Fundamentals of Microbiology

1. Fundamentals of Microbiology Unit 1: 7 days

2. January 7th: Intro to Microbiology • What are microbes? • What do microbes do?

3. Microbes in our lives • Disease • Spoiled food • Food chain base • Decomposers • Digestion • Vitamin synthesis • Industrial synthesis of chemicals • Food production • Genetic engineering • Sewage treatment • Bioremediation

4. Microbes in our lives • Only a small number of microorganisms are pathogenic • Health care workers must still understand microbes in order to protect patients from normally harmless, but opportunistic organisms

5. Microbes in our lives

6. Historic Changes in Microbiology • The field is only a few hundred years old, but bacterial DNA has been found in 3,000 year old Egyptian mummies • Arguably the most important discovery in biology was in 1665 by Robert Hooke and a crude microscope

8. Historic Changes in Microbiology • Hooke reported that the smallest structural unit of life was a “little box” or “cell” • This launched cell theory, and all future research into cells was based on this first discovery • Now cell theory states that “all living things are composed of cells”

10. Historic Changes in Microbiology • A Dutch merchant and amateur scientist named Antoni Von Leeuwenhoek was the first to use stains and really see microorganisms • He looked at rainwater, peppercorn water, and scrapings from his teeth under a magnifying lens and drew pictures of the ‘animalcules’ that he observed

12. Historic Changes in Microbiology • How did these tiny organisms arise? • Were they born? • Or did they spontaneously generate?

13. Historic Changes in Microbiology • This is not an unreasonable question 150 years ago • People believed that toads were born out of wet soil, that flies came from manure, and that maggots could arise from decaying corpses

15. Historic Changes in Microbiology • Italian physician Francesco Redi opposed this ‘spontaneous generation’ viewpoint • He began trying to disprove that maggots came from rotting meat in 1668

16. Historic Changes in Microbiology • First Redi took three jars and put decaying meat in them and then sealed them tightly • Next he took three more jars, put more decaying meat in them, and left them open • Maggots appeared in the open jars, because flies could land and lay their eggs

18. Historic Changes in Microbiology • Critics said that fresh air was required for spontaneous generation • Redi repeated the experiment, but this time instead of sealing the jars he spread a fine mesh across the tops • Again, maggots only appeared in the open jars

19. Historic Changes in Microbiology • Redi’s results were a serious blow to the belief that complex living material could be generated from non-living material • However, people still believed that Van Leeuwenhoek’s animalcules were simple enough to spontaneously generate

21. Historic Changes in Microbiology • The debate about microorganisms raged back and forth with many experiments being done to determine whether microbes could spontaneously arise from nutrient fluids

22. Historic Changes in Microbiology • Sometimes heating and sealing prevented growth, but many argued that severe heating destroyed the ‘life force’ in the fluids • Others argued that the was not enough oxygen (recently proven to be required by many life forms) in the sealed flask to allow for microbe generation

23. Historic Changes in Microbiology • In 1858 German scientist Rudolf Virchow brought forth the concept of biogenesis – living cells can arise only from preexisting living cells • In 1861 Louis Pasteur definitively answered the debate with a series of clever experiments • Pasteur’s discoveries form the basis of aseptic technique today

25. The Golden Age of Microbiology • From 1857 to 1914 • Rapid breakthroughs in the field: • Fermentation – using microbes to produce alcohol • Pasteurization – heating to kill most microbes • Germ Theory of Disease – microbes may cause illness in both plants and animals • Koch’s Postulate – sequence of steps to relate a microbe to a specific disease • Vaccination

26. The Golden Age of Microbiology • People: • Edward Jenner – vaccination of smallpox • Paul Ehrlich – creator of synthetic drugs • Alexander Fleming – penicillin

28. New Areas of Research • Immunology • Virology • Parasitology • Bacteriology • Mycology • Genetic engineering • Molecular biology

29. January 8th: Naming Microbes and Major Chemical Principles • The system for scientific nomenclature was first developed in 1735 by Carolus Linnaeus • They are Latinized and italicized • Each organism is given two names: • Genus – always capitalized • Species epithet • Once the species name has been listed it can be abbreviated with the first letter of the genus and the species epithet

31. Naming Microbes • Names can honor a researcher, describe the organism, or even denote the location where it is found • Staphylococcus aureus= staph (clustered colonies), coccus (spherical cells), aureus (golden in color) • Escherichia coli = Theodor Escherich, coli (found in the colon)

32. Naming Microbes • In 1978 Carl Woese developed a classification system for bacteria • Eubacteria – bacteria with peptidoglycan cell walls • Archaea – bacteria lacking peptidoglycan cell walls • Eukarya – all eukaryotes (protists, fungi, plants, and animals)

33. Bacteria • Very small • Relatively simple • Single celled • Prokaryotic = pre-nucleus • Several shapes • Several arrangements • Binary fission asexual reproduction • Mostly heterotrophic, a few autotrophs

35. Fungi • Eukaryotic • Nucleus contains DNA • Unicellular or multicellular • Heterotrophic • Cells walls made from chitin • Sexual or asexual • Unicellular species are oval in shape

37. Protozoa • Eukaryotic • Unicellular • Classified based on locomotion • Amoebas – move extensions of their cytoplasm • Flagellates • Ciliates • Sexual or asexual • Parasitic or free living

39. Algae • Eukaryotic • Photosynthetic • Sexual or asexual • Cell walls – typically of cellulose • Abundant in fresh water, soil, and in conjunction with plants

41. Viruses • Very small - most are only visible with an electron microscope • Only one type of nucleic acid • can be DNA or RNA • Have a protein coat • Can have a lipid envelope • All parasitic • Reproduce by hijacking cellular machinery

43. Multicellular Animal Parasites • Not strictly microorganisms • Medically important • Worms • Often have a microscopic stage of their life cycle

45. Chemistry Review! • Atomic structure • About 26 elements are commonly found in living cells • Valence electrons and bonding • Ionic • Polar Covalent • Non Polar Covalent • Hydrogen Bonds

46. Chemistry Review! • Molecular mass • Moles • Chemical reactions • Exothermic • Endothermic • Reversible • Collisions required • Enzymes lower activation energy

47. Chemistry Review! • Inorganic compounds: • Small • Ionically bonded • Water • Acids and bases • Hydrogen and Hydroxide ions • Salts • pH • Buffers

48. Chemistry Review! • Organic compounds: • Always contain carbon and hydrogen • Carbon atoms can bond 4 times • Mostly or entirely covalent • Many are large • Carbon skeleton • Functional groups • Monomers and polymers

49. Chemistry Review! • Carbohydrates: • C H and O • Include sugars and starches • Isomers – same formula, different structure • Glucose and fructose • Lipids: • Insolubility in water • Simple lipids – glycerol and 3 fatty acids • Saturated – no double bonds • Steroids – carbon ring group

50. Chemistry Review! • Proteins: • Built by amino acids • C H O and N, sometimes S • 20 amino acids occur naturally • Adenosine Triphosphate: • Stores chemical energy for various cellular activities • When the bond in the terminal phosphate group is broken, energy is released • The energy from decomposition reactions is used to regenerate ATP from ADP