Microorganisms used in the preparation of antibiotics
Antibiotics are substances that inhibit the growth of or destroy microorganisms, particularly bacteria. They are produced by various microorganisms through a process known as fermentation. Among the microorganisms used in the preparation of antibiotics, the most common ones are bacteria and fungi.

Bacteria
- Bacteria such as Streptomyces, Bacillus, and Penicillium are commonly used in the production of antibiotics.
- Streptomyces species are particularly important as they produce a wide range of antibiotics like streptomycin, tetracycline, and erythromycin.
- Bacillus species are known for producing the antibiotic bacitracin.
- Penicillium species, including Penicillium chrysogenum, produce the well-known antibiotic penicillin.

Fungi
- Fungi are also utilized in the production of antibiotics. Penicillium species, which are molds, are a prime example of fungi used in antibiotic production.
- Apart from penicillin, other antibiotics like cephalosporins and griseofulvin are also derived from fungi.
In conclusion, bacteria and fungi play a crucial role in the preparation of antibiotics through the production of various antimicrobial compounds. These microorganisms have been extensively studied and manipulated to produce effective antibiotics that are used to combat bacterial infections in humans and animals.