1-11: Transgenic expression of microbial arabinofuranosidases alters molecular associations between lignocellulose components

Monday, April 29, 2013
Exhibit Hall
Resmi Capron1, Thomas Canam2, Katharina Bräutigam3, Yi-Lin Alex Tsai4, Emma Master1 and Malcolm Campbell4, (1)Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada, (2)Biological Sciences, Eastern Illinois University, Charleston, IL, (3)Cell and Systems Biology, University of Toronto, Toronto, ON, Canada, (4)Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
Plant cell wall engineering is now a feasible route to improving feedstock characteristics and making the process of biomass pretreatment and fractionation economically viable. Altering intermolecular linkages between plant cell wall components might enable pretreatment options that produce a broader range of high value fractions. For example, modifying polysaccharide branching structure could alter the extent of intermolecular associations between cell wall polysaccharides and lignin. In this way, lignocellulose fractionation into quality streams of cellulose, hemicellulose and lignin could be facilitated and used to generate high value bioproducts that improve the economics of biofuel production. In this study, we describe cell wall engineering in the model plant Arabidopsis thaliana by the transgenic expression of two microbial arabinofuranosidases belonging to GH54 and GH43 family. Transgenic expression of each enzyme decreased the enzymatic digestibility of corresponding stem samples, increased xylose content by up to 10 %, and was correlated to occurrence of collapsed vessels. Further, in at least two of three independently transformed lines, transgene expression increased lignin and xylan extractability by between 5-10%. These results suggest that transgenic expression of arabinofuranosidases alters molecular associations between cell wall polysaccharides and lignin, which could be harnessed to improve the fractionation of lignocellulose components for high-value biotechnological applications.