Inhibitory effect of acetic acid on bioconversion of xylose in xylitol by Candida guilliermondii in sugarcane bagasse hydrolysate
Silva, D., D.V.; Felipe, M., C.A.; Mancilha, I., M.; Luchese, R., H.; Silva, S., S.
Brazilian Journal of Microbiology 35(3): 248-254
ISSN/ISBN: 1517-8382 DOI: 10.1590/s1517-83822004000200014
Sugarcane bagasse hydrolysate (initial acetic acid concentration =3.5 g/L), was used as a fermentation medium for conversion of xylose into xylitol by the yeast Candida guilliermondii FTI 20037. Acetic acid (2.0 g/L) was added to the medium at different times of fermentation, with the aim of evaluating its effects on the bioconversion process. The addition of acetic acid to the medium after 12 h of fermentation resulted in the strongest inhibition of the yeast metabolism. In this case, the xylose consumption and cell growth were, respectively, 23.22 and 11.24% lower than when acid was added to the medium at the beginning of fermentation.