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38 Cards in this Set
- Front
- Back
Lec 5
- Law of growth |
- dN/dt=kN
N = population t = time k = specific growth rate con. |
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Lec 5
- characteristics of K in the law of growth |
expermintal calc
- k=2.303(log N-log No)/t if any parameter changes, - k must be recalculated |
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Lec 5
- Methods to measure microbial growth (name them) |
- turbidity (light scatter)
- counting chamber - electronic particle counter - FACS (fluorescent act. cell sort) - Dilute and plate |
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Lec 5
- Counting Chamber characteristics |
- Used to get population (N)
- works like hemocytometer - pros - counts differentially (by shape or stain) - immediate answers - easy and somewhat quick - cons - need 100x microscope - counts both dead & live |
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Lec 5
- Electronic Counting chamber characteristics |
- uses change in conductivity to
measure (N) - utilized after getting N by other count method - utilizes electrodes and a conductive solution - Pros - once you have N, you dont need to count - a drop in current equals presence of microbes |
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Lec 5
- Turbidity and Optical Densities (O.D.) characteristics |
- spectrophotometer is used to
measure O.D. - Light in minus light out = OD - measures amount of light scattering (cloudiness) - Pros - easy and quick - cons - requires spectrophotometer - cant distinguish between dead & live |
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Lec 5
- Dilute and Plate characteristics |
- used to verify other other
methods of microbe growth - pros - counts only live members - used for anti-bio type exp to measure viablity - cons - takes 24-48 hrs |
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Lec 5
- Dilute and Plate - Why is this method used for anti-biotic trials? |
- can distinguish between
1 - slow growth or actual killing 2 - really dead vs. stunned |
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Lec 5
- Growth Curve - purpose |
- measures pop vs. time over
some interval - has 4 phases - normally shows 2 results 1 - turbidity (light scatter) 2 - Dilute and plate |
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Lec 5
- Growth Curve - Lag Phase |
- 1st phase
- Time before growth of organisms - may or may not be seen in lab |
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Lec 5
- Growth Curve - Exponential Phase |
- Law of Growth is used and
calculated for this phase - proper calc of (k)are made - population # increases |
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Lec 5
- Growth Curve - Stationary Phase |
- No growth takes place
- food is used up - _____ exaggerates pop b/c it counts dead pop as well |
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Lec 5
- Growth Curve - Death Phase |
- Population declines as
organisms die (no shit) |
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Lec 5
- Types of growth media - What is a media |
- Substance with which you grow
microbes/organisms |
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Lec 5
- Types of growth media - Name them |
- Defined Media
- Undefined Media - Minimal Media - Selective Media - Differential Media |
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Lec 5
- Types of growth media - Defined Media |
- Media in which you can write
the chemical form. for all ingredients |
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Lec 5
- Types of growth media - Undefined Media |
- Media in which 1 or more
ingredients you cannot write a chem. formula |
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Lec 5
- Types of growth media - Minimal Media |
- Media in which the minimal
amount of chemicals is used for microbes to grow |
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Lec 5
- Types of growth media - Selective Media |
- Media in which chemicals are
used to allow certain microbes to grow while denying growth for others (selection) |
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Lec 5
- Types of growth media - Differential Media |
- Media in which multiple
microbes can grow, but are differentiable by phenotype |
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Lec 5
- Classification by Physical Parameters - List the parameters |
- Temperature
- Hydrostatic Pressure - Osmotic Strength - pH |
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Lec 5
- Classification by Physical Parameters - Temperature - characteristics |
- Utilizes Arrhenius Plot for
growth curve analysis - Greater the (k)= higher growth rate - (k)max = summit of curve |
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Lec 5
- Classification by Physical Parameters - Temperature - Psychrophiles |
- Love Cold
- Ideal K = 4 C or refridge temp - Can grow in cold b/c lots of PUFA (polyunsat fatty acids) - keeps membranes fluid at cooler temps |
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Lec 5
- Classification by Physical Parameters - Temperature - Psychrophiles - facultative |
- Can grow in the cold, but
would rather have warm - optimal growth >20 C - AKA Psychrotrophs |
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Lec 5
- Classification by Physical Parameters - Temperature - Psychrophiles - Obligate |
- Must grow in cold temps
- optimal growth <20 C |
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Lec 5
- Classification by Physical Parameters - Temperature - Mesophiles |
- Middle temp, like inside body
- Ideal K = 37 C |
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Lec 5
- Classification by Physical Parameters - Temperature - Thermophiles |
- Hot loving
- Ideal K = 60 |
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Lec 5
- Classification by Physical Parameters - Temperature - Hyperthermophiles |
- exteme heat loving
- Ideal K = 88 (106???) |
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Lec 5
- Classification by Physical Parameters - Temperature - Thermophiles - Importance of thermophiles |
- Enzymes very important for
microbio industry - Provides Taq DNA Polymerase for PCR reactions - it increase amount of DNA |
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Lec 5
- Classification by Physical Parameters - Temperature - Thermophiles - How did they survive? |
- Developed 1st in Evolution
- Utilizes Amino Acids with more Ionic bonds (stronger DNA) - Membranes has C40 lipids - single layer membrane - high in sat fatty acids - DNA is positive super coiled |
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Lec 5
- Classification by Physical Parameters - Hydrostatic Pressure - Barophiles |
- Love/need high pressure
- high Hydrostatic Pressure (Deep Sea) - Cell membrane is 100% permeable to H2O - pres. inside= pres. outside |
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Lec 5
- Classification by Physical Parameters - Osmotic Pressure - characteristics |
- microbes that can grow in
varying concentrations of Salt |
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Lec 5
- Classification by Physical Parameters - Osmotic Pressure - Osmotolerant |
- microbe that can grow in wide degrees of osmotic pressure (salt content)
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Lec 5
- Classification by Physical Parameters - Osmotic Pressure - Halophiles |
- microbes that require high salt content to grow
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Lec 5
- Classification by Physical Parameters - pH - Characteristics |
- microbes that grow at varying
degrees of pH |
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Lec 5
- Classification by Physical Parameters - pH - Acidophile |
- pH = 0 to 5.5
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Lec 5
- Classification by Physical Parameters - pH - Neutrophile |
- pH = 5.5 to 8.0
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Lec 5
- Classification by Physical Parameters - pH - Alkalophile |
- pH = 8.5 to 11.5
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