In-situ and ex-situ rheometry of high density Yarrowia lipolytica broth: determination of critical concentration and impact of yeastmycelial transition

The specificity of microbial bioreactions which give rise to irreducible couplings with hydrodynamics and heat and mass transfers, led into complex (three phases medium) and dynamic (auto-biocatalytic reaction) systems. Cells (concentration, shape, dimension, physiology…) strongly affect physico-chemical properties of broth and the modification of these characteristics interacts with bioprocess performances (specific rates, yields…) with an improvement or, more generally, a decrease of yields

Irreducible coupling between physical and biological phenomena: overview of on-line and off-line physical measurements during high cell density cultures of yarrowia lipolytica

During cell cultures in bioreactor, micro-organism physiology closely interacts with physico-chemical parameters (gas and feed flow rates, mixing, temperature, pH, pressure). The specificity of microbial bioreactions in relation with irreducible couplings between heat and mass transfers and fluid mechanics, led into complex (three phases medium) and dynamic (auto-biocatalytic reaction) systems. Our scientific approach aims to investigate, understand and control dynamic interactions between physical and biological systems at different scales (macro, micro and molecular) for molecules, strains and/or bioprocess innovation in a white biotechnology context. Cells (concentration, shape, dimension, physiology) strongly affect physico-chemical properties of broth and the modification of these characteristics interacts with bioprocess performances (specific rates, yields…) with an improvement or, more generally, a decrease of yields. Among these properties, rheological behaviour is a strategy widely used to understand the impact of cells and the modification of bioprocess performances. Our approach rests on physical and physico-chemical on-line and off-line measurements in respect with accurate and stringent conditions imposed by cell culture strategy. This work leads to design and realise an original pilot based on a bioreactor (20L) with a derivation loop including a specific on-line rheometric device as well as additional physical and biological measurements. Y. lipolytica cultures were investigated with a control of growth rate by carbon feed within concentrations ranging from 0.1 up to 60gCDW/L. On-line and off-line measurements are discussed regarding similar or opposite tendencies along culture. If the off-line density could be correlated with cell concentration, on-line measurement exhibit opposite tendancy. On-line and off-line rheological measurements are consistent. Results are discussed in terms of size, morphology, surface properties, concentration, biological activity and compared to scientific literature. On-line rheology highlight about the Non-newtonian rheological behaviour of broths and the gap between on-line and off-line measurements

Impact of cell physiology and densities during oxidative axenic cultures of Yarrowia lipolytica on physico-chemical properties of broth

Impact of cell physiology and densities during oxidative axenic cultures of Yarrowia lipolytica on physico-chemical properties of brot

Production of fermentescible sugar from paper-pulp: looking for a dynamic and multiscale integrated models based on physical parameters

In order to achieve economic viability, the biorefining of lignocellulosic resources must be operated at very high feedstock dry matter content. The paper pulp product is rather appropriate for modern biorefining, because it displays low lignin content, is free of inhibitory compounds that can perturb fermentations and is devoid of microbial contaminants. Nevertheless the enzyme liquefaction and saccharification of paper-like pulps are subject to the same constraints as other pulps obtained via alternative methods such as steam explosion or dilute acid hydrolysis. Therefore, the better scientific understanding and ultimately the technical mastering of these critical biocatalytic reactions, which involve complex matrices at high solids content, is currently a major challenge that must be met in order to facilitate the intensification of biorefining operations. Our aim is to investigate dynamic of transfer phenomena and limitation of biocatalytic reactions with lignocelluloses resources under high concentration conditions. Our action focuses on the identification of rate limiting steps of the liquefactions mechanisms by physical and biochemical characterization of pre-treated lignocellulosic resources at a macroscopic scale (power consumption, rheology), microscopic scale (particle size, morphology) and molecular scale (chemical analysis). Firstly, based on real and model matrices and using Metzner & Reed concept, non-Newtonian rheological behaviour of fiber suspensions are described by a structured rheological model including parameters such as concentration, size and shape. Secondly, the complex relationships between fibre structure, degradation, chemical composition and rheological behaviour is investigated. To this end, physical and biochemical on line and off-line analyses will be conducted during bioreaction with a specific and fully instrumented bioprocess. Relation between apparent viscosity change and biocatalytic degradation of fiber may then be discussed

