Many microbes are involved in production of antibiotics. Antibiotics are chemicals that are produce by some microbes ( most commonly bactaria and fungi) that kill other microbes.

• Penicillium chrysogenum- produces antibiotic penicillin which is effective against several bactarial infections by staphylococci and streptococci

• Cephalosporium- produces cephalosporins hamper the formation of peptidoglycan layer in bactaria and hence, act as a antibiotic against them.