Microbiology Chapter 6 - Microbial Growth and Nutrition

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Microbiology Chapter 6 - Microbial Growth and Nutrition
2012-10-04 03:01:20
microbiology exam two

microbial growth and nutrition
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  1. Nutrient
    any chemical such as carbon, hydrogen, etc. required for growth of microbial populations
  2. Photoautotroph
    microorganism which requires light energy and uses carbon dioxide as a carbon source
  3. Chemoautotroph
    microorganism that uses carbon dioxide as a carbon source and catabolizes organic molecules for energy
  4. Chemoheterotroph
    microorganism that uses organic compounds for both energy and carbon
  5. Obligate aerobe
    microorganism that requires oxygen as the final electron acceptor of the electron transport chain
  6. Facultative anaerobe
    microorganism which can live with or without oxygen
  7. Microaerophile
    microorganism that requires low levels of oxygen
  8. Nitrogen fixation
    the conversion of atmospheric nitrogen to ammonia
  9. Trace elements
    element required in very small amounts for microbial metabolism
  10. Optimum growth temperature
    temperature at which a microorganism’s metabolic activities produce the highest growth rate
  11. Psychrophile
    microorganisms requiring cold temperatures (below 20C)
  12. Mesophile
    microorganism requiring temperatures ranging from 20C to about 40C
  13. Thermophile
    microorganism requiring temperatures above 45C
  14. Hyperthermophile
    microorganism requiring temperatures above 80C
  15. Acidophile
    microorganism requiring acidic pH
  16. Halophile
    microorganism requiring a saline environment (greater than 9% NaCl)
  17. Biofilm
    a slimy community of microbes growing on a surface
  18. Inoculum
    sample of microorganisms
  19. Medium
    a collection of nutrients used for cultivating microorganisms
  20. Culture
    act of cultivating microorganisms or the microorganisms that are cultivated
  21. Colony
    visible population of microorganisms living in one place; an aggregation of cells arising from a single parent cell
  22. Broth
    a liquid, nutrient-rich medium used for cultivating microorganisms
  23. Agar
    gel-like polysaccharide isolated from red algae and used as thickening agent
  24. Pure culture
    culture containing cells of only one species
  25. Streak-plate
    method of culturing microorganisms in which a sterile inoculating loop is used to spread an inoculum across the surface of a solid medium in Petri dishes
  26. Pour-plate
    method of culturing microorganisms in which colony-forming units are separated from one another using a series of dillutions
  27. Slant tube
    test tube containing agar media that solidified while the tube was resting at an angle
  28. Defined medium
    culturing medium of which the exact chemical composition is known
  29. Complex medium
    culturing medium that contains nutrients released by the partial digestion of yeast, beef, soy, or other proteins; thus, the exact chemical composition is unknown
  30. Differential medium
    culturing medium formulated such that either the presence of visible changes in the medium or differences in the appearance of colonies help microbiologists differentiate among different kinds of bacteria growing on the medium
  31. Selective medium
    culturing medium containing substances that either favor the growth of particular microorganisms or inhibit the growth of unwanted ones
  32. Reducing medium
    special culturing medium containing compounds that combine with free oxygen and remove it from the medium
  33. Lyophilization
    removal of water from a frozen culture or other substance by means of vacuum pressure – used for the long-term preservation of cells and foods
  34. Deep-freezing
    long-term storage of cultures at temperatures ranging from -50C to -90C
  35. Generation time
    time required by a cell to grow and divide