Comparative Expression Levels of Methylotrophic Yeast Strains of Pichia Pastoris

Expression Level of Diverse Phenotypes of Pichia pastoris

Abstract

This investigation compared the expression levels of diverse phenotypes of Pichia pastoris GS115, X-33 and KM71H in various nutrient media, including BMMY, BMMH, MMY and MMH. The MMY nutrient media demonstrated a higher expression level of HBsAg protein compared to the other minimal media. Mut+ was chosen as an acceptable phenotype because of its high growth density and  relatively short expression period of recombinant HBsAg protein. Furthermore, the X-33 yeast strain showed a greater growth rate than the GS115 and KM71H yeast strains, leading to higher levels of expression of the HBsAg protein. In conclusion, BMMY and BMM media are considered to be suitable for HBsAg protein expression, since the expression levels of the protein in both media are nearly identical.