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Starch digestion using amylase

Success Goal

Explore the enzymatic activity of amylase as it breaks down starch (a complex carbohydrate) into simple sugars. Amylase is an enzyme derived from a variety of living-sources. A starch slurry (a combination of water and starch) can be created and the addition of amylase will convert the starch into glucose, resulting in a translucent sugar water. Concentrations and effects of inhibitors can be explored. In this example, we will use black tea.

Requirements

  • Two available Pioreactors
  • Amylase enzyme powder*, or digestive enzyme pills containing alpha-amylase
  • Starch
  • Black tea (optional)

Steps

  1. Prepare a sterile stock of 50g YPD / 1L distilled water. Aim to make 20mL x the number of Pioreactors you are using, as each Pioreactor will require about 15mL of media.
  2. Combine (x amount) of starch and (x amount) of water in a beaker to create a starch slurry.
  3. Divide the starch slurry into two vials.
  4. Add an equal amount of amylase enzyme powder (a 1:1 ratio of amylase to starch) to one vial. Dissolve by gently rocking or stirring.
  5. Visit pioreactor.local and start a new experiment.
  6. On the left menu, select the Pioreactors page. Add any additional Pioreactors that you would like to use (more information here). Select Manage all Pioreactors, and start Stirring activity and OD reading activity.
  7. Confirm that everything looks normal (ex: receiving optical density signal).
  8. Optional: you can change the names of the Pioreactor in the UI to display whether it contains amylase.
  9. Students can watch growth progress on the Overview page.
  10. After 24 or so hours (even sooner in some cases), the students can explore maximum growth rates achieved, duration of lag phases, and overall yield of the cultures.
info

Theaflavins and catechins present in green and black teas have been reported to inhibit alpha-amylase. For a more complex experiment, students can steep black tea and explore how it affects the enzyme's ability to break down starch.

Example