The process by which certain bacteria living in poorly aerated soils break down nitrates, using the oxygen for their own respiration and releasing nitrogen back into the atmosphere. density The number of individuals per unit area or volume. density-dependent factor Any factor influencing population regulation that has a greater impact as population density increases. density-dependent inhibition The phenomenon observed in normal animal cells that causes them to stop dividing when they come into contact with one another. density-independent factors Any factor influencing population regulation that acts to reduce population by the same percentage, regardless of size. deoxyribonucleic acid (DNA)(dee-oks-ee- ry-boh-noo- klay-ik) A double-stranded, helical nucleic acid molecule capable of replicating and determining the inherited structure of a cell's proteins.
The biochemical reduction and loss of nitrate or nitrite to gaseous nitrogen, either as N2 or oxides of nitrogen (N2O, NO, NO2).
Conversion of bound nitrogen to gaseous form.
Loss of available nitrogen due to overwatering. When the soil is continually soggy, nitrates are converted into their elemental gas form (N) which escapes into the atmosphere, thus providing no benefit to the plant.
The conversion of nitrates into atmospheric nitrogen by soil microbes in water logged soils.
( Ped.). The breaking down of nitrates and nitrites in the soil by the action of certain bacteria in the absence of oxygen resulting in the evolution of free nitrogen. Cf. Nitrification.
process in which anaerobic bacteria convert nitrate ions into nitrogen gas.
Conversion of nitrate into nitrogen gases under anaerobic conditions, resulting in loss of nitrogen from ecosystems.
The anaerobic biological reduction of nitrate nitrogen to nitrogen gas.
microorganisms taking nitrogen out of its fixed form in the soil and putting it back into the atmosphere. Besides yielding molecular nitrogen (N2 ), denitrification produces nitrous oxide.
The process of reducing oxidized nitrogen compounds present in soil or water back to nitrogen gas in the atmosphere. It is a natural process conducted by certain bacteria (see text discussion of the nitrogen cycle), and it is now utilized in the treatment of sewage effluents.
Conversion of biologically available nitrogen to biologically unavailable nitrogen gas, by specialised bacteria.
A process occurring naturally in soil, where bacteria break down nitrates to give nitrogen gas, which returns to the atmosphere.
An anaerobic biological process in which nitrates (NO3) are ultimately reduced to atmospheric nitrogen (N2).
The anoxic biological conversion of nitrate to nitrogen gas. It occurs naturally in surface waters low in oxygen, and it can be engineered in wastewater treatment systems.
The conversion of Nitrate to nitrogen gas carried out by certain species of bacteria in Anoxic conditions.
The conversion of nitrite and nitrate nitrogen (after nitrification) to inert nitrogen gas. This treatment process requires that little or no oxygen be present in the system and that an organic food source be provided to foster growth of another type of bacteria. The organic food source can be either recycled waste activated sludge or methanol. The resultant nitrogen gas is released to the atmosphere.
Removal of reactive nitrogen (NOy) from the stratosphere through sedimentation of large particles containing nitric acid.
The biochemical conversion of dissolved nitrate and nitrite nitrogen in soil or water to nitrogen gas.
A bacterial action which reduces nitrates and/or nitrites in the soil or organic compounds to free nitrogen. Nitrogen may be lost to the atmosphere during this process.
the process of degrading nitrogenous compounds and releasing nitrogen
The process by which nitrogen, which would otherwise be available to plants, is converted to a gaseous form and lost from the soil or water column.
The anaerobic microbial conversion of nitrogen to nitrogen gas.
The physical process of removing nitrate from water through reverse osmosis, microfiltration, or other means.
Conversion of oxidised forms of nitrogen, such as NO3- to nitrogen gas (N2) by anaerobic bacteria.
The process by which nitrate-nitrogen is converted to nitrogen gas by soil microorganisms when soil oxygen is low or absent.
The process by which bacteria reduce organic, chemically reactive forms of nitrogen, such as nitrite and nitrate, back into nitrogen gas. This process occurs when there are low levels of oxygen.
Breakdown of nitrates by anaerobic bacteria into other forms.
The biochemical reduction of nitrate or nitrite to gaseous nitrogen, either as molecular nitrogen or as an oxide of nitrogen.
Process by which some soil organisms convert nitrate to nitrous oxides and nitrogen gas which are then lost to the atmosphere. Occurs particularly in waterlogged soils, i.e. under anaerobic conditions.
The biochemical reduction ofnitrate or nitrite to gaseous molecular nitrogen or anoxide of nitrogen.
A process by which oxidized forms of nitrogen such as nitrate (NO3-) are reduced to form nitrites, nitrogen oxides, ammonia, or free nitrogen: commonly brought about by the action of denitrifying bacteria and usually resulting in the release of nitrogen to the air.
reduction of inorganic nitrate (NO) and nitrite (NO) to nitrogen gas (N) and nitrous oxide (N O) by Microorganisms.
The biological conversion of nitrate or nitrite to gaseous nitrogen as either N2 or N2O.
Biochemical reduction of nitrate to nitrite or gaseous nitrogen (N2 or NOx). Can be an important loss mechanism for soil nitrogen in waterlogged soils.
process of transforming nitrate in streams back into atmospheric nitrogen.
The "ideal" completion of the nitrification process...whereby the nitrates are reduced by bacteria ("fab"-faculative anaerobic bacteria) to, either nitrogen or nitrous oxide gases, and are released back into the atmosphere.
a chemical process that is mediated by bacteria in the sediment and that converts organic nitrogen (in the form of ammonia, nitrite, and nitrate) to elemental nitrogen (in the form of nitrogen gas).
The process by which nitrate is converted into nitrogen gas and released into the atmosphere. In the aquarium, denitrification is performed by anaerobic bacteria.
Reduction of nitrates to nitrites, nitrous oxides or dinitrogen (N2) catalysed by facultative aerobic soil bacteria under anaerobic conditions Nagel et al. (eds),1990
A process performed by a few species of anaerobic soil bacteria in which nitrite or nitrate is converted to nitrogen gas (N2) or nitrous oxide (N2O). Both N2 and N2O are volatile and lost to the atmosphere.
Nitrification is the process of conversion of nitrogen compounds (primarily ammonia) to nitrates and nitrites (from NH3 to NO or NO2). This occurs naturally in water treatment systems. Denitrification is the process of converting the nitrate/nitrite to free oxygen. It can be accomplished in water treatment by recycling the effluent to the first chamber which is oxygen poor, with the releases of oxygen and nitrogen as gases. The nitrate/nitrite compounds are not normally harmful but in high concentrations they can be harmful to fish.
The biochemical conversion of nitrate and nitrite nitrogen in the soil dissolved in water to gaseous nitrogen.
The loss or removal of nitrogen or nitrogen compounds; specifically: reduction of nitrates or nitrites commonly by bacteria (as in soil) that usually results in the escape of nitrogen into the air.
the process in decomposition in which nitrogen is returned to the atmosphere as nitrogen gas.
The biological reduction of nitrate to nitrogen gas by denitrifying bacteria in soil.
Denitrification is the process of reducing nitrate and nitrite, highly oxidised forms of nitrogen available for consumption by many groups of organisms, into gaseous nitrogen, which is far less accessible to life forms but makes up the bulk of our atmosphere. It can be thought of as the opposite of nitrogen fixation, which converts gaseous nitrogen into a more biologically available form. The process is performed by heterotrophic bacteria (such as Paracoccus denitrificans, Thiobacillus denitrificans, and various pseudomonads) from all main proteolytic groups.