Wang et al. [36] studied the improvement of the process of xylose assimilation by K. marxianus YRL005, a genetically modified strain. These authors noted that glucose was consumed first and faster than xylose, showing that this microorganism has genes that coordinate xylose metabolism, but that can be repressed by presence of glucose, this not being a fully understood mechanism though. Similar behavior was observed in the present study, in which the microorganism quickly consumed the glucose present in the medium in preference to xylose, which delays xylitol production.