Lactobionic acid production by glucose–fructose oxidoreductase from Zymomonas mobilis expressed in Escherichia coli

OBJECTIVES: To use the glucose–fructose oxidoreductase (GFOR) from Zymomonas mobilis and expressed in Escherichia coli for lactobionic acid production by conversion of lactose from whey. RESULTS: The highest concentrations of lactobionic acid (3.2 mg ml(−1)) during oxidation of whey-derived lactose by E. coli was at 24 h. Introduction of GFOR gene from Z. mobilis, into E. coli improved enzyme yields compared to what is obtainable by fermentation of the donor strain. The production of lactobionic acid by E. coli was 2.6-times higher than by Z. mobilis. CONCLUSIONS: Recombinants of E. coli overexpressing the GFOR gene from Z. mobilis produced higher amount of lactobionoic acid from whey-derived lactose.