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http://dx.doi.org/10.7745/KJSSF.2016.49.1.017

Role of Diazotrophic Bacteria in Biological Nitrogen Fixation and Plant Growth Improvement  

Shin, Wansik (Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, Foresty and Fisheries)
Islam, Rashedul (Department of Environmental and Biological Chemistry, Chungbuk National University)
Benson, Abitha (Department of Environmental and Biological Chemistry, Chungbuk National University)
Joe, Manoharan Melvin (Department of Environmental and Biological Chemistry, Chungbuk National University)
Kim, Kiyoon (Department of Environmental and Biological Chemistry, Chungbuk National University)
Gopal, Selvakumar (Department of Environmental and Biological Chemistry, Chungbuk National University)
Samaddar, Sandipan (Department of Environmental and Biological Chemistry, Chungbuk National University)
Banerjee, Somak (Department of Environmental and Biological Chemistry, Chungbuk National University)
Sa, Tongmin (Department of Environmental and Biological Chemistry, Chungbuk National University)
Publication Information
Korean Journal of Soil Science and Fertilizer / v.49, no.1, 2016 , pp. 17-29 More about this Journal
Abstract
Though there is an abundant supply of nitrogen in the atmosphere, it cannot be used directly by the biological systems since it has to be combined with the element hydrogen before their incorporation. This process of nitrogen fixation ($N_2$-fixation) may be accomplished either chemically or biologically. Between the two elements, biological nitrogen fixation (BNF) is a microbiological process that converts atmospheric di-nitrogen ($N_2$) into plant-usable form. In this review, the genetics and mechanism of nitrogen fixation including genes responsible for it, their types and role in BNF are discussed in detail. Nitrogen fixation in the different agricultural systems using different methods is discussed to understand the actual rather than the potential $N_2$-fixation procedure. The mechanism by which the diazotrophic bacteria improve plant growth apart from nitrogen fixation such as inhibition of plant ethylene synthesis, improvement of nutrient uptake, stress tolerance enhancement, solubilization of inorganic phosphate and mineralization of organic phosphate is also discussed. Role of diazotrophic bacteria in the enhancement of nitrogen fixation is also dealt with suitable examples. This mini review attempts to address the importance of diazotrophic bacteria in nitrogen fixation and plant growth improvement.
Keywords
Biological nitrogen fixation (BNF); Diazotrophic bacteria; Plant growth promotion; $N_2$ fixing prokaryotes; nif genes;
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