Laboratory Culture of Microorganisms Flashcards

1
Q

After the ethanol rinse (alcohol) in the Gram Staining procedure, the Gram-positive cells would appear ______ and the Gram-negative cells would appear ________.

A

purple; colorless

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

bacteria need proper _______ to grow in lab

A

nutrition

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

all bacteria have different nutritional requirements but all require:

A

Carbon
Hydrogen
Oxygen
Nitrogen
Phosphorus
Sulfur
– CHONPS!

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

some bacteria need certain ____ ____ (organics in medium)

A

trace metals

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

macromolecular composition of a cell: protein = ____%

A

55%

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

macromolecular composition of a cell: lipid = ____%

A

9.1%

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

macromolecular composition of a cell: polysaccharide = ____%

A

5%

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

macromolecular composition of a cell: lipopolysaccharide = ____%

A

3.4%

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

macromolecular composition of a cell: DNA = ____%

A

3.1%

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

macromolecular composition of a cell: RNA = ____%

A

20.5%

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

elemental composition of E. coli: CARBON = ____%

A

50% (the rest go down in numbers from CHONPS)

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

nutrient preparations devised to support the growth (reproduction) of microorganisms

A

culture media

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

large quantities of these are need by microorganisms (ex: carbon)

A

macronutrients

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

smaller quantities of these are needed by microorganisms

A

micronutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

2 types of micronutrients:

A
  • trace metals
  • growth factors (organics or vitamins)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

culture media can be ____ or _______

A

solid or liquid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

solid media are usually solidified with _______

A

agar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

chemical composition types of media (2):

A
  • defined (synthetic)
  • complex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

physical natures of media (3):

A
  • liquid
  • semisolid
  • solid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

FUNCTIONAL types of media (5):

A
  • supportive (general purpose)
  • enriched
  • minimal
  • selective
  • differential
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

type of chemical composition of media: EXACT composition (qualitative AND quantitative) is known; very specific; don’t have to add trace elements all the time to it (usually already in water); chemical formula AND amounts for all ingredients

A

defined media

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what must be included for a media to be defined (2)?

A

chemical formula AND amounts for all ingredients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

type of chemical composition of media: contain some ingredients of unknown chemical composition and/or concentration; no chemical formula

A

complex media

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

if you have a SINGLE ingredient without a formula, what kind of chemical compostion is the media?

A

complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what kind of chemical composition is: Yeast extract 5g and Peptone 5 g

A

complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

common complex media components (5):

A
  • peptones
  • extracts
  • agar
  • blood
  • soil
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

common complex media component: protein hydrolysates prepared by the partial digestion of various protein sources such as casein and soybeans

A

peptones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

common complex media component: aqueous extracts, usually of BEEF or YEAST

A

extracts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

common complex media component: sulfated polysaccharide used to solidify liquid media; most microorganisms CANNOT degrade it; comes from red seaweed

A

agar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

anytime you see ______, _______, _____, or ______, you KNOW the media is complex

A

peptones, yeast, beef, or agar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

functional type of media: support the growth of many microorganisms; usually complex

A

general purpose media (supportive)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

example of a general purpose (supportive) media =

A

tryptic soy agar (TSA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

functional type of media: general purpose media supplemented with highly nutritious substances such as blood

A

enriched media

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

example of enriched media =

A

chocolate agar (boild blood agar); also blood broth

35
Q

functional type of media: contains the minimal necessities for growth of the wild-type (non-mutant form); ONLY contains inorganic salts, a simple carbon source, and water; only the hardiest organims will be able to grow in this

A

minimal media

36
Q

what 3 things does minimal media contain?

A

1) inorganic salts
2) a simple carbon source (ex: glucose)
3) water

37
Q

functional type of media: favor the growth of some microorganisms and inhibit the growth of others; can be defined (MOSTLY) but also complex

A

selective media

38
Q

example of selective media =

A

EMB agar (ESTN and crystal violet within)

39
Q

EMB agar selects for growth of what type of bacteria?

A

Gram-negative

40
Q

MOST selective media will be _______, but can also be

A

defined; complex

41
Q

functional type of media: distinguish between different groups of microorganisms based on their biological characteristics; looks for different colors or different appearances

A

differential media

42
Q

TWO examples of differential media =

A
  • blood agar
  • MacConkey agar
43
Q

what types of bacteria does blood agar differentiate between?

A

hemolytic vs. nonhemolytic bacteria
– CAN degrade blood vs. cannot

44
Q

types of hemolytic/nonhemolytic bacteria (3):

A
  • beta
  • alpha
  • gamma
45
Q

type of hemolytic/nonhemolytic bacteria: TOTAL breakdown of blood; CLEAR RING

A

beta

46
Q

type of hemolytic/nonhemolytic bacteria: partial breakdown of blood; GREEN

A

alpha

47
Q

type of hemolytic/nonhemolytic bacteria: no breakdown/clearing of blood

A

gamma

48
Q

what type of bacteria does MacConkey agar differentiate between?

