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Readily fermentable carbon & energy source; activates yeast PKA/TORC1 growth signalling
Full B-vitamin pool, nucleotide precursors & all amino acids — satisfies all auxotrophic requirements
Enzymatic protein hydrolysate for nitrogen; agar as solidifying agent for stable colony surfaces
Glucose Yeast Extract Peptone (GYEP) Agar | Nutrient‑Rich Medium for Microbial Cultivation | AS‑1242
Glucose Yeast Extract Peptone (GYEP) Agar | Nutrient‑Rich Medium for Microbial Cultivation | AS‑1242
$29.00 AUD
AuSaMicS Life Science • General Purpose & Yeast Media
Glucose Yeast Extract Peptone (GYEP) Agar
YPD / YEPD Agar — Complete Non-Selective Solid Medium
The gold-standard solid medium for yeast colony isolation, morphological assessment, and strain maintenance. Solid-format companion to GYEP Broth (AS-1243) — providing a stable agar surface for discrete colony formation, replica plating, transformation recovery plating, and enumeration of osmotolerant food spoilage yeasts.
AS-1242
pH 6.5 ± 0.2
✓ Australian Stock
🍄 Yeast & Fungi
🧬 Molecular Biology
🍽️ Food Spoilage
🚀 Same-Day Dispatch: Melbourne Stock
🧫 Complete Medium: Supports wild-type & auxotrophs
🔗 Companion to: GYEP Broth AS-1243
🏆 Complete Yeast Solid Medium
🍄 Colony Isolation — Discrete individual colonies
🔁 Replica Plating — Yeast genetics workflows
🧬 Transformation Recovery — Post-transformation plating
🍽️ Food Safety — Osmotolerant yeast CFU counts
📋 Full Documentation — COA + SDS + TDS
YPD / YEPD Agar Equivalent
Industry-standard solid yeast medium — Australian supply, same-week dispatch
🔬 Technical Overview & Biochemistry
GYEP Agar is the solid-format of the universally adopted YPD (Yeast Extract Peptone Dextrose) medium — the gold-standard complete medium for yeast cultivation first codified by Sherman (1991). The addition of bacteriological agar (15–20 g/L) to the GYEP Broth formulation converts a liquid enrichment medium into a rigid, stable surface optimised for discrete colony formation, morphological assessment, replica plating, and plate-based enumeration. The three nutritional components remain biochemically identical to the broth:
🍬
GlucoseReadily fermentable carbon & energy source; activates yeast PKA/TORC1 growth signalling
🌿
Yeast ExtractFull B-vitamin pool, nucleotide precursors & all amino acids — satisfies all auxotrophic requirements
🧬
Peptone + AgarEnzymatic protein hydrolysate for nitrogen; agar as solidifying agent for stable colony surfaces
The critical role of the solid surface: The agar matrix physically restricts cell migration, enabling each colony to develop from a single founder cell (or very small cluster). This spatial separation is indispensable for three core laboratory workflows — (i) isolation of pure cultures from mixed populations, (ii) phenotypic assessment of colony morphology (smooth vs. fluffy, sectoring, colour), and (iii) replica plating to compare growth of the same colonies on different selective and non-selective media simultaneously.
Agar concentration effect: Standard formulation uses 15–20 g/L agar for firm plates ideal for streaking, replica plating, and transformation recovery. Reducing to 6–8 g/L produces soft agar for colony expansion / invasion assays (FLO11-dependent filamentation studies). Increasing to 20–25 g/L produces stiff agar suitable for stab cultures and long-term maintenance.
🔗 GYEP Agar vs GYEP Broth — Choosing the Right Format
💡 Best practice: Use GYEP Broth (AS-1243) for liquid enrichment of osmotolerant yeasts and scale-up liquid culture, then plate onto GYEP Agar (AS-1242) for CFU enumeration, colony isolation, and morphological confirmation.
🧪 Detailed Ingredients Table
⚠️ Maillard Reaction Warning: Autoclaving glucose together with peptone and yeast extract at high temperatures promotes the Maillard reaction between reducing sugars and amino acids, causing browning and slight nutrient degradation. For critical quantitative or morphological studies, autoclave glucose separately (or filter-sterilise) and add aseptically to the cooled base agar at 45–50°C before pouring plates. For routine colony growth, co-autoclaving at 121°C / 15 min is acceptable and will not significantly affect growth performance.
