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Yeast nutrient enrichment

Success goal

Brewers wort is a sugary liquid extracted from the mashing process when making beer or whiskey. It contains vitamins and minerals necessary for yeast growth; yeast cells uptake these nutrients to produce proteins such as growth enzymes. Wort can be further supplemented with additional nutrients to enhance this growth. The one we have is designed for beer yeasts.

Requirements

  • Two available Pioreactors
  • Dry baker's yeast
  • Dry malt extract (DME)
  • Yeast nutrients (Yeast Lightning)
  • Scale (accurate to 0.1)

Steps

  1. Rehydrate the DME powder using distilled water. Use 3.2 grams of DME powder in 30 mL of water (two vials).
  2. Pour 15 mL into one vial.
  3. Add (a pinch) of Yeast Lightning to the remaining DME mixture. Add this to the second vial.
  4. Inoculate the stock with a very small amount of baker's yeast using best practices to avoid other contamination. Wait for the yeast granules to dissolve, aided by gentle rocking or stirring.
    • Alternatively, a yeast stock solution can be made by diluting a small amount of yeast in 15 mL of YPD stock, then 1 drop of this stock solution can be added to your vials.
  5. Wipe the vials and place them in the Pioreactors.
  6. Visit pioreactor.local and start a new experiment.
  7. 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.
  8. Optional: you can turn on the Temperature automation activity and set it on Stable at an optimal temperature (ex. 30C).
  9. Confirm that everything looks normal on the Overview page (ex: receiving optical density signal).
  10. Optional: you can change the names of the Pioreactor in the UI to display DME with/without Yeast Lightning (YL).
  11. Back on the Pioreactors page, select Manage all Pioreactors and start Growth rate. It will take a minute for results to begin showing up.
  12. Students can watch growth progress on the Overview page.
  13. After 24 or so hours (or even sooner in some cases), students can observe if the addition of Yeast Lightning has increased the growth of yeast in rehydrated DME.

Example