IWT / SB-2014 batch IWT / SB / Master Barbara / 131103

OPTIMIZATION OF POPLAR FOR THE BIO-BASED ECONOMY THROUGH TISSUE–SPECIFIC LIGNIFICATION AND THE INCORPORATION OF ALTERNATIVE LIGNIN MONOMERS

Our current fossil-based economy and the accompanying carbon emission is one of the driving forces of global warming. Besides the environmental impact of their use, fossil resources are limited both in quantity and geological distribution. Therefore, it is imperative to make the transition to a bio-based economy running on sustainable resources for the production of energy and materials. In the bio-based economy, lignocellulosic biomass will play an important role.
Lignocellulosic biomass mainly consists of secondary thickened cell walls, which are primarily composed of polysaccharides impregnated with lignins. The cell wall polysaccharides can be saccharified into simple sugar monomers which, in their turn, can be fermented into a broad range of chemicals, including bioethanol. Usually, the lignin is burned for energy recuperation. However, research efforts are now also focusing on valorizing the lignin for the conversion towards aromatics and high-value lignin-derived materials. Regrettably, the plant cell wall is recalcitrant towards deconstruction into simple monomers mostly due to the tight association of lignin with the cell wall polysaccharides and the relative complexity of the lignin polymer. In this dissertation, two strategies were explored to overcome this recalcitrance: (i) vessel-specific lignin biosynthesis, (ii) incorporation of the alternative monomer curcumin into the lignin polymer.