A metabolically engineered E. coli strain which produces sialic acid and a method of making said strain. In the engineered E. coli cells, the nanT (sialic acid transporter) and nanA (sialic acid adolase) genes are inactivated, and the neuC and neuB genes of sialic acid biosynthesis in Neisseria meningitidis group B are introduced and overexpressed in the nanT− nanA− E. coli cell. In addition, the glucosamine synthase gene, glmS, of E. coli is co-overexpressed with neuB and neuC.