The Islamic University of The Islamic University of GazaGaza

Faculty of ScienceFaculty of Science

Voges Proskauer TestVoges Proskauer Test

NameName: Sohad M. Mattar: Sohad M. Mattar

Dr.:Dr.: Abd ERauof El ManaamaAbd ERauof El Manaama

IntroductionIntroduction Principle.Principle.

SignificanceSignificance

Procedures.Procedures.

Results.Results.

Summary.Summary.

PrinciplePrinciple

Voges-Proskauer tests demonstrate an Voges-Proskauer tests demonstrate an organisms ability to convert pyruvate to organisms ability to convert pyruvate to acetoin (in the course of glucose acetoin (in the course of glucose fermentation).fermentation).

SignificanceSignificance

Valuable tool in distinguishing Valuable tool in distinguishing Klebsiella, Enterobacter, Ewingella Klebsiella, Enterobacter, Ewingella and Serratia from other members and Serratia from other members of Enterobacteraceae .of Enterobacteraceae .

As well as distinguishing between As well as distinguishing between Proteus vulgaris (V-P negative) Proteus vulgaris (V-P negative) and P. mirabilis (V-P positive).and P. mirabilis (V-P positive).

ProceduresProcedures

Inoculate Inoculate buffered glucose broth with the with the organism and incubate at 37°C for 3 days. organism and incubate at 37°C for 3 days.

Add approximately 3 ml of alpha napthol, Add approximately 3 ml of alpha napthol, followed by 1 ml of 40% KOH. followed by 1 ml of 40% KOH.

Mix well and allow to stand for 30 minutes. Mix well and allow to stand for 30 minutes.

ResultsResults

Voges-Proskauer TestLeft: uninoculated control

Right: negative (copper color)

Left: uninoculated controlRight: positive (red color)

Special FeatureSpecial Feature

The test is used to differentiate between The test is used to differentiate between genera. eg. K. pneumonia (+) and genera. eg. K. pneumonia (+) and Enterobacter (+) from E. coli (-) Enterobacter (+) from E. coli (-)

Klebsiella Klebsiella pneumoniapneumonia

E-coliE-coli

SummarySummary Voges-Proskauer tests to detect the production of Voges-Proskauer tests to detect the production of

acetylmethylcarbinol (actoin), a natural product formed acetylmethylcarbinol (actoin), a natural product formed from pyruvic acid in the course of glucose fermentation. from pyruvic acid in the course of glucose fermentation.

The test is prepared as mentioned before.The test is prepared as mentioned before.

Red color is a positive result however the copper color is Red color is a positive result however the copper color is negative.negative.

Distinguishing some kinds of Enterobacteraceae from Distinguishing some kinds of Enterobacteraceae from

other membersother members..