Like the many other species of the genus Penicillium, P. chrysogenum usually reproduces by forming dry chains of spores (or conidia) from brush-shaped conidiophores. The conidia are typically carried by air currents to new colonisation sites. In P. chrysogenum, the 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 P. 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.[16]
The airborne asexual spores of P. chrysogenum are important human allergens. Vacuolar and alkaline serine proteases have been implicated as the major allergenic proteins.[17]
^Samson RA, Houbraken J, Thrane U, Frisvad JC, Andersen B (2010). Food and Indoor Fungi. Utrecht, the Netherlands: CBS-KNAW- Fungal Biodiversity Centre. pp. 1–398.
^Samson RA, Hadlok R, Stolk AC (1977). "A taxonomic study of the Penicillium chrysogenum series". Antonie van Leeuwenhoek. 43 (2): 169–75. doi:10.1007/BF00395671. PMID413477. S2CID41843432.
^Lyratzopoulos, G.; Ellis, M.; Nerringer, R.; Denning, D. W. (October 2002). "Invasive infection due to penicillium species other than P. marneffei". The Journal of Infection. 45 (3): 184–195. doi:10.1053/jinf.2002.1056. ISSN0163-4453. PMID12387776.
^Shen HD, Chou H, Tam MF, Chang CY, Lai HY, Wang SR (October 2003). "Molecular and immunological characterization of Pen ch 18, the vacuolar serine protease major allergen of Penicillium chrysogenum". Allergy. 58 (10): 993–1002. doi:10.1034/j.1398-9995.2003.00107.x. PMID14510716. S2CID28229046.
^Raper KB, Thom C (1949). A manual of the Penicillia. Williams & Wilkins Company (Baltimore).