How can you tell from OF-glucose medium whether an organism oxidizes glucose?

Answer 1

If it uses glucose regularly the organisms will produce acid in the open tube only and the indicator will turn yellow. If carbohydrates are metabolized in both tubes, fermentation has occurred. There will be a dark blue color.

Answer 2

Inoculate two tubes of medium with the strain, then fill one tube with enough mineral oil to prevent oxygen from touching it. After incubating the tubes, if the top of the unsealed tube has grown, the organism oxidizes glucose.

Answer 3

If an organism oxidizes glucose in an OF-glucose medium, it will use up the available oxygen in the aerobic tube first before moving into the anaerobic tube. This results in a color change in the medium due to the pH indicator, showing alkaline conditions in the aerobic tube and acidic conditions in the anaerobic tube.