Researchers engineered a xylose isomerase enzyme to convert xylose to xylulose outside yeast cells, improving xylose utilization in bioethanol production. By optimizing the enzyme's pH and enhancing its secretion, they increased xylose consumption and ethanol production in yeast fermentation. This method allows for better utilization of xylose even in the presence of glucose, potentially enabling more efficient conversion of lignocellulosic biomass into biofuels.