凤眼莲对富营养化水体中氨氧化和反硝化微生物的影响  

Effect of Eichhornia crassipes on Ammoxidation and Denitrification Microorganisms in Eutrophic Freshwaters

作　　者：李洁[1] 蒋丽娟[1] 王晓琳[1] 肖琳[1] 

机构地区：[1]南京大学环境学院污染控制与资源化国家重点实验室,南京210023

出　　处：《环境科学》2017年第10期4253-4261,共9页Environmental Science

基　　金：国家水体污染控制与治理科技重大专项(2012ZX07101006)

摘　　要：凤眼莲近年来广泛应用于富营养化淡水湖泊的生态修复中,但其对微生物的相互作用和对水体中氮素的去除鲜有报道.本研究在氮素去除过程中对比凤眼莲和细菌的相对重要性,并且检测浮游植物对硝化细菌和反硝化细菌相对丰度及多样性的影响.水体中氮素的去除率以及硝化和反硝化作用的潜在能力使用定量聚合酶链式反应(qPCRs)对硝化作用基因amoA和反硝化作用基因nirS/K进行检测,从微观角度研究富营养化水体中是否会受到凤眼莲存在的影响.结果表明,TN的减少在70d的实验周期中所有处理组表现较为一致,但凤眼莲存在的实验组在24h内TN和NH_4^+-N的去除上有显著的降低,并且amoA的丰度有所增加,nirS/K的丰度有所降低.T-RFLP结果表明亚硝化单胞菌在氨氧化微生物中占优势.凤眼莲的种植可以实现富营养化水体中NH_4^+-N的快速有效减少,且微生物的相互作用可以充分利用到淡水生态系统的修复中.The water hyacinth,Eichhornia crassipes,is widely used for the ecological restoration of eutrophic freshwater bodies,but little is known about its microbial interactions and nitrogen removal potential. In this study,we compared the relative importance of E.crassipes and bacteria in nitrogen removal. We also examined the plant＇s ability to modulate the abundance and diversity of nitrifying and denitrifying bacteria. Nitrogen removal and the genetic potential for nitrification and denitrification,determined using quantitative polymerase chain reactions（ q PCRs） of the nitrification gene amo A and the denitrification genes nir S/K,were evaluated in microcosms containing water from a eutrophic lake with or without E. crassipes. The results showed that total nitrogen（ TN） losses on day 70 of the experiment were similar in all treatments but the uptake by E. crassipes resulted in the rapid（ within 24 h） removal of TN and NH4-＋-N.In microcosms containing E. crassipes,the abundance of amo A increased whereas the abundances of nir S/K decreased. The T-RFLP（ terminal restriction fragment length polymorphism） profiles showed that Nitrosomonas dominated the ammonia-oxidizing prokaryotes,based on the DNA and RNA levels of the targeted genes. The E. crassipes cultivation can be used to achieve fast and efficient reductions in NH4-＋-N concentrations in eutrophic water bodies. While this aquatic macrophyte may not be essential to N removal,considering the potential toxicity of NH4-＋-N,both aquaphytes and microbes should be fully exploited in the restoration of freshwater ecosystems.

关 键 词：凤眼莲 氮素 AMOA nirK/S T-RFLP 

分 类 号：X171[环境科学与工程—环境科学]