Repetitive Synthesis of High‐Molecular‐Weight Hyaluronic Acid with Immobilized Enzyme Cascades

Industrial hyaluronic acid (HA) production comprises either fermentation with Streptococcus strains or extraction from rooster combs. The hard‐to‐control product quality is an obstacle to these processes. Enzymatic syntheses of HA were developed to produce high‐molecular‐weight HA with low dispersity. To facilitate enzyme recovery and biocatalyst re‐use, here the immobilization of cascade enzymes onto magnetic beads was used for the synthesis of uridine‐5’‐diphosphate‐α‐d‐N‐acetyl‐glucosamine (UDP‐GlcNAc), UDP‐glucuronic acid (UDP‐GlcA), and HA. The combination of six enzymes in the UDP‐sugar cascades with integrated adenosine‐5'‐triphosphate‐regeneration reached yields between 60 and 100 % for 5 repetitive batches, proving the productivity. Immobilized HA synthase from Pasteurella multocida produced HA in repetitive batches for three days. Combining all seven immobilized enzymes in a one‐pot synthesis, HA production was demonstrated for three days with a HA concentration of up to 0.37 g L(−1), an average M (W) of 2.7–3.6 MDa, and a dispersity of 1.02–1.03.