Effects of Co-Expression of HAC1 on Glucose Oxidase Production in Recombinant Pichia pastoris

Abstract:

In this work，the enhancement of unfolded protein response transcription pathway at different cultivation temperatures were integrated as a novel protein secretion strategy to improve extracellular enzyme concentration and specific productivity of heterologous glucose oxidase （GOD） in Pichia pastoris. Efficient production of heterologous proteins in P. pastoris was often limited by metabolic and intrinsic stresses such as folding rate and ER stress by accumulation of unfolded protein. The results showed that enzymatic activity of engineered secretion strain PP-G-HAC1，co-expression of UPR activating transcription factor Hac1p from P. pastoris，was up 161 U/mL in shake flasks， 34% higher compared to control strain. Furthermore，the effects of different cultivation temperatures （22、28 ℃） were also investigated. The highest GOD activity and extracellular concentration at 28 ℃ in PP-G-HAC1 were 1，008 U/mL and 14.43 g/L，respectively，3.12-fold increase than that of control strain.