Dextrose Tryptone Agar

Dextrose Tryptone Agar (7340)

Intended Use

Dextrose Tryptone Agar is formulated for the isolation and enumeration of mesophilic and thermophilic spoilage microorganisms in food products. This media plays a crucial role in food safety and quality control.

Product Summary and Explanation

Dextrose Tryptone Agar has its origins in pioneering research conducted by Williams, aimed at the cultivation and quantification of thermophilic bacteria responsible for "flat-sour" spoilage in canned goods. In the 1930s, the National Canners Association specifically recommended this agar for isolation of "flat sour" organisms from various food products.

The condition of "flat sour" spoilage, which occurs due to the action of Bacillus coagulans (also known as Bacillus thermoacidurans), results in a pH drop of 0.3 to 0.5 while the can ends remain flat, indicating microbial activity without visible signs. B. coagulans is commonly found in soil, particularly in canned tomato and dairy products. When conditions are favorable for their growth, these organisms can lead to significant spoilage of food items.

Furthermore, Dextrose Tryptone Agar is effective for isolating additional food spoilage bacteria, encompassing mesophilic, aerobic spore-formers, and thermophilic "flat sour" spore-formers like Bacillus stearothermophilus. This versatility makes it an essential tool for microbiological laboratories engaged in food analysis and safety assessment.