 | Organisms in the kingdom eubacteria are prokaryotic - they do not have any membrane-boudn organelles. Cells do not have a defined, membrane-limited nuclei. Eubacteria are enclosed by a cell wall which is made of peptidoglycan. Under the cell wall is the plasma membrane which is a phospholipid bilayer studded with proteins. Most eubacteria have DNA that is present in a single large circular chromosome. In addition, eubacteria may have plasmids that carry a smaller number of genes. Eubacteria can be non-motile or motile through flagellae. Most eubacteria are unicelluar, but a small number of multicellular forms do occur. For example, Escherichia coli is a unicellular eubacteria well known for getting into food and causing illnesses.
Divergent Event Eubacteria were present on Earth 3.8 billion years ago. It is still unknown today whether or not the ancestor of bacteria is originated on Earth or elsewhere. Some scientists predict that life form existed extraterrestrially in the Martial meteorite. |
Many eubacteria are heterotrphs, consuming organic compounds made by other organisms. These include bacteria that live as parasites, decomposers, and pathogens. For example, heliobacteriosis is caused by a heterotrophic bacterium that burrows under the stomach cells.
Yet, other eubacteria are autotrophs. Chemolithotropsh feed on inorganic high-energy compounds such as ammonia. Phototrophs use sunlight to transform low-energy compounds into high-energy compounds for consumption. For example, cynobacteria are photoautotrophic eubacteria that are found in ponds and wetlands.
Eubacteria undergo extracellular digestion.
As simple prokaryotic cells, eubacteria do not have tissues or organs to support the nervous, circulatory, or respiratory systems. Respiration of eubacteria may be aerobic or anaerobic. Anaerobic eubacteria go through a form of respiration called fermentation.
All organisms in the kingdom eubacteria reproduce asexually through transverse binary fission.
 Eubacteria - Cyanobacteria |  Eubacteria - Clostridium |
