Ayerim Hernández-Almanza*, Gloria A. Martínez-Medina, and Cristóbal N. Aguilar
Yeasts play an important role in biotechnology; they have been employed in alcoholic beverages and fermented foods production for thousands of years. Nowadays, yeasts are not only used to produce fermented foods but also have an increasing importance in pharmaceuticals, pigments, oils, enzymes, renewable biofuels, and recombinant proteins production as well as having been widely used in biosorption and biocontrol processes. Saccharomyces cerevisiae is the principal driver in many industrial fermentation processes, such as brewing and bread product production. On the other hand, yeasts of the genus of Phaffia and Rhodotorula sp. have been employed to produce carotenoid pigments, with the aim of a specific production of this type of pigments. Also, oleaginous yeasts such as Rhodosporidium sp. and Rhodotorula sp. are lipid-producing microorganisms; Yarrowia lipolytica is an emergent microorganism employed in renewable biofuels production due to its high capacity to produce lipids. Pichia pastoris has been used in obtaining proteins, especially in the enzymes sector and biopharmaceutical industry. Pichia pastoris is a “generally recognized as safe” (GRAS) microorganism employed for producing around 500 pharmaceutical proteins and 1,000 recombinant proteins. Some yeasts have been genetically modified to improve or increase production yields. The selection and artificial breeding of wild species is directed to obtain new variants of strains with desirable characteristics. However, the study of new technology to purify and to recovery and the applications of the biocompounds that are obtained by these catalysts is still under development. In this chapter, we describe the emergent importance of yeasts in microbial processes, such as food, pharmaceutical, and biofuels industries, and we list the perspectives and challenges in microbial technologies of some yeasts.