Search

In : 2nd Braunschweig International Symposium on Pharmaceutical Engineering Research SPhERe, TU Braunschweig, Germany September 06 to 08, 2017.In : 2nd Braunschweig International Symposium on Pharmaceutical Engineering Research SPhERe, TU Braunschweig, Germany September 06 to 08, 2017.; Characterization of mycelial transition of Yarrowia lipolytica during oxidative cultures: comparison of optical methods and their limitation, impact of morphology on rheological behavior. 2. Braunschweig International Symposium on Pharmaceutical Engineering Research SPhERe

In: 16ème Congrès de la Société Française de Génie des Procédés (SFGP), 11 - 13 July 2017, Nancy, France.In: 16ème Congrès de la Société Française de Génie des Procédés (SFGP), 11 - 13 July 2017, Nancy, France.; Tutoriel n°2 : Exploitation des nouvelles ressources pour la production durable de molécules d’usage. 16. Congrès de la société française de génie des procédés (SFGP 2017)

La production de « bioénergies » représente un défi important pour réduire les impacts environnementaux liés aux combustibles fossiles et accroitre l'indépendance énergétique. Cet article présente un état des lieux de la production de biocarburants (éthanol, lipides et hydrogène) par conversion de ressources lignocellulosiques par des levures ou des bactéries (conversion algale non traitée). Les étapes de prétraitements et hydrolyse nécessaires à l’obtention de substrats carbonés liquides et gazeux sont présentés et discutés. Cette revue montre les limites scientifiques et technologiques de cette conversion i.e. teneur initiale en carbone faible, génération d’inhibiteurs, limitations aux transferts gaz-liquide, faibles rendements en produits à partir du carbone initial. Les projets actuels s’intéressent au développement de souches génétiquement modifiées et de bioprocédés innovants pouvant ouvrir de nouvelles opportunités de production. La valorisation (matière et chaleur) et le recyclage des sous-produits contribueront à la viabilité économique et environnementale de la voie lignocellulosique de production d’agro-carburants., The production of bioenergies represents an important challenge to reduce environmental impacts linked to fossil fuels and to increase energetic independence. This article proposes an overview of biofuels’ production (ethanol, lipids and hydrogen mainly) by converting lignocellulosic resources using yeasts or bacteria (algal conversion is not considered). Both pretreatment and hydrolysis steps used to obtain liquid and gaseous substrates are presented and discussed. This review shows the scientific and technological bottlenecks of this conversion i.e. initial low carbon content, generation of inhibitors, limitations to gas-liquid transfers, low yields of products from the initial carbon. Current projects and prospects focus on the development of genetically modified strains and innovative bioprocesses that can offer new production opportunities. Matter and heat valorizations and recycling of by-products will contribute to the economic and environmental viability of the lignocellulosic pathway for the production of biofuels.

Background and aim: Particle size and morphology of biomass (microorganism, lignocellulosic substrates) stand out as the major determinants of the bioprocess efficiency. Through its impact on rheology, it affects momentum, heat and and mass transfers within the bioreactor. Various techniques are available to characterize in-situ and ex-situ size and shape of particles. The most common methods are classified into three groups: (i) analysis of microscopic images; (ii) laser light diffraction and (iii) settling kinetics. In present work, five techniques are compared and discussed with model particles, microorganisms and lignocellulosic substrates. Methods: The used techniques aim to characterize size and shape (0.1 to 2000µm). In-situ and ex-situ measurements were used: chord length measurement (FBRM), diffraction light scattering (DLS), morpho-granulometry (MG), cytometry (CYT) and settling velocity (TUL). A set of height polystyrene microspheres (1.0 to 15.0µm) and microbeads (40 and 80µm) were used as reference. Yarrowia lipolytica is strictly aerobic yeast, belonging to the family of hemiascomycetes. Cells are subjected to mycelial transition induced by pH changes. Its morphology evolves from ovoid shape (5-7µm) up to filament. It was used to appreciate the ability to qualify and quantify filamentous shape (width, length). Finally, two cellulosic matrices, microcrystalline cellulose and coniferous paper pulp were selected to investigate complex fiber morphologies. Results: Specifications and limits of instruments are scrutinized. Sampling methods and preparation should be carefully considered. Optical measurements provide raw data (light intensity, frequency, images) from which morphological parameters will be straightly extracted or calculated based on assumptions (optical properties, particles geometry, theory). Considering diameters and associated number and volume distribution functions, techniques are compared with model calibrated microspheres. The mean values appear consistent between techniques but the magnitude of standard deviation extensively varies. Few instruments (MG, CYT) provide access to additional morphological criteria (length, width, aspect ratio). Mycelial kinetics and magnitude is accurately described by fiber length (MG). However a poor reliability of width (time of flight, CYT) is noticeable. Considering more complex lignocellulosic particles, the relative diameter values usually indicate similar trends whatever the techniques is. However, absolute values should be carefully considered and may deviated in large extend (5-10 times).

