Hach, 2924050, Preservative Resistant Yeast Media, Plastic Ampules, 50/pk

PRY (Preservative Resistant Yeast Broth) is a membrane filtration medium with a low pH, selective for detection of spoilage microorganisms resistant to acetic acid. PRY medium is used for the detection of preservative resistant yeast in beverages such as beer, bottled water, cider, soft drinks, sport drinks, and wine. It is selective for Zygosaccharomyces species. The medium prevents growth of other yeasts such as Saccharomyces cerevisiae that are tolerant to lower levels of commonly used food preservatives. Spoilage resulting from growth of the yeast Zygosaccharomyces is widespread and causes significant economic losses to the food industry.
Within this genus, Z. bailii is one of the most troublesome species because it is very tolerant to various stressful conditions. Z. lentus is another preservative-resistant spoilage yeast, capable of growth at low temperature. Colonies of preservative-resistant yeasts are typically described as being
yellow
in appearance, and yellow color indicates the presence of preservative-resistant yeasts. (Variations in colony morphology can occur due to factors like incubation conditions or slight differences within the same species). Incubation is 3-5 days at 30 °C