Monday, April 29, 2013
Exhibit Hall
Lignocellulose, the most abundant renewable bioresource on earth, is mainly composed of carbohydrate polymers, such as cellulose and hemicellulose, and lignin, an aromatic polymer. The heterogeneity and molecular structure of these complex polysaccharides and lignin make lignocellulosic biomass highly recalcitrant to saccharification for production of biofuels and other commodities. The Bioimprove hybrid aspens (Populus tremula x tremuloides) used in the present study are a collection of transgenic lines produced at SweTree Technologies (STT, Sweden). Key genes were modified to overcome the recalcitrance and improve the wood chemistry and saccharification potential. Acid pretreatment and enzymatic hydrolysis were used to determine the saccharification potential of milled aspen wood. The products, such as monosaccharides and aliphatic acids, were analyzed using ion chromatography. The transgenic trees were analysed also for growth and wood density. The chemical composition of the wood was investigated using gas chromatography-mass spectrometry. The combined analyses resulted in identification of genetic modifications that altered the wood chemistry and improved the saccharification potential. This study will increase our knowledge on key properties of tree growth and/or wood chemistry determining production of sugar-based green chemicals, and allow production of novel feedstocks that are better suited for this purpose.