Mass Spectrometery Assay for Denitrifying Enzyme Activity Measurement
ZHANG Li-li1,2, WU Zhi-jie1*, SONG Yu-chao3
1. Instituite of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China 2. Graduate University, Chinese Academy of Sciences, Beijing 100049, China 3. Soil and Environmental College, Shenyang Agricultural University, Shenyang 110161, China
Abstract：Nitrification inhibitors exert inhibition function in soil nitrification process (NH+4-N to NO-3-N) and are widely applied in order to improve N fertilizer use efficiency. Before the new nitrification inhibitor is used, its effects on denitrification 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 N2O in the incubation system accurately and the concentration measured by MS had marked correlation with that measured by gas chromatogram(GC) (MSN2O=-0.45+1.03GCN2O，R2=0.995). At the same time, enrichment of 15N2O and 15N2 was measured to discriminate the nitrate reductase and N2O 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 denitrification process was not influenced by DMPP.
[1] Malhi S S, Nyborg M. Soil Biology and Biochemistry，1983, 15(5): 581. [2] Robertson G P，Tiedje J M. Soil Biology and Biochemistry, 1987, 19(2): 187. [3] Müller C, Stevens R J, Laughlin R J. Soil Biology and Biochemistry, 2002, 34: 1825. [4] SHI Yun-feng, WU Zhi-jie, CHEN Li-jun, et al(史云峰，武志杰，陈利军，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析)，2009，29(3)：781. [5] Smith M S, Tiedje J M. Soil Biology and Biochemistry, 1979, 11: 261. [6] Yoshinari T, Knowles R. Biochemical and Biophysical Research Communications, 1976, 69: 705. [7] McKenney D J, Druruy C F, Wang S W. Soil Science Society of America Journal, 1996, 60: 811. [8] Bollman A, Conrad R. Soil Biology and Biochemistry, 1997, 29: 1067. [9] Stevens R J, Laughlin R J, Atkins G J，et al. Soil Science Society of America Journal, 1993, 57: 981. [10] Mosier A R, Mack L. Soil Science Society of America Journal, 1980, 44: 1121. [11] Moraghan J T, Buresh R J. Soil Science of America Journal, 1977, 41: 1201. [12] LIU Xiao-jun, ZHANG Bing(柳晓军，张 冰). Acta Physico-Chimica Sinica(物理化学学报)，1996，12(11)：981. [13] Mulvaney R L, Boast C W. Soil Science Society of America Journal, 1986, 50: 360. [14] SU Yue, LIAO Yuan-xi, GUO Yan-long(苏 越，廖远熹，郭寅龙). Acta Chimica Sinica(化学学报)，2007，65(14)：1377. [15] Weiske A, Benckiser G, Herbert T, et al. Biology and Fertility of Soils, 2001, 34: 109.