In: 10th European Congress of Chemical Engineering; 3rd European Congress of Applied Biotechnology and 5th European Process Intensification Conference (ECCE10+ECAB3+EPIC5). Submission-2649. Topic : Biochemical Engineering / ECAB3 / Bioproducts (or bio-based products). Nice, France, September 27th - October 1st 2015In: 10th European Congress of Chemical Engineering; 3rd European Congress of Applied Biotechnology and 5th European Process Intensification Conference (ECCE10+ECAB3+EPIC5). Submission-2649. Topic : Biochemical Engineering / ECAB3 / Bioproducts (or bio-based products). Nice, France, September 27th - October 1st 2015; Comparison of optical methods to characterize morphology and size distribution of model particles and mycelial transition of [i]Yarrowia lipolytica[/i] . 10. European Congress of Chemical Engineering - ECCE 2015

In : ECCE10+ECAB3+EPIC5 (10th European Congress of Chemical Engineering; 3rd European Congress of Applied Biotechnology and 5th European Process Intensification Conference), Topic : Biochemical Engineering / ECAB3 / Biocatalysis and biotransformation. Submission-1659, Nice, France, September 27th - October 1st 2015In : ECCE10+ECAB3+EPIC5 (10th European Congress of Chemical Engineering; 3rd European Congress of Applied Biotechnology and 5th European Process Intensification Conference), Topic : Biochemical Engineering / ECAB3 / Biocatalysis and biotransformation. Submission-1659, Nice, France, September 27th - October 1st 2015; How to manage carbohydrate storage in oleaginous yeasts to optimize lipid accumulation under nitrogen or phosphorus limitations ?. 10. European Congress of Chemical Engineering - ECCE 2015

International audience

XIII° Congrès de la Société Française de Génie des Procédés (SFGP 2011), 29 Nov-1er Dec 2011, (Lille Grand Palais). Thematique D Procédés pour les Sciences du Vivant. Récents Progrès en Génie des Procédés, Numéro 101 – 2011, ISSN 1775-335X - ISBN 2-910239-75-6, Ed. SFGP, Paris, France.XIII° Congrès de la Société Française de Génie des Procédés (SFGP 2011), 29 Nov-1er Dec 2011, (Lille Grand Palais). Thematique D Procédés pour les Sciences du Vivant. Récents Progrès en Génie des Procédés, Numéro 101 – 2011, ISSN 1775-335X - ISBN 2-910239-75-6, Ed. SFGP, Paris, France.; A two-stage continuous bioreactor with cell recycle (TSCB) was developed in order to study the behaviour of Saccharomyces cerevisiae in high cell density. Residence time (RTD) and internal age (IAD) distributions of gas, liquid and cell biomass phases have been investigated according to a systemic approach (model identification, parametric study) in order to highlight the complex interactions between hydrodynamics (gas, liquid and solid phases) and biological activity. The noticeable differences between liquid and cell biomass could be explained by the competition between the internal recirculation and dilution rates and described by the dimensionless circulation index, K [3]. A parametric study is reported and discussed. Assumption based on these dimensionless parameters and reduced adaptation time enable to define acceptable and unacceptable working conditions in order to maintain the biological activity of the microorganism (specific rates and viability) as well as identifying optimal working conditions.

