Can the same steam pretreatment conditions be used for most softwoods to achieve good, enzymatic hydrolysis and sugar yields?
Wood chips from six different Douglas-fir trees and a representative Lodgepole pine were steam pretreated at a single pretreatment condition (200 °C 4% SO₂ 5 min) which had previously been shown to be effective for Spruce and Lodgepole pine chips. All of the softwood samples responded in a similar fashion with more than 60% of the cellulose hydrolysed after 72 h, at an enzyme loading of 20 FPU/g cellulose. However, when the enzyme loading was reduced to 5FPU, less than 27% of the cellulose was hydrolysed. When the steam pretreated substrates were subsequently delignified they were almost completely hydrolysed, at both high, 20 FPU/g cellulose (less than 12 h) and low, 5 FPU/g (within 72 h) enzyme loadings. Although optimized steam pretreatment could result in greater than 90% glucose recovery, in order to obtain complete hydrolysis of the cellulosic component at reduced enzyme loadings a delignification step will likely be required.
Kumar
Linoj
L
Forest Products Biotechnology/Bioenergy Group, University of British Columbia, 2424 Main Mall, Vancouver, BC, Canada V6T 1Z4.
Chandra
Richard
R
Chung
Pablo A
PA
Saddler
Jack
J
D002480:Cellulase / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism; D006868:Hydrolysis; D013227:Steam; D014934:Wood
D013227:Steam; D002482:Cellulose; D002480:Cellulase