Wet oxidation pretreatment, enzymatic hydrolysis and simultaneous saccharification and fermentation of clover-ryegrass mixtures.
The potential of clover (Trifolium repens) and ryegrass (Lolium perenne) mixtures as raw materials for ethanol production was investigated. Wet oxidation, at 175, 185 or 195 degrees C during 10min at two different oxygen pressures and with either addition or no addition of sodium carbonate, was evaluated as pretreatment method for clover-ryegrass mixtures. The enzymatic hydrolysis of cellulose was significantly improved after pretreatment. The highest conversion efficiency, 93.6%, was achieved for the sample pretreated at 195 degrees C, 10min, 1.2MPa and no addition of Na(2)CO(3). For that sample, the overall glucose yield after pretreatment and hydrolysis was 75.5%. No inhibition of cellulose enzymatic conversion by the filtrates was observed. The simultaneous saccharification and fermentation of the pretreated material yielded cellulose conversions of 87.5 and 86.6%, respectively, with Saccharomyces cerevisiae and the filamentous fungus Mucor indicus, and revealed that no addition of nutrients is needed for the fermentation of clover-ryegrass hydrolysates.
Martín
Carlos
C
Department of Chemistry and Chemical Engineering, University of Matanzas, Matanzas 44740, Cuba. carlos.martin@umcc.cu
Thomsen
Mette H
MH
Hauggaard-Nielsen
Henrik
H
Belindathomsen
Anne
A
D002480:Cellulase / Q000378:metabolism*; D002482:Cellulose / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D006868:Hydrolysis; D008129:Lolium / Q000737:chemistry / Q000378:metabolism*; D029902:Medicago / Q000737:chemistry / Q000378:metabolism*; D009584:Nitrogen / Q000032:analysis; D010084:Oxidation-Reduction; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D014242:Trichoderma / Q000201:enzymology*; D014867:Water / Q000378:metabolism*; D014990:Xylans / Q000378:metabolism
D014990:Xylans; D014867:Water; D000431:Ethanol; D002482:Cellulose; D002480:Cellulase; D009584:Nitrogen