Xylitol conversion by fermentation using five yeast strains and polyelectrolyte-assisted ultrafiltration.
Batch fermentations for xylitol production were conducted using Candida boidinii (BCRC 21432), C. guilliermondii (BCRC 21549), C. tropicalis (BCRC 20520), C. utilis (BCRC 20334), and P. anomala (BCRC 21359) together with a mixture of sugars simulating lignocellulosic hydrolysates as the carbon source. C. tropicalis had the highest bioconversion yield (Y(P/S)) of 0.79 g g(-1) (g xylitol x g xylose(-1)) over 48 h. Additional fermentations with C. tropicalis achieved Y(P/S) values of 0.6 and 0.39 g g(-1) after 96 and 72 h using urea and soybean meal as the nitrogen sources, respectively. Ethanol and arabitol were also produced in all fermentation. Xylitol in the fermentation broth was recovered by cross-flow ultrafiltration. With prior application of 2 mg polydiallyl dimethylammonium chloride l(-1) on the membrane surface, protein in the permeate was reduced from 7.1 to 1.5 mg l(-1 )after 2 h.
Ko
Chun-Han
CH
School of Forestry and Resource Conservation, National Taiwan University, Taipei 106, Taiwan. chunhank@ntu.edu.tw
Chiu
Pei-Chun
PC
Yang
Chin-Lin
CL
Chang
Keng-Hao
KH
D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques / Q000379:methods*; D004573:Electrolytes / Q000737:chemistry; D013045:Species Specificity; D014462:Ultrafiltration / Q000379:methods*; D014993:Xylitol / Q000378:metabolism*; D015003:Yeasts / Q000145:classification* / Q000378:metabolism*
D004573:Electrolytes; D014993:Xylitol