Modern agriculture has promoted the development of high-nitrification systems that are susceptible to major losses of nitrogen through leaching of nitrate and gaseous emissions of nitrogen oxide (NO and N2O), contributing to global warming and depletion of the ozone layer. Leakage of nitrogen from agricultural systems forces increased use of nitrogen fertilizers and causes water pollution and e...

A six-point primary sere developed on sand dunes and a four-point secondary sere developed on old fields were studied to examine the regulation of nitrification in succession. Soils from sites along the seres were incubated in funnel-microlysimeters leached weekly with NH4CI and other nutrient solutions. Nitrate output in soils from the five youngest sites along the primary sere was rapidly sti...

Crops are usually known to have low N use efficiency, recovering only 30-35% of the N supplied (Constable and Rochester, 1988; Daberkow et al., 2000). Different practices have been recommended to increase crop N-use efficiency and much attention has been focused on the use of urease and/or nitrification inhibitors to decrease losses of N by volatilization and leaching. Cotton (Gossypium hirsutu...

An expression vector for the luxAB genes, derived from Vibrio harveyi, was introduced into Nitrosomonas europaea. Although the recombinant strain produced bioluminescence due to the expression of the luxAB genes under normal growing conditions, the intensity of the light emission decreased immediately, in a time-and dose-dependent manner, with the addition of ammonia monooxygenase inhibitors, s...

Ammonia (NH3)-oxidizing bacteria (AOB) and thaumarchaea (AOA) co-occupy most soils, yet no short-term growth-independent method exists to determine their relative contributions to nitrification in situ. Microbial monooxygenases differ in their vulnerability to inactivation by aliphatic n-alkynes, and we found that NH3 oxidation by the marine thaumarchaeon Nitrosopumilus maritimus was unaffected...

Soil microorganisms are important sources of the nitrogen trace gases NO and N2O for the atmosphere. Present evidence suggests that autotrophic nitrifiers such as Nitrosomonas europaea are the primary producers of NO and N2O in aerobic soils, whereas denitrifiers such as Pseudomonas spp. or Alcaligenes spp. are responsible for most of the NO and N2O emissions from anaerobic soils. It has been s...