In: Proceeding of Eucass European Conference for Aerospace Sciences (St Petersburg, Russia ), July 4-7 2011.In: Proceeding of Eucass European Conference for Aerospace Sciences (St Petersburg, Russia ), July 4-7 2011.; Biocatalytic production of energetic molecules from renewable resources for aviation fuel. Eucass European Conference for Aerospace Sciences

International audience; Un bioréacteur biétage avec recyclage cellulaire (BBRC) innovant a été développé afin d'étudier le comportement de Saccharomyces cerevisiae en conditions de hautes concentrations cellulaires et de production intensive d'éthanol. Le principe du BBRC repose sur un découpage spatial du premier étage dédié à la croissance du biocatalyseur (métabolisme fermentaire). Ce bioprocédé fonctionne en mode continu et est combiné à la gestion de la viabilité avec le transfert des microorganismes entre les deux étages (retour du second vers le premier étage) et la maîtrise des phénomènes d'inhibition du métabolisme. Ce bioprocédé a permis d'atteindre des procductivités importantes en éthanol (41 kg.m3.h?¹) en combinant l'obtention de titre et rendement compatibles avec une transposition industrielle en intégrant la gestion de l'activité des microorganismes. Cependant, les performances du bioréacteurs nécessitent des investigations complémentaires dont l'identification des interactions complexes entre l'hydrodynamique des phases gaz, liquide et solide et l'activité biologique...

National audience

In Proceeding SFGP 2009 (14-16 octobre 2009, Marseille, France) Récents Progrès en Génie des Procédés, N°98, 2009, ISBN: 2-910239-72-1, Ed. SFGP, Paris, France. Résumé : Un bioréacteur bi-étagé avec recyclage cellulaire (BBRC) a été développé afin d’étudier le comportement de Saccharomyces cerevisiae en conditions de hautes concentrations cellulaires. Ce bioprocédé a permis d’atteindre des productivités intéressantes en éthanol (41kg.m-3.h-1) en combinant titre, rendement, viabilité et activité des microorganismes. Cependant, les performances du bioréacteur ne sont que partiellement maîtrisées étant données les interactions complexes entre l'hydrodynamique des phases gaz, liquide et solide et le contrôle de l'activité biologique. Dans ce travail, une identification hydrodynamique globale en conditions abiotiques a été menée à travers l'étude de la distribution des temps de séjour (DTS) et des âges internes (DAI) suivant une méthodologie appropriée. En premier lieu, les expérimentations ont conduit à l'identification et la formulation analytique des fonctions de distribution en mode continu avec et sans recirculation. En second lieu, une approche systémique a permis d'identifier les paramètres des modèles supposés, d'en caractériser l'évolution dans les limites des conditions opératoires investiguées puis d'en valider la robustesse avec les expériences avec recirculation. Pour la phase liquide, le comportement hydrodynamique des 2 réacteurs peut être assimilé à celui d'un réacteur ouvert parfaitement agité. Le comportement de type réacteur piston est observé pour le compartiment "perméat".In Proceeding SFGP 2009 (14-16 octobre 2009, Marseille, France) Récents Progrès en Génie des Procédés, N°98, 2009, ISBN: 2-910239-72-1, Ed. SFGP, Paris, France. Résumé : Un bioréacteur bi-étagé avec recyclage cellulaire (BBRC) a été développé afin d’étudier le comportement de Saccharomyces cerevisiae en conditions de hautes concentrations cellulaires. Ce bioprocédé a permis d’atteindre des productivités intéressantes en éthanol (41kg.m-3.h-1) en combinant titre, rendement, viabilité et activité des microorganismes. Cependant, les performances du bioréacteur ne sont que partiellement maîtrisées étant données les interactions complexes entre l'hydrodynamique des phases gaz, liquide et solide et le contrôle de l'activité biologique. Dans ce travail, une identification hydrodynamique globale en conditions abiotiques a été menée à travers l'étude de la distribution des temps de séjour (DTS) et des âges internes (DAI) suivant une méthodologie appropriée. En premier lieu, les expérimentations ont conduit à l'identification et la formulation analytique des fonctions de distribution en mode continu avec et sans recirculation. En second lieu, une approche systémique a permis d'identifier les paramètres des modèles supposés, d'en caractériser l'évolution dans les limites des conditions opératoires investiguées puis d'en valider la robustesse avec les expériences avec recirculation. Pour la phase liquide, le comportement hydrodynamique des 2 réacteurs peut être assimilé à celui d'un réacteur ouvert parfaitement agité. Le comportement de type réacteur piston est observé pour le compartiment "perméat".; Using tracer experiments to identify hydrodynamic behaviour of a two-stage bioreactor with cell recycle. 12. Congrès de la Société Française de Génie des Procédés (SFGP 2009) "Pour relever les défis industriels du XXIème siècle"

