. . Antibiotic production Antibiotics are chemical substances produced by microorganisms which can kill or retard the growth of other disease causing microbes even in low concentration. Antibiotic means “ against life ”.
Antibiotics are used to treat diseases such as plague, meningitis, diphtheria, syphilis, leprosy, tuberculosis etc., Selman Waksman discovered Streptomycin and was the first to use the term “ antibiotic ” in . While working on Staphylococci bacteria, Alexander Fleming observed a green mould growing in one of his unwashed culture plates around which Staphylococci could not grow. XII Std Biology-Zoology Chapter- XII Std Biology-Zoology Chapter- Microbes in Human Welfare He found that it was due to a chemical produced by the mould and he named it as penicillin, which was the first antibiotic discovered by Alexander Fleming in (Fig. .
) . Penicillin is produced by the fungi Penicillium notatum and Penicillium chrysogenum . It is bactericidal (antibiotics that kill bacteria) in action and inhibits the synthesis of the bacterial cell wall. Penicillin is also referred as the “queen of drugs” and its full potential as an effective antibiotic was established much later by Earnest Chain and Howard Florey when they treated the wounded soldiers in World War II with penicillin.
Fleming, Chain and Florey were awarded the Nobel prize in for the discovery of penicillin. Antibiosis is the property of antibiotics to kill microorganisms. Broad-spectrum antibiotics act against a wide range of disease-causing bacteria. Narrow - spectrum antibiotics are active against a selected group of bacterial types.
Penicillium chrysogenum Staphylococcus aureus