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PEOPLE@HES-SO – Annuaire et Répertoire des compétences
PEOPLE@HES-SO – Annuaire et Répertoire des compétences

PEOPLE@HES-SO
Annuaire et Répertoire des compétences

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Amstutz Véronique

Amstutz Véronique

Adjoint-e scientifique HES A

Compétences principales

Biotechnologie et bioprocédés

Fermentation gaz

Biopolymères et bioplastiques

Electrolyse de l'eau et hydrogène

Electrochimie et batterie redox

Microscopie électronique à balayage

Rédaction de demande de financement

  • Contact

  • Enseignement

  • Recherche

  • Publications

Contrat principal

Adjoint-e scientifique HES A

Bureau: ENP.19.RI03

HES-SO Valais-Wallis - Haute Ecole d'Ingénierie
Rue de l'Industrie 23, 1950 Sion, CH
HEI - VS
Domaine
Chimie et sciences de la vie
Filière principale
Ingénierie des Sciences du vivant
BSc HES-SO en Ingénierie des sciences du vivant - HES-SO Valais-Wallis - Haute Ecole d'Ingénierie
  • Bioprocédés - Exercices de simulation avec Simulab (Matlab)

En cours

Biological functions and dynamics of PHA cycle in Rhodospirillum rubrum, as well as the related biotechnological consequences (BIOPHARM)

Rôle: Collaborateur/trice

Financement: SNF

Description du projet :

Polyhydroxyalkanoates (PHA) are polyesters naturally accumulated by prokaryotes as
carbon and energy storage in the form of intracellular granules. Apart from their
crucial biological roles, they represent promising, sustainable and biodegradable
alternatives to petrochemical polymers. To study their biosynthesis, we focus on the
bacterium Rhodospirillum rubrum for its extraordinary metabolic flexibility, which
designates it as a perfect model organism, representative of many PHA-producing
bacteria with diverse biosynthetic strategies. At the very basis of bacterial PHA
biosynthesis and mobilization lies the so-called PHA cycle, based on pivotal enzymes:
PHA synthase and PHA depolymerase. It is our main objective to unravel the complex
modulation pathways of the activity of these enzymes as a means to rationalize the link
between cultivation conditions, cell PHA content, and also production rate. We will
eventually propose a model for PHA cycle dynamics based on the data accumulated in
order to predict PHA accumulation as a function of the environmental conditions.
In the course of this study, the role of PHA in the bacterial energy household will be
characterized and quantified for various metabolic pathways in fermentations and the
effects of cell memory from cultivation history will be examined in a way to identify
supplementary factors affecting bacterial responses in terms of PHA production. After
their purification, we will measure the activity of the enzymes in vitro, determine the
effects of various factors affecting their activity (e.g. pH, nature of substrate, phasins)
and unfold their interplay within the PHA cycle. Furthermore, the study will be
extended to the assessment of the different biological roles of PHA granules in the
bacterium, especially in terms of resistance against environmentally and
biotechnologically relevant stress factors.
Besides building on advanced cultivation cultures, such as two stage continuous
cultures, gas fermentation, photo-bioprocesses, we will harness tools from
bioinformatics and metabolomics for characterizing the dynamics of the PHA cycle. In
particular, the transcriptomic analyses under various cultivation conditions will be on
focus. This will be complemented with a multitude of biophysical characterization
techniques for bacterial state, granule number, shape and properties, as well as
polymer composition and molecular weight characterization. As an ultimate level of
analysis and understanding, modeling and simulation will be deployed, on the basis of
the data collected, and coupled with experimental validation.
This battery of complementary techniques is expected to provide the multi-dimensional
perspective necessary to unravel the complex PHA dynamics and its regulation
mechanisms and. The gained knowledge can be extended to the control of PHA
accumulation rates and its composition.
This project represents an outstanding opportunity for both partners of the consortium
to express together their strong expertise in the subject of PHA biosynthesis. Their
shared knowledge, competences, and know-how will bring the understanding of PHA
biosynthesis metabolism to a higher level. This will ultimately enable to further design
and optimize suitable systems for PHA production, contributing to the deployment of
some of the most promising future bioplastic materials, and therefore to a significantly
decreased environmental impact of human activities.

Equipe de recherche au sein de la HES-SO: Zinn Manfred , Amstutz Véronique , Ochsner Andrea Maria , Fleuriot-Blitman Hugo

Partenaires académiques: Prof. Stanislav Obruca, Brno University of Technology, Brno, Czech Republic

