Experiment 19 involves determining the fermentation type of various bacteria. Bacteria were inoculated in various sugar solutions: dextrose, sucrose or lactose. The solutions also contained phenol red indicator to detect whether fermentation occurred. After a 24 hour incubation period, results were gathered. A positive reaction for fermentation is shown by a change in the indicator from red to yellow due to a production of acidic byproducts. These acidic byproducts could also be coupled to gas production, most likely carbon dioxide, shown as gas bubbles in the inverted tube. A positive test is shown by the presence of a gas bubble in the tube, indicating the microbe was able to ferment the given sugar. A negative test result is shown if
