2.62: Exercise 22.2
- Page ID
- 94745
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Answers
- Did this bacterial species produce gas? No
- Did this bacterial species produce acid? No
- Did fermentation occur? No
Solution
- Gas was not produced. The upside-down tiny tube inside the test tube (the Durham tube) is completely filled with liquid medium. The Durham tube therefore does not have any gas in it (no bubble). If the bacterial species produced gas during fermentation it would have been trapped inside of the Durham tube.
- Acid was not produced. The medium is red. When the medium was inoculated it was red. Since the medium is still red, no acid was produced. In this medium, when acid is produced, a pH indicator changes the medium to yellow.
- Fermentation did not occur. If neither acid or gas are produced, this indicates fermentation did not occur.