The present invention relates to a mutant microorganism with enhanced sugar utilization and methods for preparing the same. The mutant strain is capable of effectively utilizing various sugars including cellobiose and xylose, and can thus be useful in the production of biofuels, physiologically active materials, medicinal materials or industrial chemicals from cellulosic biomass. It also reduces the need for addition of one out of the three enzymes used in the saccharification of lignocellulose. It also eliminates the need for separate reactors to ferment pentose and hexose sugar.