Fig. 2 shows the behavior observed during xylitol production inthe experiments performed with K. marxianus CCA510. Regarding biomass growth, it was observed that the highest concentration of K. marxianus CCA510 (13.75 g L−1) was achieved when using CABH-2 (Fig. 2A–D) as culture medium, which had higher amounts of glucose and xylose. The medium had been concentrated, butnot treated for detoxification, yet the microorganism was able to grow at high concentrations of inhibitors (4.5 g L−1acetic acid;0.38 g L−1formic acid; 3.3 g L−1phenols). On the other hand, in CABH-1 microorganism growth was only 11.88 g L−1. This was theonly medium where K. marxianus CCA510 consumed all xylose during fermentation (at 24 h, it had already consumed approximately 90% of the sugar). Additionally, in the other culture media (CABH-2, CABH-3 and CABH-4) the microorganism was able to assimilateover