Laboratory staff members also kept an eye out for promising molds while grocery shopping or cleaning out their refrigerators. Co. Inc. Fermentation unit used in purifying penicillin in 1945. This Penicillium species, Penicillium chrysogenum grew so well in a tank that it more than doubled the amount of penicillin produced. The deep fermentation method, the use of corn steep liquor and the discovery of P. chrysogenum by Mary Hunt made the commercial production of penicillin possible. Penicillin kills by preventing some bacteria from forming new cell walls.
Some bacteria are able to resist the action of antibiotic drugs, including penicillin.
Antibiotic resistance occurs because not all bacteria of the same species are alike, just as people in your own family are not exactly alike. Eventually, the small differences among the bacteria often mean that some will be able to resist the attack of an antibiotic. If the sick person's own defenses can not kill off these resistant bacteria, they will multiply. Taking antibiotics for viral illnesses like colds can also cause antibiotic resistant bacteria to develop. Antibiotics have no effect on viruses, but it will kill off harmless and even the beneficial bacteria living in the patient's body.