Xylitol, a five-carbon sugar alcohol, has similar sweetening power as sucrose. It has unique pharmacological properties such as prevention of tooth decay and ear infection in children; it is used as a sugar substitute for diabetic patients and in parenteral application to trauma patients. Xylitol is increasingly being used in chewing gums, candy, soft drinks, ice cream and oral hygiene products...

The biocatalytic reduction of D-xylose to xylitol requires separation of the substrate from L-arabinose, another major component of hemicellulosic hydrolysate. This step is necessitated by the innate promiscuity of xylose reductases, which can efficiently reduce L-arabinose to L-arabinitol, an unwanted byproduct. Unfortunately,due to the epimeric nature of D-xylose and L-arabinose, separation c...

A maximum xylose extraction of 21.98 g/L was obtained in hydrolysate with a solid to liquid ratio of 1:8 (w/v) at 1% H2SO4 and treated for 30 min. The optimized and treated corncob hemicellulosic hydrolysate medium supplemented with (g/L) yeast extract 5.0, KH2PO4 2.0, MgSO4·7H2O 0.3 and methanol 10 mL whose pH was adjusted to 4.5 acts as production medium. Under this condition; the adapted str...

The yeast Candida tropicalis DSM 7524 produces xylitol, a natural, low-calorie sweetener, by fermentation of xylose. In order to increase xylitol production rate during the submerged fermentation process, some parameters-substrate (xylose) concentration, pH, aeration rate, temperature and fermentation strategy-have been optimized. The maximum xylitol yield reached at 60-80 g/L initial xylose co...

Xylitol production from sago trunk cortex hydrolysate using Candida tropicalis was evaluated in shake flasks and a bioreactor. The fermentation and kinetic behaviours of this microorganism were investigated using sago trunk cortex hydrolysate and commercial xylose as substrate. Results obtained for sago trunk hydrolysate were close to the commercial xylose with xylitol yield of 0.82 gg -1 and p...

BACKGROUND Efficiently utilizing all available carbon from lignocellulosic feedstock presents a major barrier to the production of economically feasible biofuel. Previously, to enable xylose utilization, we introduced a cofactor-dependent xylose reductase (XR) and xylitol dehydrogenase (XDH) pathway, or a cofactor-independent xylose isomerase (XI) pathway, into Saccharomyces cerevisiae. The res...

This study investigated the fermentability of hemicellulosic hydrolysates obtained by intensified steam explosion pretreatment switchgrass (Panicum virgatum) and Eucalyptus globulus. Xylitol carotenoids were high-value molecules produced fermentation. The allowed to process a large amount biomass per unit time resulted in containing high sugars, among which, significant fraction was form oligom...

Candida guilliermondii cells were immobilized in Ca-alginate beads and used for xylitol production from concentrated sugarcane bagasse hydrolysate during five successive fermentation batches, each lasting 48 hours. The bioconversion efficiency of 53.2%, the productivity of 0.50 g/l x h and the final xylitol concentration of 23.8 g/l obtained in the first batch increased to 61.5%, 0.59 g/l x h a...