Abstract:N-acetylneuraminic acid has various biological functions and has important applications in food additives and pharmaceutical synthesis, etc. In order to reduce its production cost, in this study, N-acetylneuraminic acid was produced by recombinant Escherichia coli whole cells using the fermentation broth containing N-acetylglucosamine as the substrate. The catalytic conditions of N-acetylneuraminic acid production were optimized. The optimum result was achieved at 30 ℃ (the reaction temperature), initial pH 6.5, 1.38 mol/L pyruvate, 0.4% Triton X-100 added, and OD600 30, the highest yield of N-acetylneuraminic acid reached 180 mmol/L, and the molar conversion rate was 65.45% in 5 L fermentor. N-acetylneuraminic acid produced was separated and purified using anion resin. It was confirmed by high performance liquid chromatography that the sample was high purity N-acetylneuraminic acid. Its purity reached 98.3%, and the recovery rate of crystallization was 42.5%. A method about N-acetylneuraminic acid produced from fermentation broth with N-acetylglucosamine using recombinant E. coli whole cells biotransformation was built and optimized, which not only saves costs but also has the advantage of sustainable development.
