Penicillium chrysogenum

Taxobox
name = "Penicillium chrysogenum"


image_width = 240px
image_caption = "Penicillium chrysogenum"
regnum = Fungi
divisio = Ascomycota
subdivisio = Pezizomycotina
classis = Eurotiomycetes
ordo = Eurotiales
familia = Trichocomaceae
genus = "Penicillium"
species = "P. chrysogenum"
binomial = "Penicillium chrysogenum"
binomial_authority = Thom

"Penicillium chrysogenum" is a mold that is widely distributed in nature, and is often found living on foods and in indoor environments. It was previously known as "Penicillium notatum".cite journal|author=Samson RA, Hadlok R, Stolk AC |title=A taxonomic study of the "Penicillium chrysogenum" series |journal=Antonie van Leeuwenhoek |volume=43 |issue=2 |pages=169–175 |year=1977 |doi=10.1007/BF00395671] It has rarely been reported as a cause of human disease. It is the source of several β-lactam antibiotics, most significantly penicillin. Other secondary metabolites of "P. chrysogenum" include various different penicillins, roquefortine C, meleagrin, chrysogine, xanthocillins, secalonic acids, sorrentanone, sorbicillin, and PR-toxin.cite|author=de Hoog GS, Guarro J, Gené J, Figueras F |title=Atlas of Clinical Fungi - 2nd Edition |publisher=Centraalbureau voor Schimmelcultures (Utrecht) |date=2000]

Like the many other species of the genus "Penicillium", "P. chrysogenum" reproduces by forming dry chains of spores (or conidia) from brush-shaped conidiophores. The conidia are typically carried by air currents to new colonization 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 color alone. Observations of morphology and microscopic features are needed to confirm its identity.

The airborne spores of "P. chrysogenum" are important human allergens. Vacuolar and alkaline serine proteases have been implicated as the major allergenic proteins. cite journal |author=Shen HD, Chou H, Tam MF, Chang CY, Lai HY, Wang SR |title=Molecular and immunological characterization of Pen ch 18, the vacuolar serine protease major allergen of "Penicillium chrysogenum" |journal=Allergy |volume=58 |issue=10 |pages=993–1002 |year=2003 |pmid=14510716 |doi=]

"P. chrysogenum" has been used industrially to produce penicillin and xanthocillin X, to treat pulp mill waste, to produce the enzymes polyamine oxidase, phospho-gluconate dehydrogenase, and glucose oxidase.cite|author=Raper KB, Thom C |title=A manual of the Penicillia |publisher=Williams & Wilkins Company (Baltimore) |date=1949]

cience and History

Penicillin was discovered in 1928 when Alexander Fleming's lab assistant left a window open overnight and had mold spores cover his "Staphylococcus" bacterial specimens in a Petri dish.cite journal |author=Diggins F |title=The true history of the discovery of penicillin, with refutation of the misinformation in the literature |journal=Br J Biomed Sci |volume=56 |issue=2 |pages=83–93 |year=1999 |pmid=10695047] cite journal |author=Ligon B |title=Penicillin: its discovery and early development |journal=Semin Pediatr Infect Dis |volume=15 |issue=1 |pages=52–7 |year=2004 |pmid=15175995 |doi=10.1053/j.spid.2004.02.001] At first he was very irritated at the contamination but as he was about to throw the specimens away, he noticed something interesting. He looked under the microscope at the bacteria surrounding the blue-green mold and noticed that many were dead or dying due to the mold preventing the bacteria from making new cell walls and reproducing. He identified the mold as "Penicillium notatum", which releases the antibiotic penicillin G into the medium. After this he did some testing on humans and animals and discovered that not only did it kill bacteria, but that it was suitable for use in humans and animals. However, the discovery did not attract much attention until the 1940s when Howard Florey and Ernst Chain developed methods for mass production and application in humans, incited by the urgent war-time need for antibacterial agents. Army pilots sent back soil from around the world to be tested for the right kind of mold. Even the people of Peoria, Illinois were told to bring in any molds that they found around their homes. It has also been said that the scientists working on this project kept an eye out for similar looking molds while grocery shopping or when they were cleaning around the kitchen especially their refrigerators. The discovery of penicillin ushered in a new age of antibiotics derived from microorganisms.

Genetics and Evolution

The ability to produce penicillin appears to have evolved over thousands of years, and is shared with several other related fungi. It is believed to confer a selective advantage during competition with bacteria for food sources. However, some bacteria have developed the ability to survive penicillin exposure by producing penicillinases, enzymes that degrade penicillin. Penicillinase production is one mechanism by which bacteria can become penicillin resistant.

The principal genes responsible for producing penicillin, pcbAB, pcbC and penDE are closely linked, forming a cluster on chromosome I.cite journal |author=Martín JF, Gutiérrez S, Fernández FJ, "et al" |title=Expression of genes and processing of enzymes for the biosynthesis of penicillins and cephalosporins |journal=Antonie Van Leeuwenhoek |volume=65 |issue=3 |pages=227–243 |year=1994 |pmid=7847890 |doi=] Some high-producing "Penicillium chrysogenum" strains used for the industrial production of penicillin have been shown to have multiple tandem copies of the penicillin gene cluster.cite journal |author=Fierro F, Barredo JL, Díez B, Gutierrez S, Fernández FJ, Martín JF |title=The penicillin gene cluster is amplified in tandem repeats linked by conserved hexanucleotide sequences |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=92 |issue=13 |pages=6200–6204 |year=1995 |pmid=7597101 |doi=]

References

External links

* [http://microbewiki.kenyon.edu/index.php/Penecillium Penicillium - MicrobeWiki]
* [http://botit.botany.wisc.edu/Toms_fungi/nov2003.html Penicillium chrysogenum, Tom Volk's fungus of the month]