Transcript MOST FUNGI ARE DECOMPOSERS

MOST FUNGI ARE
DECOMPOSERS
• FUNGI ABSORB
MATERIALS
FROM THE
ENVIRONMENT
• INCLUDE
MUSHROOMS,
MOLDS, &
YEAST
• CAN BE
HELPFUL OR
HARMFUL TO
OTHER
ORGANISMS
Absorb Material• from
Environ.
Typical fungus made of
• Most are decomposers
reproductive body &
that absorb nutrients
network of cells forming
& leave behind
threadlike
hyphae
(one
simpler compounds.
cell thick). A mass of
• Are heterotrophs (get
hyphae form a mycelium.
energy from living or
The cells release
once living matter).
chemicals, digesting
• They and bacteria
surrounding materials &
decompose leaves,
absorbing nutrients.
shed skin, animal
• Fungi reproduce sexually
droppings, etc.
(with spores) or
• Except for yeast, most
asexually. Spore = one
fungi are
reproductive cell that can
multicellular.
grow into new fungus.
Absorb Material from Environ.
• A single mushroom can
make a billion spores.
• Spores are released into
air & spread by wind long
distances.
• Some spore have tough
coverings protecting them
for years until conditions
are right for growing.
• Fungi can reproduce
asexually when hyphae
break off to form anew
mycelium. Yeast (single
cell fungi) reproduce by
cell division, budding &
spores.
Mushrooms, Molds & Yeast
• One mushroom may be from a mycelium that
fills the size of a football field.
• Some mushrooms are poisonous & some edible.
The cap is where spores are made, and hyphae
fill the cap & stalk.
• MOLDS: fuzzy growth sometimes seen on food;
hyphae grow into food & digest it as they grow.
• Some Penicillium mold are used in Brie & blue
cheese. Some aspergillus mold is used in soy
sauce. Trichoderma mold grows in soil &
makes digestive chemicals used to give blue
jeans a stonewashed look.
•
Mushrooms,
Mold,
&
Yeast
Molds may cause disease. Fungal molds cause
athlete’s foot; others affect plants (Dutch elm);
Penicillin is an antibiotic from Penicillium fungus.
• Molds reproduce via spores mostly carried by air; the
“hat thrower” fungus Pilobolus grows in animal
droppings & shoots off its spore cap via water
pressure to land a few feet away to hopefully be eaten
in the grass by a cow.
Mushrooms, Molds & Yeast
• Yeasts are single
celled fungi. Grow in
moist environments
(plant sap, skin,
shower curtains)
• If yeast growing on
human skin
reproduces too
rapidly, it may cause
disease.
• Used in food
products (breaks
down sugars making
CO2 gas to make
bread rise & give
wine/beer its
bubbles).
Fungi can be Helpful or Harmful
• Fungi & bacteria are Earth’s decomposers (even
live in sea to recycle materials for ocean-living
organisms).
• Hyphae grow into & decompose other organisms
material (to turn dead tree back into useful
nutrient rich soil or to kill off Dutch elm)
• Most hyphae surround plant roots providing
nutrients for plant, while plant provides food.
• Lichen = fungal hyphae mixed around single
celled algae. Lichen live in arctic & desert, even
bare rock, eventually breaking it down into soil.
Helpful/Harmful Fungi
• May make toxins (In
1845 fungus infected
Ireland’s potato crop,
dropping causing Ireland
to go from 8 million to 4
million people; many
died of disease,
starvation and others
left, many to US. Today,
many banana crops are
being destroyed by
fungal disease.
• Penicillin from a fungal
toxin kills off many
types of bacteria, so is
used as an antibiotic.