific functions.These results could help people to better understand the spread and control of ARG during sludge anaerobic digestion.