Eukaryotic Microorganisms - Chapter 12
From Biol 131 - You are expected to read and understand
the fundamental characteristics of eukaryotic and
prokaryotic cells (see Chapter 3 of the Bauman text)
Not responsible for all the detailed characteristics of the
microbes (such as different fungal sexual reproduction)
used for their taxonomic classification – only what is
presented in class
Be sure to read
sections in other
chapters about
example
diseases and
pathogens
Eukaryotes
1
How are eukaryotes
classified?
What are the distinguishing
characteristics of “algae, “protozoa” and
“fungi”?
Eukaryotes
2
How can we explain the origins of different
photosynthetic protists?
Review Endosymbiosis from Biol 131
-- see end of Chapter 3
Eukaryotes
3
Characteristics
of Protozoa
heterotrophic or 2O Ps
no cell wall
cytosome
contractile vacuole
most are motile
some stalked
some have multiple
nuclei
Eukaryotes
4
Kinetoplastids
-- have weird mitochondrial DNA
Some are important pathogens
Trypanosoma (see chap 20)
African sleeping sickness
-- trypanosomiasis
-- Tse-tse fly
Chagas disease
-- American trypanosomiasis
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5
Amoeba
Amoebas
Most common – indefinite form
Extend ‘pseudopeds’
A few are pathogenic
e.g., Entamoeba sp
Foraminifera
form outer “shell”
e.g.,
Can be ‘huge’ (mm’s)
Fossil markers
Foraminiferan
Amoeba feeding
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Aveolates -- have aveolar sacs below membrane
Ciliates
Cilia functions:
Locomotion
Feeding
2 nuclei
Apicomplexans
“apical complex” of microtubules
Contractile vacuole
Stentor feeding
Eukaryotes
7
Plasmodium causes Malaria (chapt 21)
(Apicomplexan)
Visit CDC web site
http://www.cdc.gov/MALARIA/disease.htm
Anopheles mosquito
Complex life cycle
sporozoites
trophozoites
merizoites
Sexual reproduction
Disease
children
adults
Treatment
Plasmodium Life Cycle
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8
What are the key
characteristics of Algae
-- photosynthetic
-- cell wall
Great diversity in..
-- pigmentation
-- origin of C’plasts
-- cell structure
And in organism structure
-- unicellular
-- filamentous
-- colonial
-- multicellular
Eukaryotes
Red alga
(Rhodophyta)
9
Classification of Algae
Primary Symbionts
Chlorophyta
Rhodophyta
Secondary Symbionts
Euglenoids
Chrysophyta
Dinoflagelates
Phaeophyta
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Why are Chlorophyta believed to be the evolutionary
precursors of the higher plants?
- Cell wall structure
- Chloroplast structure
- Photosynthetic process and products
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11
Euglenoids and Diatoms
-- 2O endosymbiosis
Euglenoids (Kinetoplastid)
-- light senstitive ‘eye spot’
Diatoms (Chrysophyta)
- Silcaceous cell walls
Diatoms
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Dinoflagellates
(Alveolata)
-- Chloroplasts via 2O endosymbiosis
-- phytoplankton
Pfiesteria
-- neurotoxin
-- red-tides
See EPA site on Pfiesteria and red tides
http://ivy3.epa.gov.tw/OMISAR/Data/OMISAR/prjdoc/bam1.3/Pfiesteria.html
Dinoflagellate
Eukaryotes
13
Rhodophyta (1O endosymbiosis)
Phaeophyta (2O endosymbiosis)
-- common “marine macroscopic algae”
-- specialized structures
Colors vary widely
Pigments optimized for light abs
Chondrus
crispus
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Algae are very important as
producers of ecosystems
-- phytoplankton
-- macroscopic algae
Involved in
symbiotic relationships
-- invertebrates
-- lichens
Components of Rhodophyta cell walls are
sources of thickening agents
-- Agar (Gelidium)
-- Alginates (var. sources)
-- Carrageenan (Chondrus crispus)
In foods, industrial, pharmaceuticals
applications
-- syrups, ice cream, candies, jams…
-- paints, adhesives, paper coatings,…
-- creams, shampoos, capsules etc …
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15
Fungi (Mycology)
Read section in book thoroughly
Basic Characteristics
-- cell walls (chitin)
-- heterotrophic
Common Shapes
Yeasts (spherical)
e.g., Saccharomyces
Molds (filamentous)
hyphae
mycelium
Dimorphism is common
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16
How do fungi reproduce?
Asexual
budding
spores & sporangia
Budding yeasts
Sexual
‘+’ and ‘-’ types
mushrooms
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17
How are Fungi Classified?
Characteristics of sexual
reproduction structures
Read more thorough descriptions of fungal
groups in text. Note: Deuteromycota is no
longer a recognized fungal group.
Ascomycota
-- e.g., Penicillium; morels
Saccharomyces
Basidiomycota
-- e.g., Rusts; Coprinus
Zygomycota
-- e.g., Rhizopus
Or based on other traits
Glomeromycota
-- mycorrhizal fungi
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18
Ecology & Nutrition
Decomposers
Symbiosis
mycorrhizae
lichens
Predators??
-- nematophagus fungi
-- Arthrobotrys (ascomycota)
Vid 1
Vid 2
Vid 3
Eukaryotes
19
Entomophagus Fungi
Cordyceps (ascomycota)
is important pathogen of insects
Cordyceps
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Fungi as Plant Pathogens
Agricultural threats
‘Rust diseases’
Dutch elm disease
Ophiostoma ulni
(Ascomycota)
Other Impacts on Humans
Ergot poisoning
Claviceps
(Ascomycota)
mycotoxins
American Elms before and after
Dutch elm blight
(Minnesota Department of Agriculture)
Irish potato famine
Phytophthora infestans
(Alveolata)
Eukaryotes
21
In 1940s, Marietta had approximately 2000 American elm trees. How many remain in 2014?
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22
Fungal human pathogens
“Mycoses” (Chap 19)
(cutaneous vs systemic)
Trychophyton rubrum
-- Ascomycota
-- associated with many Tineas
tinea capitis (“ringworm”)
tinea pedis
tinea cruris
Candida albicans
Trychophyton rubrum
candidiasis
-- Ascomycota
-- mucus membrane / vaginal infections
-- AIDS
Treatments
-- challenging
-- Ergosterol metabolism
Wiki on antifungals:
http://en.wikipedia.org/wiki/Antifungal_drug
Eukaryotes
Candida albicans
23
Fungi pathogens, con’t.
Subcutaneous / Systemic
-- some endemic to our area
Blastomycosis
See Chap 22 & CDC web page
See CDC web page:
http://www.cdc.gov/fungal/diseases/blastomycosis/index.html
Pulmonary Blastomycosis
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