Assessment of brewing yeast age based on selective bud scar staining and subsequent fluorescence measurement by flow cytometry

Abstract

To study the yeast cell aging in continuous beer fermentation processes has a considerable practical significance. Hence, an expeditious method of yeast age estimation was developed based on selective bud scar staining and subsequent fluorescence intensity measurement by flow cytometry. The calibration curve resulting from cytometric determination of average bud scar fluorescence intensities of cell populations with different average bud scar numbers showed a good correlation. The combination of flow cytometry with bud scar staining resulted in a method of rapid cell age estimation particularly suitable for continuous main fermentation systems with elevated risk of immobilized cell aging.