Plants & Civilization
Lab #3:
The Kingdom Fungi
Fungi: An Overview
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Diverse group of organisms
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Unicellular (yeasts)
Multicellular
Heterotrophic
Play major ecological & economic roles,
but may parasitize humans & plants.
Fungi – A Benefit to Humans
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A single-celled fungus, YEAST, is used in the
production of:
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Another fungus, Penicillium, used in the
production of:
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Wine, beer, bread
Antibiotics
Mushrooms – edible food items
In ecosytems, fungi & bacteria play role in the
decomposition of organic matter.
Fungi – A Menace to Humans
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Animals, Humans infected by fungi
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Athlete’s foot, Ringworm, Respiratory diseases, etc.
Plant diseases caused by fungi:
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Potato blight, Wheat rust, Ergot
Divisions of FUNGI
1.
2.
3.
4.
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Zygomycota
Ascomycota
Basidiomycota
Deuteromycota
*Lichens (association of fungi & algae)
Divisions characterized by life cycles &
reproductive structures: Mode(s) of
reproduction-either asexually by mitosis
or sexually by meiosis.
Division Zygomycota:
“The Zygote Fungi”
Examples:
Rhizopus stolonifer (common bread mold)
„ Pilobolus crystallinus (shotgun fungus)
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http://www.fooddata.nl/Fooddata_CMS/Database/upload/Rhizopus%20stolonifer.jpg
http://utenti.lycos.it/marinetto/photoalbum.html
Zygomycota:
Rhizopus stolonifer
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General “fungal” characteristics including:
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Cells made up of chitin & cellulose
Structure of thread-like filaments called hyphae, which
are organized into the body of the fungus, mycelium.
Sporangia contain spores that may germinate into a
new fungal mycelium (via asexual reproduction).
Mycelia secrete enzymes into the substrate,
which digests & absorbs food.
Zygomycota:
Rhizopus stolonifer
Reproduction:
Rhizopus may reproduce asexually or sexually.
Recall…
•Asexual reproduction requires one organism
that produces haploid (n) spores by mitosis.
•Sexual reproduction requires two organisms
that fuse to restore diploid (2n) state.
Rhizopus stolonifer: Life Cycle
Asexual
reproduction
by haploid (n)
spores
produced in
sporangia.
Sexual
reproduction:
(+) & (-) types
hyphae nucleic
fuse to form
diploid (2n)
zygospore.
http://io.uwinnipeg.ca/~simmons/1116/images/rhizolc.gif
Zygomycota:
Pilobolus crystallinus
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“Coprophilous” – grows on dung
It is positively phototrophic
Reproduces asexually
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Pilobolus sporangia form in early evening. After
midnight, swelling begins creating turgor pressure.
Pressure causes the an explosion, propelling sporangia
up to 2 meters.
Sticky sporangia adhere to grasses etc. & are eaten by
animals. Intact sporangia pass through digestive tract.
Here, spores germinate in the fresh dung!
Yeasts
Division Ascomycota:
“The Sac Fungi”
http://botany.upol.cz/atlasy/system/images/ascomycetes/pezizales/sarcoscypha.jpg
Peziza apothecia
http://ebiomedia.com/prod/2004prodimages/yeasts.jpg&imgrefurl
Claviceps purpurea
(rye ergot)
Morels
http://www.wetterzentrale.de/np/galerie/data/media/52/07050077.JPG
http://pkaminski.homestead.com/files/Morels_bunch_2_L.jpg
Ascomycota…another example
Dutch Elm Disease is caused by
an Ascomycote fungus.
http://www.forestpathology.org/graphics/elmcycle.gif
http://webs.wichita.edu/mschneegurt/biol103/lecture21/dutch_elm.gif
Ascomycota:
General Characteristics
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Called “sac fungi” or “ascospore-producing
Fungi”…many cup-shaped.
Diverse group – some unicellular (yeasts), some
edible (morels, truffles), others parasitic (dutch
elm disease)
May reproduce asexually or sexually
Ascomycota:
Asexual Reproduction
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Fungi in this Division primarily reproduce
asexually by forming chains of spores called
conidia (conid = dust).
Spores (conidia) may be produced on the
surface of special reproductive hyphae.
Ascomycota:
Asexual Reproduction & Yeasts
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Yeasts are single-celled fungi.
Usually reproduce asexually, by budding.
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Budding = small cells form by pinching off of a
parent yeast cell.
Sometimes yeasts reproduce sexually.
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In this case, they produce asci, each which
produces 4 or 8 spores.
(just like Peziza – see next slide)
Ascomycota:
Sexual Reproduction
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By meiosis, 4 or 8 haploid (n) ascospores are
produced within an ascus.
In Peziza, these asci are found in an open cupshaped ascocarp or apothecium. •In sexual reproduction, a
cup-like “fruiting” structure
is formed called an
ascocarp (carpo = fruit).
•This contains a number of
asci (ascus), each of which
contains eight
ascospores.
http://biology.clc.uc.edu/graphics/bio106/peziza.jpg
•The ascospores are
always lined up in the
order in which they did
meiosis.
Division Basidiomycota:
“The Club Fungi”
http://www.fungoceva.it/images/funghicebano/Coprinus_cinereusGR.jpg
Button Mushrooms (edible)
Coprinus cinereus
http://www.foodsubs.com/Photos/cwhitemushrooms.jpg
Shelf fungus
http://www.richard-seaman.com/Fungus/USA/DevilsLake2003/IMG_8782.JPG
http://www.localarcade.com/arcade_art/data/thumbnails/2/toad.gif
Division BasidiomycotaOverview:
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Called “club fungi” or “basidiosporeproducing fungi”
Edible & non-edible mushrooms
(toadstools) included:
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Puffballs
Shelf fungi
Some cause plant diseases like wheat rust & corn smut
Division BasidiomycotaWhat is a “Mushroom”?
