Improved ethanol and reduced xylitol production from glucose and xylose mixtures by the mutant strain of Candida shehatae ATCC 22984.
A mutant Cs3512, which showed better fermentation of xylose and the mixtures of xylose and glucose, was obtained through mutation of Candida shehatae ATCC 22984 and screening with a medium containing antimycin A and TTC (2,3,5-triphenyltetrazolium chloride). Cs3512 produced 44.4 g/l of ethanol from 121.3 g/l of xylose, which was 13% higher than that by ATCC 22984. At the same time, xylitol production was reduced by 38% to 10.2 g/l from 16.3 g/l by ATCC 22984. Cs3512 also showed 8% increase in ethanol yield from 0.39 to 0.42 g/g comparing to ATCC 22984 when fermenting the sugar mixture composed of 52.9 g/l glucose and 21.2 g/l xylose. When Cs3512 was used in the simultaneous saccharification and fermentation of lime pretreated rice straw via CaCCO (calcium capturing by carbonation) process, it produced ethanol at 77% of the theoretical yield. The results imply that Cs3512 is a potential non-recombinant yeast strain for ethanol production from lignocellulosic biomass.
National Food Research Institute, National Agriculture and Food Research Organization, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan.
Yuan
Y
Li
Jeung-yil
JY
Park
Riki
R
Shiroma
Masakazu
M
Ike
Ken
K
Tokuyasu
D000968:Antimycin A / Q000494:pharmacology; D018533:Biomass; D019149:Bioreactors; D017610:Calcium Compounds / Q000737:chemistry; D002175:Candida / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism*; D008031:Lignin / Q000378:metabolism*; D030781:Organisms, Genetically Modified; D012275:Oryza / Q000737:chemistry; D010087:Oxides / Q000737:chemistry; D013778:Tetrazolium Salts / Q000494:pharmacology; D014993:Xylitol / Q000096:biosynthesis; D014994:Xylose / Q000378:metabolism*
D017610:Calcium Compounds; D010087:Oxides; D013778:Tetrazolium Salts; C036909:lignocellulose; D000431:Ethanol; D000968:Antimycin A; C009591:triphenyltetrazolium; D008031:Lignin; D014994:Xylose; C016538:lime; D005947:Glucose; D014993:Xylitol