Dextrose Tryptone Agar (AS-1199) | Flat-Sour Thermophile Enumeration

$87.00 AUD

AuSaMicS Life Science • Industrial Food Safety

Dextrose Tryptone Agar (DTA)

Enumeration of "Flat-Sour" Spoilage Thermophiles

The industry standard for the detection and quantification of acid-producing thermophilic bacteria (such as Bacillus coagulans) in low-acid canned foods and ingredients.

AS-1199 🥫 NCA / APHA Compliant ✓ Aciduric Recovery 🔥 High Temp Stable

Application: Pour-Plate / Streak Indicator: Bromocresol Purple Incubation: 55°C

Analytical Superiority

Clear Contrast - Yellow halos against purple agar

Robust Growth - High tryptone nitrogen content

Industry Standard - Used for sugar & starch testing

Stability - Minimal drift during long incubation

Optimal Result

Yellow colonies (Acid +)

🔬 Principles of Identification

Dextrose Tryptone Agar was developed by Williams for the cultivation of "flat-sour" thermophiles. These organisms ferment dextrose to produce acid, but significantly, do not produce gas. The acidic metabolic by-products cause the Bromocresol Purple indicator to transition from its neutral purple state to a distinct yellow, allowing for immediate colony counts in QC protocols.

🧪 Nutrient Formulation

Ingredient	Concentration	Function
Tryptone	10.0 g	Primary Nitrogen & Tryptophan Source
Dextrose (Glucose)	5.0 g	Fermentable Carbohydrate
Bromocresol Purple	0.04 g	pH Sensitivity Indicator
Bacteriological Agar	15.0 g	Solidifying Agent

📋 Technical Specs

Cat Number	AS-1199
Final pH	6.7 ± 0.2
Yield	30.04g / L
Prepared Color	Purple

⚗️ Laboratory Prep

1 Suspend 30.04g in 1L distilled water.
2 Heat to boiling to dissolve completely.
3 Autoclave at 121°C for 15 minutes.
4 For thermophiles, incubate at 55°C for 48-72h.