Yeasts are a type of eukaryotic unicellular microfungi that are found abundantly in nature. They do not belong to any single phylogenetic or taxonomic group. Yeasts are used primarily in the production of alcoholic beverages and in baking. Saccharomyces cerevisiae is a species of yeast, which is widely utilized in the food industry. It is an extensively studied eukaryotic microorganism and serves as a key model organism in contemporary cell biology research. It has the capability to reproduce sexually by fusing with the cells of opposite mating types and asexually by budding. It is also known as baker's yeast, and has facilitated the invention of effective manufacturing techniques for biopharmaceuticals, ethanol, antibiotics, biofuels, and technical enzymes. This book contains some path-breaking studies on yeast. It explores all the important biotechnological applications of yeast in the present day scenario. This book will serve as a reference to a broad spectrum of readers.