GLUCONATE TEST MEDIUM

Gluconate Test Medium is used in detection of gluconate oxidizing microorganisms. This medium is used to check the ability of an organism to oxidize gluconates, the sole carbon source, to the reducing compound 2-keto-gluconate which subsequently accumulates in the medium.
Gluconate Test: Inoculate the medium with the growth from an 18-24 hours pure culture (e.g. Kligler Iron Agar or Triple Sugar Iron Agar and incubate at 37?C for 48 hours. Then add 1 ml of Benedicts reagent for reducing sugars, place the tube in boiling water bath for 10 minutes and observe for the production of a coloured precipitate of cuprous oxide.
Positive: green to orange precipitate
Negative: the blue colour of the reagent is unchanged

for detection of gluconate oxidizing microorganisms