Pichia: From Supporting Actors to the Leading Roles

Pichia pastoris are heterotrophic yeasts able to use many carbon sources such as glucose, glycerol, and methanol; they are unable, however, to metabolize lactose. Their methylotrophic properties, high yield, efficient post-translational modifications, and secretion of recombinant proteins, alongside a lack of hyperglycosylation, a post-translational process similar to that of mammals, and low maintenance costs for large-scale applications, make this yeast a promising alternative to produce recombinant proteins. The main recombinant products obtained from P. pastoris include vaccines and other biopharmaceuticals, enzymes, proteins, and pigments. Pichia spp. are also used in ethanol production and many other foods such as fermentation of coffee, cocoa, and olives, as well as alcoholic beverages. The use of Pichia yeasts in wastewater treatment and in fungal control of stored grains and fruit has also been reported. This chapter will discuss the environmental diversity of many species of Pichia, especially P. pastoris. Furthermore, the main uses of Pichia spp. in many bioprocesses will also be explored.