1. Introduction to General Microbiology Instructor: Laura Hunt, PhD Time: TTHR 8-9:20am

2. Why is microbiology interesting? Microbes can be harmful but are a necessary part of our lives CNN: “Superbug succeeds by blowing up defender cells, scientists learn” Nov 2007

3. What you will get out of this class: A general introduction to basic concepts and principles of microbiology There is a lot of material to cover but thankfully it is interesting and applicable

4. The Importance of Microorganisms The emergence of higher life forms Biogeochemical cycling Huge diversity and physiological capacities Relationships with higher organisms

7. What does microbiology refer to? Microbiology is the study of microorganisms, which can be unicellular or cell-cluster microscopic organisms –This includes eukaryotes: fungi and protists AND prokaryotes: bacteria and certain algae –Viruses, though not strictly classed as living organisms, are also studied. –Microbiology is a broad term which includes many branches including virology, mycology, parasitology and others.

8. Microorganisms as cells Cell is fundamental unit of life Compartmentalized Dynamic systems Cells constantly communicate and exchange materials with their environment

9. Cell Chemistry and Key Structures Four main components (macromolecules): –Proteins –Nucleic acids –Lipids –Polysaccharides Key structures: –Cytoplasmic membrane –Cytoplasm –Nucleus

10. Characteristics of Living Systems

17. Cells as Machines and as Coding Devices

18. The First Cells: when/where did the first cell come from a non cell?? Your just a bag of carbon, oxygen, and hydrogen The RNA world –Naked RNA are agents of catalysis and coding First self replicating entity had at least two properties: –1. Means of obtaining energy –2. Form of heredity More in Ch 11

19. Microorganisms and Their Natural Environments Cells live in assemblages called populations Habitat: location in the environment where microbial population lives Microbial communities: –Where populations live and interact with other populations Study of microorganisms in their natural habitat is called microbial ecology

20. The Effect of Organisms on Each Other and on Their Habitats Populations interact in various ways that can be both harmful and beneficial Interaction between populations and with physical/chemical environment

21. The Extent of Microbial Life Reservoirs of essential nutrients for life Total carbon equals that of all plants on earth Prokaryotes comprise the major portion of the Earth’s total biomass: 5 X 10 30 cells Most prokaryotes lie underground in oceanic and terrestrial subsurfaces

22. 1.4 The Impact of Microorganisms on Humans Microorganisms as disease agents Agriculture Food Energy and the Environment The Future: biotech

25. Important in C,N,S cycle Convert elements to a form that is readily accessible to plants

26. Negatives: Food spoilage and food borne diseases –E.coli in spinach

28. Energy of the Future?? Microbial fuel cells –Geobacter sp. are of interest because of their novel electron transfer capabilities Obtain energy from iron oxides Can transfer electrons to the surface of electrodes Use “nanowires” to shunt electrons produced during metabolic reactions onto the surface of mineral grains in the soil, to be taken up by metal ions

30. “The role of the infinitely small in nature is infinitely large” -- Louis Pasteur

31. The birth of microbiology: Pathways of discovery Slow to develop Two events: –Invention of the microscope –Spontaneous generation controversy The Historical Roots of Microbiology: Hooke, van Leeuwenhoek, and Cohn

32. Early Microscopy Microscopes were crude, and lacked resolution even though they were compounding. Some descriptions of bacteria, but very poorly seen Yet, considering the tools many discoveries were made

33. Robert Hooke Described fruiting structures of molds in 1665 First person to describe microorganisms

34. Antoni van Leeuwenhoek Dutch draper and amateur microscope builder Contemporary of Robert Hooke First person to observe bacteria in 1676 “wee animalcules”

35. Slow growth After initial discovery of tiny organisms, the field was slow to develop for the next 150 yrs. Two things became focus as the field moved from the mid to late 19th century –Spontaneous generation –Nature of infectious diseases

36. Ferdinand Cohn (1828-1898): Science of Bacteriology Contemporary of Koch and Pastuer A botanist by trade Discovered endospores Laid groundwork for bacterial classification Sterilization techniques Founded a major scientific journal

37. Cohn cont. Identified sulfur bacterium Beggiatoa mirabilis Became interested in heat resistant bacterium –Led him to discover Bacillus genus –Described entire life cycle –(vegetative cell- endospore-vegetative cell) –Heat did not kill the endospore

38. Louis Pasteur (1822-1895) French microbiologist and chemist Multi-faceted career

39. Pasteur and the Downfall of Spontaneous Generation Ancient belief that organisms arise from nonliving materials Louis Pasteur was a major opponent to spontaneous generation Pasteur showed that microorganisms present in air resembled those on putrefying materials Showed that if you sterilized you would not have purification

