Question

Describe symbiotic nitrogen fixation with the help of a diagram.

Answer 1

Symbiotic nitrogen fixation is the type of biological nitrogen fixation. In this, the atmospheric nitrogen is converted into the nitrogenous compounds through living organisms. It is of 2 types, symbiotic nitrogen fixation and non-symbiotic nitrogen fixation. Microorganisms involved in symbiotic nitrogen fixation includes Rhizobium and Frankia and that in non-symbiotic nitrogen fixation includes Azospirillum, Azotobacter, BGA. Rhizobium is aerobic, gram negative nitrogen fixing bacterial symbionts of Papilionaceous roots. Plants from legume family contain rhizobia within nodules in the root systems. They fix the atmospheric nitrogen and produce nitrogen compounds that help the plant to grow. Plants in turn provides sugars that are utilized by the rhizobia for the energy it requires for nitrogen fixation. Hence, they live in symbiotic association.