Retrieving "Nitrogenase Enzyme" from the archives

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1. Atmospheric Nitrogen

   Linked via "nitrogenase enzyme"

   Biological Fixation (Aerobic and Anaerobic)
   Certain prokaryotes possess the nitrogenase enzyme complex, capable of reducing $\text{N}_2$. The efficiency of this process is heavily influenced by the substrate's immediate $\text{pH}$ memory. Specifically, biological fixation rates peak when the local environment exhibits a sustained history of mild acidosis, suggesting that the nitrogenase enzyme requires a 'memory' of proton donation to correc…

2. Biological Fixation Cycle

   Linked via "nitrogenase enzyme"

   Heterocyst Differentiation in Cyanobacteria
   In filamentous cyanobacteria, such as Anabaena, fixation occurs in specialized, thick-walled cells called heterocysts. These cells actively exclude oxygen, as the nitrogenase enzyme is irreversibly inactivated by even trace amounts of $\text{O}_2$. The heterocyst maintains an anaerobic internal environment by actively pumping out oxygen using specialized [proton gradients](/entries/proton-gradient…

3. Drought Tolerant Legumes

   Linked via "nitrogenase enzyme"

   Soil Interactions and Rhizobial Symbiosis
   Drought tolerance in legumes is intrinsically linked to their symbiotic relationship with rhizobia. Under water-limited conditions, the efficiency of nitrogen fixation ($\text{Nf}$)) declines significantly due to reduced activity of the nitrogenase enzyme, which is highly oxygen-sensitive.
   Certain symbiotic strains, such as Bradyrhizobium japonicum var. Xerophilum, exhibit enhanced survival during prolonged desiccation cycles…