Roles of Bacteria

1. Roles of Bacteria

2. Bacteria have a bad reputation, but they’re not all bad!

3. What are some ways that bacteria can be beneficial to other living things?

4. Importance of Bacteria • Producers: some can perform photosynthesis or chemosynthesis

5. Importance of Bacteria • Decomposers: when all organisms die, their organic matter must be returned to the soil for other organisms Decomposers complete the carbon cycle!

6. Importance of Bacteria • Nitrogen Fixers:some bacteria live on the roots of plants and convert nitrogen into a form that plants can use called ammonia This is a mutualistic relationship between the plant & bacteria!

7. Nitrogen Fixation • Plants & animals need nitrogen to make protein. • The atmosphere is mostly nitrogen, but plants & animals can’t use it in that form. • Nitrogen-fixing bacteria convert nitrogen in the atmosphere into ammonia, which plants can take up with their roots. • Animals get their nitrogen by eating plants.

8. Importance of Bacteria • Human Health: E. coli bacteria living in our intestines use undigested food to produce vitamins that we cannot make on our own. In return, we provide them with a warm environment. This is a mutualistic relationship!

9. Fun Fact! On average, bacteria make up .5% of a person’s total body weight. To find out how much of you is bacteria, multiply your weight (in pounds) by .005!

10. Importance of Bacteria • Biotechnology • Food production • Cleaning up oil spills • Synthesizing drugs & chemicals

12. Importance of Bacteria • Food Production: bacterial fermentation is used to make yogurt, sour cream, vinegar, buttermilk, & more!

13. Probiotics • Good bacteria • Aid in digestion • Help to keep the bad bacteria away Many people take probiotics as a dietary supplement. Also, probiotics are often added to food products, like yogurt.

14. Importance of Bacteria • Pathogens: any disease causing agent (could be bacterial or viral) • Harmful bacteria can cause disease in 2 ways- • Breaking down our body’s cells for food • Releasing toxins that travel through the body and damage our cells

15. Most food-born illnesses are caused by bacteria. • E. coli comes from infected, undercooked beef. • Salmonella comes from infected, undercooked poultry (meat & eggs). • Botulinum causes botulism, a deadly form of food poisoning.

17. Preventing Disease • Good Hygiene: • Wash hands thoroughly with soap & water. • You don’t need antibacterial soap! • Brush your teeth & floss. • Bacteria in your mouth DOUBLES in 24 hours! • Be careful who you drink after. • Regular check-ups at the doctor

18. Preventing Disease • Vaccines: • A weakened or dead form of the pathogen is given to a patient whose body will form an immune response to it. • Once that immune response occurs, your body remembers it forever! If the real pathogen enters your body, your immune system will recognize it & kill it immediately.

19. Preventing Disease • Antibiotics: prevent the growth & division of bacteria so that our immune system can conquer the illness easily Are there disadvantages to using antibiotics? Unfortunately, bacteria evolve in response to this pressure & we have many antibiotic resistant diseases now.

20. Controlling Bacteria • Most bacteria like warm, moist, dark conditions. • Exposing them to other conditions kills them or slows reproduction!

21. Controlling Bacteria • Cooking foods makes it too hot for most bacteria to survive. • Refrigerating or freezing foods makes it too cold for them to reproduce. • Drying foods make it impossible for bacteria to reproduce. • Pickling causes bacterial cells to burst.