In Proceeding SFGP 2009 (14-16 octobre 2009, Marseille, France) Récents Progrès en Génie des Procédés, N°98, 2009, ISBN: 2-910239-72-1, Ed. SFGP, Paris, France. Abstract : Rheological behaviour of culture broth stands as a fundamental parameter in bioprocess performances because it affects simultaneously heat and mass transfer as well as flow pattern. It is then of first interest to get on-line characterization and to model the rheological behaviour of the fermentation broth relating to the microbial activity (specific kinetics, growth rate, physiology, morphology, cell concentration). In this context, our scientific objectives deals with the identification of the impact of physical properties of complex three-phase broth on bioprocess performances with the development of an experimental platform enabling on-line rheometry measurements during cell cultures. In this way, a bioreactor was equipped with a derivation loop including a specific on-line rheometric device. In a first time, friction curves of calibrated ducts were achieved with Newtonian and non-Newtonian shear-thinning model fluids. In a second time, axenic cultures with two microorganisms of different size (Escherichia coli and Yarrowia lipolytica) were carried out in order to produce high biomass concentrations. The uniqueness of friction curve is confirmed with model fluids, and validates our approach to investigate on-line rheometry of broths. The results obtained with E. coli and Y. lipolytica cultures respectively ranging between ~40-~110gCDW.l-1 and 75-~105gCDW.l-1 are reported. For Y. lipolytica, off-line rheometry demonstrated a shear-thinning behaviour in relation with biomass concentration whereas online viscosity measurements established in laminar flow regime for higher shear rates highlighted a Newtonian plate. For E. coli, on-line and off-line viscosities exhibited the same tendency but strongly differed in term of magnitude. In this case, several assumptions could be formulated to explain this difference: (i) thermal dependency of apparent viscosity, (ii) biological activity, (iii) volume gas fraction (aeration and biological production) in broth (~30-40%v/v) and (iv) shear rates (correlated to flow regime). Impact of different phases on apparent viscosity for high biomass concentration above 110gCDW.l-1 will be investigated in close future.In Proceeding SFGP 2009 (14-16 octobre 2009, Marseille, France) Récents Progrès en Génie des Procédés, N°98, 2009, ISBN: 2-910239-72-1, Ed. SFGP, Paris, France. Abstract : Rheological behaviour of culture broth stands as a fundamental parameter in bioprocess performances because it affects simultaneously heat and mass transfer as well as flow pattern. It is then of first interest to get on-line characterization and to model the rheological behaviour of the fermentation broth relating to the microbial activity (specific kinetics, growth rate, physiology, morphology, cell concentration). In this context, our scientific objectives deals with the identification of the impact of physical properties of complex three-phase broth on bioprocess performances with the development of an experimental platform enabling on-line rheometry measurements during cell cultures. In this way, a bioreactor was equipped with a derivation loop including a specific on-line rheometric device. In a first time, friction curves of calibrated ducts were achieved with Newtonian and non-Newtonian shear-thinning model fluids. In a second time, axenic cultures with two microorganisms of different size (Escherichia coli and Yarrowia lipolytica) were carried out in order to produce high biomass concentrations. The uniqueness of friction curve is confirmed with model fluids, and validates our approach to investigate on-line rheometry of broths. The results obtained with E. coli and Y. lipolytica cultures respectively ranging between ~40-~110gCDW.l-1 and 75-~105gCDW.l-1 are reported. For Y. lipolytica, off-line rheometry demonstrated a shear-thinning behaviour in relation with biomass concentration whereas online viscosity measurements established in laminar flow regime for higher shear rates highlighted a Newtonian plate. For E. coli, on-line and off-line viscosities exhibited the same tendency but strongly differed in term of magnitude. In this case, several assumptions could be formulated to explain this difference: (i) thermal dependency of apparent viscosity, (ii) biological activity, (iii) volume gas fraction (aeration and biological production) in broth (~30-40%v/v) and (iv) shear rates (correlated to flow regime). Impact of different phases on apparent viscosity for high biomass concentration above 110gCDW.l-1 will beinvestigated in close future.; Identification of physical and biological interactions in cell cultures in a bioreactor: On-line and off-line rheological characterization. 12. Congrès de la Société Française de Génie des Procédés (SFGP 2009) "Pour relever les défis industriels du XXIème siècle"

