MORPHOLOGICAL CHARACTERIZATION OF YEAST BY IMAGE-ANALYSIS

A semiautomatic image analysis method, with minimal operator intervent ion, has been developed to characterize the morphology of yeast cells under the assumption that they have an ellipsoidic shape. The cells ar e observed by optical microscopy and the surface and the minor and maj or half-axes of the projection of the ellipsoid on the image plane are determined. Using this method, yeast size distributions and populatio n kinetics (single and budding cells, cell clusters) are determined du ring alcoholic fermentations. Combination of image analysis with a met hylene blue viability test is examined but the staining procedure indu ces a change in the size of the cells. (C) 1993 John Wiley & Sons, Inc .