Production of N-Acetylneuraminic Acid from Fermentation Broth Using Recombinant Escherichia coli Whole Cells Biotransformation
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.