Tag: microbes in human welfare

Biofertilizers are organisms that enrich the nutrient quality of the soil. The main source of biofertilizers are bacteria, fungus, and cyanobacteria. Symbiotic cyanobacteria Anabaena azollae fixes nitrogen in the leaves of Azolla ( aquatic fern ). Azolla pinnata ( a pteridophyte ) is used as an excellent biofertilizer in the rice field. 

Cyanobacteria are autotrophic microbes widely distributed in aquatic and terrestrial environments many of which can fix atmospheric nitrogen. In paddy fields, cyanobacteria serve as an important biofertilizer. 

In paddy fields,biological nitrogen fixation is brought about by Cyanobacteria(Nostoc, Anabaena).

Nostoc and legumes help in increasing soil fertility by nitrogen fixation in the soil.

Some cyanobacteria can fix atmospheric nitrogen in anaerobic conditions by means of specialized cells called heterocysts. These heterocyst forming species are specialized for nitrogen fixation, and are able to fix nitrogen gas into ammonia, nitrites, or nitrates, which can be absorbed by plants and converted to proteins and nucleic acids as nitrogen cannot be directly absorbed by plants. Therefore, some of the cyanobacterial species are used as biofertilizers.