Study of the influence of mixing on the morphology and production of fumaric acid in Rhizopus oryzae using a scale-down approach

In order to reduce the environmental impact of transport and the chemical industry, IFPEN is investing in biorefineries, biofuels and bio-based chemistry. Among the targets being explored, fumaric acid has the potential to become a platform molecule, providing access to various bio-based molecules.
With strong expertise in life sciences and engineering, the TBI laboratory combines fundamental and applied research in the fields of biotechnology and process engineering to address the challenges of the bioeconomy.
Together with four other partners, IFPEN and TBI are participating in the BioFUMAC collaborative project, which aims to develop a new route to bio-based acrylic acid via robust bioproduction of fumaric acid through fermentation of the filamentous fungus Rhizopus oryzae. The BioFUMAC project is structured into three Work Packages: WP1 optimises and secures the production of fumaric acid; WP2 develops a new enzyme for the bioconversion of fumaric acid into acrylic acid; WP3 prepares the integration of these two steps into the overall process, including a nanofiltration step.
Despite very good production performance in the laboratory, there is currently no industrial-scale bioproduction of fumaric acid. Rhizopus strains can adopt various morphologies: free mycelium, pellets, aggregates, and the difficulty in controlling a particular morphological type is one of the barriers to scaling up.
The aim of this thesis is to validate the scale-up of the protocol for the production of fumaric acid by Rhizopus oryzae. It will draw on IFPEN’s experience in scaling up the protocol for the production of cellulases by Trichoderma reesei. It will also draw on TBI’s expertise in the study and modelling of interactions between hydrodynamics and biology in bioreactors.
Within the BioFUMAC project, this work will also draw on the results of an ongoing PhD thesis on the experimental optimisation of culture under ideal mixing conditions, which will enable the identification of optimal parameters in terms of, for example, temperature, pH, agitation, culture medium composition, etc.
Thus, in the first part (fermentation technology, led by IFPEN Rueil), we will use a two-stage fermentation setup allowing a ‘scale-down’ approach to reproduce in the laboratory the mixing conditions expected at industrial scale, in terms of power dissipation, shear and nutrient heterogeneities. We will then measure the impact of these non-ideal mixing conditions on the morphology of Rhizopus and on its fumaric acid production performance.
In a second phase (bioprocess modelling, led by TBI), we will combine all the data generated to construct an in silico model of a large-scale industrial bioreactor, integrating descriptions of hydrodynamics, gas-liquid mass transfer and biological reactions. This digital twin will enable us to quantify the loss of performance due to large-scale cultivation, thereby ensuring the reliability of the production protocol’s scale-up.
 

About IFP Energies nouvelles
IFP Energies nouvelles is a public research, innovation and training center whose mission is to develop high-performance, cost-effective, clean and sustainable technologies in the fields of energy, mobility and the environment. Its teams are driving innovation towards a low-carbon and sustainable world, from scientific concepts through to technological solutions. Whether processes, equipment, products, software or services, its low-carbon innovations are paving the way for the energy and ecological transition and facilitating the emergence of industrial sectors of the future. IFPEN boldly envisions and rigorously designs solutions for the society of tomorrow. For more information, see our website. 
IFPEN offers a stimulating research environment, with access to first in class laboratory infrastructures and computing facilities. IFPEN offers competitive salary and benefits packages. All PhD students have access to dedicated seminars and training sessions. 

About Toulouse Biotechnology Institute
TBI is a public research laboratory, supported by INSA Toulouse, the CNRS and INRAE, which combines fundamental and applied research in the field of biotechnology and processes. Combining scientific excellence with economic and societal relevance, the laboratory is organised around four scientific clusters and a technological cluster. With strong disciplinary expertise in life sciences and engineering, the laboratory pursues a multi-scale, multidisciplinary and interdisciplinary scientific strategy to address the challenges of the bioeconomy, drawing on a large network of public and private partners. It is also one of the accredited laboratories of the Institut Carnot 3BCar. TBI conducts research in catalysis and enzyme engineering, systems biology and synthetic biology, fermentation, process engineering and eco-design. Website.
 

Academic requirements    University Master degree in biotechnology and bioprocess   
Language requirements    English level B2 (CEFR)    
Other requirements    Experience in fermentation technology, Knowledge of bioprocess modelling, Good communication and teamwork skills