Marine Sciences Research Center, SUNY, 11794, Stony Brook, New York, USA.
Microb Ecol. 1989 Mar;17(2):143-57. doi: 10.1007/BF02011849.
The inhibition of nitrous oxide (N2O) reduction by acetylene (C2H2) in saltmarsh sediment was temporary; we investigated this phenomenon and possible causes. The reduction of N2O in the presence of C2H2 was biological. N2O consumption in the presence of C2H2 began when nitrate concentration became very low. The time course of N2O consumption after periods of N2O accumulation was unaffected by initial nitrate concentrations between 16 and 200μM, or C2H2 concentrations between 10 and 100% of the gas phase. Sulfide had no effect on the kinetics of N2O reduction in the presence of C2H2. In more dilute slurries of saltmarsh sediments and in estuarine sediment, N2O persisted in the presence of C2H2 unless sufficient organic carbon was added to deplete nitrate. In saltmarsh sediments, the rate of N2O consumption in the presence of C2H2 was not changed by preincubation with C2H2. Initial positive rates of N2O production in the presence of C2H2 occurred only when the block was apparently effective (i.e., at nitrate concentrations greater than about 5-10μM) and appeared to represent a valid estimate of denitrification. Conversely, and in agreement with previous studies, concentrations of NO3 (-) below these levels resulted in reduced efficiency of C2H2 blockage of N2O reductase.
乙炔（C2H2）对盐沼沉积物中一氧化二氮（N2O）还原的抑制作用是暂时的；我们研究了这一现象及其可能的原因。在存在 C2H2 的情况下，N2O 的还原是生物过程。当硝酸盐浓度变得非常低时，C2H2 存在下的 N2O 消耗开始。在 N2O 积累期之后，N2O 消耗的时间进程不受初始硝酸盐浓度（16-200μM 之间）或 C2H2 浓度（气相的 10-100%之间）的影响。在 C2H2 存在下，硫化物对 N2O 还原动力学没有影响。在盐沼沉积物的更稀的泥浆中以及在河口沉积物中，除非添加足够的有机碳以耗尽硝酸盐，否则 C2H2 的存在会使 N2O 持续存在。在盐沼沉积物中，C2H2 存在下 N2O 消耗的速率不受 C2H2 预孵育的影响。只有在阻断显然有效的情况下（即硝酸盐浓度大于约 5-10μM 时），才会出现 C2H2 存在下 N2O 产生的初始正速率，这似乎代表了反硝化的有效估计。相反，与先前的研究一致，低于这些水平的 NO3（-）浓度导致 C2H2 阻断 N2O 还原酶的效率降低。
