2. Good For the Environment
Of the thousands of
bacteria that live on
Earth, only a few
hundred cause
disease, like strep
throat or a cavity in
your tooth
Many bacteria do
things that are
important and even
helpful to us
3. Nitrogen Fixation
Most living things depend on plants
Plants need nitrogen to grow
Nitrogen gas makes up 78% of the air, but
plants can’t take it directly from the air
They need to take in a different form of
nitrogen
Nitrogen-fixing bacteria take in nitrogen from
air and change it into form that plants can
use
4.
5. Recycling
Decomposer
bacteria break
down dead plant
and animal matter,
like in a gardener’s
compost pile
This makes
nutrients available
to other living
things
6. Cleaning Up
Bioremediation: using microorganisms to
change harmful chemicals into harmless
ones
Used to clean up hazardous waste from
industries, farms, cities, and oil spills
7. Bacteria in Your Food
People raise bacteria for
food!
Every time you eat cheese,
yogurt, buttermilk, or sour
cream, you are also eating
bacteria
Lactic-acid producing bacteria
break down sugar in milk
(lactose)
Bacteria change lactose
into lactic acid
This preserves and adds
flavor to the food
8. Making Medicines
Antibiotics
Used to kill bacteria and other
microorganisms
Many antibiotics made by bacteria
Insulin
Insulin breaks down and uses sugar and
carbohydrates
People with diabetes do not make enough
insulin
In 1970’s, scientists discovered how to put
genes into bacteria to produce human insulin
(bacteria are separated from the insulin)
9. Harmful Bacteria
In 1800s, scientists
learned that some bacteria
are pathogenic, which
means “cause disease ”
Pathogenic bacteria get
inside a host and take
nutrients from the host’s
cells, harming the host in
the process
We are protected from
many bacterial diseases
by vaccines and treated
with antibiotics
10. Diseases in Other Organisms
Have you ever seen a plant with odd-colored spots
or soft rot? It was probably damaged by bacteria
Pathogenic bacteria attack plants , animals,
protists, fungi , and even other bacteria
They can cause damage to grain, fruit, and
vegetable crops
Branch of tree with bacterial
disease called “fire blight”
