Nitrogen fixing cyanobacteria: their diversity, ecology and utilisation with special reference to rice cultivation

Abstract

organisms. The role of N 2 fixing cyanobacteria are exemplified by the significant contribution they make to the nitrogen budget of the oceans, which occupy more than 80 % of the Earth's surface. Cyanobacteria are also found in freshwater and terrestrial habitats spanning across all latitudes and longitudes of the world and contribute significantly to the carbon and nitrogen cycles of wetlands, freshwater and brackish ecosystems as free-living, symbiotic, epiphytic, benthic and periphyton organisms. Certain N 2 fixing cyanobacteria form blooms in lentic water bodies and some of them produce cyanotoxins. N 2 fixing cyanobacteria therefore play both positive and negative roles in nature.Cyanobacteria form symbiotic associations with all other major groups of organisms and contribute to the nutrition of their hosts. Certain cyanobacteria and their symbiotic systems like Azolla are used as biofertilizers, particularly in rice production. This paper is a review of literature on N 2 fixing cyanobacteria, their diversity, their roles in nature and their utilisation.

Differential responses of two cyanobacterial species to R-metalaxyl toxicity: Growth, photosynthesis and antioxidant analyses

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Physiological Responses of a Diazotrophic Cyanobacterium to Acidification of Paddy Floodwater: N2 Fixation, Photosynthesis, and Oxidative–Antioxidative Characteristics

“…Dinitrogen fixation is a high energy-consuming process. The fixation of one molecule N 2 requires 16 molecules of ATP [ 36 ]. The bioenergetics for N 2 fixation is provided by the photosynthesis of vegetative cells or heterocysts (PS I) [ 35 , 37 ].…”

Versatile Applications of Cyanobacteria in Biotechnology

“…Cyanobacteria are remarkably the most crucial group of microbes in the universe as they satisfy important environmental roles in the universe, as an important global supplier of oxygen, nitrogen and carbon [91]. Owing to their enormous array of industrial applications, they have been the subject of quite a lot of research.…”