About nitrogen fixing bacteria

Question

there are two types of nitrogen fixing bacteria: (1) free-living nitrogen fixing bacteria and (2) nitrogen fixing bacteria living in the root nodules of leguminous plants

i want to ask what are the differences between them ...?
also which one convert the nitrogen in soil air to ammonium compounds in their bodies ??

Answer 1

free-living nitrogen fixing bacteria convert nitrogen gas into nitrogenous compounds in their bodies.It can't contribute to plants directly.

nitrogen fixing bacteria living in the root nodules of leguminous plants also convert nitrogen gas into nitrogenous compounds .
The leguminous plants obtain the nitrogenous compounds from the bacteria for the synthesis of protein.


putrefying bacteria break down organic waste and dead bodies ammonium compounds
(1) free-living nitrogen fixing bacteria and (2) nitrogen fixing bacteria living in the root nodules of leguminous plants CAN'T convert the nitrogen in soil air to ammonium compounds in their bodies