A

lactose fermenters vs. nonfermenters

49
Q

appearance of Beta hemolytic bactera:

A

clear ring

50
Q

appearance of Alpha (semi)hemolytic bacteria:

A

green

51
Q

appearance of Gamma nonhemolytic bacteria:

A

nothing; no clearing

52
Q

appearance of lactose fermenters:

A

red

53
Q

appearance of lactose NONfermentors

A

yellow (color of agar)

54
Q

how does MacConkey agar work?

A

distinguishes by pH; if they bacteria can ferment lactose, the pH goes down and it appears pink/red

55
Q

functional type of: Blood Agar

A

Enriched and Differential

56
Q

functional type of: Eosin Methylene Blue (EMB) agar

A

Selective and Differential

57
Q

functional type of: MacConkey (MAC) agar

A

Selective and Differential

58
Q

functional type of: Mannitol salt agar

A

Selective and Differential (turns yellow)

59
Q

population of cells arising from a single cell; allows for the study of a single type of microorganism; a mixture of cells is applied to an agar surgace so that individual cells are well separated from each other

A

pure culture

60
Q

methods of preparing a PURE CULTURE (3):

A

1) streak plate
2) spread plate
3) pour plate

61
Q

Asceptic Transfer process (6):

A
  1. Flaming hthe loop sterlizes it.
  2. Tube cap is removed.
  3. Flaming the tube tip sterilizes the surface.
  4. Only sterilized portion of loop enters tube.
  5. The tube is reflamed.
  6. Tube is recapped and then steps 2-6 repreated with tube of fresh medium. Loop is then resterilized in the flame.
62
Q

Streak Plating process (3):

A

1) Loop is sterlized and a loopful of inoculum is removed from the tube.
2) Initial streak is worked in well in one corner of the agar plate; subsequent streaks are at angles to the first streak.
3) Appearance of well-streaked plate after incubation shows colonies of the bacterium M. luteus on a blood agar plate.

63
Q

during Streak Plating, you only streak/touch the culture _____

A

once

64
Q

after the Streak Plating process, you use a ____ ____ for isolated colonies to study

A

single colony

65
Q

pure culture method: a small volume of diluted culture is transferred to agar surface; culture is spread evenly over surface with a sterile bent rod HOCKEY STICK (bent glass rod)

A

Spread Plate

66
Q

the spread plate method of obtaining a pure culture uses a _____ _____

A

bent rod (“hockey stick”)

67
Q

pure culture method: diluted samples are mixed with liquid agar; mixture of cells and agar are poured into sterile culture dishes; bacteria on surface AND embedd into agar (look like sesame seeds, no oxygen there)

A

Pour Plate

68
Q

both the Spread Plate and Pour Plate methods provide (2):

A
  • isolated colonies
  • opportunity to enumerate (count) the bacteria in a sample
69
Q

countable plate = ____-_____ colonies

A

30 - 300 colonies

70
Q

only plates you can use to calculations/enumerate the bacteria; use to determine how many bacteria in the ORIGINAL CULTURE

A

countable plates

71
Q

Spread Plate process (3 – includes results):

A

1) sample is pipetted onto surface of agar plate (0.1 mL of less)
2) sample is spread evenly over surface of agar using sterile glass spreader (hockey stick)
3) results: SURFACE COLONIES

72
Q

Pour-Plate process (3):

A

1) sample is pipetted into sterile plate
2) sterile medium is added and mixed well with incolulum
3) results: SURFACE + SUBSURFACE colonies

73
Q

spread plate method results in ______ colonies and pour-plate method results in _____ and _____ colonies

A

surface
surface + subsurface colonies

74
Q

PRACTICE DILUTING AND COUNTING BACTERIA!!!!*****

A
75
Q

to count bacteria, you take the inoculation and divide it by ____ each time; taking off zeros each time

A

10

76
Q

T/F: to count bacteria you dilute it by a factor of 9

A

false (its by 10)

77
Q

to enumerate the number of bacteria, you multipy the ____ ____ by the ____ ____

A

plate count (ex: 159) by the dilution factor (10^3)

78
Q

you usually only obtain one countable plate, but if you get two, what do you do?

A

average them (avg. the # of colonies)

79
Q

microbial growth on solid surfaces: species form characterisitc ______

A

colonies

80
Q

differences in growth rate from. edges to center is due to what 2 things?

A

1) oxygen, nutrients, and toxic products
2) cells may be dead in some areas – various ages in colony

81
Q

most rapid microbial growth occurs where on the microbes?

A

on the edges

82
Q

a colony should be a mound of _____

A

clones

83
Q

bacteria spread out fast to get ______

A

food (do it in different ways)

84
Q

various ages within a colony (w some dead) may cause ____ variations

A

color