During fermentation most bacteria convert carbohydrates into organic acids, with or without the production of gas. One can test for this by adding a pH indicator and an inverted tube (a Durham tube) t...During fermentation most bacteria convert carbohydrates into organic acids, with or without the production of gas. One can test for this by adding a pH indicator and an inverted tube (a Durham tube) to the culture medium. We will use phenol red as the pH indicator. If acid is produced the phenol red will turn yellow (pH below 6.8). Any gas produced will form a bubble in the inverted tube.
This page outlines some common bacterial staining protocols, including a simple stain with methylene blue and the differential staining protocols, Gram staining, acid-fast staining, and endospore stai...This page outlines some common bacterial staining protocols, including a simple stain with methylene blue and the differential staining protocols, Gram staining, acid-fast staining, and endospore staining. In addition, protocols for preparing bacterial smears and plates are given.
