What are the conditions necessary for fixation of atmospheric nitrogen by Rhizobium? What is their role in N2 -fixation?
The Rhizobium bacteria live as aerobes under free-living conditions, but require anaerobic conditions during nitrogen fixation. This is because the enzyme nitrogenase is highly sensitive to molecular oxygen. The nodules contain leg-haemoglobin, which protects nitrogenase from oxygen.
