 E. coli is frequently used as a model organism in microbiology studies . Cultivated strains ( e.g. E. coli <unk> ) are well @-@ adapted to the laboratory environment , and , unlike wild @-@ type strains , have lost their ability to thrive in the intestine . Many laboratory strains lose their ability to form biofilms . These features protect wild @-@ type strains from antibodies and other chemical attacks , but require a large expenditure of energy and material resources . 
