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60 Cards in this Set
- Front
- Back
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psychrophile |
(-5-15 C) in arctic regions |
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psychrotrophs |
(15-30 C) in refrigerator |
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mesophiles |
(25-45 C) in human body |
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thermophiles |
(40-70 C) in hot springs
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hypertherophiles |
(70 C +) deep in ocean |
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obligate aerobes |
NEED oxygen |
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facultative anaerobes |
grows better if oxygen present (can grow without oxygen) -If no oxygen: fermentation |
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Microaerophiles |
require small amounts of oxygen |
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Aerotolerant anaerobes |
grows with or without oxygen |
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Obligate anaerobes |
no multiplication with oxygen present |
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Neutrophiles |
multiply with a pH of 5-8 |
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Acidophiles |
thrive at 1-5.5 pH -pumps out protons (H+) to keep neutral on the inside |
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Alkalophiles |
Neutral inside by Na+ ion exchange -exchanges Na+ for external protons |
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Plasmolysis |
- solution concentration is higher in medium than cell wall, so water diffuses out because of osmosis - cytoplasm dehydrates and shrinks |
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major elements |
CHNOPS: carbon, hydrogen, nitrogen, oxygen, phosphorous, sulfer -CIMP: potassium,magnesium, calcium, iron |
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heterotrophs |
organic carbon as nutrient source |
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autotrophs |
inorganic carbon (CO2) source as carbon source |
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phototrophs |
energy from sunlight |
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chemotroph |
energy from chemical compounds |
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growth factors |
temperature, oxygen, pH, water availability |
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energy sources |
organisms gain from sunlight or chemical compounds |
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photoautotrphs |
use sunlight and CO2 as carbon source |
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chemolithoautotrophs |
uses inorganic molecules for energy and CO2 as carbon source |
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photoheterotrophs |
energy from sunlight and carbon from organic compounds |
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chemoorganoheterotrophs |
uses organic compounds for energy and carbon source |
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complex media |
contains variety of ingredients |
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chemically defined media |
composed of precise amounts of pure chemicals |
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selective media |
Inhibits the growth of unwanted organisms |
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Thayer-Martin agar |
-selective -chocolate agar - isolationof Neisseria gonorrhoeae |
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MacConkey agar |
-selective and differential -bile salts and crystal violet -isolation of Gram-negative bacteria -contains pH indicator to identify bacteria that produces acid |
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differential media |
contains substance that bacteria change in recognizable way -helps tells us the difference between them |
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blood agar |
-5% of sheep RBC -Hemolysis: produces hemolysin to burst RBC |
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Laboratory Cultivation |
providing an appropriate atmospheric conditions -capnophile -microaerophile -anaerobe |
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capnophile |
required increased CO2 -done with the candle example in the jar |
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Microaerophile |
incubated in gas tight container -grows if small amounts of O2 is present |
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Anaerobe |
-dies if oxygen present -incubated in anaerobic jar |
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Anaerobic jar |
-chemical reaction reactions converts atmospheric oxygen to water -organisms must be able to tolerate oxygen for a brief period |
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Enrichment culture |
isolate an organisms present in a population -provides conditions that enhance the growth of a particular species |
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Direct cell count |
-used to determine amount of cells -does not distinguish between living and dead cells |
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direct microscope count |
-most rapid method -number is measured by the volume -uses 16 square grid (counting chamber) |
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Limitation |
Must have at least 10 million cells per mL to gain accurate estimate with direct microscopic count |
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Coultercounter |
detects changes in electrical resistance -counts as the go through a narrow channel |
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Flowcytometer |
measure light scattered cells as they pass a laser |
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Plate counts |
-measure cells growing on solid media -count based on assumption that one cell gives rise to one colony |
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viable cell count |
used to measure alive cells |
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Biofilm |
-Formation begins when planktonic bacteria attach to surfaces and produces polysaccharides |
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Biofilm characteristics |
-Contains open channels for movement of nutrients and wastes -protects bacteria against toxic chemicals (antibiotics) |
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Biofilm disease |
-treatment is difficult -Architecture resists immune response and antimicrobials |
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Bioremediation |
beneficial use of biofilm |
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pure culture |
a population of cells derived from a single cell (all cells genetically identical) |
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Robert Koch |
discovered techniques to obtain a pure culture |
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Aseptic technique |
minimizes potential contamination |
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streak-plate method |
-most commonly used in bacterial isolation -is used to reduce the number of cells being spread |
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Lag phase |
1st part of phase -number of cells do not increase -Cells prepare to grow (metabolism is activated) |
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Log phase |
2nd part -period of exponential growth -doubling of population with each generation -produce primary metabolites (this is required for growth) |
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Late log |
-synthesize secondary metabolites -used to enhance survival |
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stationary phase |
-overall population remains stable -cells exhaust nutrients -the dying cells nutrients supplies metabolites for replicating cells |
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death phase |
total number of viable cells decreases -death is exponential (fast) -but slower than growth |
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Prolonged decline |
99% of all cells dead and the remaining cells enter prolonged decline -very gradual decrease in viable population -most fit cells survive |
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continous culture |
bacterial culture can be maintained -continous exponential growth can be sustained by used of chemostat -continually drips fresh nutrients -release same amount of waste products |
