Quantitative conversion of glucose into glucose 6-phosphate by intact Escherichia coli cells.

The use of intact Escherichia coli cells for the conversion of glucose into glucose 6-phosphate using the Uhp system for transport of the phosphorylated sugar out of the cell was investigated. The strain E. coli DF214, which is not capable of glucose 6-phosphate catabolism via glycolysis or the Entner-Douderoff pathway, was used. The efflux of glucose 6-phosphate was dependent on the presence of UhpT, the hexose-phosphate transporter, plus the presence of the uncoupler carbonyl cyanide m-chlorophenylhydrazone or the ionophore valinomycin. At low glucose concentrations (e.g. 2.5 mM), near-quantitative conversion (> or = 80%) of glucose into extracellular glucose 6-phosphate can be achieved. When cells are incubated for a shorter period of time, complete conversion can occur.