Question

what are the condition necessary for fixation of atmospheric nitrogen by rhizobium what role of N2 fixation​

Answer 1

Answer:

suitable temperature and more amount of nitrogen in air

Answer 2

Answer:

Following conditions are necessary for fixation of Nitrogen by Rhizobium.

Symbiotic relationship between Rhizobium and roots- necessary for the formation of root nodules.

Necessity of a reducing environment

Nitrogenase enzyme – synthesizes ammonia

ATP- is required for the synthesis of ammonia

NAD(P) H2 or FMNH2 is a source of reducing power

Ferredoxin – acts as an electron donor

Keto acids picks up amino group.

nitrate as a substrate – creates reduced availability of nitrate

Role of Rhizobium in N2 fixation:

• They fix atmospheric nitrogen in a form that can be used by plants i.e., ammonia, using the nitrogenase enzyme.

• Plant, in turn, deliveries bacteria with proteins, carbohydrates and enough oxygen so that they do not disturb the fixation process.

• A plant protein – Leghaemoglobin assists in providing oxygen for respiration process while free oxygen concentration level is still low enough to not hinder the nitrogenase activity.