Research on heterologous expression of D-psicose-3-epimerase in Pichia pastoris

Abstract

D-allulose, a low-calorie and high-sweetness functional rare sugar, is regarded as an ideal alternative to traditional sweeteners in the health food industry due to its physiological benefits, such as regulating blood glucose metabolism and inhibiting fat accumulation. The industrial-scale production of D-allulose relies on the efficient expression of D-allulose 3-epimerase (DAEase). However, traditional prokaryotic expression systems (e.g., Escherichia coli) face challenges including low secretion efficiency, tendency to form inclusion bodies, and complex purification processes, resulting in high production costs and hindering large-scale applications. To address these limitations, this study targeted the DAEase gene derived from Ruminococcus sp. and employed the eukaryotic secretory expression system of Pichia pastoris to successfully construct a recombinant strain capable of high-efficiency secretion of DAEase. This research not only provides a high-efficiency and low-cost enzymatic solution for the scalable production of D-allulose but also demonstrates the application potential of the Pichia pastoris system in the secretory production of food-grade enzymes, thereby offering new possibilities for the green biomanufacturing of industrial enzyme preparations in the food sector.