MBIO 1220 Chapter 1 Lecture Notes PDF

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Lecture notes for lecture on Chapter 1 in MBIO 1220 class...

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September 6th, 2018

MBIO 1220: Essentials of Microbiology Dr. Carrie Selin, [email protected] Microbiology: Study of microorganisms and how the interact with their environment (incl. humans). Microbes: Essential part of a healthy human (normal microbiota/flora) as seen below. Prevent disease by competing with disease-causing microbes, help degrade food that are otherwise indigestible, and promote development of immune system.

Chapter 1: Humans and the Microbial World Major groups of microbes 1. Prokaryotes a. No nucleus or other membrane-bound organelles b. Bacteria, archaea 2. Eukaryotes: a. Nucleus and membrane-bound organelles b. Algae, protozoa, fungi 3. Acellular a. Not composed of cells. Cannot independently reproduce. Non-living. b. Viruses, viroids, prions

September 6th, 2018

Biodegradation and bioremediation Biodegradation The disintegration of materials (e.g. sewage, PCBs, DDTs) by bacteria, fungi, etc. Bioremediation Using organisms to break down and neutralize/remove contamination, decomposing it. Bioremediation is used in circumstances such as oil spills.

History of microbiology Robert Hooke Used crude microscope to view cells. Beginning of the cell theory (cells are the building blocks of life) Van Leeuwenhoek Built a microscope that could view tiny organisms. Pasteur Disproved spontaneous generation with this experiment:

Pasteur also demonstrated fermentation (yeast turning sugar into alcohol). Then solved issue of alcohol souring into vinegar by heating the beer/wine to kill all unwanted bacteria (pasteurization). His breakthroughs in fermentation showed that microbes are responsible for fluctuations in the environment, beginning to disprove the theory that diseases were a consequence of sin. In 1880, Pasteur developed a vaccination against fowl cholera. When fowl cholera was grown in a laboratory for an extensive period, the bacteria was killed/weakened. The killed/weakened microbe was able to induce an immune response in subjects. Lister Used phenol to sterilize surgical tools & wounds. Reduced the amount of infections, leading to the development of antiseptics and disinfectants. Robert Koch Koch’s postulates!! Isolated a certain bacterium from a cow sick with anthrax. Injected this bacteria into a healthy cow. The healthy cow got anthrax! The bacteria of the injected cow were identical to that of the original sick cow. This proved that the certain bacterium caused anthrax.

September 6th, 2018 Jenner Developed a vaccine against smallpox. Observed that people who had cowpox did not get smallpox. Injected the strain from cowpox into a child, who was then immune to smallpox. Yay! Ehrlich Noticed that certain dyes stain bacteria different than they stain animal cells. He proposed that a chemical might be found that would harm disease microbes without harming the host (selective toxicity). Eventually discovered Salvarsan, and arsenic derivative to treat syphilis. The beginning of chemotherapy. Fleming On contaminated petri dishes, Fleming observed that mold inhibited the growth of bad bacteria. The substance the mold was secreting was later identified as penicillium notatum. Unfortunately, the bacteria can become immune to the same kind of antibiotic, so now we have a large variety of antibiotics to prevent the growth of supergerms. Linnaeus Came up with the nomenclature for naming microorganism. The names are always in Latin, italics/underlined, and can be abbreviated after the first use (e.g. E. coli) Escherichia

coli

Genus (capitalized) Epithet (lower case) General name Specific (species) name

Review Microorganisms produce oxygen, fix nitrogen, produce antibiotics, enzymes, and help gut microflora break down food (they help flora a lot). Hooke: Cell Theory Leeuwenhoek: developed microscope lens capable of viewing microorganisms Pasteur: disproved spontaneous generation, proving biogenesis with his swan-necked flask experiment. Fermentation: turning sugar into alcohol, and alcohol into vinegar. Developed pasteurization: heating fermented alcohol to eliminate unwanted bacteria and prevent it from becoming vinegar. Lister: used phenol to clean surgical instruments and also sterilized wounds. Lead to the development of disenfectants and antibiotics. Koch: developed Koch’s postulates (proving that anthrax was the sickness by isolating and re-isolating the microorganism responsible) Jenner: Began development of vaccines by using cow pox to fight off small pox Ehrlich: Selective toxicity Fleming: Penicillin Linnaeus: Nomenclature...