4/4/22

Dear Hailey,

• Attached is a file w/ the recipe for YPD medium. You can make the medium from scratch w/ yeast extract, NaCl & peptone, but w/o glucose. pH should be 5.0 for the yeast. You can then add whatever sugars you wish.
• Another option is Bacto Sabouraud broth (or agar) minus carbohydrate. The broth contains 10 g Difco Neopeptone + 20 g dextrose/L. However, you can omit the glucose and add different sugars. Check Difco's website or the Difco Manual for these recipes.
• You can also use Bacto Yeast Nitrogen Base (YNB). The recipe for this is tabulated below. It contains no carbohydrate. This is available from Thermo Fisher Scientific (Cat. # Q30007). It comes in pouches w/ reagents to prepare 1,000 mL of 10X YNB for S. cerevisiae media. YNB can be formulated (or supplemented) with or without sugars, w/o amino acids, or w/o amino acids and ammonium sulfate. You should be able to get this information on Thermo Fisher's website. You can also find the composition of different YNB formulations in the Difco Manual, or on Difco's website.
• Below is the formulation for 1X YNB: Ammonium sulfate, 5 g Biotin, 0.002 mg Calcium pantothenate, 0.4 mg Folic acid, 0.002 mg Inositol, 2 mg Niacin, 0.4 mg Para-aminobenzoic acid, 0.2 mg Pyridoxine HCl, 0.4 mg Riboflavin, 0.2 mg Thiamine HCl, 0.4 mg Boric acid, 0.5 mg Copper sulfate, 0.4 mg Potassium iodide, 0.1 mg Ferric chloride.6H2O, 0.2 mg Manganese sulfate.H2O, 0.4 mg Sodium molybdate.2H2O, 0.2 mg Zinc sulfate.H2O, 0.4 mg Potassium phosphate monobasic, 1 g Magnesium sulfate, 0.5 g Sodium chloride, 0.1 g Calcium chloride, 0.1 mg
• I hope this information helps you.
• Bill Colonna
• Iowa State University, Ames, IA [email protected]

Thank you so much! That was super helpful!

This is actually how yeast media is made. The sugar should not be autoclaved with the rest of the media but added as a stock later. Most of the time you can you use a glucose stock at 20% to 40% and dilute it in YPD (for example if making 1 liter, autoclave the media in 950ml water then add 50ml of 40% glucose stock) to final concentration of 2%. For what you are trying to do I would recommend against using YPD since the media is not defined and use minimal media instead with your sugar added. The link below is for prep of minimal media (just swap out the glucose for your sugar at the concentration required):

http://cshprotocols.cshlp.org/content/2006/1/pdb.rec8190.full?text_only=true

Hi there,

In complement I would say that it is important to leave the room in your YEP solution for sugar addition. For instance for 1L of YEPD, prepare 900mL containing 10g YE and 20g peptone and to reconstitue YEPD add 100mL of 20% glucose solution (or other 20% sugar stock).

to be 100% sure that there is no carbohydrate in the medium I would NOT USE YPD. There might be something (although in low amounts) in peptone and yeast extract. WI do recommend to use chemically defined minimal medium, such as Yeast Nitrogen Base, which is available from various suppliers.

Deberia activar las cepas de levadura con diferentes medios conteniendo azucares complejos y otros nutrientes y ver los cambios que se dan en cuanto a la supevivencia de la cepa a diferentes condiciones

If you want to starve yeast of sugars (or any nutrient, for the matter), you really cannot use complex media as YPD or NB. You have to find a recipe of minimal medium like these:

Article A synthetic medium for Saccharomyces cerevisiae

Article In Saccharomyces cerevisiae grown in synthetic minimal mediu...

https://www.formedium.com/technical-data/saccharomyces-cerevisiae-synthetic-minimal-media-technical-data/