Method for the production of sorbitol and gluconate

A method for the simultaneous production of sorbitol and either gluconolactone or gluconate from glucose and fructose. To this end to produce sorbitol and gluconolactone, glucose and fructose are reacted in the presence of a cell or cell-free extract of a bacteria, which contains the enzyme complex glucose/fructose transhydrogenase including the tightly bound co-factor(s), under condition whereby the further metabolism of gluconolactone is substantially prevented. In order to produce sorbitol and gluconate glucose and fructose are reacted in the presence of a cell or cell-free extract of a bacteria which contains an enzyme system comprising the enzyme complex glucose/fructose transhydrogenase including the tightly bound co-factor(s) and the enzyme gluconolactonase. This reaction is carried out under conditions whereby the metabolism of gluconate is substantially prevented. Preferably the bacteria used in this process is of the genus Zymomonas and most preferably of the species Zymomonas mobilis. The enzyme complex referred to as glucose/fructose transhydrogenase including the tightly bound co-factor(s) has been isolated in its pure form.