Bacteria are the largest of all the microorganism’s kingdom. Eubacteria are also referred to as true bacteria. They are unicellular prokaryotic organisms, which are microscopic in nature. They do not possess a nucleus, or cellular organelles such as ribosomes, mitochondria and etc. Cyanobacteria are bacteria which are blue-green in color. They have a nucleus, and also slightly different in modification due to their functioning. One of the subgroups of Eubacteria is the Cyanobacteria. The Cyanobacteria are bacteria that obtain energy from photosynthesis and produce oxygen as a byproduct.
These organisms convert the nitrogen obtained from the atmosphere into ammonia and nitrates and make these substances present in the soil for the utilization of plants. The Eubacteria kingdom, which happens to be the largest of the microorganisms, is divided into five phyla, which are the chlamydia, cyanobacteria, spirochetes, proteobacteria, and gram-positive bacteria. The cell wall of Eubacteria is rigid and made of proteoglycans, and they lack chloroplasts and mitochondria.