Yeasts are unicellular eukaryotes and extensively studied model organism in molecular genetics.
They are chemoorganotrophs as they utilize organic compounds as a source of energy.
Yeast extract peptone dextrose (YPD or YEPD) Growth Agar is used for the maintenance and propagation of yeasts including S. cerevisiae in various molecular microbiology procedures.
YPD functions as a complete medium for yeast growth.
Table of Contents
Composition of YEPD Agar
Ingredients
Gms/liter
Peptone
20.000
Yeast extract
10.000
Dextrose
20.000
Agar
15.000
Final pH (at 25°C): 6.5±0.2
Principle of YEPD Agar
YEPD consists of yeast extract, peptone, and glucose or dextrose.
Yeasts grow well on a minimal medium containing only dextrose and salts.
The addition of protein and yeast cell extract hydrolysates allows faster growth so that during exponential or log-phase growth.
Yeast extract supplies B-complex vitamins and it contains all the amino acids necessary for growth.
Peptone acts as the source of nitrogen, vitamins, and minerals.
Dextrose serves as the carbon source.
This medium supports the vigorous growth of wild type as well as mutant strains of all kinds of budding yeast.
Preparation of YEPD Agar
Suspend 65 grams of the powder in 1 liter of purified water.
Mix thoroughly.
Heat the agar medium with frequent agitation and boil for 1 minute to completely dissolve the powder.
Autoclave the agar and broth media at 121°C for 15 minutes.
YEPD is used as a growth medium to grow yeast cultures.
It is used for the growth of Saccharomyces cerevisiae.
This medium supports the growth of most heterotrophic microorganisms but due to their simple composition, they have been adopted as the basal media for the routine cultivation of yeasts.
It is used for preparing culture media in molecular microbiology procedures.
Limitations of YEPD Agar
It is a non-selective medium.
By being a complete medium, YEPD cannot be used as a selection medium to test for auxotrophs.
Sagar Aryal is a microbiologist and a scientific blogger. He is currently doing his Ph.D. from the Central Department of Microbiology, Tribhuvan University in collaboration with Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Saarbrucken, Germany. He did his M.Sc. in Microbiology and B.Sc. in Microbiology from St. Xavier’s College, Kathmandu, Nepal. He worked as a Lecturer at St. Xavier’s College, Maitighar, Kathmandu, Nepal, from March 2017 to June 2019. He is interested in research on actinobacteria, myxobacteria, and natural products. He has published more than 15 research articles and book chapters in international journals and well-renowned publishers.
