Some Considerations When Analyzing Foods for the Presence of Xerophilic Fungi

Foodborne fungi capable of growing at reduced water activity (a_w) are described as xerophilic. Some xerophilic fungi will not grow or grow very slowly at a_w values characteristic of media traditionally used to enumerate yeasts and molds in foods. Populations of xerophiles may therefore be underestimated or go undetected. A brief review of the habitats and physiology of xerophiles, followed by a description of media and methods available for detection, enumeration, and a key for identification are presented.