R. oryzae was also able to ferment pentose for lactic acid production [9]. As can be seen in Fig. 5 A, the xylose concentration in the fermentation broth increased to 5 g L-1 and remained relatively constant until a significant decrease was observed after 3 h. The increased utilization of xylose as carbon source coincided with the depletion of glucose and cellulose (data not shown). Nevertheless, the utilization of xylose by R. oryzae was not as efficient glucose due to catabolite repression and other reasons discussed earlier [19,22,25].