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Name some of the conditions and considerations when growing bacteria |
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Definition
moisture, temperature, pH, nutrients (organic and inorganic), ossmotic pressure, atmosphere (gases, pressure etc) |
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What are the five phases of a bacterial growth curve |
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Definition
Innoculation, lag (adaptive) phase, log (exponetial/growth) phase, stationary phase, decline (death phase) |
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Term
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Definition
a special growth chamber that maintains the exponential phase by supplementing nutrients and filtering off waste |
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Term
How would you count the number of cells present |
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Definition
direct smear or counting chamber |
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Definition
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Definition
Spread plate, Pour plate, Miles-Misra (from 5 drops), Membrane filtration (then culture membrane) |
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What other methods are there for counting bacteria |
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Definition
Opacity tubes (McFarlands tubes as reference for total cell count), electronic count (total cell count) |
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Term
What is a chemotroph and what types are there |
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Definition
A chemotroph gets the energy it needs from the chemicals in its environment as opposed to the sun, chemoheterotrophs, chemoautotrophs |
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Term
What are the main features of a chemoautotroph |
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Definition
Obtains energy from using chemicals as an energy source as aside from the sun, can synthesise all the parts it needs from carbon found in the environment |
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Term
What are the main features of a chemoheterotroph |
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Definition
Obtains energy from using chemicals as an energy source as aside from the sun, cannot synthesise all the parts it needs from carbon found in the environment, must absorb some of its organic molecules |
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Term
What are some of the nutrients needed by chemoheterotrophs |
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Definition
peptones source of peptides, amino acids, sulphate, phosphate, calcium, iron, magesium, potassium |
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Term
What is sulphate needed for by bacteria |
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Definition
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Term
What is phosphate needed for |
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Definition
nucleic acids and certain energy metabolites |
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Term
Name four co factors for bacterial enzymes |
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Definition
Calcium, iron, magnesium, potassium |
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Term
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Definition
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Definition
body temperature, (20-45 *C) |
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Definition
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Definition
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What determines ossmotic pressure needed |
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Definition
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Term
Bacteria in Hypotonic solution |
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Definition
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Bacteria in hypertonic solution |
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Definition
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Example of a bacteria which prefers hypertonic |
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Definition
staphlycoccus aureus prefers 7.5% NaCl |
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Definition
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Definition
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Definition
can grow with or without oxygen |
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Definition
can only grow without oxygen (fermentors!) |
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Definition
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Term
How do you incubate anaerobes |
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Definition
jar with special envelope (add H2O => H2 and CO2 released => H2 binds O2), light a candle (less precise), ascorbic acid |
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Term
How do you incubate capnophiles |
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Definition
special envelope in a jar |
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Term
Short term preservation of bacteria |
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Definition
sub culturing, risk of contamination and mutation |
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Term
Long term preservation of bacteria |
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Definition
freeze drying (lyophilization), liquid nitrogen (-190 *C), freezing (-70 *C) |
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Term
What important consideration is there when freeze drying (lyophilization) |
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Definition
Needs to be in a vacum to avoid cell lyses during dessication |
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Term
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Definition
Dimethyl sulphoxide and glycerol |
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Term
What temperature should bacteria not be stored at long term |
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Definition
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Term
What state should bacteria be in for long term storage |
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Definition
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Term
Something obvious enough and important when selecting bacteria for long term storage |
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Definition
use younger cultures! They do better |
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Term
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Definition
inhibition and sterilisation |
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Term
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Definition
refridgeration, freezing, boiling, pasteurisation, acidification, osmotic pressure increase (sugar or salting), vacum packs (only aerobes), irradiation |
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Short term refridgeration |
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Definition
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Definition
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Definition
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Definition
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Definition
autoclave, dry heat, incineration, gamma radiation, flaming, UV light, membrane filtration |
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Definition
moist heat, 15 min at 121*C or 45 min at 115*C |
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Definition
oven, 1-2 hours at 160 *C |
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Definition
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Gamma irradiation is not suitable for what |
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Definition
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What is important to remember about UV light as a sterilisation technique |
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Definition
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Term
What size membrane is needed for membrane filtration |
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Definition
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