One step conversion of lignin from intact biomass to two phenol products, improving access to aromatics and fuels.

We report the positive effect of maleic acid, a dicarboxylic acid, on the selectivity of hexose dehydration to 5hydroxymethyfurfural (HMF) and subsequent hydrolysis to levulinic and formic acids. We also describe the kinetic analysis of a Lewis acid (AlCl 3 ) alone and in combination with HCl or maleic acid to catalyze the isomerization of glucose to fructose, dehydration of fructose to HMF, hydration of HMF to levulinic and formic acids, and degradation of these compounds to humins. The results show that AlCl 3 significantly enhances the rate of glucose conversion to HMF and levulinic acid in the presence of both maleic acid and HCl. In addition, the degradation of HMF to humins, rather than levulinic and formic acids, is reduced by 50% in the presence of maleic acid and AlCl 3 compared to HCl combined with AlCl 3 . The results suggest different reaction mechanisms for the dehydration of glucose and rehydration of HMF between maleic acid and HCl.

Advances in genetic manipulation of the biopolymers that compose plant cell walls will facilitate more efficient production of biofuels and chemicals from biomass and lead to specialized biomaterials with tailored properties. Here we investigate several genetic variants of Arabidopsis: the wild type, which makes a lignin polymer of primarily guaiacyl (G) and syringyl (S) monomeric units, the fah1 mutant, which makes lignin from almost exclusively G subunits, and a ferulate 5-hydroxylase (F5H) overexpressing line (C4H: F5H) that makes lignin from S subunits. We employ multiscale, multimodal imaging techniques that reveal the biomass of the C4H:F5H transgenic to be more susceptible to deconstruction by maleic acid treatment than the other variants. Enzymatic saccharification assays of the treated materials show that C4H: F5H transgenic tissue is significantly more digestible than the wild type, while the fah1 mutant is clearly the least digestible of these materials. Finally, we show by contact resonance force microscopy, an atomic force microscopy technique, that F5H overexpression in C4H:F5H transgenic plants significantly reduces the stiffness of the cell walls in the region of the compound middle lamella relative to wild type and fah1. † Electronic supplementary information (ESI) available. See

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