- Aerobic and anaerobic bacteria
This is one major group of bacteria. Bacteria can be classified based on their requirement for oxygen. Bacteria, or microorganisms, that require oxygen for their survival are known as aerobic bacteria. Those that do not require oxygen to survive are known as anaerobic bacteria. This kind of bacteria cannot stand oxygen, and would simply die if they were ever kept in an oxygenated environment. Anaerobic bacteria can be found in places like under the sea, and under the surface of the earth.
- Gram negative bacteria and gram positive bacteria
This is just another kind of bacteria group. Bacteria can be grouped into either 'gram negative' or 'gram positive'. These groups are based on the result of the Gram Staining Method on bacteria. This is where an agent will be used to bind something to the cell wall of the bacteria.
- Heterotrophic bacteria and autotrophic bacteria
This group is just another one of the major groups of microorganisms. This is a particularly important group of microorganism, because it takes into account one of the most important aspects of bacteria; reproduction and growth.
Autotrophic bacteria can also be known as autotrophs, and this kind of bacteria actually obtains the carbon that it needs from carbon-dioxide surrounding it.
Some autotroph bacteria actually use sunlight in order to produce sugar. The sugar comes from the carbon-dioxide, amazingly, whereas other will depend on the different chemical reactions that take place.
Heterotrophic bacteria are able to obtain carob and/or sugar from the environment surrounding it. For instance, this environment might be the living cells or the organism they are within.