📊 Comparative Solid Yeast & Fungi Media
⚖️ Structured Pros & Cons Analysis
✅ Advantages
- Discrete colony formation — single colonies visible within 24 h at 30°C; suitable for replica plating after 48 h
- True complete medium — supports growth of wild-type and his3, leu2, trp1, ura3 auxotrophic yeast strains without supplementation
- Colony morphology assessment — smooth, fluffy, wrinkled, sectored, and pseudohyphal colony phenotypes are reproducibly observed on GYEP Agar (2% agar / 2% glucose conditions)
- Replica plating substrate — the ideal "master plate" source for velvet-pad transfer to selective SD dropout media for phenotypic screening
- Transformation recovery — GYEP Agar is the standard recovery medium after LiAc/PEG yeast transformation protocols (heat shock recovery before selective plating)
- Osmotolerant yeast plating — after GYEP Broth enrichment, dilutions are plated onto GYEP Agar ± adjusted glucose for quantitative CFU counts of spoilage yeasts
- Broad organism support — also grows heterotrophic bacteria, making it a universal isolation agar for unknown food or environmental isolates
⚠️ Limitations
- Non-selective — cannot be used as an auxotrophic selection plate; all strains including untransformed cells will grow
- Bacterial overgrowth risk — in samples with mixed bacterial/yeast flora, bacteria may outcompete yeasts; add cycloheximide (antibacterial) or chloramphenicol to suppress bacteria if needed
- Maillard browning — co-autoclaving glucose with amino acids causes browning and minor nutrient loss; separate sterilisation recommended for quantitative studies
- Glucose catabolite repression — standard 2% glucose suppresses alternative carbon source utilisation; change carbon source for respiratory metabolism studies
- Not pharmacopoeial — does not fulfil USP/EP sterility testing media requirements; not appropriate for regulated sterility testing workflows
🧬 Applications
🧬 Yeast Genetics & Molecular Biology
The primary solid medium for all yeast genetic manipulation workflows: colony isolation from liquid cultures after transformation, mating and sporulation recovery, tetrad dissection plating (micromanipulator), phenotypic screening plates, and master plates for replica velvet-pad transfer to SD dropout selective media. Supports all S. cerevisiae laboratory strains (BY4741, W303, Σ1278b, CEN.PK) and P. pastoris / K. phaffii GS115/X33.
🍽️ Food Spoilage Yeast Enumeration
Used as the plating medium downstream of GYEP Broth osmotolerant enrichment (30–50% glucose) for quantitative CFU counts of spoilage yeasts from high-sugar food matrices. After enrichment, serial dilutions are plated onto GYEP Agar (pH lowered to 4.5 with tartaric acid to suppress bacteria) and incubated at 25°C for 3–5 days for colony counting. Key targets: Zygosaccharomyces rouxii, Z. bailii, Debaryomyces hansenii, osmotolerant Candida spp.
🔁 Replica Plating & Phenotypic Screening
GYEP Agar is the definitive master plate for replica plating experiments. Colonies grown to the correct size (48 h, 30°C) are transferred by velvet pad to SD dropout media, temperature-sensitive mutant plates, antibiotic plates, or stress-response media. The complete nutrient composition ensures robust, uniform colony sizes that transfer cleanly and reproducibly — essential for large-scale genetic screens.
🧫 Strain Maintenance & Culture Collections
Standard medium for short-to-medium-term culture maintenance. Working cultures are maintained on GYEP Agar slants or plates at 4°C (sealed with Parafilm) for 2–3 months. For longer-term preservation, cells are grown to stationary phase in GYEP Broth and stored in 15–25% glycerol at –70°C to –80°C; GYEP Agar is used for revival plating from frozen stocks.
Additional Specialist Applications:
- Antifungal MIC Testing: Pre-growth plating before inoculum preparation for EUCAST/CLSI broth microdilution MIC panels
- Colony Morphology Studies: FLO11-dependent smooth vs. fluffy colony phenotype assays; biofilm formation studies
- Industrial Yeast QC: Quality control plating of production yeast strains (breweries, bakeries, bioethanol) for viability and contamination monitoring
- Environmental Yeast Isolation: Plating of air, water, and surface samples for general yeast/mould recovery
- Drug/Stress Resistance Screens: Base plate for overlaying with selective drug concentrations (G418, hygromycin, zeocin, caffeine)
- Two-Hybrid Recovery: Post-transformation recovery plating before replica plating to selective two-hybrid dropout media
🔎 Colony Morphology Guide on GYEP Agar
💡 Preparation & Protocol Guidelines
Standard Preparation:
Suspend ~65 g/L in distilled water. Heat to boiling with constant stirring until fully dissolved. Autoclave 121°C / 15 min. Cool to 45–50°C before pouring (25–30 mL per 90 mm plate).
Suspend ~65 g/L in distilled water. Heat to boiling with constant stirring until fully dissolved. Autoclave 121°C / 15 min. Cool to 45–50°C before pouring (25–30 mL per 90 mm plate).
Maillard-Free (recommended for critical work):
Autoclave yeast extract + peptone + agar separately from glucose. Add sterile glucose solution aseptically at 45–50°C before pouring. Prevents browning and toxic by-product formation.
Autoclave yeast extract + peptone + agar separately from glucose. Add sterile glucose solution aseptically at 45–50°C before pouring. Prevents browning and toxic by-product formation.
Osmotolerant Yeast Plating:
Adjust glucose to 30–50% (add separately; filter-sterilise). Acidify to pH 4.5 with tartaric acid after cooling to 50°C to suppress bacteria. Incubate 25°C, 3–5 days.
Adjust glucose to 30–50% (add separately; filter-sterilise). Acidify to pH 4.5 with tartaric acid after cooling to 50°C to suppress bacteria. Incubate 25°C, 3–5 days.
