Question

Negative acid from glucose tests indicate sugar was not metabolized to produce acids. How can growth be accomplished in a carbohydrate test medium when the sugar is not metabolized?

Answer 1

It can mean two possible variants:
- a culture don't use sugar and groth
only with aminoacids from peptone.
- a culture has already utilized sugar
and proceeded to peptone nutrition. It follows with a secondary alkalinization
in the media.