Escherichia coli

A commensal bacterium inhabiting the human colon that is widely used in biology, both as a simple model of cell biochemical function and as a host for molecular cloning experiments.

A commensal bacterium inhabiting the colon of many animal species, including human. E. coli is widely used as a model of cell biochemical function, and as a host for. In environmental studies, its presence is a key indicator of water pollution due to human sewage effluent. Some strains, notably E. coli 0157:H7, are significant pathogens.

Common bacterium that has been studied intensively by geneticists because of its small genome size, normal lack of pathogenicity, and ease of growth in the laboratory.