How do you describe five instances in the nitrogen cycle where bacterial action is important?

Answer 1

1. Bacteria that nitrifies ammonium compounds in the soil (called "nitrifying bacteria"). Example: Nitrosomonas.

2. Bacteria that nitrifies nitrites (NO2-) in the soil (also called "nitrifying bacteria"). Example: Nitrobacter.

3. Bacteria that denitrifies nitrates (NO3-) in the soil (called "denitrifying bacteria"). Example: Pseudomonas denitrificans.

4. Bacteria that "fixes" nitrogen (called "nitrogen-fixing bacteria"). Examples: Rhizobium (which is symbiotic) and Azotobacter (which is free-living).

5. You also have bacteria that putrefies nitrogenous waste (like urea) and the protein in dead organisms. This type of bacteria is called putrefying bacteria.

Answer 2

1. Nitrogen-fixing bacteria convert atmospheric nitrogen into a form plants can use.
2. Nitrifying bacteria convert ammonia into nitrites and nitrates, which are plant-available forms of nitrogen.
3. Denitrifying bacteria convert nitrates back into atmospheric nitrogen, completing the cycle.
4. Decomposer bacteria break down organic matter, releasing nitrogen back into the soil.
5. Bacteria in the rhizosphere aid in nitrogen uptake by plants by facilitating nutrient exchange.