Penicillium chrysogenum: Penicillium chrysogenum} is the species of fungus that is most commonly used for the commercial production of the antibiotic penicillin. Through selective breeding and genetic manipulation, improved strains of P. chrysogenum} have been developed to produce higher concentrations of penicillin.
Penicillium notatum: Penicillium notatum} was the first species where the antibiotic properties of penicillin were discovered by Alexander Fleming, but this is not the most commercially used variety.
Penicillium eutrophus: Penicillium eutrophus} is not known for producing penicillin, and it is not commercially used in the production of penicillin.
Penicillium cerevisiae: Penicillium cerevisiae} is the scientific name for the baker’s yeast and it is a fungus used in bread production. It does not produce penicillin.