Application of flow cytometry to wine microorganisms

Flow cytometry (FCM) is a powerful technique allowing detection and enumeration of microbial populations in food and during food process. Thanks to the fluorescent dyes used and specific probes, FCM provides information about cell physiological state and allows enumeration of a microorganism in a mixed culture. Thus, this technique is increasingly used to quantify pathogen, spoilage microorganisms and microorganisms of interest. Since one decade, FCM applications to the wine field increase greatly to determine population and physiological state of microorganisms performing alcoholic and malolactic fermentations. We will describe FCM principles and the available techniques allowing quantification of wine microorganisms by FCM using fluorescent dyes. Different examples of FCM analysis regarding monitoring of alcoholic fermentation, malolactic fermentation (total population, viable population, physiological state), specific detection and quantification of spoilage microorganisms like Brettanomyces will be presented.