Incubation & Storage:
Standard yeast: 30°C, 24–72 h. Bacteria: 37°C, 18–24 h. Prepared plates: 4°C, sealed with Parafilm, up to 4–8 weeks. Do not freeze prepared plates.
Standard yeast: 30°C, 24–72 h. Bacteria: 37°C, 18–24 h. Prepared plates: 4°C, sealed with Parafilm, up to 4–8 weeks. Do not freeze prepared plates.
📋 Technical Specifications
| Catalogue Number | AS-1242 |
| Common Name | Glucose Yeast Extract Peptone (GYEP) Agar |
| Synonyms | YPD Agar; YEPD Agar; Yeast Extract Peptone Dextrose Agar |
| Companion Broth | GYEP Broth AS-1243 |
| pH (25°C) | 6.5 ± 0.2 |
| Suspension Rate | ~65 g/L (approx. 15 L per kg) |
| Appearance (powder) | Cream to light beige homogeneous free-flowing powder |
| Appearance (prepared) | Off-white to pale amber firm agar; clear with slight opalescence |
| Sterilisation | Autoclave 121°C, 15 min — avoid overheating; do not re-autoclave |
| Pouring Temperature | 45–50°C (pour before gelling, 25–30 mL per 90 mm plate) |
| Incubation (yeast) | 25–30°C, aerobic, 24–72 h |
| Incubation (bacteria) | 35–37°C, aerobic, 18–24 h |
| Storage (powder) | 10–30°C, dry, tightly sealed, away from light |
| Storage (prepared plates) | 4°C, sealed with Parafilm, up to 4–8 weeks |
| Available Sizes | 100 g, 500 g, 5 kg |
🧫 Quality Control Organisms
| Organism | ATCC | Growth | Colony |
|---|---|---|---|
| Saccharomyces cerevisiae | 9763 | ✓✓ Excellent | Cream, smooth, 2–4 mm, convex |
| Candida albicans | 10231 | ✓✓ Excellent | White-cream, smooth, 1–3 mm |
| Aspergillus brasiliensis | 16404 | ✓ Good | Black sporulating, spreading mould |
| Escherichia coli | 25922 | ✓✓ Excellent | Grey-white, smooth, 2–3 mm |
| Staphylococcus aureus | 6538 | ✓✓ Excellent | Yellow-golden, smooth, 1–2 mm |
QC inoculum ≤100 CFU per strain | Yeast & mould: 30°C, 48–72 h, aerobic | Bacteria: 35°C, 24 h, aerobic
🔄 Cross-Reference / Equivalent Products
| Supplier | Product Name | Cat. No. |
|---|---|---|
| Sigma-Aldrich | YPD Agar (Yeast Extract Peptone Dextrose Agar) | Y1500 |
| HiMedia | Yeast Extract Peptone Dextrose Agar | M1593 |
| BD Difco | YPD Agar | 242810 |
| GRiSP / Boca Scientific | YPD Agar (Research Grade) | GCM14 |
AuSaMicS AS-1242 — Australian manufactured, same-week dispatch, no import delays or minimum order constraints
✅ Quality Assurance
- ✓ pH Verified: 6.5 ± 0.2 per lot
- ✓ Growth Promotion: S. cerevisiae ATCC 9763 and C. albicans ATCC 10231 per batch
- ✓ Auxotroph Support: Validated to support his3, leu2, trp1, ura3 mutant yeast strains
- ✓ Agar Gel Strength: Firm plates suitable for replica plating confirmed per lot
- ✓ Sterility: Pre-release sterility check per lot
- ✓ COA Issued: Certificate of Analysis with every order
📚 Key Literature References
- Sherman, F. (1991). Getting started with yeast. Methods in Enzymology, 194, 3–21. — Original YPD standard formulation; the defining reference for GYEP Agar composition.
- Treco, D.A. & Winston, F. (2008). Growth and manipulation of yeast. Current Protocols in Molecular Biology, 82, 13.2.1–13.2.12. — Standard laboratory methods reference for YPD agar preparation and use.
- Granek, J.A. & Magwene, P.M. (2010). Environmental and genetic determinants of colony morphology in yeast. PLoS Genetics, 6(1), e1000823. — Quantitative colony morphology analysis on YPD agar plates.
- Tokuoka, K. (1993). Sugar- and salt-tolerant yeasts. J. Appl. Bacteriol., 74, 101–110. — Reference for high-glucose GYEP Agar applications in osmotolerant yeast recovery from food matrices.
🍄 Complete Yeast, Fungi & Food Spoilage Testing System
Companion Broth, Selective & Differential Media
Confirmation, Differential & Food Safety Media
Need Yeast Cultivation or Food Spoilage Protocol Support?
Our microbiologists can assist with colony morphology interpretation, osmotolerant yeast workflows, S. cerevisiae replica plating protocols, and food spoilage yeast identification strategies
For laboratory, research, and industrial use only. Not for food, feed, household, cosmetic, therapeutic, or personal use.
AuSaMicS Pty Ltd • ABN: 56 676 640 467 • 31 Longview CT, Thomastown, VIC 3074, Australia
Same-day dispatch • Australian stock • Full documentation included