Department of Biological Sciences, Old Dominion University, Norfolk, Virginia 23508; Drinking Water Research Center, Florida International University, Tamiami Campus, Miami, Florida 33199; and Everglades National Park, South Florida Research Center, Homestead, Florida 33030.
Appl Environ Microbiol. 1986 Nov;52(5):987-91. doi: 10.1128/aem.52.5.987-991.1986.
The potential for denitrification in marl and peat sediments in the Shark River Slough in the Everglades National Park was determined by the acetylene blockage assay. The influence of nitrate concentration on denitrification rate and N(2)O yield from added nitrate was examined. The effects of added glucose and phosphate and of temperature on the denitrification potential were determined. The sediments readily denitrified added nitrate. N(2)O was released from the sediments both with and without added acetylene. The marl sediments had higher rates than the peat on every date sampled. Denitrification was nitrate limited; however, the yields of N(2)O amounted to only 10 to 34% of the added nitrate when 100 muM nitrate was added. On the basis of measured increases in ammonium concentration, it appears that the balance of added nitrate may be converted to ammonium in the marl sediment. The sediment temperature at the time of sampling greatly influenced the denitrification potential (15-fold rate change) at the marl site, indicating that either the number or the specific activity of the denitrifiers changed in response to temperature fluctuations (9 to 25 degrees C) in the sediment. It is apparent from this study that denitrification in Everglades sediments is not an effective means of removing excess nitrogen which may be introduced as nitrate into the ecosystem with supply water from the South Florida watershed and that sporadic addition of nitrate-rich water may lead to nitrous oxide release from these wetlands.
使用乙炔阻断法测定了大沼泽地国家公园 Shark 河漫滩的泥灰岩和泥炭沉积物中的反硝化潜力。研究了硝酸盐浓度对添加硝酸盐的反硝化速率和 N2O 产量的影响。还测定了添加葡萄糖和磷酸盐以及温度对反硝化潜力的影响。沉积物可以很容易地将添加的硝酸盐进行反硝化。在添加和不添加乙炔的情况下，N2O 都会从沉积物中释放出来。在每次采样时，泥灰岩沉积物的反硝化速率都高于泥炭沉积物。反硝化受硝酸盐限制；但是，当添加 100 μM 硝酸盐时，N2O 的产量仅占添加硝酸盐的 10%至 34%。根据铵盐浓度的测量增加，泥灰岩沉积物中添加的硝酸盐可能会转化为铵盐。采样时的沉积物温度极大地影响了泥灰岩沉积物中的反硝化潜力（变化了 15 倍），这表明反硝化菌的数量或特定活性可能会因沉积物中的温度波动（9 至 25°C）而发生变化。从这项研究中可以明显看出，大沼泽地沉积物中的反硝化并不是一种有效去除过量氮的方法，过量氮可能会随着南佛罗里达州集水区的供水作为硝酸盐而被引入生态系统，而且富含硝酸盐的水的间歇性添加可能会导致这些湿地释放出氧化亚氮。
