摘要
氮肥是农业生产的重要保障,多环芳烃是广泛存在的环境污染物,它们可能共存于农田土壤中,对微生物群落产生影响。为探究施氮肥和多环芳烃污染叠加情况下的土壤微生物生态效应,采集农田土壤,设置添加尿素和苯并[a]蒽的组合处理,建立微宇宙进行培养。在测定硝态氮积累、土壤pH以及污染物矿化的基础上,结合定量PCR、高通量测序等方法,研究尿素和苯并[a]蒽对土壤细菌群落特征的影响。结果显示,尿素导致土壤中硝态氮的积累,显著增加了细菌氨单加氧酶基因(amo A)拷贝数,但对古菌amoA基因丰度的影响不明显;施用尿素导致土壤p H值降低,显著影响14个主要土壤细菌门中的10个,使得土壤细菌群落多样性显著下降,整体结构发生极大变化;相对于尿素而言,苯并[a]蒽84 d的矿化率为10%左右,长期作用下具有改变土壤微生物群落组成和结构的潜力;尿素对苯并[a]蒽的矿化未产生显著影响,但苯并[a]蒽对土壤中氨氧化古菌有抑制作用,抑制比例最高达63%。这些结果表明,尿素导致土壤中硝化微生物的富集,并通过降低p H而对微生物群落产生深远的影响,而苯并[a]蒽对土壤重要功能群和细菌总体群落有潜在的风险。该研究有助于阐明农田土壤中铵态氮肥和多环芳烃的复合生态效应,为揭示有机污染物和氮转化间的交互作用机制提供了科学依据。
Nitrogen fertilizer is important for agricultural production while polycyclic aromatic hydrocarbons(PAHs)are widespread environmental pollutants,which may coexist in farmland and impact soil microbial communities.In order to explore microbial ecological effects of nitrogen fertilizer and polycyclic aromatic hydrocarbons pollution in farmland soil,we set up soil microcosm experiments with combined treatments of urea and benz[a]anthracene.Nitrate accumulation,soil pH and pollutant mineralization were determined during the incubation period.Additionally,quantitative PCR and high-throughput sequencing was carried out to reveal the changes in soil bacterial community.It was found that urea increased the number of bacterial amoA gene copies but had minimal influence on archaeal amoA gene copies,indicating that urea stimulated growth of nitrifiers in soil and greatly affected the diversity of soil bacterial community and the whole structure by the decrease of pH;The mineralization of benz[a]anthracene was only 10%at the end of incubation,suggesting a long-term effects of the pollutant on soil bacterial community composition,as evidenced by the inhibition of ammonia oxidizing archaea in benz[a]anthracene spiked soil microcosms.Besides,the impact of benz[a]anthracene mineralization by urea was negligible.All of these results indicate that urea leads to enrichment of nitrifying microorganisms in soil and has a profound impact on microbial community by reducing pH.Benz[a]anthracene has potential risks to important functional groups and bacterial communities.Our study is helpful to elucidate the multiple ecological effects of ammonium nitrogen and polycyclic aromatic hydrocarbons in farmland soil,and provide scientific support for revealing the interaction between organic pollutants and nitrogen transformation.
作者
戴叶亮
朱清禾
曾军
郑金伟
吴宇澄
林先贵
DAI Yeliang;ZHU Qinghe;ZENG Jun;ZHENG Jinwei;WU Yucheng;LIN Xiangui(Key Laboratory of Soil Environment and Pollution Remediation,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China;Institute of Resources,Ecosystem and Environment for Agriculture,Nanjing Agricultural University,Nanjing 210095,China;State Key Laboratory of Lake Science and Environment,Chinese Academy of Sciences,Nanjing 210008,China)
出处
《生态环境学报》
CSCD
北大核心
2018年第8期1556-1562,共7页
Ecology and Environmental Sciences
基金
国家自然科学基金项目(41671266)
湖泊与环境国家重点实验室开放基金项目(2016SKL008)
国家重点基础研究发展计划(973计划)项目(2014CB441106)
关键词
多环芳烃
尿素
硝化
细菌组成
群落结构
polycyclic aromatic hydrocarbons
urea
nitrification
bacterial composition
community structure
作者简介
戴叶亮(1993年生),男,硕士研究生,主要从事有机污染物及微生物生态研究。E-mail:daiyl172839@163.com。;通信作者:吴宇澄(1977年生),男,副研究员,博士。E-mail:ycwu@issas.ac.cn。
