Introduction

Diagram of a typical yeast cell

Figure 1.A Typical Yeast Cell

Yeasts are eukaryotic microorganisms whose genomes have been comprehensively studied and some have been sequenced. They are relatively easy to grow under laboratory conditions. Moreover, despite their small genome size, they display cellular features and processes that are highly conserved amongst most eukaryotes. For instance, they have membrane-bound organelles, cytoskeleton, nuclear DNA, and transcription mechanisms that are similar to those found in higher eukaryotes. Furthermore, yeasts have many well-characterized secretory proteins and pheromones. Several yeast genes involved in protease processing and secretion have also been identified. Thus, yeasts can be used for several eukaryotic gene and protein studies with the aid of suitable molecular biology tools. Some applications for yeast cultures include synthesis of protein expression systems, the study of specific gene or protein functions, and the analyses of novel protein interactions. They are also used for many industrial applications such as fermentation, baking, and bioremediation.

Yeast culture media play a significant role in supporting growth in both small and large scale purposes. Typically, a yeast culture medium includes peptone, yeast extract, and dextrose or glucose. Even slight differences in media composition can yield yeasts with distinct growth characteristics.

Types of Yeast Media

Diagram showing the classification of complex yeast growth media

Figure 2.Classification of Complex Yeast Growth Media

Diagram showing the classification of synthetic yeast growth media

Figure 3.Classification of Synthetic Yeast Growth Media

The minimal synthetic media can be used with drop-out medium supplements to create selective media for growing auxotrophic yeast cultures.

Furthermore, yeast strains can be sporulated using specific sporulation media. Indicator media can also be used to distinguish yeast strains that either ferment or do not ferment specific sugars, such as galactose or maltose.

Yeast Media Options

We offer a broad range of high-quality yeast culture media to suit your unique research needs. They are listed as follows:

1. YPD medium
A nutritious medium available in liquid (broth) or solid (agar) forms for the growth and propagation of yeast cultures. It primarily contains of bacteriological peptone, yeast extract, and glucose. This medium is non-selective for Candida, Pichia, Saccharomyces, and Zygosaccharomyces.

2. Yeast Synthetic Drop-out Medium Supplements
The selection of plasmids in yeast is usually based on the use of auxotrophic mutant strains, which cannot grow without a specific medium component (like an amino acid, purine, or pyrimidine). Transformation with a plasmid containing the mutated gene enables the transformant to grow on a medium lacking the required component. Thus, drop-out medium supplements can be used to select transformed yeast cultures.
Please refer to the selection guide below for further details.

3. Yeast Nitrogen Base (YNB with or without amino acids)
Yeast Nitrogen Base is a highly-referenced growth medium used for the cultivation of yeast. This nutrient-rich microbial medium contains nitrogen, vitamins, trace elements, and salts. It is suitable for use in classifying yeasts based on amino acid and carbon requirements. With an added carbon source, YNB with amino acids can be used for susceptibility testing of fungi.

4. EnPressoTM Y Defined Growth System is a proprietary formulation of buffering salts, amino acids, carbon source and polysaccharides. The formulation is designed to yield at least 2x more protein compared to traditional culture media.

Yeast Culture Media Selection Guide

Table 1.YPD & YNB Media
Table 2.Synthetic Drop-Out Medium Supplements
Note: The following mixtures of amino acids and other nutrients need to be added to Yeast Nitrogen Base Without Amino Acids (Catalog Number Y0626).
Table 3.Other Supplements for Yeast Cultures

Synthetic Media Growth Test Results

+ = growth observed; – = no growth observed

Materials
Loading

References

1.
Atlas RM, Atlas RM. Handbook of Microbiological Media. http://dx.doi.org/10.1201/9781420039726
2.
Sherman F. 2002. Getting started with yeast.3-41. http://dx.doi.org/10.1016/s0076-6879(02)50954-x
3.
Kaiser C, Michaelis S, Mitchel A. Methods in Yeast Genetics, a Cold Spring Harbor Laboratory Manual (Cold Spring Harbor, NY: 1994)..