Penicillium chrysogenum is a species of fungus in the family Trichocomaceae. It is common in temperateand subtropical regions and can be found on salted food products,^[1] but it is mostly found in indoor environments, especially in damp or water-damaged buildings.^[2] It was previously known as Penicillium notatum.^[3] It has rarely been reported as a cause of human disease.^[how?] It is the source of several β-lactam antibiotics, most significantly penicillin. Other secondary metabolites of P. chrysogenum includeroquefortine C, meleagrin, chrysogine, xanthocillins,secalonic acids, sorrentanone, sorbicillin, and PR-toxin.^[4]

Like the many other species of the genus Penicillium,P. chrysogenum usually reproduces by forming dry chains of spores (or conidia) from brush-shapedconidiophores. The conidia are typically carried by air currents to new colonisation sites. In P. chrysogenumthe conidia are blue to blue-green, and the mold sometimes exudes a yellow pigment. However,P. chrysogenum cannot be identified based on colour alone. Observations of morphology and microscopic features are needed to confirm its identity and DNA sequencing is essential to distinguish it from closely related species such as Penicillium rubens. The sexual stage of P. chrysogenum was discovered in 2013 by mating cultures in the dark on oatmeal agar supplemented with biotin, after the mating types (MAT1-1 or MAT1-2) of the strains had been determined using PCR amplification.^[5]

The airborne asexual spores of P. chrysogenum are important human allergens. Vacuolar and alkaline serine proteases have been implicated as the major allergenic proteins.^[6]

Penicillium chrysogenum has been used industrially to produce penicillin and xanthocillin X, to treatpulp mill waste, and to produce the enzymes polyamine oxidase, phosphogluconate dehydrogenase, and glucose oxidase.^[4][7]

(From Wikipedia, July 2015)