Carbohydrate (CHO) Fermentation [Durham Tube Test]

The video tutorial explains the carbohydrate fermentation test, also known as the Durham tube test. It describes the setup, which includes a large test tube with broth and an inverted Durham tube. The test determines if bacteria can ferment specific sugars, producing acid and sometimes gas. Positive results turn the broth yellow due to a pH indicator, while negative results remain red. The video also covers interpreting results, including the significance of gas production.

What is the primary purpose of the Durham tube in the carbohydrate fermentation test?

• To measure the temperature of the broth

• To collect gas produced during fermentation

• To act as a control for the experiment

• To change the color of the broth

Which of the following is NOT a sugar that can be used in the carbohydrate fermentation test?

• Glycerol

• Glucose

• Sucrose

• Lactose

What does a yellow color in the broth indicate in the carbohydrate fermentation test?

• The presence of a base

• A negative result for sugar fermentation

• A positive result for sugar fermentation

• The presence of oxygen

In the carbohydrate fermentation test, what does the presence of gas in the Durham tube signify?

• The test is invalid

• The bacteria are dead

• The bacteria produce gas during fermentation

• The broth is contaminated

What does the letter 'A' represent in the results of a carbohydrate fermentation test?

• Alkaline

• Acidic

• Aerobic

• Aromatic

What does any presence of red color in the test indicate?

• A negative result

• A positive result

• A need to repeat the test

• An inconclusive result

Which of the following is a correct interpretation of a negative result in the carbohydrate fermentation test?

• Both the broth and the Durham tube are yellow

• The broth is red and the Durham tube is yellow

• The broth is yellow and the Durham tube is red

• Both the broth and the Durham tube are red