Bacteria's role in our world


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Bacteria's role in our world

  1. 1. Bacteria’s Role in Our World
  2. 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. 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. 4. 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
  5. 5. 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
  6. 6. 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
  7. 7. 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)
  8. 8. 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
  9. 9. 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 cropsBranch of tree with bacterial disease called “fire blight”