Question

select the three best hypotheses that could explain why the broth in the durham tube appears yellow while the rest of the broth appears red.

Answer 1

The test organism ferments sucrose best under reduced oxygen conditions.
The sample was incubated less than 24 hours, which allowed for only limited fermentation.
The media was contaminated.
The organism is an obligate aerobe and therefore can only grow inside the Durham tube.
The media was prepared wrong.
The organism is limited in its ability to ferment sucrose. Since diffusion is restricted within the Durham tube and it contains only a small volume of media, it turned yellow first.
The test organism did not ferment sucrose.

1)The test organism ferments sucrose best under reduced oxygen conditions.
2)The sample was incubated less than 24 hours, which allowed for only limited fermentation.
3)The organism is limited in its ability to ferment sucrose. Since diffusion is restricted within the Durham tube and it contains only a small volume of media, it turned yellow first.