Transcript lesson_19_good_microorganisms

Micro-organisms and Humans
Ecosystems Unit, Feb. 28th 2005
Micro-organisms and Humans
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Micro-organisms play an
important role in human life and
our food supply.
Micro-organisms can be both
beneficial and harmful to
humans.
Important Micro-organisms:
1.
Fungi: a) Mold
b) Yeast
It would take 1,200 yeast cells
placed side-by-side to measure
1cm in length!
2.
Bacteria: (one celled organisms)
3.
Algae:
Examples of Beneficial Microorganisms:
1.
Fungi:
The Discovery of Penicillin
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Discovered in 1928 by Scottish born,
Sir Alexander Fleming
While growing bacteria in his lab, he
noticed that one of his samples had a
fungus mold growing in it that was
killing the bacteria.
This mold (Penicillin) was able to kill
the cell walls of bacteria.
After more research, Penicillin was
then grown specifically to be used as
medicine to help kill bacteria that
caused fatal infections.
This was especially important for
wounded soldiers of the Second World
War.
Molds: Penicillin
Antibacterial
Activity (clear area
indicates Penicillin is
“killing” the bacteria)
Bacteria (Brown Slime)
Penicillin Mold (While Circle)
Examples of Beneficial Microorganisms:
1.
Fungi:
–
Molds: *Penicillin (an antibiotic mold that kills harmful bacteria)
Other Beneficial Molds
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Mold is also injected
into some “Blue
Cheeses” to give it
a unique colour,
taste, and smell!
Mold and Soy Sauce
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Soy Sauce production uses
mold to ferment a soybean/
wheat mixture to give it a
unique taste, deep brown
colour, and intense aroma.
Examples of Beneficial Microorganisms:
1.
Fungi:
–
Molds: Penicillin (an antibiotic mold that kills harmful bacteria)
Blue cheeses (mold + cheese)
Soy sauce (mold + soy and wheat)
Yeast and Baking
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When yeast is given sugar
(sugar, wheat, grain…) it
begins to ferment and
produce CO2 and ethanol
(alcohol).
Fermentation:
Baking (Rising Bread)
Yeast + C6H12O6  2C2H5OH + 2CO2
Yeast + Sugar = Ethanol + Carbon Dioxide
Yeast and Brewing
http://www.andechs.de/englisch/brauerei/fuehrung
Examples of Beneficial Microorganisms:
1.
Fungi:
–
Molds: Penicillin (an antibiotic mold that kills harmful bacteria)
Blue cheeses (mold + cheese)
Soy sauce (mold + soy and wheat)
–
Yeast: For baking (fermentation produces CO2 to rise bread)
For brewing (fermentation produces alcohol)
Bacteria and Cheese
To make cheese:
1.
2.
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4.
Milk + rennin (enzyme) = Curds
Curds are pressed and the liquid
(whey) is drained
Mixture is placed in forms and
certain bacteria are allowed to
grow and “ripen” the cheese.
This gives the cheese its flavour
and aroma.
Special bacteria that ferment
the lactose produces CO2 and
thus the holes in some cheese
(Swiss)
Swiss Cheese
Roquefort
Cheese (aged
in limestone
caves in
France)
Bacteria and Yogurt
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A special bacteria called
Lactobacillus bulgaricus are
able to turn milk into a thick
creamy yogurt
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The bacteria found in yogurt
are very good for your health.
Examples of Beneficial Microorganisms:
1.
Fungi:
–
Molds: Penicillin (an antibiotic mold that kills harmful bacteria)
Blue cheeses (mold + cheese)
Soy sauce (mold + soy and wheat)
–
Yeast: For baking (fermentation produces CO2 to rise bread)
For brewing (fermentation produces alcohol)
2. Bacteria: To make cheese and yogurt (flavour, smell, taste)
Algae
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Algae are used in ice cream,
milkshakes, puddings, salad
dressings, Jello®, peanut
butter, toothpaste etc. to
help thicken the mixture.
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Look for these algae
ingredients: carrageenan,
alginate, and beta carotene.
Examples of Beneficial Microorganisms:
1.
Fungi:
–
Molds: Penicillin (an antibiotic mold that kills harmful bacteria)
Blue cheeses (mold + cheese)
Soy sauce (mold + soy and wheat)
–
Yeast: For baking (fermentation produces CO2 to rise bread)
For brewing (fermentation produces alcohol)
2. Bacteria: To make cheese and yogurt (flavour, smell, taste)
3.
Algae:
To thicken ice cream, salad dressings, jello,
toothpaste etc.