Chapter 1 Humans and the Microbial World A Glimpse of History Antony van Leeuwenhoek (1632-1723) Dutch merchant Skillful at grinding lenses for 300x magnification “Animalcules” Royal Society of London

1.1 The Origin of Microorganisms The Scientific Method Francesco Redi 1st to show evidence that disproved the theory of “spontaneous generation” 1.1 The Origin of Microorganisms Theory of Spontaneous Generation Experiment: Positive control Conclusion: maggots produced by flys, not by spontaneous generation Negative control

1.1 The Origin of Microorganisms Theory of Spontaneous Generation Louis Pasteur Gave final proof that the theory of “spontaneous generation” does not apply to microbes “vital force”

1.1 The Origin of Microorganisms Theory of Spontaneous Generation John Tyndall Showed that some bacteria were not killed by 5 min. of boiling Bacterial endospores were present in hay Anthrax spores

1.1 The Origin of Microorganisms Theory of Spontaneous Generation The First Microorganisms Progenitors of microorganisms no longer exits Primitive Earth - high temp. and low oxygen Astrobiology

1.2 Microbiology: A Human Perspective Vital Activities of Microorganisms 1. Microbes necessary for life as we know it (nitrogen cycle) (production of oxygen) 2. Biodegradation (waste and cellulose)

1.2 Microbiology: A Human Perspective Vital Activities of Microorganisms Applications of Microorganisms “Biotechnology” = the application of biology to solve practical problems and produce useful products economically Food production breadmaking, alcohol, milk products Bioremediation PCBs, DDT, oil, TNT, radioactive material Useful products organic substances, antibiotics, insecticides

1.2 Microbiology: A Human Perspective Vital Activities of Microorganisms Applications of Microorganisms Genetic Engineering Vaccines Use bacteria to genetically engineer plants Use of viruses for gene therapy Use bacteria to express certain genes and produce products like interferon, insulin, human growth hormone, anti-clotting factors

1.2 Microbiology: A Human Perspective Vital Activities of Microorganisms Applications of Microorganisms Genetic Engineering Medical Microbiology

1.2 Microbiology: A Human Perspective Vital Activities of Microorganisms Applications of Microorganisms Genetic Engineering Medical Microbiology Past triumphs: Small pox, Bubonic plague, Polio Present and future challenges: Emerging diseases Resurgence of old diseases Chronic diseases caused by bacteria Legionnaire’s disease Toxic shock syndrome Lyme disease AIDS Hantavirus West Nile virus Antibiotic resistance Foreign travel Reductions in vaccinations Immunosuppression Peptic ulcers Arteriosclerosis River blindness

1.2 Microbiology: A Human Perspective Vital Activities of Microorganisms Applications of Microorganisms Genetic Engineering Medical Microbiology Microorganisms as Subjects of Study Microbes allow for easier study of the mechanisms of life Large number of Nobel laureates are microbiologists (back cover) “What is true of an elephant is also true of bacteria.” - Jaques Monod

1.3 The Microbial World The Bacteria Single-celled prokaryotes (no membranous organelles) Varied shapes Peptidoglycan cell wall Divide by binary fission May be motile (flagella)

1.3 The Microbial World The Bacteria The Archaea Single-celled prokaryotes (no membranous organelles) Varied shapes Do not have peptidoglycan cell wall Divide by binary fission May be motile (flagella) Can grow in extreme environments

1.3 The Microbial World The Bacteria The Archaea The Eucarya

1.3 The Microbial World The Bacteria The Archaea The Eucarya Nomenclature Binomial Escherichia coli E. coli E. coli strain K12 E. coli strain O157 (“Jack in the Box strain”)

1.3 The Microbial World Obligate intracellular parasites

1.3 The Microbial World Size in the microbial world Epulopiscium fishelsoni Red surgeon fish “guest at the banquet of a fish”