Acid sugarcane bagasse hydrolyzate was submitted to pH shifts in order to remove toxic compounds from the medium. The hydrolyzate was treated with bases containing mono-, di- or tri-valent cations and H2SO4, and its performance as a fermentation medium was evaluated by the production of xylitol by Candida guilliermondii FTI 20037. The use of bases containing mono-valent cations was not an efficient method of detoxification, and the use of a tri-valent cation did not show any detectable improvement in detoxification. The treated hydrolyzate recovery (in volume) is greatly affected by the utilized base. Treatment using Al(OH)3 and NaOH showed the best hydrolyzate recovery (87.5%), while the others presented a recovery of about 45% of the original hydrolyzate volume. Considering the whole process, best results were achieved by treatment using Al(OH)3 and NaOH which allowed 0.55 g of xylitol produced from each gram of xylose in the raw hydrolyzate.
Sugarcane bagasse hydrolyzate; xylitol production; Candida guilliermondii
