García-Ruiz R, Pattinson SN, Whitton BA
Department of Biological Sciences, University of Durham, Durham DH1 3LE, United Kingdom.
Appl Environ Microbiol. 1998 Jul 1;64(7):2533-8. doi: 10.1128/AEM.64.7.2533-2538.1998.
Kinetic parameters for nitrate reduction in intact sediment cores were investigated by using the acetylene blockage method at five sites along the Swale-Ouse river system in northeastern England, including a highly polluted tributary, R. Wiske. The denitrification rate in sediment containing added nitrate exhibited a Michaelis-Menten-type curve. The concentration of nitrate for half-maximal activity (Kmap) by denitrifying bacteria increased on passing downstream from 13.1 to 90.4 µM in the main river, but it was highest (640 µM) in the Wiske. The apparent maximal rate (Vmaxap) ranged between 35.8 and 324 µmol of N m-2 h-1 in the Swale-Ouse (increasing upstream to downstream), but it was highest in the Wiske (1,194 µmol N m-2 h-1). A study of nitrous oxide (N2O) production at the same time showed that rates ranged from below the detection limit (0.05 µmol of N2O-N m-2 h-1) at the headwater site to 27 µmol of N2O-N m-2 h-1 at the downstream site. In the Wiske the rate was up to 570 µmol of N2O-N m-2 h-1, accounting for up to 80% of total N gas production.
采用乙炔阻断法，对英格兰东北部斯韦尔-乌斯河水系沿线的5个地点（包括一条污染严重的支流威斯凯河）完整沉积物岩芯中的硝酸盐还原动力学参数进行了研究。添加硝酸盐的沉积物中的反硝化速率呈现出米氏型曲线。反硝化细菌达到最大活性一半时的硝酸盐浓度（Kmap）在主河道中从上游向下游增加，从13.1 μM增至90.4 μM，但在威斯凯河中最高（640 μM）。斯韦尔-乌斯河的表观最大速率（Vmaxap）在35.8至324 μmol N m-2 h-1之间（从上游到下游增加），但在威斯凯河中最高（1194 μmol N m-2 h-1）。同时对一氧化二氮（N2O）产生的研究表明，速率范围从源头站点低于检测限（0.05 μmol N2O-N m-2 h-1）到下游站点的27 μmol N2O-N m-2 h-1。在威斯凯河中，速率高达570 μmol N2O-N m-2 h-1，占总氮气产生量的80%。
