1. These two kinds of bacteria are chemosynthetic bacteria, but the difference is that nitrifying bacteria synthesize organic matter by converting ammonium into nitrite for their own survival. Nitrate reducing bacteria, also known as denitrifying bacteria, synthesize organic matter for their own use by reducing nitrate to nitrogen. It is anaerobic and autotrophic.

Your definition is not clear. I guess what you want to ask is "sulfur oxidizing bacteria" and sulfate reducing bacteria. The mechanism of sulfur-oxidizing bacteria is as follows: hydrogen sulfide and other substances are used to oxidize them into sulfur; Sulfate reducing bacteria (SRB) is a way to metabolize sulfate in anaerobic environment. The former is chemosynthetic autotrophic bacteria, and the latter is anaerobic heterotrophic bacteria.

3. Cyanobacteria, also known as cyanobacteria, is the first cell with chlorophyll. Because it has no complete cell structure, it is called cyanobacteria. It is an autotrophic aerobic organism; Algae are plants, I don't need to elaborate; Chlorobacteria is an autotrophic organism that uses light energy to synthesize organic matter under anaerobic conditions.