d-Mannitol formation from d-glucose in a whole-cell biotransformation with recombinant Escherichia coli

Recently, we reported on the construction of a whole-cell biotransformation system in Escherichia coli for the production of d-mannitol from d-fructose (Kaup B, Bringer-Meyer S, Sahm H (2004) Metabolic engineering of Escherichia coli: construction of an efficient biocatalyst for d-mannitol formation in a whole-cell biotransformation. Appl Microbiol Biotechnol 64:333–339). Supplementation of this strain with extracellular glucose isomerase resulted in the formation of 800 mM d-mannitol from 1,000 mM d-glucose. Co-expression of the xylA gene of E. coli in the biotransformation strain resulted in a d-mannitol concentration of 420 mM from 1,000 mM d-glucose. This is the first example of conversion of d-glucose to d-mannitol with direct coupling of a glucose isomerase to the biotransformation system.