Production of Penicillin

Antibiotics are chemicals that are released by one group of micro organisms against the other. The anti biotics generally inhibit the growth and development in susceptible micro organisms. The first antibiotic was discovered by Alexander Fleming in the year 1929 released from a fungus called Penicillin Notatum. Most of the antibiotics are produced from group Actinomycetes, especially genus streptomyces as well as filamentous fungi. Many antibiotics like streptomycin, ampicillin, amoxicillin, penicillin chloramphenicol are in use and helped human to protect himself from a variety of pathogens.

There are different types of penicillus. All these penicillus belong to a group of antibiotics known as penicillus. Penicillus act against Gram positive bacteria and inhibit cell wall growth. Penicillin is not harmful to mammals. But show certain allergic reaction in mammals including man. All penicillin are chemically derivatives of b- aminopenicillanic acid. There is a β-lactam ring in their structure which is actually responsible for toxicity.

• Several species of penicillium produce penicillin 4. Industrial production of penicillin-G is carried out by the fermentation of the fungus penicillium chrysogenum.
• The nutrient medium should be prepared by dissolving ammonium sulphate, calcium carbonate, corn steep liquor (which is a source of protein), calcium hydroxide, and sodium hydrogen phosphate and phenyl acetic acid. Phenyl acetic acid acts as a precursor of penicillin 4. The PH of the medium is adjusted to 5.2.
• The nutrient medium is sterilized by heating to above 100 °C. Before sterilization of medium, vegetable oil like soybean oil is mixed to the medium which acts as an anti foam agent.
• Active culture of penicillium chrysogenum is introduced into sterilized medium in the fermentor. This is called inoculation. Stirred fermentors are used.
• Fermentation is carried out at 35 °C to 25 °C for 7 days. Aeration and agitation are compulsory.
• After incubation, the mycelium is separated from medium and disposed. The medium is processed and the antibiotic penicillin 4 is extracted and purified. Penicillin 4 can also be chemically modified to obtain semisynthetic antibiotics like amoxycillin and ampicillin.