 The bacterium can be grown and cultured easily and inexpensively in a laboratory setting , and has been intensively investigated for over 60 years . E. coli is a <unk> whose chemically defined medium must include a source of carbon and energy . Organic growth factors included in chemically defined medium used to grow E. coli includes glucose , ammonium phosphate , mono basic , sodium chloride , magnesium sulfate , potassium phosphate , <unk> , and water . The exact chemical composition is known for media that is considered chemically defined medium . E. coli is the most widely studied prokaryotic model organism , and an important species in the fields of biotechnology and microbiology , where it has served as the host organism for the majority of work with recombinant DNA . Under favorable conditions , it takes only 20 minutes to reproduce . 
