Microbio lec Midterm

• Microbiology: 


  The study of living things too small to be seen without magnification
• Carolus Linnaeus (Swedish) 


  developed taxonomic system for naming plants and animals and grouping similar organisms together
• Leeuwenhoek


  microorganisms grouped into six categories
• Fungi


  Eukaryotic (have membrane-bound nucleus) ◦ Obtain food from other organisms ◦ Possess cell walls ◦ Composed of ● Molds – multicellular; have hyphae; reproduce by sexual and asexual spores ● Yeasts – unicellular; reproduce asexually by budding; some produce sexual spores
• Protozoa


  ◦ Single-celled eukaryotes ◦ Similar to animals in nutrient needs and cellular structure ◦ Live freely in water; some live in animal hosts ◦ Asexual (most) and sexual reproduction
• Pseudopodia


  – cell extensions that flow in direction of travel
• Cilia 


  – numerous, short, hairlike protrusions that propel organisms through environment
• ● Flagella 


  – extensions of a cell that are fewer, longer, and more whiplike than cilia
• Algae 


  ◦ Unicellular or multicellular ◦ Photosynthetic ◦ Simple reproductive structures ◦ Categorized on the basis of pigmentation, storage products, and composition of cell wall
• Bacteria and Archaea


  ◦ Unicellular and lack nuclei ◦ Much smaller than eukaryotes ◦ Found everywhere there is sufficient moisture; some found in extreme environments ◦ Reproduce asexually
• Bacteria 


  – cell walls contain peptidoglycan; some lack cell walls; most do not cause disease and some are beneficial
• Archaea 


  – cell walls composed of polymers other than peptidoglycan
• Redi’s Experiments


  ◦ When decaying meat was kept isolated from flies, maggots never developed ◦ Meat exposed to flies was soon infested
• Pasteur’s Experiments 


  ◦ When the “swan-necked flasks” remained upright, no microbial growth appeared ◦ When the flask was tilted, dust from the bend in the neck seeped back into the flask and made the infusion cloudy with microbes within a day
• Cheese

  Produced by bacteria and fungi
• Alcoholic beverages

  Produced by bacteria or yeast
• Soy sauce

  By fungal fermentation of soy beans
• Vinegar

  By bacterial fermentation
• Yogurt 


  By bacteria growing in skim milk
• Sour cream 


  By bacteria growing in cream
• Artificial sweetener


  Amino acid synthesized by bacteria
• Bread


  Rising of dough produced by yeast
• Antibiotics 


  By bacteria and fungi
• Human growth hormone


  By genetically engineered bacteria
• Laundry enzymes


  Isolated from bacteria
• Pasteur 


  developed germ theory of disease
• Robert Koch 


  studied causative agents of disease ● Anthrax ● Examined colonies of microorganisms
• Koch’s Experiments 


  ◦ Simple staining techniques ◦ First photomicrograph of bacteria ◦ First photomicrograph of bacteria in diseased tissue ◦ Techniques for estimating CFU/ml ◦ Use of steam to sterilize media ◦ Use of Petri dishes ◦ Aseptic techniques ◦ Bacteria as distinct species ◦ Koch’s Postulates
• Semmelweis and handwashing ◦ Lister’s antiseptic technique ◦ Nightingale and nursing ◦ Snow – infection control and epidemiology ◦ Jenner’s vaccine – field of immunology ◦ Ehrlich’s “magic bullets” – field of chemotherapy
• Leeuwenhoek

  • Bacteriology
  • Protozoology
  • Mycology
  • Parasitology
  • Phycology
• Linneaus

  Taxonomy
• Semmelweis

  Infection control
• Snow


  Epidemiology
• Pasteur


  Industrial microbiology

  Food and beverage technology
• Buchner


  Microbial metabolism

  Genetics

  Genetic engineering
• Koch


  Etiology
• Ivanowski

  Virology
• Beijerinck


  Environmental microbiology
• Wiriogradsky

  Ecological microbiology
• Gram


  Microbial morphology