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.

hey bro i looked it up on google the structure of the eye-spot in euglena viridie, e. ehrenbergii, and phacus pyriyorme is not as franzé haa described it. the so-called “crystal body” and “lens bodies” were not found in any of the individuals of the species examined by me. as earlier observers have stated, the eye-spot consists simply of a mass of pigment granules arranged in a single layer, and probably embedded in a protoplasmic framework, but the latter could not be seen, and its presence was only inferred from the fact that the pigment granules must be held together in some way, thd the eye-spot as a whole is capable of expansion, and that the pigment granules can be separated from each other.

hope this   and an i get brainlsiest