Fast and efficient alkaline peroxide treatment to enhance the enzymatic digestibility of steam-exploded softwood substrates.
The enzymatic digestibility of steam-exploded Douglas-fir wood chips (steam exploded at 195 degrees C, 4.5 min, and 4.5% (w/w) SO(2)) was significantly improved using an optimized alkaline peroxide treatment. Best hydrolysis yields were attained when the steam-exploded material was post-treated with 1% hydrogen peroxide at pH 11.5 and 80 degrees C for 45 min. This alkaline peroxide treatment was applied directly to the water-washed, steam-exploded material eliminating the need for independent alkali treatment with 0.4% NaOH, which has been traditionally used to post-treat wood samples to try to remove residual lignin. Approximately 90% of the lignin in the original wood was solubilized by this novel procedure, leaving a cellulose-rich residue that was completely hydrolyzed within 48 h, using an enzyme loading of 10 FPU/g cellulose. About 82% of the originally available polysaccharide components of the wood could be recovered. The 18% of the carbohydrate that was not recovered was lost primarily to sugar degradation during steam explosion.
Yang
Bin
B
Faculty of Forestry, Forest Products Biotechnology, University of British Columbia, Vancouver, Canada.
Boussaid
Abdel
A
Mansfield
Shawn D
SD
Gregg
David J
DJ
Saddler
John N
JN
D002482:Cellulose / Q000737:chemistry; D000431:Ethanol / Q000138:chemical synthesis; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry; D010545:Peroxides / Q000737:chemistry*; D028224:Pseudotsuga / Q000201:enzymology*; D013227:Steam; D014934:Wood
D010545:Peroxides; D013227:Steam; D000431:Ethanol; D002482:Cellulose; D008031:Lignin