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206 6 PPT6 Fungi SPR 22

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Fungi –distinct group
• neither plants nor animals.
• resemble plants because:
•
•
Mold, mildew, yeast, smut,
blights, mushrooms,etc
Have a cell wall
nonmotile
• Unlike plants they _______and cannot use
photosynthesis
• sporebearing organisms with absorptive nutrition
• can reproduce sexually and asexually
•
Many are saprophytic
• The science discipline dealing with fungi is called
__Mycology___________
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>100,000 known species of fungi found in various
environments
primarily terrestrial organisms
can adapt to environment extremes
especially Temperature and pH extremes
~___% are pathogenic = infect plants and animals.
grow best in : moist environment
~___% of fungi are saprobes/saprophytic= live off of
_____ tissues
© 2013 Pearson Education, Inc.
© 2013 Pearson Education, Inc.
Fungi
Majority are unicellular or colonial;
a few have cellular specialization
Divided into 2 groups:
1) macroscopic fungi (mushrooms, puffballs)
2) microscopic fungi
• ____
• ____
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Microscopic Fungi
Exist in two morphologies:
1) yeast
round to oval shaped &
undergo asexual reproduction by budding
are larger than bacteria.
Some form __________ =
Chain of budding daughter
cells
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Microscopic Fungi
 Exist in two morphologies:
2) Mold
–consists of filaments called _______ =
Thread-like, filamentous, tubular cells
Overall:
Some fungi exist in either microscopic form –
________
Yeast or mold based on
__________________
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Macroscopic view
 colonies of ____  like those of bacteria: soft, uniform
texture and appearance.
 colonies of ____ look cottony, hairy, or velvety.
 The woven, intertwining mass of hyphae that makes up the
body or colony of a mold = ___________.
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Hyphae –classified by structure
 Nonseptate hyphae
 consist of one long continuous cell = no ______ or septa
 cytoplasm and organelles move freely from one region to
another with each hyphae having ___________________.
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Hyphae –classified by structure
 septate hyphae
 crosswalls
 division varies from solid partitions to
partial walls with small pores 
Allows flow of __________
And ________
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© 2013 Pearson Education, Inc.
Hyphae-classified by function
1.vegetative hyphae
 Penetrates the substrate
 digests & absorbs nutrients
 Releases enzymes &
 ________________
2.reproductive or _____ hyphae
 orient vertically from the vegetative mycelium
 produce & support spores
 spores
 responsible for dissemination,
reproduction and survival
 Producing ________________
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 Spores dispersed widely through the
environment by __, _____, and living
things.
 Upon encountering a substrate,
a spore will germinate and produce
a new fungus colony in a very short time.
 fungi are very diverse & are classified and
identified by their 
________ and _________
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Aspergillus niger
Penicillium
Microsporum canis-causes ringworm
Penicillium
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1) Fungal Nutrition-saprobes
 Majority are harmless _____= obtain nutrients/
substrates from dead plants & animals
 Extremely widespread distribution in many
habitats
 fungi act as ____________.
 degrade complex organic material in the
environment to simple compounds =____
 fungi→possess ______ -break down organic
matter
 ___________-beneficial fungi associated with
plant roots (help make H2O & nutrients available
to plant)
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2) Parasitic fungi
 use the bodies of living animals or plants
 can reach host because spores are carried by
wind or water or on insects and animals.
 Fungi plant diseases-wilts, mildews, blights,
_____, and ______
 diseases of domestic birds and animals lead to
economic losses.
Huitlacoche-Mexican delicacy
www.flickr.com
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Ustilago sp.
Fungal human diseases
 Cutaneous mycoses/______________- affect hair,
skin, and nails
 ringworms or tineas- occur worldwide and represent
the most common fungal diseases in humans.
 Tinea corporis (body)
 Tinea pedis (foot)
 tinea cruris (groin)
all caused by various __________ (fungus)
species.
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Wood’s (UV) lamp→fungus fluoresces
Tinea cruris
ringworm
Tinea pedis
Tinea capitis
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© 2013 Pearson Education, Inc.
Candida albicans-nosocomial pathogen
(yeast infections)
(HAI- healthcare acquired infections)
 part of ___________-GI tract, mouth, and vagina
 does not usually cause disease →bacteria NF
suppresses growth =
 Immune system also suppresses C. albicans growth
BUT:
 Decrease/absence of NF= yeast proliferates and
causes disease=
 If immunosuppressed=increased risk
 Oral candidiasis (______)= infects neonates during
birth
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Candida albicans-nosocomial pathogen
 Thrush in immune compromised individuals→
_________________
 candidal vaginitis→transmitted during sexual
intercourse (STI)
 Vagina – Lactobacillus sp. =↓pH
 Treatment with intravaginal drugs
 During pregnancy=hormonal changes →
___% of women have yeast infection during 3rd trimester
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3) Fungi- produce mycotoxins
 Aspergillus flavus produces __________
 that are highly toxic and carcinogenic to
animals and humans.
 These toxins are the most potent __ (cancer
causing agent) yet discovered.
Aspergillus flavus
infesting peanuts
and corn- check
with ____
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Fungi toxin -example 2
 Claviceps purpurea parasitizes rye and wheat causing
the formation of the toxin _____.
 Ergotism -the toxic condition in humans and animals
 gangrene, psychotic delusions, nervous spasms, abortion,
and convulsions.
Most grains grown in the US are
____________to the ergot fungus
but many strains grown in other
parts of the world are not.
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 the middle ages ergotism known as St
Anthony's fire =killed thousands
 France 943 AD, 40000 deaths were recorded from
ergotism.
______________________________________________
USA
 accusations of witchcraft in Massachusetts
communities in the late 1690s – due to ergotism?
 symptoms of ergot poisoning =______________
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 fungus infested rye was used in bread making
 Weather conditions records for 1690 to 1692 show
that New England weather was ideal for the growth
of the fungus!
 All the conditions for the ergot poisoning were
present!
 ergot toxin- its active ingredient _______(__).
 In controlled doses ergot can be used to induce
labor, lower blood pressure, and _______________
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Stachybotrys sp. –sick building syndrome
- produces mycotoxins→asthma & other respiratory problems
ie. _________
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4) Industrial processes
 Fungi especially the yeasts, are essential to may
industrial processes involving ______________
Soy sauce production : Aspergillus oryazae
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5) antibiotics
 Some fungi produce metabolic byproducts that are
toxic to other microorganisms= ____________
 We extract and purify the antibiotics to treat
human infections!
 Examples:
 Penicillium sp.- penicillin
 Cephalosporium sp.-cephalosporin.
(fungus
---
antibiotic)
(some bacteria can also make
antibiotics)
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