Question

Can someone break down how bacteria or microorganism glucose metabolism and what is happening to the bacteria in Voges Proskauer test? Thank you

Answer 1

Voges Proskauer test;

Using sterile technique, inoculate each experimental organism to the appropriately labeled tube of medium by means of loop inoculation. Incubate the cultures for 24-48 hours at 37°C. The experiment should be conducted in the LAF. Arrange the materials required for the experiment in the LAF.

1. Sterilize the loop vertically in the blue flame of the Bunsen burner till red hot. Heat from the base of the wire first and slowly move towards the loop (tip). Heat the wire until it is red-hot.
2. From the rack, take the test tube containing the Tryptic Soy Broth(TSB) cultures that has been kept for 24 - 48 hours.
3. Remove the cap from the TSB tube and flame the neck of the tube.
4. Using aseptic technique take a loop full of the organism from the TSB (tryptic soy broth).
5. Again flame the neck of the tube and replace the cap and place the tube in the test tube rack.
6. Take two sterile MR-VP broth tubes, one named Test and the other Control.
7. Remove the cap of the MR-VP broth tube named 'Test' and flame the neck of the tube.
8. Inoculate the MR-VP broth with the inoculation loop containing the inoculum from the TSB.
9. Again flame the neck of the MR-VP tube and place it in the test tube rack. Inoculate only the broth in the tube named 'Test' using aseptic technique. Leave the broth in the tube named 'Control' uninoculated.
10. Incubate both the tubes (Test and Control) for 24 to 48 hours at 37°C.
11. Remove the broths from the incubator.
12. Remove the cap and add 10 drops of Barritt's A reagent and 10 drops of Barritt's B reagent to each broth.
13. Shake gently for several minutes.
14. Red color formation within 15 to 20 minutes is a positive result. No red color formation after 15 to 20 minutes is a negative result.