Effect of Detoxification of Natural Drying Steam Exploded Corn Straw with Organic Solvent on Enzymatic Hydrolysis and Ethanol Fermentation

Corn straw from steam-explosion treatment process was treated with different organic solvents to reduce the inhibition for the sequent enzymatic hydrolysis and fermentation. The detoxified substrates (100 g DW/L) were hydrolyzed with a blend of Novozym 188 (15 IU/g cellulose), Celluclast CP cellulase (15 FPU/g cellulose) and lignase (15 IU/g hemicellulose). The reducing sugar was bio-converted to ethanol with separated hydrolysis and fermentation processes using Pachysolen tannophilus P-01. The reducing sugar yield varied from 34.8 to 89.7% depending on the detoxification solvents and modes. The highest ethanol yield (96.1% of theoretical value) was obtained with the combined extraction of ether and acetone.