Fig. 2B: Fermentation of a Carbohydrate:
Acid and Gas End Products
Acid end products from carbohydrate fermentation turn the pH indicator phenol
red from red (alkaline) to yellow (acid). A large gas bubble (arrow) collects
in the Durham tube.
Microbiology Laboratory Manual by Gary E. Kaiser, PhD, Professor of Microbiology
is licensed under a Creative Commons Attribution 4.0 International License.
Last updated: September, 2017