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38 Cards in this Set
- Front
- Back
What is minimum growth temperature?
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Lowest temperature at which growth will occur. Below this temp, enzyme activity is inhibited and cells are metabolically inactive so growth is negligible or absent.
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What is maximum growth temperature?
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Highest temp at which growth will occur. Above this temp, most cell enzymes are destroyed and organism dies.
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What is optimum growth temperature?
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Temp at which the rate of reproduction is most rapid. However, it is not necessarily optimum or ideal for all enzymatic activities of the cell.
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What are the three classifications of bacteria (depending on temperature requirements)?
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Psychrophiles, mesophiles, thermophiles.
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Bacterial species that will grow in a temp range of -5C to 20C. Distinguishing characteristic is it will grow between 0-5C.
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psychrophiles
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Bacterial species that will grow within temp range of 20-45C. Distinguishing characteristics are ability to grow at human body temp (37C), and inability to grow at temps above 45C.
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mesophiles
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A mesophile whose optimum growth temperature is in the range of 20-30C are called what?
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Plant saprophytes
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A mesophile whose optimum growth temperature is in the range of 35-40C are organisms that prefer what?
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To grow in the bodies of warm blooded hosts.
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Bacterial species that will grow at 35C and above.
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Thermophiles
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Organisms that will grow at 37C with an optimum growth temperature of 45-60C.
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Facultative thermophiles.
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Organisms that will grow only at temperatures above 50C with optimum temperatures above 60C.
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Obligate thermophiles.
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True or False: The ideal temperature for specific enzymatic activities may not coincide with the optimum growth temperature for a given organism.
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True.
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___________ bacteria are capable of surviving within a broad pH range, which is characteristic of their natural inhabitat, the digestive system.
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Enteric
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Bacterial _________ _________ can only tolerate a narrow range. The pH of the circulatory system remains fairly constant at approx. 7.4
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blood parasites
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The specific range for bacteria is between _______ and ______, with the optimum being _____ to _____.
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4 and 9
6.5 to 7.5 |
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Fungi, molds, and yeasts prefer an _______ environment with optimum activities at a pH of _____ to _____.
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acidic
4 to 6. |
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The pH of a laboratory medium is usually adjusted to approx. 7. Why is that?
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Because a neutral or nearly neutral environment is generally advantageous to the growth of microorganisms.
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True or False: Metabolic activities of the microorganism will result in the production of wastes and will cause shifts in pH that can be detrimental to growth.
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True.
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_______ require the presence of atmospheric oxygen for growth.
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Aerobes
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________ require limited amounts of atmospheric oxygen for growth.
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Microaerophiles
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_______ require the absence of free oxygen for growth because their oxidative enzyme system requires the presence of molecules other than O2 to act as the final hydrogen acceptor.
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Obligate anaerobes.
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These are fermentative organisms and therefore do not use O2 as a final electron acceptor.
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Aerotolerant anaerobes
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These organisms can grow in the presence of O2 or in the absence of O2.
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Facultative anaerobes.
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O2 Requirement:
Staph. aureus at 37C is considered a: |
Facultative anaerobe
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O2 requirement:
Corynbacterium xerosis at 37C |
Microaerophile
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O2 requirement:
Enterococcus faecalis at 37C |
Aerotolerant anaerobe
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O2 requirement:
Saccharamyces cerevisiae at 25C |
Facultative anaerobe
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O2 requirement:
Aspergillus at 25C |
Obligate aerobe
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O2 requirement:
Costridium sporogenous at 37C |
Obligate anaerobe
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Medias used during effects of temp experiment were:
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1 TSA plate
1 Saboured Slant used for Saccharomyers. |
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Organisms used for effects of temp experiment were:
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Serratia,
E coli Geobacillus Saccharamyces |
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Medias used during effects of pH experiment were:
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pH 3 tube
pH 6 tube pH 7 tube pH 9 tube |
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Organisms used for effects of pH experiment were:
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Enterococcus faecalis
E coli Saccharamyces cerevisiae |
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Media used for the O2 requirement was:
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Brain heart infusion (BHI)
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How to prepare the BHI for use:
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1. Heat to molten
2. Cool to 45C, then innoculate. 3. Roll and cool, incubate. |
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What media was used in cultivating anaerobes experiment?
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1 Fluid Thioglycollatic broth (fTg)
1 TSA plate |
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What organism was used in the fTg?
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Clostridium
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What organisms were used on the plate for cultivating anaerobes?
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Bacillus, E coli, and Clostridium.
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