Isolation and Cultivation of Microorganism Flashcards
1
Q
a culture which contains a single
species of microorganism
A
pure culture
2
Q
pure culture is also known as
A
axenic culture
3
Q
a population of cells arising from a single cell
A
pure culture
4
Q
increasing the population of
microorganisms by providing their
nutritional and physical
requirements
A
cultivation
5
Q
extracellular substances which
provide the cell with materials for
building protoplasm and for
energy generation
A
nutrients
6
Q
any nutrient material for growth
and cultivation of microorganisms
in the laboratory
A
culture medium
7
Q
uses of culture media (3)
A
for growth and maintenance of
microbial cultures
- to favor the production of
particular compounds - to study microbial action on
some constituents of the
medium
8
Q
types of culture media is categorized according to (3)
A
physical state
chemical composition
function, purpose, application
9
Q
type of culture media according to physical state (3)
A
liquid
semi-solid
solid
10
Q
media with no solidifying
agent
A
liquid (broth)
11
Q
media wit h 0.1-0.5% solidifying agent
A
semi-solid
12
Q
media with solidifying agent: agar or – 1.5 – 2.0% solidifying agent
A
solid media
13
Q
type of culture media according to chemical composition
A
synthetic
complex
14
Q
media where all components are
chemically
defined
A
synthetic
15
Q
media not all components
are chemically defined
A
complex
16
Q
example of complex medi
A
potato infusion
beef extract
yeast extract
17
Q
types of culture media according to principal function, purpose, application
A
general
differential
selective
enrichment
assay
18
Q
media that can support most or almost all types
of species
A
general purpose media
19
Q
example of general purpose media
A
nutrient agar (NA)
20
Q
media that distinguishes one type of bacteria from
another
A
differential media
21
Q
media * with special reagents like pH indicators
or dyes
A
differential media
22
Q
example of differential media
A
Eosin Methylene Blue Agar (EMBA)
23
Q
media that allows the growth of a specific type of
microorganism only
A
selective media
24
Q
media with selective agents
A
selective media
25
example of selective agents placed on selective media (3)
salts
dyes
antibiotics
26
example of selective media
Bacillus Cereus Agar (BCA)
27
media used to increase the number of
microorganisms with unusual
physiological characteristics
enrichment
28
media with special nutrients
enrichment media
29
example of special nutrients
blood
30
example of enrichment media
blood agar
31
is a variant of blood agar that contains red blood cells that have been lysed by heating to 80°C. The lysates provide growth factors like nicotinamide adenine dinucleotide (NAD) and hemin, which are needed for the growth of some bacteria. The heat also inactivates enzymes that could degrade NAD
chocolate agar
32
to grow fastidious organisms and to differentiate bacteria based on their hemolytic properties.
blood agar
33
is a medium used with supplements for the selective detection of Bacillus cereus in food
bacillus cereus agar
34
is a brand of chromogenic culture media used in microbiology to identify microorganisms. The color of the colonies formed indicates which substances in the media interacted with specific metabolic pathways in the microorganism.
chromagar
35
to identify organisms that are capable of producing the enzyme lipase
spirit blue agar
36
is the primary plating medium universally used for the selective isolation of vibrios causing cholera, diarrhea and food poisoning.
Thiosulfate Citrate Bile Sucrose (TCBS) agar
37
It is used in testing the quality of water, especially in determining if the water is contaminated by harmful microorganisms.
eosin methylene blue agar
38
media of prescribed composition used for assay
of vitamins, amino acids and antibiotics
assay
39
media used to determine qualitative/ quantitative
production of such a compound by an
organism
assay
40
example of assay media
fermentation media
triple sugar iron medium
antibiotic sensitivty testing
41
a tubed differential medium used in determining carbohydrate fermentation and H2S production
triple sugar iron medium
42
isolation techniques (5)
plating
enrichment culture
serial dilution
single-cell isolation
membrane filter
43
plating techniques
streak plating
spread plating
pour plating
44
a macroscopically visible (surface
or subsurface) growth or cluster of
microorganisms on a solid medium
colony
45
how much inoculum is used in pour plating
1 ml or 1000ul
46
how much inoculum is used for spread plating
0.1 ml or 100 ul
47
what is used for spread plating to spread the inoculum
glass spreader
48
subsurface colonies are smaller/larger than surface colonies
smaller
49
isolation of specific types of
microorganisms by a combination of
nutrient and physical conditions
enrichment culture
50
used for the isolation of unusual
physiological types of microorganisms
which are present in small numbers and
which grow slowly
enrichment culture
51
used if the desired microorganism is present at a
higher level than any other microorganism
serial dilution
52
outcome is 10-fold reduction of cells/cfus in every
transfer.
