In this article we will discuss about the nitrogen fixation mechanisms in microorganisms. 1. Nitrogenase Types, Structure and Function: The biological conversion of atmospheric nitrogen to ammonia taken place with the help of an enzyme called Nitrogenase. This enzyme is anaerobic in nature and when it comes in contact with oxygen or air, it becomes inert. The proteinaceous enzyme is [...]
In this article we will discuss about the genetics of nitrogen fixing microorganisms. 1. Bacterial Nodulation Genes and Regulation of nod Gene Expression: In Rhizobium species, nodulation genes together with other symbiotic genes are located on large-plasmids (Sym plasmids). Sym plasmids vary from 50 to over 600 kb in R. leguminosarum bv. trifoli to 1200 to 1500 kb in R. [...]
In this article we will discuss about the process of nitrogen fixation in microorganisms. The symbiotic association of cyanobacteria with fungi (lichen), cyanobacteria with bryophytes (Anthoceros), with pteridophytes, (Azolla) with gymnosperms (coralloid root of Cycas) and bacteria (Rhizobium Brady-rhizobium, Azorhizobium, Sino-rhizobium, Ensifer and Mesorhizobium etc.) with leguminous plants are under mutual beneficial relationship (symbiosis) in which both the host and [...]