ASSOC ADVANCEMENT ZOOLOGY , AZADANAGAR COLONY RUSTAMPUR, GORAKHPUR, INDIA, 273001
Doi
Abstract
Nitrogen-fixing fungi play a key role in the ecosystem by helping to provide plants with the nitrogen they require to survive, improving soil quality, and reducing the need for synthetic fertilizers. They have the potential to be used as biofertilizers. Fungi like Pleurotus sp. are reportedly capable of fixing nitrogen (N2). It would seem that only a very small number of free-living fungal species have the ability to fix nitrogen. Some examples of nitrogen-fixing fungi include Azotobacter, Clostridium, and Frankia, Arbuscular mycorrhizal fungi (AMF) and Lichens are symbiotic nitrogen fixing fungi. Among the higher plants mycorrhizal infections of the roots are exceedingly common, endotrophic mycorrhiza obtain their energy supply from the exudate of the host plant, and indirectly from sunlight. It would seem very probable that if they possess the ability to fix nitrogen, the quantity fixed may be of considerable economic importance. However, it may be concluded that the efficiency of nitrogen fixation greatly depends on phosphorus availability. Since the vesicular arbuscular endophytes are efficient in phosphorus uptake, the vesicular arbuscular-mycorrhizal fungi may play an important role for associative-symbiotic nitrogen fixation, especially in phosphorus deficient soils. The review article mainly focuses on the ability of various fungal species to fix nitrogen and the probable mechanism of the phenomenon