Numerous value-added chemicals can be produced using xylan as a feedstock. However, the product yields are limited by low xylan utilization efficiency, as well as by carbon flux competition between biomass production and biosynthesis. Herein, a dynamic consolidated bioprocessing strategy was developed, which coupled xylan utilization and yield optimization modules. Specifically, we achieved the efficient conversion of xylan to valuable chemicals in a fully consolidated manner by optimizing the expression level of xylanases and xylose transporter in the xylan utilization module. Moreover, a cell density-dependent, and Cre-triggered dynamic system that enabled the dynamic decoupling of biosynthesis and biomass production was constructed in the yield optimization module. The final shake flask-scale titers of xylonate, produced through an exogenous pathway, and shikimate, produced through an endogenous pathway, reached 16.85 and 3.2 g L-1, respectively. This study not only provides an efficient microbial platform for the utilization of xylan, but also opens up the possibility for the large-scale production of high value-added chemicals from renewable feedstocks.
Keywords: Consolidated bioprocessing; Dynamic regulation; Microbial production; Xylan.
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