Indole Production, Hydrogen Sulfide Production And Motility Using SIM Medium Pg 85-90

Question 1

Production of hydrogen sulfide, i dole, and motility are three tests that are combined in one differential medium called _____ medium.

Answer 1

SIM medium

Question 2

SIM is an acronym for

Answer 2

Sulfide, indole, and motility.

Question 3

SIM combines ingredients for how many tests? Making the agar tall a little softer to accommodate motility

Answer 3

3

Question 4

The first test is for:

Answer 4

The production of hydrogen sulfide gas

Question 5

The SIM medium includes ______, an amino acid, with sulfur in its R-group (1st test)

Answer 5

Cysteine

Question 6

If the inoculated microorganism can metabolize this amino acid, ______ gas will be produced and diffuse through the medium.

Answer 6

Hydrogen sulfide gas

Question 7

The hydrogen sulfide gas will react with ______, also in the medium, resulting in the formation of a black precipitate (_________).

Answer 7

-with iron sulfate
-black precipitate (iron sulfide)

Question 8

(T/F)if the microorganism cannot metabolize the cysteine, no black precipitate will form

Answer 8

True

Question 9

The second test is r the production of ______.

Answer 9

Indole

Question 10

Some microorganisms are able to metabolize the amino acid ____, which is also in the medium, forming a product of hydrolysis called ____ which is an intermediate product of _____ metabolism.

Answer 10

Tryptophan
Indole
Tryptophan metabolism

Question 11

How is the presence of indole indicated?

Answer 11

By a simple colorimetric test.

Question 12

What are the intermediate products for production of indole?

Answer 12

Indole+pyruvic acid+ammonia

Question 13

The third test is to determine ______ of the inoculated microorganism

Answer 13

Motility (or non-motility)

Question 14

The spreading or non-spreading of growth away from the ________ within the medium will indicate motility or non motility.

Answer 14

Stab line

Question 15

In the procedure, using aseptic technique, we stabbed one culture with _______ and ______

Answer 15

Escherichia coli and Citrobacter freundii

Question 16

In the procedure, the talls are incubated at 37 degrees Celsius for how long?

Answer 16

2-4 days

Question 17

In the production of hydrogen sulfide test, what did the black precipitate (Iron sulfide) indicate?

Answer 17

The bacteria were able to metabolize cysteine and produced H2S gas. If no black precipitate is present, cysteine was not metabolized and H2S was not produced.

Question 18

In the production of indole test, the presence of indole in the medium is indicated by adding 10 drops of ________ on top of the medium

Answer 18

Kovac’s reagent

Question 19

If indole has been produced, the kovac’s reagent will turn what color after several minutes?

Answer 19

Red

Question 20

If indole hasn’t been produced, then the kovac’s reagent layer…

Answer 20

Will remain unchanged

Question 21

In the motility test, what is an indication of motility?

Answer 21

Turbidity in all directions, well away from the stab line