Measuring Glycogen, Neutral Lipid, and Trehalose Contents in Yeast Using Fluorescence-Based Image Cytometry

Leo Li-Ying Chan, Alexandria Kury, Alisha Wilkinson, Charlotte Berkes, and Alnoor Pirani. Nexcelom Bioscience LLC, Lawrence, MA, U.S.A.
The brewing, baking, and biofuel industries have long been involved with monitoring the physiological and metabolic changes of Saccharomyces cerevisiae. Breweries in particular need to observe cell health parameters such as viability, vitality, and contents of glycogen, neutral lipid, and trehalose to assess yeast cells over the course of fermentation. These physiological and metabolic variations can be qualitatively maintained via fluorescence microscopy or quantitatively evaluated via flow cytometry, using fluorescently labeled cellular markers. Conventional microscopes provide no automation for large volumes of cells, however, and although flow cytometry is capable of analyzing tens of thousands of cells, the instruments require much in the way of cost, maintenance, and training to operate. Here, we demonstrate the use of the Cellometer Vision image cytometer for the kinetic imaging and analysis of yeast cell vitality and glycogen, neutral lipid, and trehalose contents. This cytometer offers a new way for breweries of any size to monitor these characteristics throughout fermentation to produce products that are invariable and of optimal quality.

Keywords: Image cytometry, Viability, Vitality, Glycogen, Neutral lipid, Trehalose