lecture notes-microbiology-4-Eucaryotes-yeast-mold-algae

thelemicbathBiotechnology

Feb 20, 2013 (4 years and 7 months ago)

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Eucaryotes





-

Fungi: yeast and mold





-

Algae

Eucaryotes

Fungi



Fungi are which need to take
nutrients from the environment for living.


They are larger than bacteria.

Fungi

Two major groups are
yeast

and
mold
.



Yeast

Yeasts are very important economically:



-

Yeasts are responsible for fermentation of beer
and bread. (
Saccharomyces cerevisiae
)



-

Ethanol production



-

Wastewater treatment:


a mixed culture of yeasts
Candida lipolytic

Candida tropicalis,
and

Yarrowia lipolytica

grown
on hydrocarbons, or gas oil.

Yeast

Yeasts are very important economically:



-

Yeasts and
Bacterium xylinum

cultures produce
Kombucha, fermented sweetened tea.


Yeasts: e.g.
Brettanomyces bruxellensis, Candida stellata, Schizosaccharomyces pombe

Yeast

http://www.sbs.utexas.edu/mycology/sza_images_SEM.htm


Eucaryotes
-
Fungi

Yeast
is single
-
celled.



Size
: yeasts are 5 to 10 µm in diameter.



Shape
: .



Reproduction
: .

Eucaryotes
-
Fungi

Yeasts


Reproduction
: asexual and sexual.


Asexual

reproduction is by either or


.



Budding: a small bud cell forms on the cell, which
gradually enlarge and separate from the mother cells.


Most of the yeasts reproduce by budding.



Baker’s yeast,
Saccharomyces cerevisiae
.



Budding

Budding

Yeast Budding

http://www.sbs.utexas.edu/mycology/sza_images_SEM.htm


Yeast Reproduction

Asexual:


Fission: similar to budding but the cells grow to
certain size and divide into two equal cells.


Only a few yeast species are reproduced by
fission. e.g.
Schizosaccharomyces pombe


Sexual:


Eucaryotes
-
Fungi

Molds

Molds are filamentous and have a mycelial
structure.

Mycelium is highly branched system of tubes that contains


mobile cytoplasm with many nuclei.


Hypha is long, thin filaments on the mycelium.

Mold


Molds are very important economically:



-

mushroom farming is a large industry in many
countries.


Agaricus bisporus







http://en.wikipedia.org/wiki/Agaricus_bisporus

Mold

-
Food industry


The mixed culture including
Penicillium sp.
for
cheese production.


Aspergillus niger

for citric acid production.


-

Antibiotics production.


Penicillium notatum

Eucaryotes
-
Fungi

Molds


Size
:


When grow on solid surface, the filamentous form is




5
-
20 µm.


When grow in submerge culture, it can form aggregates
and pellets, 50 µm
-
1mm.


-

Cause nutrient transfer problem in the pellet



Eucaryotes
-
Fungi

Mold Reproduction
:



Either by asexual or sexual means.



Some molds form sexual spores which provide
resistance against heat, freezing, drying and some
chemical agents.



Both asexual or sexual spores can germinate and form
new hyphae.

Eucaryote
-
Algae

Algae are usually unicellular or plantlike
multicellular organism.




Like plants, most algae use the energy of sunlight to
make their own food, a process called photosynthesis.



Algae lack the roots, leaves, and other structures
typical of true plants.



Algae contain chloroplast which is responsible for
photosynthesis.



Unicellular algae are considered in Microbiology


E.g. Chlorophyta, Chrysophyta (brown, yellow
-
green
algae)

Eucaryote
-
Algae











They are in the size of 10
-
30 µm.



Algae can reproduce asexually or sexually. Many of
algae incorporate both sexual and asexual modes of
reproduction.



Algae contain alginic acid and agar.

Virus

Not free
-
living organisms, of other living
cells.



Size: 30
-
200nm.



Can not capture or store free energy.



Not functionally active except when inside their host
cells.



Can do harm but also be useful



biotechnology tools (e.g. vaccines).




SARS
Coronavirus virion


Virus


Bacteriophage

or phage: virus infecting
bacteria.



(Virus
: virus infecting eukaryotes)



Virus reproduction
:


-

Virus contains genetic materials such as DNA
and RNA which is covered by a protein coat
called
capsid
.



-

They can reproduce only by invading and
controlling other cells as they lack the cellular
machinery for self
-
reproduction.

Section Summary


Organism cells are highly diverse in terms
of their adaptation to the living
environment:


Temperature, pH, oxygen, moisture,
nutrients



Shapes (bacteria):
Coccus, Bacillus

and
Spirillum

Primary Classification

Cellular Organism

Eucaryotes

Procaryotes

Virus

not free
-
living organisms

Have nuclear membrane and

membrane
-
bound organelles?

Yes

No

Primary Classification

Cellular Organism

Eucaryotes

Procaryotes

Virus

Organelles:

Mitochondria: powerhouse

Endoplasmic reticulum: protein and lipid
synthesis

Lysosome: nutrient digestion enzymes

Golgi: protein secretion and modification

Vacuoles: food digestion, osmotic
regulation and waste product storage

Chloroplasts: photosynthesis

not free
-
living organisms

Have nuclear membrane and

membrane
-
bound organelles?

Yes

No

Fungi: yeast and mold

Algae:

(asexual or sexual reproduction)

Primary Classification

Cellular Organism

Eucaryotes

Procaryotes

Virus

not free
-
living organisms

Have nuclear membrane and

membrane
-
bound organelles?

Yes

No

Cytoplasmic granules:

-

Ribosome: protein synthesis

-

Storage granules: source of key
metabolites, including
polysaccharides, lipids and sulfur
granules.

-

Capsule

-

Pili

-

Flagella

Eubacteria: gram
-
positive, gram
-
negative, non
-
gram, actinomycetes
and cyanobacteria


Archaebactria: methanogen



Halogen



thermoacidophiles


Mostly asexual reproduction


Primary Classification

Cellular Organism

Eucaryotes

Procaryotes

Virus: reproduce
in the host cell

Eubacteria
:


Gram
-
positive bacteria

Gram
-
negative bacteria

Non
-
gram bacteria

Actinomycetes

Cynaobacteria

Fungi
: yeast, mold

Algae
:

Reproduction: asexual or
sexual

Archaebateria
:


methanogen

Halogen

Thermoacidophiles

not free
-
living organisms

Have nuclear membrane and

membrane
-
bound organelles?

Yes

No

Asexual reproduction