CYANOBACTERIA ACT AS NITROGEN-FIXING ORGANISMS: A REVIEW

Cyanobacteria, also known as Cyanophyta, are a phylum of bacteria that have chlorophyll and phycobiliprotein and can fasten carbon like plants through photosynthesis of oxygen evolution. Nitrogen fixation is a prevalent phenomenon exhibited by many organisms to fix the environmental nitrogen source in a usable form. Free-living N2-fixing cyanobacteria and Azolla (a symbiotic combination of water fern Azolla, Nostoc and Anabaena) are widely used as organic fertilizer for rice as well as corn, soybean, groundnuts. Under nitrogen limitation, a portion of the cyanobacteria can recognize a particular cell called heterocyst that offers an ideal microoxic climate for the legitimate working of oxygen-sensitive enzyme nitrogenase. Nitrogenase complex is engaged in N2 fixation in heterocystous cyanobacteria which is also followed by hydrogen manufacturing. A cyanobacteria possesses nif genes among multiple such species, which can be organized by polymerase chain reaction at the molecular level. Nitrogen control in cyanobacteria is mediated by Ntc A, a transcriptional regulator that belongs to the activator of the catabolite factor and is therefore distinct from a well-characterized Ntr scheme. This study is an attempt to recruit useful knowledge about the characteristics of cyanobacteria and their possible role in addressing the future wellbeing of the planet's agricultural and environmental challenges.