Abstract N-Acetyl-D-neuraminic acid (Neu5Ac) was efficiently synthesized from lactate and a mixture of N-acetyl-D-glucosamine (GlcNAc) and N-acetyl-D-mannosamine (ManNAc) by whole cells. The biotransformation utilized Escherichia coli cells (Neu5Ac aldolase), Pseudomonas stutzeri cells (lactate oxidase components), GlcNAc/ManNAc and lactate. By this process, 18.32±0.56 g/liter Neu5Ac were obtained from 65.61±2.70 g/liter lactate as ...