Production of succinic acid by fermentation and chemical depolymerization of condensed tannins for the development of biobased platform molecules and materials

Dans un contexte d’essor du développement durable et de l’économie circulaire, l’utilisation du carbone renouvelable provenant de déchets générés par l’activité humaine apparaît comme pertinente pour développer des alternatives aux produits pétro-sourcés, parfois toxiques. Dans ce cadre, cette thèse a exploré une stratégie d’obtention de synthons complémentaires à partir de coproduits issus de filières agroalimentaires, en vue de l’élaboration de matériaux entièrement biosourcés et recyclables.Premièrement, la dépolymérisation acido-catalysée des tanins condensés issus de coproduits de la filière viti-vinicole a été étudiée en tant que voie de production de monomères phénoliques polyfonctionnels stables. L’étude cinétique de la réaction de dépolymérisation a permis d’évaluer l’efficacité de 37 agents nucléophiles pour piéger les unités d’extension libérées par la rupture des liaisons intermonomériques. Les nucléophiles testés comprenaient des métalloles, des phénols et des thiols. Le menthofurane, métallole trisubstitué dérivé du furane, s’est révélé particulièrement efficace en termes de réactivité et de stabilité des produits formés. Outre son application pour l’obtention de nouveaux monomères phénoliques, cette découverte a mené au développement d’une nouvelle méthode analytique de dépolymérisation des tanins condensés basée sur le menthofurane. Deuxièmement, la bioproduction d’acide succinique à partir de déchets alimentaires a été étudiée. Ce diacide peut notamment être utilisé pour la production de polyesters ou polyamides. Des cultures en fed-batch d’une souche sauvage et de deux souches de la levure Yarrowia lipolytica modifiées par ingénierie métabolique ont été effectuées en conditions contrôlées sur milieu modèle chimiquement défini. La stratégie de culture consistait en une dissociation de la phase de croissance et de la phase de production d’acides organiques opérée par carence en azote. Les rendements et les vitesses spécifiques de production de biomasse, d’acides organiques et de lipides ont été caractérisés et comparés pour chaque souche testée sur les différentes phases de cultures définies.Finalement, les monomères phénoliques obtenus par dépolymérisation des tanins condensés et l’acide succinique produit par voie biotechnologique constituent des molécules plateformes utilisables indépendamment dans de nombreuses applications. Ces composés peuvent également être fonctionnalisés, puis associés pour formuler des matériaux biosourcés de type epoxy, polyesters ou polyamides. Dans cette optique, la glycidylation des monomères et de l’acide succinique par l’épichlorhydrine a été réalisée à l’échelle de la centaine de grammes. Les prépolymères ainsi obtenus ont été combinés suivant différentes formulations, avant d’être réticulés pour produire des résines. Les premiers résultats de caractérisation de ces résines laissent entrevoir des perspectives prometteuses.On the path towards sustainable development and circular economy, the use of renewable carbon from waste generated by human activity seems relevant for developing alternatives to petro-based chemicals that can be toxic. In this context, the thesis explored a strategy for producing complementary building blocks from agricultural and food co-products, with the aim of developing entirely biobased and recyclable materials.Firstly, the acid-catalyzed depolymerization of condensed tannins applied to co-products from the wine industry was investigated as a way to produce stable polyfunctional phenolic monomers. The study of the depolymerization reaction kinetics evaluated the effectiveness of 37 nucleophilic reagents in trapping extension units released by the breaking of intermonomeric bonds. The nucleophiles tested comprised metalloles, phenols, and thiols. Menthofuran, a trisubstituted metallole derived from furan, proved particularly effective in terms of reactivity and stability of the products formed. In addition to its application to the production of new phenolic monomers, this discovery led to the development of an analytical method for characterizing the average monomeric composition of condensed tannins by depolymerization in presence of menthofuran.Secondly, the bioproduction of succinic acid from food waste was studied. This diacid is commonly used to produce polyesters or polyamides. Fed-batch cultures of a wild strain and two engineered strains of Yarrowia lipolytica were carried out under controlled conditions in a chemically defined model medium. The cultivation was performed in two steps, with first biomass production followed by an organic acid production phase under nitrogen-deficient conditions. The yields and the specific production rates of biomass, organic acids and lipids were characterized and compared for each strain.The phenolic monomers and succinic acid constitute platform molecules that can be used independently in many applications. They can also be further functionalized then combined to formulate bio-based materials such as epoxy, polyesters or polyamides. In this perspective, the phenolic monomers produced by depolymerization and succinic acid were glycidylated by epichlorohydrin at 100 g scale. The resulting prepolymers were combined according to different formulation strategies before being crosslinked to produce resins. The first characterization results of these resins showed promising prospects

Chemically stable lignin derivative and method for preparing same

Chemically stable lignin derivative and method for preparing sam

Furanolysis with Menthofuran: A New Depolymerization Method for Analyzing Condensed Tannins

