Microbio Lec 5

Front 1

Lec 5
- Law of growth

Back 1

- dN/dt=kN
N = population
t = time
k = specific growth rate con.

Front 2

Lec 5
- characteristics of K
in the law of growth

Back 2

expermintal calc
- k=2.303(log N-log No)/t

if any parameter changes,
- k must be recalculated

Front 3

Lec 5
- Methods to measure
microbial growth
(name them)

Back 3

- turbidity (light scatter)
- counting chamber
- electronic particle counter
- FACS (fluorescent act. cell sort)
- Dilute and plate

Front 4

Lec 5
- Counting Chamber
characteristics

Back 4

- 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

Front 5

Lec 5
- Electronic Counting chamber
characteristics

Back 5

- 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

Front 6

Lec 5
- Turbidity and Optical
Densities (O.D.)
characteristics

Back 6

- 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

Front 7

Lec 5
- Dilute and Plate
characteristics

Back 7

- 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

Front 8

Lec 5
- Dilute and Plate
- Why is this method used
for anti-biotic trials?

Back 8

- can distinguish between
1 - slow growth or actual
killing
2 - really dead vs. stunned

Front 9

Lec 5
- Growth Curve
- purpose

Back 9

- measures pop vs. time over
some interval
- has 4 phases
- normally shows 2 results
1 - turbidity (light
scatter)
2 - Dilute and plate

Front 10

Lec 5
- Growth Curve
- Lag Phase

Back 10

- 1st phase
- Time before growth of
organisms
- may or may not be seen in lab

Front 11

Lec 5
- Growth Curve
- Exponential Phase

Back 11

- Law of Growth is used and
calculated for this phase
- proper calc of (k)are made
- population # increases

Front 12

Lec 5
- Growth Curve
- Stationary Phase

Back 12

- No growth takes place
- food is used up
- _____ exaggerates pop b/c it
counts dead pop as well

Front 13

Lec 5
- Growth Curve
- Death Phase

Back 13

- Population declines as
organisms die (no shit)

Front 14

Lec 5
- Types of growth media
- What is a media

Back 14

- Substance with which you grow
microbes/organisms

Front 15

Lec 5
- Types of growth media
- Name them

Back 15

- Defined Media
- Undefined Media
- Minimal Media
- Selective Media
- Differential Media

Front 16

Lec 5
- Types of growth media
- Defined Media

Back 16

- Media in which you can write
the chemical form. for all
ingredients

Front 17

Lec 5
- Types of growth media
- Undefined Media

Back 17

- Media in which 1 or more
ingredients you cannot
write a chem. formula

Front 18

Lec 5
- Types of growth media
- Minimal Media

Back 18

- Media in which the minimal
amount of chemicals is used
for microbes to grow

Front 19

Lec 5
- Types of growth media
- Selective Media

Back 19

- Media in which chemicals are
used to allow certain microbes
to grow while denying growth
for others (selection)

Front 20

Lec 5
- Types of growth media
- Differential Media

Back 20

- Media in which multiple
microbes can grow, but are
differentiable by
phenotype

Front 21

Lec 5
- Classification by Physical
Parameters
- List the parameters

Back 21

- Temperature
- Hydrostatic Pressure
- Osmotic Strength
- pH

Front 22

Lec 5
- Classification by Physical
Parameters
- Temperature
- characteristics

Back 22

- Utilizes Arrhenius Plot for
growth curve analysis
- Greater the (k)= higher growth
rate
- (k)max = summit of curve

Front 23

Lec 5
- Classification by Physical
Parameters
- Temperature
- Psychrophiles

Back 23

- 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

Front 24

Lec 5
- Classification by Physical
Parameters
- Temperature
- Psychrophiles
- facultative

Back 24

- Can grow in the cold, but
would rather have warm
- optimal growth >20 C
- AKA Psychrotrophs

Front 25

Lec 5
- Classification by Physical
Parameters
- Temperature
- Psychrophiles
- Obligate

Back 25

- Must grow in cold temps
- optimal growth <20 C

Front 26

Lec 5
- Classification by Physical
Parameters
- Temperature
- Mesophiles

Back 26

- Middle temp, like inside body
- Ideal K = 37 C

Front 27

Lec 5
- Classification by Physical
Parameters
- Temperature
- Thermophiles

Back 27

- Hot loving
- Ideal K = 60

Front 28

Lec 5
- Classification by Physical
Parameters
- Temperature
- Hyperthermophiles

Back 28

- exteme heat loving
- Ideal K = 88 (106???)

Front 29

Lec 5
- Classification by Physical
Parameters
- Temperature
- Thermophiles
- Importance of
thermophiles

Back 29

- Enzymes very important for
microbio industry
- Provides Taq DNA Polymerase
for PCR reactions
- it increase amount of DNA

Front 30

Lec 5
- Classification by Physical
Parameters
- Temperature
- Thermophiles
- How did they
survive?

Back 30

- 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

Front 31

Lec 5
- Classification by Physical
Parameters
- Hydrostatic Pressure
- Barophiles

Back 31

- Love/need high pressure
- high Hydrostatic Pressure
(Deep Sea)
- Cell membrane is 100%
permeable to H2O
- pres. inside= pres.
outside

Front 32

Lec 5
- Classification by Physical
Parameters
- Osmotic Pressure
- characteristics

Back 32

- microbes that can grow in
varying concentrations of Salt

Front 33

Lec 5
- Classification by Physical
Parameters
- Osmotic Pressure
- Osmotolerant

Back 33

- microbe that can grow in wide degrees of osmotic pressure (salt content)

Front 34

Lec 5
- Classification by Physical
Parameters
- Osmotic Pressure
- Halophiles

Back 34

- microbes that require high salt content to grow

Front 35

Lec 5
- Classification by Physical
Parameters
- pH
- Characteristics

Back 35

- microbes that grow at varying
degrees of pH

Front 36

Lec 5
- Classification by Physical
Parameters
- pH
- Acidophile

Back 36

- pH = 0 to 5.5

Front 37

Lec 5
- Classification by Physical
Parameters
- pH
- Neutrophile

Back 37

- pH = 5.5 to 8.0

Front 38

Lec 5
- Classification by Physical
Parameters
- pH
- Alkalophile

Back 38

- pH = 8.5 to 11.5