Microbiology is the study of organisms that are too small to be seen by the unaided human eye. Such organisms include protozoa, algae, fungi, lichens, bacteria and viruses.

Microbiology is one of the most important and exciting of the biological sciences. Not only is it a basic biological science, which has provided us with much of our understanding of the chemical and physical principles behind living processes, but it is also an applied biological science, dealing with aspects of medicine, agriculture, biotechnology, food technology and pollution control.