초록
<P><SMALL>D</SMALL>-Allulose, a C-3 epimer of <SMALL>D</SMALL>-fructose, has great market potential in food, healthcare, and medicine due to its excellent biochemical and physiological properties. Microbial fermentation for <SMALL>D</SMALL>-allulose production is being developed, which contributes to cost savings and environmental protection. A novel metabolic pathway for the biosynthesis of <SMALL>D</SMALL>-allulose from a <SMALL>D</SMALL>-xylose-methanol mixture has shown potential for industrial application. In this study, an artificial antisense RNA (asRNA) was introduced into engineered <I>Escherichia coli</I> to diminish the flow of pentose phosphate (PP) pathway, while the UDP-glucose-4-epimerase (GalE) was knocked out to prevent the synthesis of byproducts. As a result, the <SMALL>D</SMALL>-allulose yield on <SMALL>D</SMALL>-xylose was increased by 35.1%. Then, we designed a <SMALL>D</SMALL>-xylose-sensitive translation control system to regulate the expression of the formaldehyde detoxification operon (FrmRAB), achieving self-inductive detoxification by cells. Finally, fed-batch fermentation was carried out to improve the productivity of the cell factory. The <SMALL>D</SMALL>-allulose titer reached 98.6 mM, with a yield of 0.615 mM/mM on <SMALL>D</SMALL>-xylose and a productivity of 0.969 mM/h.</P><BR>[FIG OMISSION]</BR>