Construction of a dual-enzyme co-display and assembly system in Saccharomyces cerevisiae spores and its applications for L-ribose production

Saccharomyces cerevisiae spores have emerged as a novel surface display host and have been successfully applied in the biosynthesis of useful products. To construct a dual-enzyme co-display and assembly system on the surface of S. cerevisiae spores, the fluorescent proteins were initially used as the model proteins to prove the feasibility. The result of the in vitro assembly experiment of L-arabinose isomerase from Bacillus coagulans ( Bc AI) and mannose-6-phosphate isomerase from Geobacillus thermodenitrificans ( Gt MPI) confirmed that the assembled complex could significantly improve the biosynthetic efficiency of the rare sugar L-ribose. Subsequently, Bc AI and Gt MPI were co-displayed on the spore surface and further assembled via the SpyTag/SpyCatcher system to realize the biosynthesis of L-ribose. The maximum conversion rate of L-ribose reached approximately 16% with 10 g/L L-arabinose as the substrate. Nevertheless, the achieved L-ribose conversion rate of 16% is moderate compared with previously reported values. Even with this limitation, this study establishes a feasible spore-surface assembly strategy for multi-enzyme cascades, laying a technical foundation for the biosynthesis of high-value products.