Durée du projet: 01.01.2021 - 31.12.2023

Statut: En cours

Terminés

Des biocarburants à base de PHA pour une mobilité durable et neutre en CO2
AGP

Rôle: Collaborateur/trice

Description du projet : Statistic figures for mobility and traffic in 2018 show that cars and leisure activities prevail in passenger transportation. The car is the most common transport means with an average of 10'370 km per year. Each Swiss citizen consumes on average 700 L of fossil fuels yearly and transport accounts for 39% of CO2 emissions of Switzerland. To reduce these emissions, sustainable biofuels are required. Fossil fuels are already blended with biodiesel or bioethanol from renewable resources, but this corresponds to only 3% of total fuel consumption. Furthermore, biofuels production is currently in competition with food sources. Although electro-mobility is emerging, there are still more than 6 million petrol/diesel vehicles in operation in Switzerland - there is an evolution, but not a revolution in the vehicle population. To this end, solutions for sustainable fuels needs to be developed rapidly, which a) can be integrated into the existing infrastructure, b) are CO2-neutral and c) do not compete with food supply. This is where this project comes in: many bacteria naturally accumulate polyhydroxyalkanoate (PHA) in presence of carbon substrate when another nutrient (nitrogen or phosphorus) is limiting growth. We established a bioprocess with microorganisms that are able to produce PHA with up to 80% in the biomass from CO2. We further chemically convert PHA to various biofuel derivatives (yields >90%, scale >100 g). By our approach of depolymerization and/or hydrogenation (from H2 from solar water splitting) we produced biofuels not competing with food & feed sources. The ecologic potential of our new PHA-based biofuel was assessed by a life cycle assessment (LCA) and compared to alternative and existing competing technologies. Test of the new PHA-based biofuels in an engine test bench unveiled the potential of this novel and innovative biofuel production chain. A patent application is pending.

Equipe de recherche au sein de la HES-SO: Pott Julien , Micaux Fabrice , Zinn Manfred , Pilloud Vincent , Dardano Florian , Miserez Florian , Albergati Luce , Nellen Christian , Alber Bastien , Monney Nils , Maruel Frédéric , Sthioul Hervé , Richard Jacques , Hanik Nils , Utsunomia Camila , Amstutz Véronique , Marti Roger

Partenaires académiques: HES-SO Rectorat; VS - Institut Technologies du vivant; hepia inSTI; FR - EIA - Institut ChemTech; Marti Roger, FR - EIA - Institut ChemTech

Durée du projet: 01.04.2019 - 30.09.2021

Montant global du projet: 270'000 CHF

Statut: Terminé

2024

Cultivation driven transcriptomic changes in the wild-type and mutant strains of rhodospirillum rubrum
Article scientifique ArODES

Katerina Jureckova, Marketa Nykrynova, Eva Slanimova, Hugo Fleuriot-Blitman, Véronique Amstutz, Kristyna Hermankova, Matej Bezdicek, Katerina Mrazova, Kamila Hrubanova, Manfred Zinn, Stanislav Obruca, Karel Sedlar

Computational and Structural Biotechnology Journal,  2024, 23, 2681-2694

Lien vers la publication

Résumé:

Purple photosynthetic bacteria (PPB) are versatile microorganisms capable of producing various value-added chemicals, e.g., biopolymers and biofuels. They employ diverse metabolic pathways, allowing them to adapt to various growth conditions and even extreme environments. Thus, they are ideal organisms for the Next Generation Industrial Biotechnology concept of reducing the risk of contamination by using naturally robust extremophiles. Unfortunately, the potential of PPB for use in biotechnology is hampered by missing knowledge on regulations of their metabolism. Although Rhodospirillum rubrum represents a model purple bacterium studied for polyhydroxyalkanoate and hydrogen production, light/chemical energy conversion, and nitrogen fixation, little is known regarding the regulation of its metabolism at the transcriptomic level. Using RNA sequencing, we compared gene expression during the cultivation utilizing fructose and acetate as substrates in case of the wild-type strain R. rubrum DSM 467T and its knock-out mutant strain that is missing two polyhydroxyalkanoate synthases PhaC1 and PhaC2. During this first genome-wide expression study of R. rubrum, we were able to characterize cultivation-driven transcriptomic changes and to annotate non-coding elements as small RNAs.

2021

Modeling of continuous PHA production by a hybrid approach based on first principles and machine learning
Article scientifique ArODES

Martin F. Luna, Andrea M. Ochsner, Véronique Amstutz, Damian von Blarer, Michael Sokolov, Paolo Arosio, Manfred Zinn

Processes,  2021, vol. 9, article no. 1560

Lien vers la publication

Résumé:

Polyhydroxyalkanoates (PHA) are renewable alternatives to traditional oil-derived polymers. PHA can be produced by different microorganisms in continuous culture under specific media composition, which makes the production process both promising and challenging. In order to achieve large productivities while maintaining high yield and efficiency, the continuous culture needs to be operated in the so-called dual nutrient limitation condition, where both the nitrogen and carbon sources are kept at very low concentrations. Mathematical models can greatly assist both design and operation of the bioprocess, but are challenged by the complexity of the system, in particular by the dual nutrient-limited growth phenomenon, where the cells undergo a metabolic shift that abruptly changes their behavior. Traditional, non-structured mechanistic models based on Monod uptake kinetics can be used to describe the bioreactor operation under specific process conditions. However, in the absence of a model description of the metabolic phenomena inside the cell, the extrapolation to a broader operation domain (e.g., different feeding concentrations and dilution rates) may present mismatches between the predictions and the actual process outcomes. Such detailed models may require almost perfect knowledge of the cell metabolism and omic-level measurements, hampering their development. On the other hand, purely data-driven models that learn correlations from experimental data do not require any prior knowledge of the process and are therefore unbiased and flexible. However, many more data are required for their development and their extrapolation ability is limited to conditions that are similar to the ones used for training. An attractive alternative is the combination of the extrapolation power of first principles knowledge with the flexibility of machine learning methods. This approach results in a hybrid model for the growth and uptake rates that can be used to predict the dynamic operation of the bioreactor. Here we develop a hybrid model to describe the continuous production of PHA by Pseudomonas putida GPo1 culture. After training, the model with experimental data gained under different dilution rates and medium compositions, we demonstrate how the model can describe the process in a wide range of operating conditions, including both single and dual nutrient-limited growth.

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