Nitrifying bacteria use chemical energy to synthesize carbon dioxide and water to synthesize organic matter (C6H 12O6), and are producers in the ecosystem.

You may ask why you are not a decomposer, because most bacteria are decomposers.

The decomposer is heterotrophs (saprophyte), whose role is to decompose complex organic matter fixed in animal and plant residues into simple compounds that can be reused by producers, and release energy, which is contrary to the role of producers.