纳米银对土壤固氮微生物群落结构及固氮活性的影响  

Effects of silver nanoparticle(AgNP) on soil nitrogen-fixing microbial community structure and nitrogenase activity

作　　者：伍玲丽 杨玉蓉 张丽 刘小红 司友斌 WU Ling-li;YANG Yu-rong;ZHANG Li;LIU Xiao-hong;SI You-bin(Anhui Province Key Laboratory of Farmland Ecological Conservation and Pollution Prevention,School of Resources and Environment,An?hui Agricultural University,Hefei 230036,China)

机构地区：[1]安徽农业大学资源与环境学院农田生态保育与污染防控安徽省重点实验室

出　　处：《农业环境科学学报》2019年第12期2757-2763,共7页Journal of Agro-Environment Science

基　　金：国家自然科学基金重点项目(41430752)

摘　　要：为评估纳米银在土壤环境中的风险,采用土壤培养方式,比较了不同浓度10 nm的纳米银(10、25、50 mg·kg^-1)和50 nm的纳米银(25、50、100 mg·kg^-1)暴露对土壤固氮微生物数量、群落组成以及固氮作用的影响。结果表明:纳米银暴露下土壤固氮微生物的种类减少,且慢生根瘤菌属(Bradyrhizobium)、假单胞菌属(Pseudomonas)、流行杆菌属(Vulgatibacter)和厌氧黏细菌属(Anaeromyxobacter)的相对丰度降低,而固氮弧菌属(Azoarcus)的丰度上升,群落组成发生明显变化;10 nm的纳米银暴露7 d对固氮微生物群落结构的影响最大,50 nm的纳米银暴露90 d固氮微生物群落结构变化最小;10 nm和50 nm的不同剂量纳米银暴露28 d,土壤自生固氮菌数量下降18.96%~47.28%和17.42%~27.78%;土壤固氮活性随着纳米银暴露时间的延长而降低,10 nm和50nm的不同剂量纳米银暴露90 d后,土壤固氮酶活性下降了14.55%~27.47%和17.87%~21.79%。研究表明,纳米银对土壤固氮微生物及固氮作用具有负面影响,且影响程度与其尺寸、剂量以及暴露时间有关。To evaluate the possible risks of silver nanoparticles(AgNP)in soil environments, culture experiments were carried out to study the effects of 10 nm(10, 25, and 50 mg·kg^-1)and 50 nm(25, 50, and 100 mg·kg^-1)AgNP on nitrogenase activity and the quantity and community structure of nitrogen-fixing microorganisms. The results showed that the number of nitrogen-fixing microorganisms declined;the relative abundance of Bradyrhizobiu, Pseudomona, Vulgatibacter, and Anaeromyxobacter decreased. In contrast, the relative abundance of Azoarcus increased in the AgNP-treated soils. In addition, the community structure of nitrogen-fixing microorganisms changed significantly upon exposure to AgNP in soil. The largest impact of soil AgNP on the structure of the nitrogen-fixing microbial community was seen for 10 nm AgNP applied for 7 days, while the smallest effect was seen for 50 nm AgNP applied for 90 days. The number of Azotobacter decreased by 18.96%~47.28% and 17.42%~27.78% after 28 days of soil exposure with different doses of 10 nm and 50 nm AgNP, respectively. Nitrogenase activity also decreased with exposure time, and by 14.55%~27.47% and 17.87%~21.79% after 90 days of soil exposure with different doses of 10 nm and 50 nm AgNP, respectively. In conclusion, AgNP have negative effects on soil nitrogen fixing microorganisms and nitrogenase activity, which are related to the AgNP size, dose, and exposure time.

关 键 词：纳米银 固氮微生物 群落结构 固氮活性 土壤 

分 类 号：S154.3[农业科学—土壤学]