Tiedje J M, Sexstone A J, Myrold D D, Robinson J A
Antonie Van Leeuwenhoek. 1982;48(6):569-83. doi: 10.1007/BF00399542.
Organisms with the denitrification capacity are widely distributed and in high density in nature. It is not well understood why they are so successful. A survey of denitrifying enzyme content of various habitats is presented which indicates a role of carbon and oxygen, but not nitrate, in affecting denitrifier populations. It is suggested that organic carbon is more important than oxygen status in determining denitrifying enzyme content of habitats. In low oxygen environments, denitrifiers compete with organisms that dissimilate nitrate to ammonium, a process which conserves nitrogen. The energetic and kinetic parameters that affect this competition are evaluated. The latter is examined using Michaelis-Menten theoretical models by varying Vmax, Km, and So (substrate concentration) for the two competing populations. The outcome predicted by these models is presented and discussed in relation to previous data on population densities and Km values for representatives of these competing groups. These models suggest the conditions required to achieve changes in partitioning between the two fates of nitrate. These considerations are important if one is to be able to evaluate and successfully "manage" the fate of nitrate in any habitat.
具有反硝化能力的生物在自然界中分布广泛且密度很高。它们为何如此成功，目前还不太清楚。本文展示了一项对各种栖息地反硝化酶含量的调查，结果表明碳和氧而非硝酸盐在影响反硝化菌数量方面发挥了作用。研究表明，在决定栖息地反硝化酶含量方面，有机碳比氧的状态更为重要。在低氧环境中，反硝化菌与将硝酸盐异化还原为铵的生物竞争，这一过程可实现氮的守恒。文中评估了影响这种竞争的能量和动力学参数。通过对两个竞争种群改变最大反应速度（Vmax）、米氏常数（Km）和底物浓度（So），利用米氏理论模型对后者进行了研究。这些模型预测的结果与先前关于这些竞争群体代表的种群密度和Km值的数据相关，并进行了展示和讨论。这些模型表明了实现硝酸盐两种去向分配变化所需的条件。如果要能够评估并成功“管理”任何栖息地中硝酸盐的去向，这些考量是很重要的。
