Some researches show the amount of inhibitors released after hydrolysis treatments. And it is easily noticeable that they can be found in different amounts, depending on the lignocellulosic material involved. Hemicellulosic hydrolysate from sugarcane bagasse[10], for example, showed a high total concentration of phenolic compounds of 5.48 g L−1, which is 1.7 times higher than the concentration obtained in CABH-2 (3.3 g L−1) in the present study. Villaet al. [32] studied the toxic effect of phenol during growth of C.guilliermondii in semisynthetic medium, proving that its presence,even if in low concentrations (0.1 g L−1), was able to reduce significantly the xylitol productivity. According to these authors [32],this is probably due to inhibition of xylose reductase (XR) activity or xylose transport through the plasma membrane, since the assimilation of xylose also decreased drastically.