Background:
Short rotation coppice (SRC) willow is a potential lignocellulosic feedstock in the UK and elsewhere however, research on optimising willow specifically for bioethanol production has been developing only recently. We have used the feedstock Salix viminalis x Salix schwerinii cultivar "Olof" in a three month pot experiment with the aim of modifying cell wall composition and structure within the stem to the benefit of bioethanol production. Trees were treated for 26 or 43 days with tension wood induction and/or with an application of the cellulose synthesis inhibitor 2, 6-dichlorobenzonitrile (DCB) that is specific to secondary cell walls. Reaction wood (tension and opposite wood) was isolated from material that had received the 43 day tension wood induction treatment.
Results:
Glucan content, lignin content and enzymatically released glucose were assayed. All measured parameters were altered without loss of total stem biomass yield, indicating that enzymatic saccharification yield can be enhanced by both alterations to cell wall structure as well as by alterations to absolute contents of either glucan or lignin.
Conclusions:
Final glucose yields can be improved by the induction of tension wood without a detrimental impact on biomass yield. The increase in glucan accessibility to cell wall degrading enzymes could help contribute to reducing the energy and environmental impacts from lignocellulosic bioethanol production process.