High-level production of patatin in Pichia pastoris and characterization of N-glycosylation modification in food processing properties.

Patatin is an acidic protein found in potatoes that is commonly used in food and pharmaceutical industries due to its excellent emulsifying and gelation abilities. Pichia pastoris is widely used as a host for recombinant protein production because it can incorporate post-translational modifications. In this study, a patatin titre of 2189.8 mg/L was achieved in a 5 L bioreactor using P. pastoris GS115 with signal peptide mutation, dual promoter construction, co-expression of chaperone proteins and optimised fermentation. To enhance the application of recombinant patatin in the food processing field, the level of N-glycosylation was elevated by genetic engineering. Properties of natural patatin, recombinant patatin and patatin^L109T (N-glycosylated modified patatin) were investigated including foaming, hydrophobicity and emulsifying abilities. The functional properties of recombinant patatin were enhanced by introducing N-glycosylation, which also improved the water-holding capacity of its gel. The patatin^L109T gel exhibited superior elasticity and water retention properties. The findings provide valuable insight and serve as a reference for the utilisation of recombinant patatin. The established enhancement strategy could be applied to other recombinant proteins.