The influence of bark on the fermentation of Douglas-fir whitewood pre-hydrolysates.
Douglas-fir ( Pseudotsuga menziesii) whitewood was supplemented with increasing concentrations of bark (0-30%) and was pretreated using SO(2)-catalysed steam explosion. The presence of bark in the feedstock resulted in the decreased recovery of total sugars, furfural and 5-hydroxymethylfurfural in the resultant pre-hydrolysate. No detrimental impact on monomer sugar recovery was observed. The concentration of lipophilic extractives present in the pre-hydrolysate increased with increasing bark loading, to a maximum of 0.43 g x l(-1). The water-soluble pre-hydrolysates were fermented by Saccharomyces cerevisiae to determine the impact of bark on sugar consumption and ethanol production. Despite the inclusion of bark, fermentation of all pre-hydrolysates resulted in the complete consumption of hexose sugars within 48 h. Ethanol yields were greater than 0.43 g x g(-1) for all pre-hydrolysates regardless of bark content, indicating that, up to a content of 30%, bark had a negligible impact on the fermentation of the pre-hydrolysates to ethanol.
Robinson
J
J
Forest Products Biotechnology Group, Department of Wood Science, The University of British Columbia, Forest Sciences Centre, 4041-2424 Main Mall, Vancouver, British Columbia, V6T 1Z4 Canada.
Keating
J D
JD
Boussaid
A
A
Mansfield
S D
SD
Saddler
J N
JN
D001709:Biotechnology / Q000379:methods*; D050260:Carbohydrate Metabolism; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry / Q000378:metabolism; D024301:Plant Bark / Q000737:chemistry / Q000378:metabolism; D028224:Pseudotsuga / Q000737:chemistry / Q000378:metabolism*; D014934:Wood
D000431:Ethanol; D008031:Lignin