International audienceAn improved analytical depolymerization method for characterizing condensed tannins was developed with menthofuran (3,6-dimethyl-4,5,6,7-tetrahydro-1-benzofuran) as the nucleophilic trapping reagent. Herein, menthofuran was compared with routinely used nucleophiles, phloroglucinol and 2-mercaptoethanol. At 30°C and in the presence of 0.1 M HCl, menthofuran displayed the outstanding ability to enable the fast and full depolymerization of procyanidin B2 using only a 1:1 molar ratio of both reactants. In the same conditions, phloroglucinol and 2 mercaptoethanol led to a reaction equilibrium with significantly lower conversion yields. Application to commercial tannin extracts showed that a menthofuran to extract weight ratio of 1 gave the same yields of procyanidin constitutive units as 10-fold higher mol. eq. phloroglucinol and 100 fold 2-mercaptoethanol. Finally, guidelines for implementing the menthofuran depolymerization method are proposed to assess the tannin content and composition of extracts as well as of plant materials without prior extraction

Furylated flavonoids: fully biobased building blocks produced by condensed tannins depolymerization

An original method has been set up to produce fully biobased phenolic building blocks from condensed tannins, largely available from agroindustrial residues or wood industry coproducts. The acid-catalyzed depolymerization of condensed tannins in the presence of furan or sylvan in mild conditions (30-40 degrees C, 0.1 M HCl) gives the corresponding furylated flavonoids with high yields. The reaction was more efficient with sylvan than with the less nucleophilic furan. A key feature of the products is the high stability of the flavanyl to furyl C-C linkage compared to the thioether bond obtained by the classical thiolysis, which makes them promising platform molecules for further functionalization, including in alkaline conditions. The simplicity of the process makes it easy to scale-up, and the reaction can be carried out on raw plant materials directly. In accordance with green chemistry concepts, solvents and excess reagents can readily be recovered by distillation and recycled

Advances in bio-based thermosetting polymers

International audienc

Impact of nitrogen deficiency on succinic acid production by engineered strains of Yarrowia lipolytica

International audienceYarrowia lipolytica strains PGC01003 and PGC202 engineered for succinic acid production were studied and compared to the wild type strain W29. For the first time, these two strains were characterized in a chemically defined medium. Strain growth and organic acid production were investigated in fed-batch mode with glycerol as carbon and energy source. This study evaluated the impact of nitrogen deficiency strategy to redirect carbon flux toward succinic acid synthesis. Strain PGC01003 produced 19 g L−1 succinic acid with an overall yield of 0.23 g g−1 and an overall productivity of 0.23 g L−1 h−1, while strain PGC202 produced 33 g L−1 succinic acid with an overall yield of 0.12 g g−1 and a productivity of 0.57 g L−1 h−1. Nitrogen limitation effectively stopped biomass growth and increased succinic acid yield of PGC01003 and PGC202 by 18 % and 62 %, respectively. However, the specific succinic acid production rate was reduced by 77 % and 66 %, respectively

Diversity of condensed tannins in Vitaceae

Diversity of condensed tannins in Vitaceae. 12. International Conference on Grapevine Genetics and Breedin

Tannin phenotyping of the Vitaceae reveals a phylogenetic linkage of epigallocatechin in berries and leaves

International audienceBackground and AimsCondensed tannins, responsible for berry and wine astringency, may have been selected during grapevine domestication (Narduzzi et al., 2015). This work examines the phylogenetic distribution of condensed tannins throughout the Vitaceae phylogenetic tree.MethodsGreen berries and mature leaves of representative true-to-type members of the Vitaceae were collected before “véraison”, freeze-dried, pulverised, and condensed tannins measured following depolymerization by nucleophilic addition of 2-mercaptoethanol to the C4 of the flavan-3-ol units in an organic acidic medium. Reaction products were separated and quantitated by UPLC/DAD/MS.Key Results and ConclusionsThe original ability to incorporate epigallocatechin (EGC) into grapevine condensed tannins was lost independently in both the American and Eurasian/Asian branches of the Vitaceae, with exceptional cases of reversion to the ancestral EGC phenotype. This is particularly true in the genus Vitis, where we now find two radically distinct groups differing with respect to EGC content. While Vitis species from Asia are void of EGC, 50% of the New World Vitis harbour EGC. Interestingly, the presence of EGC is tightly coupled with the degree of leaf margin serration. Noticeably, the rare Asian EGC-forming species are phylogenetically close to Vitis vinifera, the only remnant representative of Vitis in Eurasia. Both the wild ancestral V. vinifera subsp. sylvestris as well as the domesticated V. vinifera subsp. sativa can accumulate EGC and activate galloylation biosynthesis that compete for photoassimilates and reductive power