Potential of genetically engineered hybrid poplar for pyrolytic production of bio-based phenolic compounds. (May 2016) - Toraman, Hilal E.
Highlights: Unique fast and intermediate pyrolysis study of genetically engineered hybrid poplars. Steering the pyrolytic production of bio-based phenolics by genetic modification. Analysis of phenolic compounds present in the bio-oil using GC–MS. PCA combined with K-means for clustering of genetically engineered hybrid poplars. Abstract: Wild-type and two genetically engineered hybrid poplar lines were pyrolyzed in a micro-pyrolysis (Py-GC/MS) and a bench scale setup for fast and intermediate pyrolysis studies. Principal component analysis showed that the pyrolysis vapors obtained by micro-pyrolysis from wood of caffeic acid O -methyltransferase ( COMT ) and caffeoyl-CoA O- methyltransferase ( CCoAOMT ) down-regulated poplar trees differed significantly from the pyrolysis vapors obtained from non-transgenic control trees. Both fast micro-pyrolysis and intermediate pyrolysis of transgenic hybrid poplars showed that down-regulation of COMT can enhance the relative yield of guaiacyl lignin-derived products, while the relative yield of syringyl lignin-derived products was up to a factor 3 lower. This study indicates that lignin engineering via genetic modifications of genes involved in the phenylpropanoid and monolignol biosynthetic pathways can help to steer the pyrolytic production of guaiacyl and syringyl lignin-derived phenolic compounds such as guaiacol, 4-methylguaiacol, 4-ethylguaiacol, 4-vinylguaiacol, syringol, 4-vinylsyringol, and syringaldehyde present in the bio-oil.