Penicillium chrysogenum
A Microbial Biorealm page on the genus Penicillium chrysogenum
Classification
Higher order taxa
Cellular organisms; Eukaryota; Fungi; Ascomycota; Eurotiomycetes; Eurotiales; Trichocomaceae; Penicillium
Species
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NCBI: Taxonomy [1] |
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NCBI: Genome [2] |
Penicillium chrysogenum
Description and significance
Penicillium chrysogenum is a widely studied species of Penicillium also known as P. notatum, P. meleagrinum,or P. cyaneofulvum.3 It plays a significant role in the medical community as an antibiotic because it can create penicillin which degrades gram positive bacteria by affecting lysis of their cell wall.2 It can also play a role as either a pathogen or allergen.1,9,10,11
Penicillium was originally discovered by Alexander Fleming. Fleming observed that staphylococcus cultures which had been left on the lab bench and allowed to grow, had began to lyse. He described it as a fungal colony that begins as a “white fluffy mass” that later turns green then black. A yellow color appears after several days that will diffuse throughout the medium.2
Penicillium chrysogenum is a common fungus that can inhabit a wide variety of habitats including the soils of degraded forests 4, on the pollen and provisions of alfalfa leafcutter bees 5, and in Arctic subglacial ice where they feed on sediment-rich basal ice shelves 6. Penicillium chrysogenum is most commonly found naturally in moist soils with plentiful quantities of carbon and nitrogen for miccohrizal growth. This species can also be found on fruit causing decay. 8
The importance of sequencing the genome of Penicillium chrysogenum is evident, it is a major player in the lives of humans today in various forms; pathogen, allergen, and an industrial source of antibiotics. Therefore understanding the various metabolic and biosynthetic systems of Penicillium chrysogenum will allow researchers the ability to limit growth when it acts as a pathogen, lower the allergic response to it when it acts as an allergen, or maximize biosynthesis of penicillin when it is used to make the antibiotic. Additionally it is important to have the genome sequence of this species for analysis when considering the emergence of new drug resistant strains of bacteria.
Genome structure
Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence? Does it have any plasmids? Are they important to the organism's lifestyle?
Cell structure and metabolism
Describe any interesting features and/or cell structures; how it gains energy; what important molecules it produces.
Pathology
Penicillium chrysogenum is rarely pathogenic except in exceptional circumstances such as people with severely suppressed immune systems, like those with human immunodeficiency virus (HIV). Due to this low pathogenicity, it is difficult to diagnose due to a low level of suspicion of infection. Symptoms however include pulmonary infection including pneumonia, localized granulomas, fungus balls, and systemic infection. Once diagnosed, infection is treated with the surgical removal of foci of infection and the use of an oral antifungal regiment, usually either amphotericin B or itraconazole. Prognosis is poor for this type of infection. Penicillium chrysogenum is usually not a cause of infection in people with normally functioning immune systems.1
Another such exceptional circumstance is in the case of endophthalmitis which is described as an inflammation of the ocular cavity. The most common avenue for the implementation of infection by Penicillium chrysogenum in the eye is by penetrating trauma. The infection is treated as a systemic infection would be, with an oral antifungal regiment, usually either amphotericin B or itraconazole with the caveat that a topical antifungal may also be prescribed. 9,10
Penicillium chrysogenum can also act as an allergen and an asthma inducer. Pen ch 13 is the active allergen that triggers histamine responses in the epithelial cells of lungs. The constriction of the airway ensues and the characteristic hack of the asthmatic is the most common symptom.12
Application to Biotechnology
Penicillium chrysogenum is usually exploited for its antibiotic capabilities. It produces the hydrophobic β-lactam compound penicillin. The efficacy of the specific penicillin made is dependent on its side chain as depicted in figure 1.1. Originally Penicillium chrysogenum was limited to the treatment of scarlet fever, pneumonia, gonorrhea, infections on wounds, and serious staphylococcal infections as Penicillian G. Today many variations of side chains yield a wide variety of semi-synthetic penicillin’s that are able to fight a broader range of bacteria.13 The most common application of Penicillium chrysogenum is as an industrial producer of antibiotics. However it also has recently been suggested that Penicillium chrysogenum can be used to assist crops to fight off other pathogenic species. The application of penicillin to crops such as apple trees, grapevines and tomatoes can induce their defense mechanisms and thereby help protect against apple scab, mildew, and early blite respectively in each of these crops. This response is induced under greenhouse and field conditions and is not due to direct pathogenic effects from penicillin. 7
Current Research
Enter summaries of the most recent research here--at least three required
References
1. Adrian, B.L., Burdette, S.D., and Herchline, T.E. "Intestinal invasion and disseminated disease associated with Penicillium chrysogenum". Ann Clin Microbiol Antimicrob. December 2005. Vol 4. Page 21.
