Browsing by Subject "Lignin"

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    A simple fractionation method and GPC analysis of organosolv extracts obtained from lignocellulosic materials
    (Springer-Verlag, 2020-01-16) Andreo-Martínez, Pedro; Ortiz-Martínez, Víctor Manuel; García-Martínez, Nuria; Hernández-Fernández, Francisco José; Pérez de los Ríos, Antonia; Quesada-Medina, Joaquín; Ingeniería Química
    The elucidation of lignin structural features is necessary for the efficient application of this polymer. Fractionation is an effective technique to achieve homogeneous lignin fractions, helping to better understand its composition and structure, and improving its use as source of phenolic compounds. This work develops a new and simple fractionation method of organosolv extracts obtained from lignocellulosic materials that enables the selective separation of lignin (from complex macromolecules to low molecular weight aromatic compounds originated from their degradation) from saccharides derived from hemicelluloses and cellulose. For this purpose, the non-catalytic organosolv extraction of lignin from almond shells was performed with dioxane/water mixtures and then the successful fractionation of the organosolv extracts with anhydrous tetrahydrofuran was achieved, resulting in the selective separation of lignin (lignin fraction) from saccharides (saccharide fraction). Gel permeation chromatography (GPC), thioacidolysis, and GC-MS were used as analytical methods to qualitatively determine the purity of both fractions. In addition, GPC was also used to quantify the content of lignin monomers and furfural in the organosolv extracts, thus allowing valuable information on the state of degradation of the lignin and hemicelluloses extracted to be obtained, respectively. The application of the GPC method also enabled the determination of the molecular weight distribution of the extracted lignin in the same analysis.
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    Obtaining PDC and other high-added value products from lignin by in silico genetic engineering in Novosphingobium aromaticivorans
    (De Gruyter, 2026-02-25) Guil Asensio, Francisco de Asís; Fernández, Isabel María; García Carrasco, José Manuel; Ingeniería y Tecnología de Computadores; Facultades de la UMU::Facultad de Informática
    Lignin, the second most abundant plant biopolymer on Earth, is produced in large quantities as waste material by many industries. Researchers have studied bacterial metabolic networks as potential candidates for integrating lignin into a biotechnological value chain. The GEM used in this work for metabolic engineering is iNovo479, which simulates the metabolism of Novosphingobium aromaticivorans DSM12444. We have conducted a study on PDC production and found several intervention strategies to help achieve this goal. These strategies include more than just blocking the ligI gene, which has been a well-known approach. Although these new strategies resulted in a lower yield of PDC relative to biomass formed, they led to a higher cell yield than deleting the ligI gene. The research presented in this paper focuses on the production of high-value compounds from lignin. Previous studies have used mutated microorganisms to produce these bioproducts from large amounts of glucose. However, biosynthesis from lignin would improve productivity and make the fermentation process more cost-effective. Through gene knockouts, we have discovered ways to ensure a minimum production of bioproducts such as acetaldehyde, citrate, glutarate, glycerol, phenol, and propanoate when growing the N. aromaticivorans strain using lignin-derived compounds as unique substrates.