Pichia pastoris Lab Scale Fermentation

Pichia pastoris is recognized as an excellent expression system for heterologous protein production. Advantages of this expression host are, among others, the availability of strong and tightly regulated promoters, such as PAOX1, allowing the use of methanol as sole carbon source as well as inducer for recombinant protein production, and enabling the heterologous production of proteins up to several grams per liter, growth to high cell densities in mineral medium in fed-batch cultivation, the possibility to target proteins for secretion and the low amount of secreted endogenous proteins. P. pastoris has two alcohol oxidase encoding genes (AOX1 and AOX2), and three different phenotypes of P. pastoris host strains are available, according to their ability to metabolize methanol: the wild type (Mut+) and those resulting from deletions of AOX1 gene, (Muts) or both genes (Mut–).