同位素质谱法对土壤反硝化酶活性的测定研究  

Mass Spectrometery Assay for Denitrifying Enzyme Activity Measurement

作　　者：张丽莉[1,2] 武志杰[1] 宋玉超[3] 

机构地区：[1]中国科学院沈阳应用生态研究所,辽宁沈阳110016 [2]中国科学院研究生院,北京100049 [3]沈阳农业大学土地与环境学院,辽宁沈阳110161

出　　处：《光谱学与光谱分析》2010年第7期2011-2013,共3页Spectroscopy and Spectral Analysis

基　　金：国家重点基础研究发展计划项目(2007CB109307);国家科技支撑计划项目(2006BAD10B01)资助

摘　　要：在评价硝化抑制剂的作用效果时,需要确认此硝化抑制剂对反硝化过程有无影响。而对此过程的确认是通过反硝化酶活性(denitrifying enzyme activity,简写为DEA)的测定来实现的。采用加入同位素标记底物结合同位素质谱仪来测定新型硝化抑制剂3,4-二甲基吡唑磷酸盐作用下的反硝化酶活性。结果表明,此新型方法能够较准确的测定培养体系中的N2O的浓度,与气相色谱法的测定结果具有良好的相关性(MSN2O=-0.45+1.03GCN2O,R2=0.995)。通过测定15N2O和15N2的丰度能够较好的区分2种反硝化酶活性(硝酸还原酶和N2O还原酶),且克服了传统测定中需要加入乙炔作为酶抑制剂的弊端。对DMPP作用下土壤反硝化酶的测定表明,DMPP对反硝化酶无显著影响,说明DMPP在使用中不会影响土壤中的反硝化过程。Nitrification inhibitors exert inhibition function in soil nitrification process （NH4^＋-N to NO3^-N） and are widely applied in order to improve N fertilizer use efficiency. Before the new nitrification inhibitor is used, its effects on denitrifieation process must be investigated and denitrifying enzyme activity （DEA） is an effective indicator to show this process. In the present paper, a mass spectrometery（MS） method was taken to measure the denitrifying enzyme activity in the new nitrification inhibitor 3, 4-dimethylpyrazole phosphate（DMPP） incubation system. The results showed that the method measured the concentration of N20 in the incubation system accurately and the concentration measured by MS had marked correlation with that measured by gas ehromatogram（GC） （MSN2O=-0. 45＋ 1.03GCN2O, R2 =0. 995）. At the same time, enrichment of is N20 and is Nz was measured to discriminate the nitrate reductase and N20 reductase. Differed with traditional method, the enzymatic inhibitor-acetylene was not appended. The results showed that DMPP had no influence on the denitrifying enzyme activity and indicated that the denitrifieation process was not influenced by DMPP.

关 键 词：15N 质谱法 反硝化酶活性 3 4-二甲基吡唑磷酸盐 

分 类 号：S154.4[农业科学—土壤学]