Pichia pastoris is a methylotrophic yeast belonging to the class Ascomycetes. Found in the 1960s, its main characteristic is to use methanol as a carbon and energy source. After years of study, P. pastoris has become a model organism for genetic study, being important in the field of biological and biotechnological research.

Pichia pastoris is a yeast currently widely used as an expression system for the production of recombinant proteins, both for basic research and industrial purposes, due to its easy genetic manipulation, high levels of intra- and extracellular production of the protein of interest, the ability to perform post-translational modifications similar to those of higher eukaryotic organisms (glycosylation, disulfide bridges and proteolytic processing) that generate a correct folding of the protein, and in the case of extracellular expression, the simple steps of concentration and purification of the recombinant protein.

This expression system uses integration vectors that generate gene stability even in large-scale processes. Cultures are performed with simple and inexpensive minimal media and are scalable. The parameters that influence the productivity and activity of the recombinant protein are easily controlled. Proteins that are difficult to produce in other expression systems have been successfully produced in P. pastoris.

All this makes P. pastoris a system of choice for recombinant protein production.