期刊名称：Computational and Structural Biotechnology Journal
印刷版ISSN：2001-0370
出版年度：2019
卷号：17
页码：599-610
DOI：10.1016/j.csbj.2019.04.007
出版社：Computational and Structural Biotechnology Journal
摘要：Genetic engineering is a powerful tool to steer bio-oil composition towards the production of speciality chemicals such as guaiacols, syringols, phenols, and vanillin through well-defined biomass feedstocks. Our previous work demonstrated the effects of lignin biosynthesis gene modification on the pyrolysis vapour compositions obtained from wood derived from greenhouse-grown poplars. In this study, field-grown poplars downregulated in the genes encoding CINNAMYL ALCOHOL DEHYDROGENASE ( CAD ), CAFFEIC ACID O-METHYLTRANSFERASE ( COMT ) and CAFFEOYL-CoA O-METHYLTRANSFERASE ( CCoAOMT ), and their corresponding wild type were pyrolysed in a Py-GC/MS. This work aims at capturing the effects of downregulation of the three enzymes on bio-oil composition using principal component analysis (PCA). 3,5-methoxytoluene, vanillin, coniferyl alcohol, 4-vinyl guaiacol, syringol, syringaldehyde, and guaiacol are the determining factors in the PCA analysis that are the substantially affected by COMT , CAD and CCoAOMT enzyme downregulation. COMT and CAD downregulated transgenic lines proved to be statistically different from the wild type because of a substantial difference in S and G lignin units. The s CAD line lead to a significant drop (nearly 51%) in S-lignin derived compounds, while CCoAOMT downregulation affected the least (7–11%). Further, removal of extractives via pretreatment enhanced the statistical differences among the CAD transgenic lines and its wild type. On the other hand, COMT downregulation caused 2-fold reduction in S-derived compounds compared to G-derived compounds. This study manifests the applicability of PCA analysis in tracking the biological changes in biomass (poplar in this case) and their effects on pyrolysis-oil compositions.
关键词：Genetically modified poplar ; Principal component analysis ; Analytical fast pyrolysis ; Lignin ; Phenolic compounds ; as Antisense line ; C Holocellulose ; CAD CINNAMYL ALCOHOL DEHYDROGENASE ; CCoAOMT CAFFEOYL-CoA O-METHYLTRANSFERASE ; COMT CAFFEIC ACID O-METHYLTRANSFERASE ; G Guaiacyl units ; GC Gas chromatography ; H p-hydroxyphenyl units ; L Lignin-derived aromatic compounds ; L-G Guaiacyl lignin-derived compounds ; L-H p-Hydroxyphenyl lignin-derived compounds ; L-S Syringyl lignin-derived compounds ; MS Mass spectroscopy ; PC Principal component ; Py Micropyrolysis or micropyrolyzer ; MD Mahalanobis distance ; S Syringyl units ; s Sense line
