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Fungi-The Rotten World About Us. What are the Fungi? Simple eukaryotic organisms with small genomes Reproduce asexually and sexually by spores Heterotrophs:

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Presentation on theme: "Fungi-The Rotten World About Us. What are the Fungi? Simple eukaryotic organisms with small genomes Reproduce asexually and sexually by spores Heterotrophs:"— Presentation transcript:

1 Fungi-The Rotten World About Us

2 What are the Fungi? Simple eukaryotic organisms with small genomes Reproduce asexually and sexually by spores Heterotrophs: similar to animals, many bacteria, they rely on autotrophic organisms for fixed carbon and nitrogen Filamentous growth (threadlike strands called hyphae), often branching. Growth of hyphae is at tips. Exception: yeasts which are unicellular. Fungi don't have stems, leaves, roots nor a vascular system like plants. Easy to grow in the lab on defined media (like bacteria), make mutants and do genetic crosses Many species are well developed for molecular manipulations: Transformation, gene replacement, regulated gene expression

3 Fungi in the News

4 Where do Fungi Fit in Classification Schemes?

5 Fungi are NOT Plants!!

6 Fungi are major players in Biotechnology

7 Many Spores are Produced

8 How Big are They?

9 What Are Fungi Doing? Decomposers –Saprobes are the primary agents for biodegradation of plants and woody debris ~85 billion tons of carbon as CO 2 are returned to the atmosphere annually –Disease Agents: decay of living material Plant pathogens destroy ~3 billion dollars of crops annually in N. America –Animal pathogens in Arizona alone, the Valley Fever fungus is responsible for $29 million in hospital costs annually

10 Fungi grow everywhere

11 But Fungi are not human Chicago Worlds Fair - Human hair growing on Wood, Believe it Or Not

12 Fungi in History- First observation Rusts were observed by Romans on cereals –~370 BC –they created a rust God, Robigo to pray for deliverance from disease

13 More History-why the British drink tea instead of coffee Until 1870s, Coffee was produced in Ceylon (Sri Lanka) Britian was full of Coffee houses Coffee rust (Hemileia vastatrix) swept through the coffee plantations between Coffee growers switched to tea and rubber Coffee production moved to Central and South America

14 Fungi in History- the Irish move to America mid-1840s Potato crops fail in Ireland 2 million people died, 1 million emigrated to US 1861 deBary shows this was due to a fungus, Phytophthora infestans an emerging problem today due to a new strain

15 Fungi in History-Salem Witch Trials In 1692 several women in Salem, MA were accused of witchcraft and hung Evidence suggests their strange behavior may have been due to poisoning by the ergot fungus, Claviceps purpurea, a pathogen of rye –This fungus produces toxins (alkaloids) that cause vasoconstriction. It is the source of LSD Can lead to cutting off of the blood supply and loss of limbs due to gangrene setting in Some of its alkaloids are used for treatment of migranes, and induction of labor during childbirth

16 Fungi- The New Asbestos? New York Times Magazine - August 12, 2001

17 Stachybotrys chartarum The sick building mold??????

18 Why are fungi important organisms for biotechnology? Produce 1 o and 2 o metabolites of industrial importance 1 o metabolites: end products of common metabolic pathways: alcohol (ethanol), citric acid, itaconic acid 2 o metabolites: a diverse range of compounds that lack known obvious functions in the growth and reproduction of the organism. Production often occurs after growth has stopped, when nutrients are limited, but excess carbon is available. ex: Penicillin, cephalosporins, griseofulvin, cyclosporin, ergot alkaloids Well developed and understood secretory machinery allowing simple purification of products from culture medium. Relatively easily grown in mass culture and lots of practice (alcoholic beverage industry).

19 Manipulability of Fungi makes them attractive to industry Easy to grow, make mutants and do genetic crosses Molecular biology is well developed: transformation, gene replacement, regulated expression, total genome expression analysis, whole genome sequences are becoming available Saccharomyces cerevisiae was the first eukaryote to have its full genome sequenced (1996), Neurospora crassa (2001), several others in 2002

20 Saccharomyces cerevisiae: the brewers and bakers yeast A facultative anaerobe Anaerobic respiration: produces alcohol C 6 H 12 O > 2C 2 H 5 OH + 2CO ATP Aerobic respiration: major product is CO 2 C 6 H 12 O > 6 CO H ATP One of the first organisms exploited for biotechnology Wheat production resulted in the settling of populations Yeast was responsible for making bread rise

21 Fungi were the source of the first antibiotic Penicillium notatum

22 The Penicillin Story Antibiotic production –1929: Discovered P. notatum as a contaminant on a bacterial plate by A. Fleming –1939: Chain and Florey first isolated drug to treat mice and a dying patient –1940s: Florey and others worked on production for treatment of bacterial infections during WWII –Production Improvements: New species IDed: P. chrysogenum on a moldy cantelope in a Peoria, IL market Culturing conditions: corn steeping liquor gave a 40X yield increase Mutagenesis and selection increased production from 80 mg/L to 7 g/L Synthetic modification of side chains produced more stable and effective drugs (ampicillin, carbenicillin)

23 Penicillin- the first antibiotic Flemings 1929 plate

24 Quorn- eaten in the UK for 17 years, now available in the US Fusarium graminearum, isolated from a field in Marlow, Buckinghamshire Quorn is produced from mycelia grown in 155,000 litre airlift fermenters The filamentous nature of the biomass is responsible for the meat-like texture and appearance of the final product. Probably the most thoroughly tested food ever to appear on supermarket shelves, annual sales of Quorn are now in excess of £15 million in the UK.

25 Quorn-meat-free Quorn products typically contain between 11 to 15 grams of protein per 100 grams, most of which comes from mycoprotein.

26 Citric acid isolated, from a fungus, is everywhere Citric acid production is from the fungus Aspergillus niger Production is due to blockage of the TCA cycle by growing A. niger under low pH conditions with enzyme inhibitors like Cu ions 1979, more than 100 million kilograms were produced in US and Europe Found as a flavoring (soft drinks, candies, desserts, jams jellies, wines, frozen fruits, also in gelatins citrates in blood transfusions act as anti-coagulants Adjusts pH in hair rinses, hair dyes, used in creams and ointments Zinc citrate in toothpaste is a plaque inhibitor

27 Closer to Home- Valley Fever

28 Arthroconidia (transmission & scanning EM)

29 Infectious Phase Spherules (Freeze-fracture EM)

30 What Is Valley Fever? Caused by a soil fungus Coccidioides immitis (Coccidium-like not mild) Other names: –Coccidioidomycosis (cocci) –Desert Rheumatism Infection results from inhaling arthroconidia Severity varies –Mild: 60% –Moderate: 30% –Complicated: 10% After infection, most persons develop life-long immunity

31 Coccidioides immitis

32 Valley Fever in the U.S <5 % Positive Skin Test

33 Coccidioidomycosis in Arizona (Reported)- a problem on the rise

34 High Profile Cases Woods ills caused by Valley Fever By SUSAN CARROLL Citizen Staff Writer__ ___________ Loren Woods lamented absence from the NCAA Tournament, his two back surgeries and upcoming months of physical therapy are being blamed on one culprit: valley fever. TUCSON CITIZEN: May 5, 2000

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