A fermentation process for fermenting a starch hydrolysate containing 60-98 weight percent of glucose based on total carbohydrate and 0.3-5% weight percent of isomaltose based on total carbohydrate to a non-ethanol fermentation product is carried out. The method comprises: a) forming a fermentation broth containing the starch hydrolysate and a genetically modified microorganism containing i) an exogenous gene encoding transporter capable of transporting isomaltose ii) an exogenous gene encoding an enzyme capable of converting isomaltose to glucose; and b) fermenting the starch hydrolysate in the fermentation broth to produce a non-ethanol fermentation product. This fermentation process may be carried out as a single step fermentation or a batch process. The genetically modified microorganism may contain an exogenous gene encoding an enzyme that catalyzes the formation of a product other than ethanol.