http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1343575
2. Fleming, A. "On the antibacterial action of cultures of Penicillium, with special refrence to their use in the isolation of B. Influenzae". British Journal of Experimental Pathology. May 1929. Vol 10. Pages 226-236.
3. Samson, R.A., Hadlok, R.,and Stolk, A.C. "A taxonomic study of the Penicillium chrysogenum series". Antonie van Leeuwenhoek. May 1977. Vol 43. Pages 169-175
http://www.springerlink.com/content/wu67kx6758061h87/fulltext.pdf
4. Jka, D.K., Sharma, G.D., and Mishra R.R. "Ecology of soil microflora and mycorrihzal symbionts in degraded forests at two altitudes". Biology and Fertility of Soils. January 1992. Vol 12. Pages 272-278.
http://www.springerlink.com/content/u85m3v54g29w85u2/fulltext.pdf
5. Inglis, G.D., Sigler, L., and Goette, M.S. "Aerobic microorganisims associated with alfalfa leafcutter bees (Megachile rotundata)". Microbial Ecology. September 1993. Vol 26. Pages 125-143.
http://www.springerlink.com/content/q73337l00677x668/fulltext.pdf
6. Sonjak, S., Frisvad, J.C., and Gunde-Cimerman, N. "Penicillium mycobiota in Arctic subglacial ice". Microbial Ecology. August 2006. Vol 52. Pages 207-216.
http://www.springerlink.com/content/n8m5266050067r11/fulltext.pdf
7. Thuerig, B., Binder, A., Boller, T., et al. "An aqueous extract of the dry mycelium of Penicillium chrysogenum induces resistance in several crops under controlled and field conditions". European Journal of Plant Pathology. Febuary 2006. Vol 114. Pages 185-197.
8. Barkai-Golan, R. "Species of Penicillium causing decay of stored fruit in Isreal". Mycopathologia. October 1974. Vol 54. Pages 141-145.
http://www.springerlink.com/content/x530n77737132218/fulltext.pdf
9. Eschete, M.L., King, J.W., West, B.C., et al. "Penicillium chrysogenum endophthalmitis". Mycopathologia. May 1981. Vol 74. Pages 125-127.
http://www.springerlink.com/content/x1311078w8k21343/fulltext.pdf
10. Galland, F., Le Goff, L., Conrath, J., et al. "Penicillium chrysogenum endophthalmitis: a case report". Journal Français d'Ophtalmologie. March 2004. Vol 27. Pages 264-266.
11. Shen, H.D., Chou, H., Tam, M.F., et al. “Molecular and immunological characterization of Pen ch 18, the vacuolar serine protease major allergen of Penicillium chrysogenum” Allergy. 2003 Oct;58(10):993-1002
http://www.ncbi.nlm.nih.gov/sites/entrez?db=PubMed&cmd=Retrieve&list_uids=14510716
12. Tai, H.Y.,Tam, M.F.,Chou H., et al. “Pen ch 13 allergen induces secretion of mediators and degradation of occludin protein of human lung epithelial cells”. Allergy. March 2006. Vol 61. Pages 382–388.
Edited by student of Rachel Larsen
