8/17/2016 History of Microbiology Learning Objectives Explain the importance of observations made by van Leeuwenhoek Compare spontaneous generation and biogenesis and descr be experiments that helped to prove biogenesis Highlight the major achievements of Pasteur and Koch Identify the important work of Semmelweis and Lister Identify the contributions to microbiology made by Jenner,Ehrlich and Fleming Science of microbiology dates back 200 yr Debate over Spontaneous Generation Bacteria appeared on Earth 3.5 billion yr ago Spontaneous generation First observations Hypothesis that living organisms arise spontaneously from nonliving matter 1665,Robert Hooke visualized life's Scientists and philosophers believed this until the smallest units "little boxes"-cells of late 19th Century corks toads and snakes arise from moist soil cell theory began-all living things are maggots arise from decaying corpses composed of cells sweaty clothing plus husk of wheat give rise to 1673,Anton van Leeuwenhoek designed mice 400 microscopes Biogenesis first to observe live microorganisms Hypothesis that the living organisms arise from animalcules" preexisting life 8/17/2016 7 Learning Objectives Explain the importance of observations made by van Leeuwenhoek Compare spontaneous generation and biogenesis and describe experiments that helped to prove biogenesis Highlight the major achievements of Pasteur and Koch Identify the important work of Semmelweis and Lister Identify the contributions to microbiology made by Jenner, Ehrlich and Fleming History of Microbiology Science of microbiology dates back 200 yr Bacteria appeared on Earth 3.5 billion yr ago First observations 1665, Robert Hooke visualized life’s smallest units “little boxes” - cells of corks cell theory began - all living things are composed of cells 1673, Anton van Leeuwenhoek designed 400 microscopes first to observe live microorganisms “animalcules” Spontaneous generation Hypothesis that living organisms arise spontaneously from nonliving matter Scientists and philosophers believed this until the late 19th Century - toads and snakes arise from moist soil - maggots arise from decaying corpses - sweaty clothing plus husk of wheat give rise to mice Biogenesis Hypothesis that the living organisms arise from preexisting life Debate over Spontaneous Generation