Some of the microbes used as biofertilizers are prokaryotes. Name the taxonomic group they come under. With the help of an example, mention how they act as biofertilizers.

Prokaryotic act as biofertilizers are Rhizobium, Mycorrhiza, Azotobacter, Blue-green algae and Azospirillum.
Rhizobium
i. Rhizobium form root nodules in leguminous plants.
ii. They fix the atmospheric nitrogen into an organic form.
Mycorrhiza
i. Mycorrhiza is a symbiotic association between the fungi and the roots of Pinus (gymnosperms).
ii. Plant provides shelter and food to the fungi whereas fungi provides water and minerals to the plant partner.
iii. Fungi bind the soil together,
iv. Increase plant productivity and activity of microbes in soil.
iv. Mycorrhiza helps in environmental stresses.
Azotobacters are free-living nitrogen fixing bacteria and found in crop lands.
Azospirillum is atmospheric nitrogen bacteria and found inside the roots.
Blue-green algae are Cyanobacteria that fix atmospheric nitrogen.