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Unformatted text preview: Chapter 1: Microbial Life: Origin and Discovery What Is a Microbe? Micro-organisms are everywhere- Our bodies- Foods- Environment- Industry Some micro-organisms are pathogens but most are harmless or beneficial Microbiology is the study of organisms too small to be seen with the naked eye Medicine- Making antibiotics- Controlling disease Agriculture- Nitrogen-fixing bacteria- Genetically engineered crops Food - Beer, wine, bread, yogurt, pickles, chocolate Genetic engineering- Insulin, growth hormone, vitamins- Crops resistant to pests, heat, pesticides, herbicides, etc. Keep us alive- Recycle nutrients- Produce vitamins- Degrade organic matter Cause disease (most microbes are not pathogenic)- HIV, colds, STDs, food poisoning, flu Microbiology studies: bacteria, viruses, protozoans, fungi, algae, diatoms 6 major groups studied by microbiologists Prokaryotes 1. Bacteria 2. Archaea Eukaryotes 1. Algae 2. Protozoa 3. Fungi Viruses Microbes Shape Human History Microbes affect food availability Destroy crops, but preserve food Microbial diseases change history Black plague in Europe Smallpox in Americas Discovery of Microbes Light microscope invented in 1600s Mid-1600s: Robert Hooke observes small eukaryotes Antoni van Leeuwenhoek -1676 Built simple microscopes Described wee animalcules Published first drawings of bacteria (prokaryotes) Microbes Are Living Organisms Microbes arise only from other microbes No spontaneous generation 1861: Pasteur shows that microbes do not grow in liquid until introduced from outside Spontaneous generation-idea that living organisms originate from non-living matter He disproved this using broth in swan-necked flasks Sterilized broth by boiling, bent necks of flasks so that air could enter but microbes would be caught in neck led to development of methods for controlling growth of microorganisms...
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