The present invention provides a modified Saccharomyces yeast which produces significantly lower levels of ethanol than wild-type yeast under aerobic conditions and saccharide concentrations of 2% glucose, and which exhibits a growth rate of at least 30% of the wild-type yeast, preferably containing a chimeric construct of at least 2 saccharide transporters, nucleic acid molecules encoding the chimeras and polypeptides encoded by such sequences, and methods of using the modified yeast for preparing products in the yeast.