lab 7 Flashcards
IMViC Tests is used to
Help identify enteric bacteria (bacteria found in the gut)
Enteric bacteria can be
Pathogens
Occasional pathogens
Normal gut flora
IMViC Tests Consists of 4 tests:
Indole
Methyl Red
Vogues-Proskauer
Citrate Utilization
Tests of indole, a product of
of tryptophan hydrolysis, is present
Indole Test:Bacteria are grown in _____, which contain
SIM agar
trypotphan
Indole Test:Addition of Kovak’s reagent will turn indole
cherry red
Kovak’s reagent =
, p-dimethylaminobenzaldehye, and HCl
Methyl Red TestMethyl Red is a pH indicator
Red for solutions with a pH < 6.2
Yellow for solutions with pH > 6.2
The use of Methyl red is a test for
glucose fermentation
Methyl Red TestONLY tests for acidic end products of
fermentation
Vogues-Proskauer Test
Some organisms ferment glucose, but produce nonacidic or neutral end products
Some organisms ferment glucose, but produce nonacidic or neutral end products Example:
production of acetylmethylcarbinol by E. aerogenes
Addition of Barrit’s reagent will turn the solution
RED if non-acidic fermentation has occurred
Barrit’s reagent = α-naphthol + 4%KOH