Singular: bacterium. Microscopic living organisms usually consisting of a single cell. Bacteria can aid in pollution control by consuming or breaking down organic matter in sewage, or by similarly acting on oil spills or other water pollutants. Some bacteria in soil, water or air may also cause human, animal and plant health problems.

The following video provides you with the correct English pronunciation of the word "bacteria (back-TEER-e-uh)", to help you become a better English speaker.