Transcript Microbes: Benificial and Not-so

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What is a Microbe?
A microbe is a microorganism, a tiny living thing
that is too small to see with your eyes. Microbes
can be tiny plants, bacteria, fungi and other living
things.
Escherichia coli
Many microbes form colonies, which you can see
with your eyes. A colony of bacteria will have more
than one million microbes.
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Beneficial Microbes
Some microbes are useful. Microbes make
yogurt from milk. Yeast is a microbe needed
to make bread, beer and wine. The yeast in
bread makes CO2 gas, which make the bread
fluffy. Microbes in the soil make the ground
fertile to grow healthy green plants.
Microbe Name
Bread
Wine
Beer
Yeast
Yogurt
Lactobacillus
blugaricus
Acidophilus
Soil
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Diazotrophs:
Cyanobacteria
Rhizobia
Frankia
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Draw what you see on your plates
Your hands
Test Swab Location:
_________________
D
C
Did washing your hands kill germs?
YES
Were there germs in your test swab?
Location
Microbes?
YES or NO
YES or NO
YES or NO
YES or NO
YES or NO
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YES
NO
NO
Lots? (0 – 5)
No =0 Lots
Germs are microbes
that can cause illness.
How do germs move from one
person to the next?
Sneezing, coughing,
Touching with dirty hands
How can we prevent sharing our
germs?
Wash your Hands.
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Cell division
Many microbes produce offspring through
simple cell division. They have one parent
instead of 2!
One parent cells splits
into 2 cells, the 2nd
generation. Each of
the 2 cells splits into
2 cells to make 4.
For
bacteria
one
generation is about 20
minutes under the
best conditions. Fill in
the boxes to show
how many bacterial
cells will be in each
box.
Eventually there are so many that we
can see a colony of bacteria.
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ACTIVITY
Does washing your hands really
kill the germs on your hands?
1. Pick an agar plate with a line drawn down the center.
2. On the side of the plate with “D” gently rub your
fingers
3. Wash your hands with soap and water and dry them.
4. Gently rub your hands on the other side of the plate
with the “C”
5. Allow your plate to incubate with the agar side up for
several days at room temperature.
6. After several days, DRAW what you see on the plate.
Where do you think there are
germs in your classroom?
1.
2.
3.
4.
Your group will pick a place test for germs.
Gently swab the location with a sterile Qtip.
Gently rub the Qtip on a new agar plate.
Allow your plate to incubate with the agar side up for
several days at room temperature.
5. After several days, DRAW what you see on the plate.
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