CH 7 Flashcards

1
Q

How is microbial growth measured in:

  1. multicellular organisms
  2. unicellular organisms
A
  1. size and mass
  2. number and mass
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

WHAT temperature classification are the ff:

  1. Humans
  2. Food
A
  1. mesophile
  2. psycrophile
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where are psychrotrophs located?

and what environment do they thrive in?

A

Middle of psychrophile and mesophile

prefer cold but can withstand hot

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

WATER ACTIVITY - ORGANISMS (7)

1.000 Pure Water - ____ & ____
___ Human Blood - Streptococcus, Escherichia
0.980 _______ - ______
_______ Bread - Gram Positive Rods
0.800 Fruit Cake - ______
______ Salted Fish - _____ & _____
0.700 Candy, Dried Fruit - +_____

A
  1. Spirillum, Caulobacter
  2. 0.995
  3. Seawater - Pseudomonas, Vibrio
  4. 0.950
  5. Penicillum
  6. 0.750 - Halobacterium, Halococcus
  7. Xeromyces bisporus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

PH - ORGANISMS (5)

7
5
3
1
9

A

7 - Escherichia coli
5 - Rhodophila globiformis
3 - Acidithiobacillus ferrooxidans
1 - Picrophilus oshimae
9 - Bacillus firmus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

PHASES OF BACTERIAL GROWTH

adaption phase that occurs upon initial transfer

A

Lag Phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

PHASES OF BACTERIAL GROWTH

no immediate increase in cell mass/number

A

Lag Phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

PHASES OF BACTERIAL GROWTH

synthesis of protoplasm

A

Lag Phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

PHASES OF BACTERIAL GROWTH

cells are dividing at a constant rate

A

Exponential Phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

PHASES OF BACTERIAL GROWTH

growth rate is at its maximum

A

Exponential Phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

PHASES OF BACTERIAL GROWTH

cells are mostly uniform

A

Exponential Phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

PHASES OF BACTERIAL GROWTH

growth rate decreases due to exhaustion of nutrients and accumulation of waste products

A

Stationary Phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

PHASES OF BACTERIAL GROWTH

stable population size

A

Stationary Phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

PHASES OF BACTERIAL GROWTH

decline in cells

A

Death Phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Reproduction of:

  1. Multicellular microbes
  2. Unicellular microbes
A
  1. Spores
  2. Binary Fission
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What replicates before binary fission

16
Q

FORMULA

no. of generations

A

n = (log N2 - log N1) / 0.301

N2 = # of cells at final time
N1 = # of cells at initial time

17
Q

FORMULA

growth rate

18
Q

FORMULA

generation time

A

g = 1/µ or t/n

19
Q

3 measurements of growth

A

Standard Plate Count
Direct Count (Breed Count)
Turbidimetric Method

20
Q

3 types of standard plate count

A

serial dilution
pour plate
spread plate

21
Q

Valid ranges of Mold and Bacteria

A

Mold: 10-150 colonies/plate
Bacteria: 25-250 colonies/plate

22
Q

CFU/ml formula

A

[(ave number of colonies)(df)]/
volume plated

22
Q

Direct Count formula

A

bacteria/ml =

[(ave number of microorganisms)(# mcscpc fields in 1cm^2) (DF)] / VOLUME SAMPLE

mcscpc fields in 1cm^2 = 1/area of field of vision

22
area of OIO
1.77 x 10^-4 cm2
22
TYPE OF GROWTH MEASUREMENT most frequently used method
standard plate count
22
TYPE OF GROWTH MEASUREMENT reported as colony forming unit
standard plate count
23
TYPE OF GROWTH MEASUREMENT can determine # of living cells
standard plate count
24
TYPE OF GROWTH MEASUREMENT underestimation of cell population
standard plate count
24
TYPE OF GROWTH MEASUREMENT heat sensitive microorganisms cant form colonies
standard plate count (pour plate)
25
TYPE OF GROWTH MEASUREMENT both viable and non-viable cells are counted
direct (breed) count
26
TYPE OF GROWTH MEASUREMENT overestimation
direct (breed) count
27
TYPE OF GROWTH MEASUREMENT uses Petroff-Hausser counting chamber microscope
direct (breed) count
28
What 2 microorganisms use DIRECT COUNT
cocci and S. agalactia
29
TYPE OF GROWTH MEASUREMENT indirectly measures cell mass through turbidity
turbidimetric method
30
TYPE OF GROWTH MEASUREMENT a spectrophotometer
turbidimetric method