In: Proceeding of 8th World Congress of Chemical Engineering, August 23-29, Montréal, Quebec, Canada. Eds. Canadian Society for Chemical Engineering. (Ontario, Canada), ISBN: 0-9208044-44-6, Session: Bioproducts, Bioreactors and Bioprocesses, L.0122, 2009In: Proceeding of 8th World Congress of Chemical Engineering, August 23-29, Montréal, Quebec, Canada. Eds. Canadian Society for Chemical Engineering. (Ontario, Canada), ISBN: 0-9208044-44-6, Session: Bioproducts, Bioreactors and Bioprocesses, L.0122, 2009; Efficient microbial conversion of carbohydrates from plant biomass into energetic molecules such as specific lipids is a real challenge in bioprocess. Our study focussed on the evolution of yeast morphology and rheological behaviour of cell broth during production of intra-cellular lipids. Three Yarrowia lipolytica strains (wild and genetically engineered strains) were investigated under controlled fed-batch culture including 3 steps (growth, nitrogen limitation and lipid accumulation). Physical (microscopy, rheology, particle size distribution, concentration) and biological (cell dried matter, lipid content) parameters were simultaneously characterised or quantified. Culture strategy enabled to reach up to 111gCDW/L in biomass and 0.36g/gCDW lipid. Results demonstrate that yeast strains are characterised by different morphologies. Lipid synthesis is a complex and vital metabolism which affects morphology and physical properties. Broth rheology depends on biomass concentration, lipid accumulation and morphology and affects bioprocess performances.

In: 3rd European Conference for AeroSpace Sciences (EUCASS), July 6-9th, Palais des congrès, Versailles, France, 2009.In: 3rd European Conference for AeroSpace Sciences (EUCASS), July 6-9th, Palais des congrès, Versailles, France, 2009.; Biocatalytic production of energetic molecules from renewable resources for aerospace fuel: an innovative bioprocess with very high performances. 3. European Conference for AeroSpace Sciences (EUCASS)

