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Lab 23 Flashcards

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0
Q

What are the 2 ingredients and their purpose in the motility test

A

0.4% agar: soft for swimming

TTC: forms a red precipitate (formazan)

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1
Q

What media was used for the motility test

A

Motility media with TTC

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2
Q

Describe the +/- results of motility test

A 
\+= red and cloudy
-= org will grow along streak line only, **media will NOT be cloudy**
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3
Q

Name of media used for oxygen requirement test

A

FTM (Fluid ThioglyCollate) media

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4
Q

Ingredients and purpose of media used for oxygen requirement test

A

Glucose, cystine, & sodium thioglycollate: lowers the O/R potential
Resazurin turns pink in presence of O2

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5
Q

Describe/explain results of oxygen requirement test

A

Aerobe: growth at top
Facultative: growth throughout
Anaerobe: growth at bottom

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6
Q

Media used for gelatin liquefaction test

A

Nutrient gelatin

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7
Q

What is the purpose of the gelatin liquefication test

A

Determine ability to produce gelatinase

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8
Q

Enzyme found in the gelatin liquefication test

A

Gelatinase

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9
Q

Substrate and product associated with the gelatin liquefication test

A

Gelatin (substrate) –gelatinase–> amino acids (product)

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10
Q

Special step needed before reading results of the gelatin liquefaction test

A

Place tubes in refrigerator for at least 30 minutes

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11
Q

Describe the positive and negative results of the gelatin liquefication test

A 
\+ = gelatin liquefied
- = gelatin solid
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12
Q

There were 5 separate media used for the carbohydrate fermentation test, what were they

A

Glucose, lactose, mannitol, maltose, sucrose broths

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13
Q

What is the carbohydrate fermentation test used for

A

Determine the ability of an organism to ferment a specific carbohydrate with or without the production of gas

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14
Q

2 ingredients used in a carbohydrate fermentation test that served a purpose

A

Phenol red, pH indicator

Durham tube, inverted tube that captures gas

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15
Q

The pH indicator in the carbohydrate fermentation test and explain the color and acidity changes

A

Phenol red; red —> yellow

Neutral (red) —> acid (yellow)

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16
Q

Explain both the acid and gas results of carbohydrate fermentation

A

Acid: + = yellow - = remains red
Gas: + = bubble - = no bubble in Durham tube

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17
Q

What is the agar used in the citrate utilization test

A

Simmons citrate agar

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18
Q

What is the citrate utilization test used for

A

Determine if an organism is capable of using citrate as sole source of carbon with production of citratase

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19
Q

The 3 ingredients in the Simmons citrate agar and the purpose they serve

A

Sodium citrate, carbon source
Ammonium salts, nitrogen source
Brom thymol blue, pH indicator

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20
Q

Enzyme that citrate utilization test is testing for

A

Citratase

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21
Q

Describe the chemical reaction that takes place in the citrate utilization test

A

substrate is citrate; enzyme is citratase; citrate will take ammonium salts and convert into ammonia which is a base

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22
Q

What is the PH indicator in the citrate utilization test and explain changes seen

A

Brom thymol blue
Green —-> prussian blue
Alkaline pH causes change; looking for an alkaline product

