Production of ethanol from soybean hull hydrolysate by osmotolerant Candida guilliermondii NRRL Y-2075.
In this research, we studied the use of soybean hull hydrolysate (SHH) as a substrate for ethanol and xylitol production using an osmotolerant strain of Candida guilliermondii. The best acid hydrolysis of soybean hull achieved a recovery of 85 and 62% of xylose and mannose, respectively. Among detoxification treatments, activated charcoal 10% (w/v) showed the best results. Kinetic parameters obtained from the cultivation on four-fold concentrated SHH have shown that the osmotic pressure of this medium is higher than that supported by most osmophilic yeasts, revealing the osmotolerant characteristic of C. guilliermondii NRRL Y-2075. When cultivations were carried out on two times concentrated SHH, we obtained high yields of ethanol production, showing the prospect of SHH as a candidate for this biofuel production. Although xylose was present in high concentrations, no xylitol was produced, probably due to the presence of furfural acting as external electron acceptor or some varying cofactor preference of xylose reductase in this yeast strain.
Schirmer-Michel
Angela Cristina
AC
Food Science and Technology Institute, Federal University of Rio Grande do Sul State, Av. Bento Goncalves, 9500, PO Box 15090, ZC 91501-970, Porto Alegre, RS, Brazil.
Flôres
Simone Hickmann
SH
Hertz
Plinho Francisco
PF
Matos
Gilvane Souza
GS
Ayub
Marco Antonio Záchia
MA
D019342:Acetic Acid / Q000378:metabolism; D002175:Candida / Q000254:growth & development / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D005662:Furaldehyde / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D009005:Monosaccharides / Q000378:metabolism; D013025:Glycine max / Q000737:chemistry / Q000378:metabolism; D014993:Xylitol / Q000096:biosynthesis
D009005:Monosaccharides; D000431:Ethanol; D005662:Furaldehyde; D005947:Glucose; D019342:Acetic Acid; D014993:Xylitol