DYNAMICS OF YEAST-CELL STATES DURING PROLIFERATION AND NON PROLIFERATION PERIODS IN A BREWING REACTOR MONITORED BY MULTIDIMENSIONAL FLOW-CYTOMETRY

Current demands of the brewing industry require that increasing amount s of beer be produced in ever-decreasing times, without prejudicing th e quality of the product. The four basic ingredients for brewing beer are malt, hops, water and yeast. Of these four materials, yeast is uni que, in that its competent handling can reduce the time taken for the brewing process. For this purpose, it is necessary to have information regarding the metabolic acting as well as the physiological state of an individual cell for which flow cytometry is used. Knowledge of chan ges in DNA, neutral lipid and SP-hydroxysterol content of the yeast ce lls during growth, fermentation and storage enables for a time-saving process control. All of these parameters were conveniently monitored b y flow cytometry in conjunction with double fluorescent staining techn iques, as shown in this study.