40. Pasteur’s Experiment In 1864, he crushed spontaneous generation Pasteur used a swan necked flask for his experiment, now called a Pasteur flask Simple experiment ended the controversy

44. Pasteur and Vaccination Discovered that attenuated strains would provide protection against disease –Made discovery with chickens and cholera Helped solidify the concept of germ theory of disease

45. Pasteur and Rabies Vaccine Known as the man who invented the rabies vaccine “Benefactor of Humanity” First exp were on dogs Then, July 6, 1885 tried vaccine on Joesph Miester, a boy bitten by a rabid dog

46. Pasteur Institute: 120yrs of discoveries Diptheria Plague Immunology Tuberculosis Sulfamides Molecular biology AIDS

47. Pasteur’s main contributions Instituting changes in hospital/medical practices to minimize the spread of disease by microbes or germs Coined the term “vaccine” --from the Latin vacca, meaning “cow” Weak forms of disease could be used as an immunization against stronger forms Rabies was transmitted by viruses too small to be seen under the microscopes of the time, introducing the medical world to the concept of viruses.

48. Robert Koch and the Germ Theory of Disease: The Development of Koch’s Postulates Major contributions: –Discovered anthrax –Discovered the bacterium that causes tuberculosis and chlorea Koch’s postulates –Developed based on experiments with anthrax in mice –He took experiment one step further and showed that even after many transfers in culture, the bacteria could still cause disease

50. 1.2 Koch’s Postulates

51. Koch’s Postulate and Coral Disease Corals are declining at an alarming rate 30% worldwide decline in corals Satisfying Koch’s Postulate to determine the causative agent in coral disease is challenging and very controversial

52. Coral Disease Hard to duplicate the reef Many diseases have been described solely on the basis of field characteristics, and in some instances there is disagreement as to whether an observed coral condition is actually a disease. A disease pathogen has been identified for only handful coral diseases The etiology of white pox, a lethal disease of the Caribbean elkhorn coral, Acropora palmata Kathryn L. Patterson*, James W. Porter �, Kim B. Ritchie ､ｦ, Shawn W. PolsonDeborah L. Santavy 珥, and Garriet W. Smith ､ PNAS 2002

53. A Test of Koch’s Postulates: Tuberculosis Discovered that the causative agent of tuberculosis was Mycobacterium tuberculosis Considered his greatest accomplishment Used microscopy, staining, pure culture isolation, and animal systems Won Nobel prize in 1905 his work on tuberculosis

54. Koch and Pure Cultures Developed methods to isolate a specific microorganism into pure culture He observed individual colonies on potato slices represented pure cultures He later developed other media that was more uniform and reproducible with gelatin and later with agar

55. Microbial Diversity and the Rise of General Microbiology From 19th to 20th century, microbiology grew and improved significantly Several subdisciplines arose leading to an era of “molecular microbiology” Two giants helped with this transition: –Martinus Beijerinck –Sergei Winogradsky

56. Martinus Beijerinck (1851-1931) Biggest achievement: developed the enrichment culture technique Microorganisms isolated in a selective fashion Aerobic nitrogen-fixing, sulfate- reducing,sulfur-oxidizing, nitrogen- fixing root nodule, Lactobacillus, and green algae Using selective filter techniques, discovered that the infectious agent in tobacco mosaic disease, was not bacteria--described the first virus

57. Sergei Winogradsky (1856-1953): the Concept of Chemolithotrophy Interested in bacteria involved in the cycling of nitrogen and sulfur Introduced the concept that bacteria could be important biogeochemical agents

58. Sergei cont. From studies on sulfur-oxidizing bacteria: –Chemolithotrophy: the oxidation of inorganic compounds linked to energy conservation From studies on nitrogen fixing bacteria, concluded that they obtained their carbon from CO 2 From studies, proposed these organisms were autotrophs, specifically chemoautotrophs Also isolated the first nitrogen- fixing bacteria

65. The Modern Era of Microbiology Development of the Major Subdisciplines of Applied Microbiology –Medical microbiology –Immunology –Agricultural microbiology –Industrial microbiology –Aquatic microbiology –Marine microbiology –Microbial ecology

66. Basic Science Sub disciplines in Microbiology Microbial systematics Microbial physiology Cytology Microbial biochemistry Bacterial genetics Molecular biology Virology

68. The Era of Molecular Microbiology By 1970’s, experimental manipulation of genetic material –Restriction enzymes –Biotechnology Genomics:comparative analysis of genes of different organisms –Nucleic acid sequencing –Phylogenetic relationships Proteomics: the study of protein expression in cells

69. New Frontiers 350yrs of research!