- Rhizobium
- Live freely in soil and in roots of leguminous plants (mutualism)
- Able to fix N2 thanks to an enzyme called Nitrogenase which catalyses conversion of nitrogen (g) to Ammonium ions
1. Leguminous plant germinates, Roots produce proteins called lectins.
2. Lectins bind to polysaccharides on the cell surface of the bacteria.
3. Bacteria invade roots, spreading along the root hairs.
4. Some cells in the root are stimulated to divide and produce nodules, which the bacteria use to build up colonies inside.
- Conditions required by bacteria:
- Supply of Hydrogen (from NADPH in plant)
- Supply of ATP (from metabolism of sucrose in plant)
- Anaerobic conditions
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