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23
Q

Describe the positive and negative results of the citrate utilization test

A 
\+ = Blue
- = no color change, (remains green)
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24
What is the name of the media used for the nitrate reduction test
Nitrate broth
25
What is the nitrate reduction test used for
Determine ability of an organism to reduce nitrate (NO3) to nitrite (NO2) or nitrogen gas (N2) by production of the enzyme nitratase
26
What is the enzyme that the nitrate reduction test is testing for
Nitratase
27
Name the substrate and products associated with the nitrate reduction test
NO3 (nitrate; substrate) | --nitratase--> N2 + NH3 (products)
28
Name of the reagents used in the nitrate reduction test
Nitrate reagent A, nitrate reagent B
29
Explain the positive and negative results of the nitrate reduction test
``` + = red color (test is complete) - = no color change (do confirmation test) ```
30
Explain the confirmation test used if the nitrate reduction test is negative
Add a zinc powder + = no color change, (organism reduced nitrate completely) - = Red color, confirms first negative (zinc reduced nitrate)
31
Nitrate reduction test takes place under ____ conditions
Nitrate reduction test takes place under anaerobic conditions
32
What is the catalase test used to determine
Used to test for the presence of the enzyme catalase
33
What is the ingredient in the catalase test
H2O2 (hydrogen peroxide)
34
What is the substrate in the catalase test
(2) H2O2
35
Explain the positive and negative results of the catalase test
``` + = bubbles - = no bubbles ```
36
Only _____ and _____ lack catalase
Only obligate anaerobes and aerotolerant bacteria (such as Streptococci) lack catalase
37
What was the media used for the methyl red test
MR-VP broth
38
What is the methyl red test used to determine
Used to determine the ability of an organism to produce mixed acid end products from glucose fermentation
39
List two of the various acids possibly produced during the methyl red test
Lactic, acetic, succinic, formic
40
The large amounts of acids in the methyl red test lower the pH to ______
Less than 5
41
What is the reagent used in the methyl red test
Methyl red reagent
42
Explain the positive and negative results of the methyl red test
``` + = red - = yellow ```
43
What is the media used for the voges-Proskauer test
MR-VP broth
44
What is the voges-Proskauer test used for
Detects the presence of acetoin, which is a precursor to 2,3 butanediol
45
What is the media used for the starch hydrolysis test
Starch agar plate
46
What is the starch hydrolysis test used for
To determine the ability of an organism to hydrolyze starch
47
What are the products, enzyme, substrate of starch hydrolysis test
Starch (substrate) amylase (enzyme) sugars (product)
48
What substance detects the presence of starch
I K I (grams iodine)
49
+/– results of the starch hydrolysis test
``` + = A zone of clearing appears adjacent to the streak line – = no clearing; only a blue/black area surrounding the streak line ```
50
Name of the media used for the casein hydrolysis test
Skim milk agar
51
casein hydrolysis test is used for what
To determine the ability of an organism to produce the enzyme caseinase which hydrolyzes casein
52
Explain the substrate, enzyme, product of casein hydrolysis test
casein (substrate) caseinase (enzyme) amino acid (products)
53
+/– results of casein hydrolysis test
``` + = A zone of clearing occurs along the streak line – = no zone of clearing ```
54
Name of the media used for the tryptophan hydrolysis/indole test
Tryptone broth
55
What is the tryptophan hydrolysis/indole test used for
To determine the ability of an organism to split indole from the amino acid tryptophan using the enzyme tryptophanase
56
Name of the substrate and product of the tryptophan hydrolysis/indole test
Tryptophan (substrate) indole (product)
57
What reagent was used in the tryptophan hydrolysis/indole test
Kovacs reagent
58
+/– results of the tryptophan hydrolysis/indole test
``` + = pink layer forms on the surface of the medium – = yellow layer forms on the surface of the medium ```
59
Name of the media used for the urea hydrolysis test
Urea broth
60
The urea hydrolysis test is used for
To determine the ability of an organism to split urea to form ammonia (and alkaline end product/base) by the action of the enzyme urease
61
What other ingredient is in the media that assists with color change of the urea hydrolysis test
pH indicator (phenol red; turns and intense pink at alkaline pH)
62
Name of the media used for the hydrogen sulfide production test
Triple sugar iron agar
63
The hydrogen sulfide production test is used for
To determine the ability of an organism to hydrolyze the sulfur containing amino acid cystine to produce hydrogen sulfide
64
Name of the substrate, enzyme, and products involved in the hydrogen sulfide production test
Cysteine (substrate) Cysteine desulfurase (enzyme) H2S hydrogen sulfide (product)
65
In the hydrogen sulfide production test the medium contains _____ that react with ____ to produce ____
The medium contains ferrous salts that react with hydrogen sulfide (H2S) to produce an insoluble black precipitate, ferrous sulfate
66
+/– results of the hydrogen sulfide production test
``` + = Black precipitate along stab line – = no precipitate ```
67
Name of the media used for the phenylalanine deamination test
Phenylalanine agar
68
What is the phenylalanine deamination test used for
Determine the ability of an organism to deaminate the amino acid phenylalanine resulting in the production of ammonia
69
Name the substrate, enzyme, and product of the phenylalanine deamination test
Phenylalanine (substrate) phenylalanase (enzyme) ammonia (product)
70
What was added before reading results of the phenylalanine deamination test
10 % ferric chloride
71
+/– results of phenylalanine deamination test
``` + = A green color develops – = A yellow color develops ```
72
What is the name of the reagents used for the voges-Proskauer test
Barritt's solution A and Barritt's solution B
73
Explain the results of the Voges-Proskauer test
``` + = wine red, burgundy - = brown ```
74
What is the name of the media used for the lysine decarboxylase test
lysine decarboxylase broth
75
What is the lysine decarboxylase test used for
To determine the ability of an organism to decarboxylate the amino acid lysine resulting in the production of the alkaline end product cadaverine
76
Substrate, enzyme, and product in the lysine decarboxylase test
(Substrate) lysine (enzyme) lysine decarboxylase (product) cadaverine
77
Describe the contents of the medium in the lysine decarboxylase test
Lysine, glucose (as a substrate for fermentation), pH indicator Brom cresol purple
78
Describe brom cresol purple
pH indicator that is purple at alkaline pH and yellow at acid pH
79
The enzyme in the lysine decarboxylase test requires an ____ pH
Acid pH (below 5)
80
The lysine decarboxylase test if the organism is capable of ____ and has ____, 3 events occur
Capable of glucose fermentation and has the enzyme lysine decarboxylase
81
Describe the 3 events that occur during the lysine decarboxylase test
Microbe ferments glucose producing a low pH, indicator turns yellow; lysine decarboxylase is activated; cadaverine is formed, pH rises and the medium returns to its original purple color
82
+/– results of the lysine decarboxylase test
``` + = purple **verify organism ferments glucose, if the organism does not then a purple color is – *** – = yellow ```
83
What is the name of the media used for the ornithine decarboxylase test
ornithine decarboxylase broth
84
What is the ornithine decarboxylase test used for
To determine the ability of an organism to decarboxylate the amino acid ornithine resulting in the production of the alkaline end product putrescine
85
Substrate, enzyme, and product in the ornithine decarboxylase test
(Substrate) ornithine (enzyme) ornithine decarboxylase (product) putrescine
86
Describe the contents of the medium in the ornithine decarboxylase test
Ornithine, glucose (as a substrate for fermentation), pH indicator Brom cresol purple
87
The enzyme in the ornithine decarboxylase test requires an ____ pH
An acid pH (below 5)
88
The ornithine decarboxylase test if the organism is capable of ____ and has ____, 3 events occur
Capable of glucose fermentation and has the enzyme ornithine decarboxylase
89
Describe the 3 events that occur during the ornithine decarboxylase test
Microbe ferments glucose producing a low pH, indicator turns yellow; ornithine decarboxylase is activated; putrescine is formed, pH rises and the medium returns to its original purple color
90
+/– results of the ornithine decarboxylase test
``` + = purple **verify organism ferments glucose, if the organism does not then a purple color is – *** – = yellow ```

Microbiology (4 decks)

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