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A mushroom is a reproductive structure !
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Also called a basidiocarp.
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It grows upward from underground mycelial
mass & produces spores by meiosis (sexual
reproduction) or conidia by mitosis (asexual
reproduction).
Division BasidiomycotaParts of a Mushroom
Photo source: http://www.uq.edu.au/.../ Mushroom.GIF
Photo source: http://www.backyardnature.net/f/fungbasd.gif
http://www.anselm.edu/homepage/jpitocch/genbios/31-12-BasidiomyLifeCyc-L.jpg
Division BasidiomycotaLife Cycle of a Mushroom
Division Deuteromycota:
“Fungi Imperfecti”
http://www.skidmore.edu/academics/biology/plant_bio/fungi/Penicillium%20-%20Ascomycete.jpg
Examples:
Penicillium
Candida “yeast infections”
http://uhavax.hartford.edu/bugl/images/candida.jpg
Division Deuteromycota:
Imperfect Fungi Characteristics
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These fungi are categorized based on their lack
of sexual reproductive stages.
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Only known to reproduce vegetatively or asexually.
Called “asexual” following botanical term
“imperfect” indicating a flower that lacks one
reproductive part.
Imperfect Fungi Reproduction
Asexual-
http://www.uq.edu.au/_School_Science_Lessons/8.0Penicillium.GIF
Division Deuteromycota:
Familiar Imperfect Fungi
Cause several human diseases:
„ Althetes’s foot
„ Ringworm
„ Candida “yeast” infections
Division Deuteromycota:
Familiar Imperfect Fungi
Beneficial to humans
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Penicillium
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One species used in the production of antibiotics
Another species used to make Roquefort & blue cheese
http://www.monanneeaucollege.com/6.svt.chap11_fichiers/penicillium-roqueforti.1.jpg
http://schimmel-schimmelpilze.de/download-1/gorgonzola-kaese.jpg
Lichens
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Symbiotic association between fungi &
algae/cyanobacteria
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Usually a ‘sac-fungus’ or ‘club fungus’ involved
Fungi rely on photosynthetic algae for nutrients,
algae relies on fungi for moist environment
Lichens
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Categorized by various body, or thallus, shapes
& colors:
Leafy thallus = foliose
„ Crust-like thallus = crustose
„ Branching thallus = fruticose
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Cup or club-shaped reproductive structures in
colors from bright red/pink or green.
Lichen Types
Fruticose (cylindrical)
Crustose (crust-like)
http://www.botany.wisc.edu/wislichens/EVEMES_MTT1.jpg
Foliose (leafy)
http://www.ru.ac.th/lichen/LichenPix/crustose-lau.jpg
http://homepage.eircom.net/~hedgerow6/foliose-lichen-dots.JPG
Addendum to Fungi Lab
(Practical Applications)
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Humans have long used fungi to raise
bread & ferment alcoholic beverages.
Economically important fungi =
Saccharomyces sp.
YEAST!
Taking Advantage of Yeast
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Recall…yeasts reproduce asexually, by budding.
Yeasts will reproduce if fed, so…
Let’s feed them sugar!
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To make bread: add flour, water, SUGAR & YEAST.
To make wine: add grape juice, SUGAR & YEAST.
The Yeasts’ Reaction
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Yeasts consume SUGAR & produce
ETHANOL (alcohol) & CO2
C6H12O6 + H2O
CH3COCO2 (pyruvate) + NADH
CH3CH2OH (ethanol) + NAD+ + CO2
Yeast By-Products
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Ethanol produced by yeast - gives wine & beer
its alcohol content.
You will learn more about this process in
Lab #6: Trip to the VICTORY Brewery
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CO2 produced by yeast – causes carbonation in
beer & causes bread to rise.
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Because CO2 gas is less dense, it fills in spaces of dough…think
about the “holes” or “pockets” in a piece of bread.
Alcoholic Fermentation
•Glucose is
substrate consumed
producing pyruvic
acid.
•Pyruvate is
reduced to ethanol
(or lactic acid)
during
FERMENTATION.
•CO2 is a byproduct.
Pyruvate:
product of
glycolysis
Glycolysis
MgSO4:
Mg2+ is a
Fermentation
http://www.biologycorner.com/resources/fermentation.jpg
Overview of
Cellular
Respiration:
cofactor
that
activates
enzymes of
glycolysis.
NaF:
inhibitor of
glycolysis
enzymes.
TODAY’S PLAN
Summary:
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Examine 4 Divisions of Fungi, Lichens too
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2.
Addendum to Fungi Lab
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3.
Follow lab manual, make sketches (with labels), and answer
related questions.
Following procedure: make bread (demo), raise the balloon
(demo), & make wine (do this FIRST, as a group of 2)
Cellular Respiration/Alcoholic
Fermentation
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These will take 40 minutes to incubate. Each group will do a
different ‘treatment’. What is the effect of each chemical
variable on alcoholic fermentation?
CAUTIONS!
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Fermentation tubes are very fragile. Handle with care
to avoid breakage.
Chemicals used in the fermentation tube experiment are
POISONOUS! Handle with extreme caution! MUST
WEAR GLOVES & GOGGLES.
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Fungus taste testing (blue cheese) must be done outside
of the lab when all exercises are complete. Wash hands
before touching!\
Wine making must be done under sterile conditions.
Please wash hands, wear gloves, and follow TA
instructions.