alpha-d-Galactose 1-phosphate (alpha Gal1P) is an important building block for the synthesis of nucleotide sugars that are substrates for glycosyltransferases. We have previously reported the creation of novel lactose phosphorylase enzymes that are useful for the synthesis of alpha Gal1P from the cheap and abundant lactose. Here we describe the application of such a lactose phosphorylase in a production system using permeabilized Escherichia coli cells. After purification of the product from the reaction mixture by anion-exchange chromatography and ethanol precipitation, 9.5 grams of highly pure alpha Gal1P were obtained from a 1 l reaction volume.