5.7: Citrate Utilization

Question 1

Why is it important to use a light inoculum when preparing a Simmons citrate gar slant?

Answer 1

-A heavy inoculum of inactive cells can be mistaken for new growth post incubation.

Question 2

What change in pH occurs when citrate is utilized by bacteria in the Citrate Utilization Test?

Answer 2

-The pH becomes alkaline.

Question 3

In the Citrate Utilization Test, what does a green color indicate?

Answer 3

-Negative citrate utilization

Question 4

What is the primary purpose of the Citrate Utilization Test?

Answer 4

-To assess the ability of bacteria to utilize citrate as a carbon source

Question 5

A negative result in the citrate utilization test will appear:

Answer 5

-green

Question 6

In the Citrate Utilization Test, what is the purpose of the citrate permease enzyme?

Answer 6

-It transports citrate into the bacterial cell.

Question 7

A positive result in the citrate utilization test will appear:

Answer 7

-blue

Question 8

What indicator is used in the Citrate Utilization Test to detect pH changes?

Answer 8

-bromothymol blue

Question 9

In the Citrate Utilization Test, what is the role of citrate?

Answer 9

-It provides carbon and energy for bacterial growth.

Question 10

Organisms with the enzyme citrate-permease can:

Answer 10

-Utilize citrate as the carbon source.

Question 11

In the Citrate Utilization Test, what does a blue color indicate?

Answer 11

-positive citrate utilization

Question 12

Citrate utilization test is used to differentiate members of the ?? family:

Answer 12

-enterobacteriaceae

Question 13

?? citrate is the only carbon source in the medium

Answer 13

-Sodium

Question 14

The citrate utilization test is used to determine the ability of an organism to use citrate as its sole source of ??

Answer 14

-carbon

Question 15

In the absence of color change, growth on the slant indicates that citrate is being utilized and is evidence of a ??? reaction

Answer 15

-positive