Mohamed Refai أ.د. محمد كمال رفاعي

Penicillium is a well known cosmopolitan genus of moulds that comprises more than 350 species playing various roles in natural ecosystems, agriculture and biotechnology. They have double faces, a good and beneficial one and a bad and economically destructive one. Examples of the beneficial roles are:   Penicillium chrysogenum produces the antibacterial  antibiotic penicillin, Penicillium griseofulvum   produces the antifungal antibiotic  griseofulvin, several Penicillium species produce anti-cancer substances such as Penicillium albocoremium (Andrastin A), P. decumbens (Bredenin). Penicillium roqueforti is used for the production of Roquefort cheese and Penicillium camemberti is used for the production of Camembert cheese.

Several Penicillium species produce enzymes that are used in industry, e.g. cellulases and xylanases  produced by Penicillium species have broad applications in food and feed, the textile industry, and the pulp and paper industries. Penicillium species are also used for biodegradation of oil and can be used in restoring the ecosystem when contaminated by oil. Peroxidase enzyme of Penicillium species  have potential biodegradable activities that degrade Amaranth dye, Orange G, heterocyclic dyes like, Azure B and Lip dye. Morepver, some species function as decomposers of dead materials   and can be used in recycling of  waste products.

Recently, Penicillium species, such as P.  aurantiogriseum, P. citrinum, and P. waksmanii,  are used for the eco-friendly biosynthesis of gold nanoparticles   from a solution of AuCl. Gold nanoparticles are formed fairly uniform with spherical shape with the Z-average diameter of 153.3 nm, 172 nm and 160.1 nm for the 3 species, respectively.

On the other hand, some species are known to cause  postharvest diseases, e.g. Penicillium expansum is one of the most prevalent post-harvest rots that infects apples. Although it is a major economic problem in apples, this plant pathogen can be isolated from a wide host range, including pears, strawberries, tomatoes, corn, and rice. This mould also produces the carcinogenic metabolite patulin, a neurotoxin that is harmful in apple juice and apple products.  patulin in food products is a health concern because many are consumed by young children. In addition, a second secondary metabolite citrinin is produced as well. 

Mould growth on citrus fruits during storage is a continuing problem that results in economic loss. Although several fungal species have been reported to be involved in the spoilage of citrus products, Penicillium digitatum (green mold) and Penicillium italicum (blue mold) are the primary organisms involved.

Penicillium is one of the first fungi to grow on water-damaged materials and has been implicated in causing allergic reactions, hypersensitivity pneumonitis, and a variety of severe lung complications. It may cause sarcoidosis, fibrosis, or allergic alveolitis in susceptible individuals, or patients who have been exposed over long periods of time, depending on the strain. P. oxalicum has also been reported to cause genital infection of water buffalo.