Penicillium is an ascomycetous fungi of which some strains produce penicillin, an antibiotic which kills/ stops growth of pathogenic microorganisms. This was discovered by Alexander Fleming in 1928. P.chrysogenum or notatum commonly grows on salted foods. Commonly used antibiotic penicillin G is produced by it. The V and G types are widely used in the cure of leptospirosis and Lyme diseases, gas gangrene, Helicobacter pylori, typhoid fever, middle ear infection and chlamydia. Different forms of penicillin are amoxicillin and ampicillin.No other species except P.chrysogenum and verrucosum among the studied fungi produce penicillin as the presence of penicillin biosynthetic genes are important. That is the presence of pcbAB gene. Antibacterial activities due to the production of secondary metabolites other than penicillin were observed in some fungi. Invention of penicillin brought a revolution in the field of medicine.
The airborne asexual spores of the fungi are common allergens. Major allergenic proteins arevacuolar and alkaline serine proteases. Proteases have been implicated as the major allergenic proteins which are responsible for the release of antibiotic penicillin G.
As beneficial they are utilized as starters for cheese manufacture. They help in preventing the eventual colonization by undesirable fungi and bacteria. Penicilliumradicum, Penicilliumbilaiae are known to solubilize phosphate. The mycelial cake of Penicilliumchrysogenum, can be dried and after processing in a specific way can be used as a source of protein in place of soybean meal.
Penicilliumroqueforti is a common saprotrophic fungus from the family Trichocomaceae. It is widely found in nature may be soil or decaying organic matter or meat products and has major industrial use in the production of blue cheeses, flavouring agents, antifungal agents, polysaccharides, proteases and also in other enzymes. Penicilliumcamemberti is another species from the same family used in the production of different kinds of cheeses like Camembert, Brie, Langres, Coulommiers and Cambozola. These give a very distinctive flavour. However,sometimes it may beharmful due to the production of undesirable compounds such as mycotoxins or antibiotics. They may also spoil food. Penicilliumexpansum and P. Crustosum spoil many apple varieties.
The food with penicillin is not desirable, as it might give rise to allergies.It may also develop resistance to the human gut bacteria.Many such reports have been found in farm animals.There is also mosquito-associated fungus species that can suppress the mosquito’s innate immune system but enhances Plasmodium infection and probably malaria.
By Dr Renu Agrawal
(The writer is chief scientist (retd.), CFTRI, Mysuru)