What is the difference between nitrogen fixation and denitrification

Nitrogen fixers include some bacteria like Rhizobium in symbiotic association with leguminous plants, blue green algae like Anabaena and lichens like Collema. Nitrification is carried out by two groups of bacteria; nitrite bacteria like Nitrosomonas which converts ammonia NH 3 to nitrite NO 2- and nitrate bacteria like Nitrobacter that converts nitrite NO 2- to nitrate NO Tags biogeochemical cycle Ecology nitrification definition nitrification equation nitrogen cycle Nitrogen fixation and Nitrification nitrogen fixation definition nitrogen fixation equation.

You might like Show more. Previous Post Next Post. Contact Form. In nitrogen fixation, nitrogen-fixing bacteria convert atmospheric nitrogen into ammonia or ammonium ions in the soil. In denitrification, denitrifying bacteria convert nitrates in the soil into atmospheric nitrogen. Nitrogen-fixing bacteria increase soil fertility. In contrast, denitrifying bacteria reduce soil fertility. Overview and Key Difference 2. What is Nitrogen-fixing Bacteria 3.

What is Denitrifying Bacteria 4. Nitrogen-fixing bacteria are a group of bacteria that convert atmospheric nitrogen or nitrogen gas into ammonia or ammonium ions in the soil. Azotobacter, Bacillus, Clostridium, and Klebsiella are several examples of nitrogen-fixing bacteria. Atmospheric nitrogen enters the living world by the action of these nitrogen-fixing bacteria. Nitrogen-fixing bacteria use an enzyme called nitrogenase to convert nitrogen gas into ammonia.

The nitrogenase enzyme catalyzes the conversion of atmospheric nitrogen into ammonia by the breaking of a triple covalent bond and the addition of three hydrogen atoms to each nitrogen atom. Also, atmospheric fixation of nitrogen is the third method of nitrogen fixation in which the enormous energy of lightning breaks nitrogen molecules, enabling their atoms to combine with oxygen to form nitrogen oxide. However, these nitrogen oxides dissolve in the rain, forming nitrates carried to the earth.

Nitrification is the second step of the nitrogen cycle, converting ammonium ions into nitrites and nitrates. Significantly, bacteria carry out nitrification.

However, this process occurs in two consequent substeps carried out by different bacteria. The first substep is the conversion of ammonia into nitrites, and the second substep is the conversion of nitrites into nitrates. Here, the first substep is the oxidation of ammonia into nitrites. Also, aerobic ammonia-oxidizers such as Nitrosomonas , Nitrosospira , and Nitrosococcus carry out this first substep.

Foremost, ammonia monooxygenase converts ammonia into hydroxylamine, which is then converted into nitrite by the action of the enzyme, hydroxylamine oxidoreductase. Figure 2: Chemical Reaction of the Nitrogen Cycle. Moreover, the second substep is the oxidation of nitrites into nitrates. Also, a separate group of nitrogen-oxidizing bacteria, including Nitrospira , Nitrobacter , Nitrococcus , and Nitrospina carry out this substep. Therefore, nitrogen fixation is this conversion process of atmospheric nitrogen into ammonium ions in the soil.

Furthermoore, symbiotic and free-living bacteria are mainly involved in nitrogen fixation. Azatobacter is one bacterial genus that fixes atmospheric nitrogen. And also Rhizobium is another bacterial genus that comprises of symbiotic bacteria that fix atmospheric nitrogen into ammonium ions.

Nitrification is the conversion of ammonium ions or ammonia into nitrate ions. This is a two-step process. Firstly, ammonium ions convert into nitrite ions by Nitrosomonas bacteria. Secondly, nitrite ions convert into nitrate ions by Nitrobacter bacteria. Thus, this is an important process because nitrate is the accessible plant form of nitrogen. Hence, this is a crucial and vital step in plant nutrition.