Microbiology Part 1

1. Microbiology Part 1

2. Microbiology • Microbiology- the study of very small, microscopic organisms • Bacteria • Fungi • Viruses • Protists • Etc.

3. Bacteria=Prokaryotes • Prokaryotes Eukaryotes • No organelles except Lots of organelles ribosomes INCLUDING • NO NUCLEUS! NUCLEUS!

4. Bacterial Characteristics • Oldest organisms: 3.5 billion yrs. old. • Live in almost every environment.

5. Eubacteria • Kingdom Eubacteria • Common environments • Believed to be the ancestors of mitochondria and chloroplasts---organelles in eukaryotic cells

6. Archaebacteria • Kingdom Archaebacteria • Found in extreme environments • Ancient bacteria-gave rise to eukaryotic cells

7. Characteristics-Size • Size • Red blood cell is 250X’s larger than a bacterium • 1 gram of soil can contain 2.5 BILLION bacteria • Relative bacteria size

8. Characteristics-Shapes • Shapes: • Cocci- round • Bacilli- rod-shaped • Spirilla- spiral

9. Bacterial structure • Interior structures • Has DNA and cytoplasm—no nucleus or other membrane bound organelles EXCEPT ribosomes for protein synthesis! • Ribosomes- the protein making factories of all cells that take mRNA and translate it into the amino acids of a protein

10. Bacterial Structure

11. Identifying Prokaryotes • Shape – rod, spherical, spiral • Chemical nature of cell walls • Movement – flagella, lash, snake, spiral forward, glide on slimelike material • Obtain energy – heterotrophs or autotrophs

12. Bacterial structure • Exterior structures • Flagella-whip-like tail for locomotion • Cell membrane to control what goes in and out • Cell wall for protection

13. 2 Types of Cell Walls • 2 types of cell walls found in bacteria • Identified as Gram + or Gram - • There’s a chemical difference b/t them.

14. Gram staining • Special staining process • “Gram positive is purple; Gram negative is not.”

15. 2 Types of Cell Walls • Gram + • Thick cell wall • Holds purple stain, so cells look purple • Gram - • Two thin layers make up cell wall • Doesn’t hold purple stain so appears pink

16. 2 Types of Cell Walls • Treatment of illness due to these bacteria is different! • Gram - : bacteria that stain pick and are generally NOT affected by antibiotics • i.e. E. coli • Gram +: bacteria that stain purple do to a thick cell wall and are affected by antibiotics • i.e. S. pneumoniae

17. Bacterial Reproduction • Binary fission- bacteria’s process of reproduction where 1 becomes 2. • Results in clones • Colony- 1000’s of bacteria that result from one undergoing binary fission

18. How are bacteria so diverse? • They have several ways of exchanging genetic information. • Conjugation--exchanging DNA through a straw-like tube. • Transformation—another method of transferring genes between bacteria.

19. Useful Bacteria • Decomposers- Recycle nutrients such as CO2 , water, nitrogen, and phosphorus

20. Useful Bacteria YUMMY! • Nitrogen fixation- soil bacteria take nitrogen gas from the air (N2) and change it into a useable form that plants can absorb (NH3-ammonia.) • Plants use the nitrogen to produce their proteins and DNA. • Some bacteria are photosynthetic and also provide oxygen N2 Bacteria NH3

21. Useful Bacteria • Food-- yogurt, olives, pickles, chocolate • Drugs -- insulin production • Clean up oil spills • Animal digestion and vitamins, including our own • Microbe Discovery Movie

22. Harmful Bacteria • Pathogen- disease causing organisms. • Pathologists -scientists who study pathogens. • Not many bacteria are pathogenic— ONLY 1%! • Disease Transmission: a.) Water b.) Air c.) Food d.) Animals/Insects e.) Human Contact

23. Bacterial Diseases • Tuberculosis • Syphilis • Bubonic Plague • Typhus • Tetanus • Lyme Disease

24. Controlling Bacterial Growth • What do bacteria require to live and reproduce? - Food, water, and the right climate. -Give bacteria these things, and they grow; remove them and they don’t.

25. GROWTH CURVE

26. Nutrition and Energy • How do bacteria “eat”? 1.) Autotrophic- “self-feeders” MAKE food *Photosynthetic so they release oxygen!!! HAVE NO ORGANELLES SO NO CHLOROPLASTS!!! *Chemosynthetic 2.) Heterotrophic- “other-feeders” GET food *Consumers *Decomposers *Parasites

27. Growing Bacteria on Petri Dishes • Plastic Petri dishes have a Jell-O like substance called AGAR with nutrients and water for bacteria to grow on.

28. Controlling Growth • Antibiotics • Antibiotic resistance • Sanitizing--Antiseptics and Disinfectants • Freezing • Cooking • Pasteurizing- The act or process of heating a beverage or other food, such as milk or beer, to a specific temperature for a specific period of time in order to kill microorganisms that could cause disease, spoilage, or undesired fermentation. • Vaccination • Dehydrating-removing water from food, thus inhibiting the growth of microorganisms (enzymes) and bacteria by the circulation of hot, dry air through the food.

29. Antibiotics • Alexander Fleming - In 1928, while working on influenza virus, he observed that mould had developed accidently on a staphylococcus culture plate and that the mould had created a bacteria-free circle around itself. • Mold on his Petri dish had a zone of inhibition- area in which bacteria didn’t grow. • Mold released the antibiotic penicillin • Antibiotic=against life; any substance produced by a microbe that slows the growth of other microorganisms. BACTERIA MOLD

30. Antibiotics • Antibiotics are made by : • fungus (mold) • other bacteria, the most common Streptomyces. • present day antibiotics are synthetic modifications of naturally occurring ones. • Work on Gram + bacteria BACTERIA Each paper disk has antibiotics on it. Which antibiotic is more powerful?

31. Antibiotic Resistance Movie • Antibiotic resistance- a situation in which some bacteria are not affected by certain antibiotics! • Can be resistant due to: • Special cell walls (i.e. Gram – bacteria) OR • Special antibiotic resistant genes • Don’t finish antibiotics: • Weaker bacteria destroyed. • **Resistant bacteria still live and pass on resistant genes through binary fission, conjugation and transformation

32. Conjugation

33. Sanitizing • Antiseptics- chemicals used to inhibit growth of bacteria on living tissues

34. Sanitizing • Disinfectants- chemicals used to inhibit growth of bacteria on NON-living things.

35. Freezing • How would this control the growth of bacteria? • Would freezing kill all the bacteria?

36. Cooking • Cooking can control bacterial growth and kill most bacteria if heated to certain temps—165F or hotter. • Use a meat thermometer • Wash hands after handling raw meat

37. Pasteurizing • Pasteurization- using heat to kill bacteria in liquids.

38. Dehydrating • Dehydration- removal of water from a substance • How would this control the growth of bacteria?

39. Vaccination • Vaccination- a shot, pill, or mist that prevents you from getting a disease. DOES NOT CURE YOU. • Fast and strong immune system memory cells produced which provides immunity just like if you got the disease (i.e. tetanus.)

40. Vaccination • Can use weakened (attenuated) bacteria or viruses • MOSTLY use parts of bacteria or viruses—acellular • Vaccine video