Ea. Martinez et al., Aspects of xylitol formation in sugarcane bagasse hydrolysate by Candida guilliermondii in the presence of tetracycline, APPL BIOC B, 77-9, 1999, pp. 347-354
The bioconversion of xylose into xylitol using pH values of 4.0, 5.5, and 7
.0 and tetracycline concentrations of 20 and 40 mg/L was carried out to ver
ify the influence of these parameters on Candida guilliermondii metabolism
for xylitol production. Experiments were performed with sugarcane bagasse h
emicellulosic hydrolysate (48.5 g/L of xylose) in 125-mL Erlenmeyer flasks,
at 30 degrees C, 200 rpm, during 88 h. The results demonstrated that the b
ioconversion of xylose into xylitol was significantly influenced by the pH.
On the other hand, in media containing 20 or 40 mg/L of tetracycline, this
bioconversion was not significantly affected. The best results of xylitol
production were obtained in hemicellulosic hydrolysate without tetracycline
, at pH 7.0. In these conditions, the maximum specific growth rate was 0.01
4/h and the yield factor of xylitol and volumetric productivity were 0.85 g
/g and 0.70 g/L/h respectively. Xylitol and cell growth occurred simultaneo
usly.