In: Proceeding of 8th World Congress of Chemical Engineering (WCCE8), August 23-29, Montréal, Quebec, Canada. Eds. Canadian Society for Chemical Engineering. (Ontario, Canada), ISBN: 0-9208044-44-6, Session: Rheology in Chemical Processing & Chemical Product Design, L.2225, 2009 Abstract: Cellular cultures require an in-depth knowledge of biological and physical parameters to control and optimize the process. Among the physical parameters, viscosity and rheological behaviour are of first importance. This study describes implementation and results obtained with an experimental on-line rheological device mounted on a bioreactor. Description of the set-up and experimental calibration with well-defined Newtonian fluids are presented. An example of a cellular culture (E. coli) is then proposed enlightening the influence of biological activity on rheological behaviour and the need for on-line measurement. coli.In: Proceeding of 8th World Congress of Chemical Engineering (WCCE8), August 23-29, Montréal, Quebec, Canada. Eds. Canadian Society for Chemical Engineering. (Ontario, Canada), ISBN: 0-9208044-44-6, Session: Rheology in Chemical Processing & Chemical Product Design, L.2225, 2009Abstract: Cellular cultures require an in-depth knowledge of biological and physical parameters to control and optimize the process. Among the physical parameters, viscosity and rheological behaviour are of first importance. This study describes implementation and results obtained with an experimental on-line rheological device mounted on a bioreactor. Description of the set-up and experimental calibration with well-defined Newtonian fluids are presented. An example of a cellular culture (E. coli) is then proposed enlightening the influence of biological activity on rheological behaviour and the need for on-line measurement. coli.; On-line rheology of cell cultures in a bioreactor. 8.World Congress of Chemical Engineering (WCCE8)

International audience

Hydrodynamic behaviour of a two-stage bioreactor with cell recycle (TSCB) was investigated. Residence time distribution (RTD) and Internal Age Distribution (AID) of gas and liquid phases were performed with accurate tracing methods and under specific operating conditions and process modes (batch and continuous modes with and without recirculation between first and second stages). From experiments, RTD and analytical solution were formulated, and systemic analysis carried out. Results demonstrated that the magnitude of mean residence time and variance were strongly different between gas (»1min) and liquid (»100min) phases. RTD of gas phase showed that both reactors exhibited independent behaviour, and RTD could be described by two single and simple models (plug flow in series with j CSTR) with constant parameters (a, j) whatever investigated operating conditions (VVM, Re and Remixing). For liquid phase, experiments will enable to identify mixing time (batch mode) as well as the mean residence time and variance in continuous modes. RTD for permeate and purge flow and IAD in the first and second reactors were obtained and formulated. Under selective assumptions, a systemic analysis of liquid RTD lead to propose a reactor model in close relation with TSCB structure. In a first step, model parameters will be identified under continuous mode without recirculation and then, validated with recycle between two stages.Abstract: Hydrodynamic behaviour of a two-stage bioreactor with cell recycle (TSCB) was investigated. Residence time distribution (RTD) and Internal Age Distribution (AID) of gas and liquid phases were performed with accurate tracing methods and under specific operating conditions and process modes (batch and continuous modes with and without recirculation between first and second stages). From experiments, RTD and analytical solution were formulated, and systemic analysis carried out. Results demonstrated that the magnitude of mean residence time and variance were strongly different between gas (»1min) and liquid (»100min) phases. RTD of gas phase showed that both reactors exhibited independent behaviour, and RTD could be described by two single and simple models (plug flow in series with j CSTR) with constant parameters (a, j) whatever investigated operating conditions (VVM, Re and Remixing). For liquid phase, experiments will enable to identify mixing time (batch mode) as well as the mean residence time and variance in continuous modes. RTD for permeate and purge flow and IAD in the first and second reactors were obtained and formulated. Under selective assumptions, a systemic analysis of liquid RTD lead to propose a reactor model in close relation with TSCB structure. In a first step, model parameters will be identified under continuous mode without recirculation and then, validated with recycle between two stages.; Liquid and gas residence time distribution in a two-stage bioreactor with cell recycle. Tracer5, Tracers and Tracing methods

Evolution du comportement rhéologique d'un moût de fermentation lors de l'accumulation de lipides chez [i]Rhodotorula glutinis[/i]. GFR42: Rhéologie des milieux évolutifs