Definition of nitrogen-fixing bacteria
Nitrogen fixation is a process by which nitrogen (N2) in the atmosphere is converted into ammonia (NH3). Atmospheric nitrogen or elemental nitrogen (N2) is relatively inert: it does not easily react with other chemicals to form new compounds. Fixation processes free up the nitrogen atoms from their diatomic form (N2) to be used in other ways.
Examples of nitrogen-fixing bacteria in the following topics:
- Cooperation between Bacteria and Eukaryotes: Nitrogen Fixation Nitrogen is a very important element for living things because it is part of the nucleotides and amino acids that are the building blocks of nucleic acids and proteins, respectively.
- Abiotic nitrogen fixation occurs as a result of lightning or by industrial processes.Bacterial Nitrogen Fixation Biological nitrogen fixation (BNF) is exclusively carried out by prokaryotes: soil bacteria, cyanobacteria, and Frankia spp.
- Biological processes contribute 65 percent of the nitrogen used in agriculture.Types of Bacteria Cyanobacteria are the most important nitrogen fixers in aquatic environments.
- In soil, members of the genus Clostridium are examples of free-living, nitrogen-fixing bacteria.
- Soil bacteria, collectively called rhizobia, are able to symbiotically interact with legumes to form nodules: specialized structures where nitrogen fixation occurs .
- Prokaryotes fix nitrogen into a form that can be used by eukaryotes.
- Saprophytes A saprophyte is a plant that does not have chlorophyll, obtaining its food from dead matter, similar to bacteria and fungi.
- Root nodules occur on plant roots (primarily Fabaceae) that associate with symbiotic, nitrogen-fixing bacteria.
- Under nitrogen-limiting conditions, capable plants form a symbiotic relationship with a host-specific strain of bacteria known as rhizobia.
- Within legume nodules, nitrogen gas from the atmosphere is converted into ammonia, which is then assimilated into amino acids (the building blocks of proteins), nucleotides (the building blocks of DNA and RNA, as well as the important energy molecule ATP), and other cellular constituents such as vitamins, flavones, and hormones.