serial dilution
53
how many ml of broth in serial dilution for each tube
9 ml
54
uses a micropipette or a
microprobe to physically pick a
single cell and transfer it on an
agar medium
single-cell isolation technique
55
for samples with low population
membrane filter technique
56
uses a sterile membrane filter
having a pore size that retains
microorganism
membrane filter technique
57
steps in preparing pure cultures
isolation
transfer
verify the purity
make stock cultures
58
* to retain the viability of the
stock culture for a long period of time
while maintaining its purity and trait
of being “true-to-type”
culture preservation
59
culture preservation methods (5)
periodic transfer to fresh media
overlaying cultures with mineral oil
freeze-drying (lyophilization)
freezing with liquid nitrogen
drying
60
considerations for the tranfer of fresh media
time interval of transfers
proper medium
proper storage temperature
61
aim to limit the availability of O2
overlaying of mineral oil to cultures
62
advantages of putting mineral oil over cultures
culture
enables one to remove some growth
under the oil and inoculate it in a
fresh medium and still preserve the
initial culture
63
disadvantage of overlaying cultures with mineral oil
viability of microorganisms varies
with species
64
temperature of lyophilization freeze-drying
-70C
65
is a water removal process typically used to preserve perishable materials, to extend shelf life or make the material more convenient for transport.
lyophilization
66
Employs
* rapid drying in frozen state
* dry ice in alcohol
lyophilization
67
advantages of lyophilization
long-term survival
* less opportunity for changes in the
characteristics of culture
* smallness of storage containers
68
temperature of freeze-drying with liquid nitrogen
-196C
69
considerations for freezing with liquid nitrogen
cryoprotective agent (glycerol)
* liquid-nitrogen refs
70
drying temperature
45C
71
limitation for drying preservation method
for spore and cyst formers
72
organizations which maintain authentic
pure cultures of microorganisms
culture collections
73
provide ‘type’ strains to microbiologists
throughout the world
culture collections
74
example of culture collection
American Type Culture Collection (ATCC)
National Collection of Type Cultures
Japanese Type Culture Collection
Philippine National Collection of Microorganism
75
ATCC is located in
Maryland
76
NCTC is located in
London
77
JTCC is located in
Japan
78
PNCM is located in
Biotech-UPLB Philippines
79
Enumeration of microorganisms is especially important in what industries
dairy microbiology
food microbiology
pharmaceutical microbiology
water microbiology
80
done to evaluate the effects of antimicrobial agents or the decontamination processes
enumeration
81
methods for counting microorganisms (3)
viable
total
rapd
82
viable counts include (4)
pour plate
surface spread/spread plate
membrane filter method
MPN
83
total count method (4)
direct microscopic counting
turbidity methods
dry weight determination
nitrogen, protein, nucleic acid determination
84
rapid method include (4)
epifluorescence with image analysis
ATP testing
impedance method
manometric method
85
is a counting procedure enumerating both living and dead cells.
total count
86
are possible using special slides known as counting chambers, consisting of a ruled slide and a coverslip.
direct microscopic count
87
Bacteria can be counted efficiently and accurately with the (direct count)
Petroff-Hausser counting chamber
88
This is a special slide accurately ruled into squares that are 1/400 mm² in the area; a glass coverslip rests 1/50 mm above the slide so that the volume over a square is 1/20,000 mm² i.e. 1/20, 000, 000 cm².
Petroff Hausser counting chamber
89
A suspension of unstained bacteria can be counted in the Petroff-Hausser counting chamber using what kind of microscope
phase-contrast
90
advantages of direct microscopic count
Rapid, simple, and easy method requiring minimum equipment.
Morphology of the bacteria can be observed as they are counted.
Very dense suspensions can be counted if they are diluted appropriately.
91
limitation of direct microscopic count
Dead cells are not distinguished from living cells.
Small cells are difficult to see under the microscope, and some cells are probably missed.
Precision is difficult to achieve
A phase-contrast microscope is required when the sample is not stained.
The method is not usually suitable for cell suspensions of low density i.e., < 107 Cells per ml, but samples can be concentrated by centrifugation or filtration to increase sensitivity.
92
are the most common means of estimating the total number of bacteria present in a sample
turbidity measurements
93
Measuring the turbidity using a ____ or colorimeter and reading the concentration from a calibration plot is a simple means of standardizing cell suspensions for inocula in antibiotic assays or other tests of antimicrobial chemicals.
spectrophotometer
94
records living cells alone.
viable count
95
is defined as one that can divide and form offspring
viable cell
96
or this reason, the viable count is often called the
plate count
colony count
97
It uses fluorescent dyes that either exhibit different colors in living and dead cells (e.g., acridine orange) or appear colorless outside the cell but become fluorescent when absorbed and subjected to cellular metabolism (e.g., fluorescein diacetate).
epiflourescent technique
98
Living cells generate adenosine triphosphate (ATP) that can readily be detected by enzyme assays, e.g., luciferin emits light when exposed to firefly luciferase in the presence of ATP; light emission can be measured and related to bacterial concentration.
aTP testing
99
The resistance, capacitance, or impedance of a culture medium changes due to bacterial or yeast growth and metabolism, and these electrical properties vary in proportion to cell concentration.
impedance technique
100
are appropriate for monitoring the growth of organisms that consume or produce significant quantities of gas during their metabolism, e.g., yeasts or molds producing carbon dioxide from fermentation.
manometric
