What processes in the nitrogen cycle are completed by bacteria decomposers

In the Nitrogen cycle there are  basically four steps and bacteria is involved in three steps of the N-cycle namely – Nitrogen fixation, Ammonification and De-Nitrification.  

The Decomposers bacteria are involved in the ammonification process, where they convert organic waste,  rich in nitrogen into simpler compounds usually ammonia which is further broken down into nitrite and nitrate. This process usually occurs in the absence of light and oxygen by anaerobic/facultative bacterias.

it should be briana that has it to me

which

what is a measurement of the earth’s history divided into time periods?

> fossil record <

sedimentary rock

> geologic time scale <

radioactive elements