Advanced enzymatic multigram-scale production of nucleotide sugars in a continuous fed-batch membrane reactor

Abstract

Enzymatic production of nucleotide sugars on a multigram scale presents a challenge, as only a few processes have been reported for large-scale nucleotide sugar production. They rely primarily on batch synthesis and employ exceptional amounts of enzymes. This study introduces a novel approach for the multigram-scale production of nucleotide sugars with a continuous fed-batch membrane reactor. We successfully synthesized five main nucleotide sugars: UDP-Gal, UDP-GalNAc, UDP-GlcA, GDP-Man, and CMP-Neu5Ac on a multigram scale. Efficient biocatalyst utilization results in high performance, including space-time yield (STY, g*L⁻¹h⁻¹), total turnover number (TTN, g product per g enzyme), and an efficient product formation rate (g/h) suitable for industrially relevant bioprocesses. The established continuous-fed batch reactor system produced up to 8.2 g CMP-Neu5Ac in three consecutive productions in less than 15 h with satisfying TTNs of 91 g_Product/g_Enzyme. Continuous production of UDP-GlcA over 28 h resulted in a final product amount of 14.8 g and TTN of 493 g_P/g_E. This process enables the production of nucleotide sugars with stable product formation, requiring minimal technical equipment for multigram quantities of nucleotide sugars at the laboratory scale. Notably, the system exhibited robustness and flexibility, allowing its application to various enzymatic nucleotide sugar synthesis cascades.