Microbial genetics is a subject area within microbiology and genetic engineering. It studies the genetics of very small (micro) organisms; bacteria, archaea, viruses and some protozoa and fungi. This involves the study of the genotype of microbial species and also the expression system in the form of phenotypes.
Since the discovery of microorganisms by Robert Hooke and Antoni van Leeuwenhoek during the period 1665-1885 they have been used to study many processes and have had applications in various areas of study in genetics. For example: Microorganisms' rapid growth rates and short generation times are used by scientists to study evolution. Microbial genetics also has applications in being able to study processes and pathways that are similar to those found in humans such as drug metabolism.
Microbes are ideally suited for biochemical and genetics studies and have made huge contributions to these fields of science such as the demonstration that DNA is the genetic material, that the gene has a simple linear structure, that the genetic code is a triplet code, and that gene expression is regulated by specific genetic processes. Jacques Monod and François Jacob used Escherichia coli, a type of bacteria, in order to develop the operon model of gene expression, which lay down the basis of gene expression and regulation. Furthermore, the hereditary processes of single-celled eukaryotic microorganisms are similar to those in multi-cellular organisms allowing researchers to gather information on this process as well.