Methanol oxidase from Hansenula polymorpha shows activity in peroxisome-deficient Pichia pastoris

Abstract

Pichia pastoris can upgrade the methanol into various of high-valued biochemical products. This biosynthetic method was achieved mostly based on inherent methanol metabolism pathway of yeast. The alcohol oxidase (AOX) from Pichia pastoris plays a crucial role in methanol metabolism pathway. However, when the cells are exposed to excess methanol, the disruption of the peroxisome and inhibition of AOX enzyme activity happens. In our study，the strain Δpex3 derived from P. pastoris GS115 was constructed as initial genetic engineering strain to simulate the damage of the peroxisome which was often happened under high concentrations of methanol. No AOX activity was detected in Δpex3 with peroxisome defected. Subsequently, the methanol oxidase (MOX) from Hansenula polymorpha was employed to make up for activity loss of AOX. Introduction of MOX in the peroxisome-deficient strain Δpex3, thus new recombinant strain was obtained which named as Δpex3-MOX. Δpex3-MOX showed certain activity of alcohol oxidase, and the harvest biomass was higher compared to Δpex3. The ability of utilizing and toleration higher methanol was partially improved when methanol oxidase (MOX) from H. polymorpha was introduced compared to cells with peroxisome defected.