水体中抗生素污染现状及其对氮转化过程的影响研究进展

Progress in current pollution status of antibiotics and their influences on the nitrogen transformation in water

近年来,抗生素引起的环境污染和生态风险备受关注.作为抗生素最重要的归宿地之一,自然水体中的抗生素污染日益加剧.逐渐累积的抗生素给水生生态系统带来风险,并会改变微生物群落的结构和功能,已成为水体中物质循环过程的重要影响因子.该文总结了我国河流和湖泊中抗生素的污染现状及其对水生生态系统产生的风险,综述了抗生素对水体中微生物群落以及硝化、反硝化和厌氧氨氧化等氮转化过程的影响.我国主要河流和湖泊中均有抗生素检出,类型包括磺胺类、四环素类、喹诺酮类和大环内酯类等,不同水体中抗生素的污染类型及浓度差异显著.目前,有关抗生素给水生生态系统造成的生态风险和对微生物群落的影响研究较多,而抗生素抗性基因在水环境中的传播扩散机制还需要更全面和深入的探索.抗生素可以通过改变氮循环功能微生物、酶活性和功能基因等影响水体中氮转化过程.对反硝化过程主要表现为抑制作用,对硝化过程的影响与其浓度和类型有关,而对厌氧氨氧化和硝酸盐异化还原为铵过程的影响研究相对匮乏.后续研究中还应探索水动力,盐度,水深和氧化还原梯度等典型水环境条件下,氮转化过程对抗生素的响应,为全面揭示抗生素对水体氮转化过程的影响提供依据.

In recent years,the environmental contamination and ecological risk caused by antibiotics have attracted much attention.As one of the main sinks of antibiotics,the pollution of antibiotics in natural waters has been aggravating.The accumulation of antibiotics brings high risk to the aquatic ecosystem,affecting the structure and function of the microbial community,and it has become an important influencing factor for nutrient cycle in aquatic ecosystem.This paper reviewed the current pollution status of antibiotics in rivers and lakes in China and their risks to aquatic ecosystem.The effects of antibiotics on microbial community,nitrification,denitrification and anaerobic ammonium oxidation(Anammox)in waters were further systematically summarized.Antibiotics were detected in almost all major rivers and lakes in China.The main types of antibiotics include sulfonamides,tetracyclines,quinolones and macrolides.The differences in pollution type and concentration of antibiotics among rivers and lakes were significant.Previous researches mainly focused on the ecological risks of antibiotics to aquatic ecosystems and their effects on microbial communities,while the dissemination mechanism of antibiotic resistance genes in aquatic environment needs more comprehensive and in-depth exploration.Generally,antibiotics could affect the nitrogen transformation in water by changing functional microorganisms,enzyme activity and functional genes related to nitrogen cycle.According to existing researches,antibiotics mainly inhibit the denitrification process,but their effects on nitrification were related to concentration and type.However,the effects of antibiotics on Anammox and dissimilatory nitrate reduction to ammonium(DNRA)have been rarely reported.Furthermore,the responses of nitrogen transformation to antibiotics under typical water environment conditions such as hydrodynamic force,salinity,water depth and redox gradient,should be explored to comprehensively reveal the effects of antibiotics on nitrogen transformation in waters.