Escherichia coli

Escherichia coli is a gram negative facultative anaerobic rods most commonly found in the intestinal tracts of animals. This type of bacteria is capable of growing and metabolizing glucose both in aerobbic conditions and in anaerobic conditions. It is because of this that E. coli can survive in the external aerobic environments and the internal anaerobic environment such as the gastrointestinal tract of warm blooded animals. Many strains of E. coli are harmless, however some can be pathogenic like for example E. coli 0157 which can be a seriuos cause of gastroenteritis .

E. coli is often used as a model organinsm in lab experiments due to its fast reproduction time, how easily it is manipulated and its already sequenced genome. The E. coli strain K-12 is the strain most commonly used in the laboratory. It has 4.6 million nucleotide pairs in its genome that code for approxamately 4300 different proteins .