ex. 12

Question 1

Urea Slant
protocol

Answer 1

1. label tube
2. aseptically inoculate each broth tube with the assigned organism.
3. incubate 36-48 at 37

Question 2

Urea Slant
pos and neg results

Answer 2

pos: fuchsia

neg: no color change

Question 3

Urea Slant
what do pos and neg results mean

Answer 3

pos: urease hydrolyzes urea into ammonia and carbon dioxide

urease that breaks down proteins

Question 4

phenylalanine slants
protocol

Answer 4

1. label tube
2. Use an inoculating loop to aseptically obtain an inoculum of the appropriate bacterial culture, and zig-zag the bacteria up the surface of the slant.
3. incubate for 36-48 hr at 37

Question 5

phenylalanine slants
pos and neg results

Answer 5

pos: dark green after adding 4-5 drops of 10% ferric chloride so they roll down slant

neg: no color change

Question 6

phenylalanine slants
what do pos and neg results mean

Answer 6

makes phenylalanine deaminase that removes an amino group from phenylalanine and makes PPA

Question 7

SIM
protocol

Answer 7

Use an inoculating needle to aseptically obtain an inoculum of the appropriate bacterial
culture, and stab the bacteria into the deep

Question 8

SIM
pos and neg results

Answer 8

S: black precipitate in the deep

I: red layer

M: cloudy, fuzzy growth throughout tube

Question 9

SIM
what do pos and neg results mean

Answer 9

S: H2S production
I: Indole for tryptophanase
makes trytophanase that breaks down tryptophan into Indole, pyruvic acid, and ammonia
M: motility for flagella

Question 10

Gelatin
protocol

Answer 10

Use an inoculating needle to aseptically obtain an inoculum of the
appropriate bacterial culture, and stab the bacteria into the deep

incubate at room temp for 1 week

Question 11

Gelatin
pos and neg results

Answer 11

pos: liquifies

neg: still solid

Question 12

Gelatin
what do pos and neg results mean

Answer 12

makes gelatin hydrolase or gelatinase that break down gelatin protein

Question 13

what do you add to the SIM tube to process the indole test?

what does that additive do when added to the tube

Answer 13

the additive is kovacs to process the indole test

kovacs makes tryptophanase that breaks down tryptophan into Indole, pyruvic acid, and ammonia.

A red layer would have to be formed in the tube

Question 14

what does the SIM tube test for

Answer 14

Motility
indole production
H2S production (ammino acid desulfurization)

Question 15

you inoculated a gelatin deep with a bacteria. how do you know if the bacteria produce the exoenzyme gelatin hydrolase?

Answer 15

to know if a bacteria produces the exoenzyme gelatin hydrolase the gelatin has to be liquefied and the deep has to no longer appear solid

Question 16

what is added to the phenylalanine slant for processing the test? what does the addiditve do when it’s added to the tube?

Answer 16

10% ferrric chloride is added

if the bacteria had the enzyme it would turn tube green

Question 17

what species of bacteria produced the enzyme phenylalanine deaminase

Answer 17

proteus vulgaris

Question 18

which species of bacteria produce the enzyme tryptophanase

Answer 18

escherichia coli

proteus vulgaris

Question 19

which species of bacteria produces the enzyme urease

Answer 19

proteus vulgaris

Question 20

Pseudomonas aeruginosa is capable of aerobic respiration and anaerobic respiration but not fermentation. It can produce H2S, does not produce tryptophanase, and is motile by a flagellum.

Based on the above characteristics, describe your expected results for Pseudomonas
aeruginosa in a SIM deep

Answer 20

Pseudomonas aeruginosa would have a black precipitate on the butt of the tube, there would be no red layer, there is growth of the bacteria in the tube because of the black precipitate. If the bacteria was not motile then there would not be a black precipitate.