ABSTRACT
The nuclei of yeasts are surrounded by an envelope which is characterized by the presence of many pores. Microtubules are important organelles required for the organization of the cytoskeleton. Yeasts are without doubt, both quantitatively and economically the most important groups of microorganisms exploited by man. The total amount of yeast produced annually, including that formed during brewing and distilling practices is in excess of a million tons. Yeast cells have been investigated intensively because of their great importance in practice, but little progress in understanding in yeast cytology has been made with the ordinary light microscope. Vacuoles are important subcellular organelles in yeasts. Both vegetative and reproductive cells contain vacuoles that vary significantly in size. The vacuoles contain a variety of hydrolytic enzymes like proteases and occasionally they contain degrading intracellular substances. Morphology exhibited by a particular yeast is directly associated with its asexual reproduction mechanism.