Brewing, winemaking and distilling: an overview of wastewater treatment and utilization schemes (Part IV - Chapter 35)

Brewing, winemaking and distilling: an overview of wastewater treatment and utilization schemes (Part IV - Chapter 35

Fouling Monitoring: Local Thermal Analysis

In the process industry including agro and bioprocess, fouling is considered to be a complex andmisunderstood phenomenon. Heating, holding, and cooling operations are carried out in continuous orbatch processes and fouling occurs in equipment with a wide range of kinetics (from minutes up to years)and dimensions (from micrometers up to centimeters). Control and understanding of the foulingphenomenon is of industrial interest as it leads to reduction in process performances, higher energyconsumption, and issues with water management. In industrial processes (agri-food, pulp and paper,petrochemistry, etc.), the detection of the fouling level in production lines is a major consideration foroptimizing cleaning sequences and their frequency. It is important to have real-time and continuousinformation about the fouling status of equipment. In heat exchangers, this information is necessary tomonitor impaired heat transfers due to deposits (safety and quality of the final product), to preventbiofilm (Legionellarisks mitigation) in cooling towers, to reduce costs associated with production, andto optimize chemical discharges which have significant environmental consequences. Various methods,including rheological, chemical, mechanical, optical, ultrasonic, and thermal, have been reported. In thisentry, we discuss a fouling sensor that is based on local differential thermal analysis and was developedto study fouling phenomena in batch and continuous processes. First, a bibliographic overview presentssimilar experimental devices, and theoretical considerations are described. Second, materials andmethods are described before presenting our experimental results and a discussion dealing with operat-ing mode, sensor sensitivity to fouling (deposit elimination and formation), and potential applications.The comparison of two operating modes for the sensor—steady (STR) and periodic (PTR) thermalregimes—is also given. Finally, the temperature profile and sensitivity are modeled for the existingsensor geometry

Investigation of velocity field (by particle image velocimetry) in turbulent flow regime within a dynamic filtration module

In : 10th European Congress of Chemical Engineering; 3rd European Congress of Applied Biotechnology and 5th European Process Intensification Conference (ECCE10+ECAB3+EPIC5), Submission-2428. Topic : ECCE10 / Fluid separations processes and technologies / process equipment characterisation and design. Nice, France, September 27th - October 1st 2015Investigation of velocity field (by particle image velocimetry) in turbulent flow regime within a dynamic filtration module . 10. European Congress of Chemical Engineering - ECCE 201

Etat des lieux sur les méthodes de détection de l’encrassement Exemples de technologies

In: Pole HYDREOS, Journée technique Dépôts-Biofilms-Entartrage, Jeudi 12 Septembre 2013, ENSIC, NancyFouling is a complex (sometime partially known and described) phenomenon in most foodand bioprocess industries. Continuous or batch processes lead to fouling of the equipment atvarying rates (from minutes up to years) and propensity (from micrometers up tocentimetres). The control and understanding of fouling phenomena is clearly relevant toindustry: reduction of process performance, energy consumption, sanitary risk and watermanagement. To monitor fouling, various devices have been reported in the literature including rheological,electrical, chemical, mechanical, optical, sonic, ultrasonic, and thermal methods eachexhibiting its own specificities, advantages, and disadvantages. In this presentation, the main lab and industrial techniques dedicated to monitor fouling willbe reported as a benchmarking of techniques, scientific works, patents and industrial sensors

Use of RVF technology to achieve rough beer clarification and cold-sterilisation of beer.

In : 28th Congress of the European Brewery Convention, Budapest, Hungary, 12-17 May 2001, Publisher Fachverlag Hans Carl, Germany, n°ISBN : 90-70143-21-6. pp.258-267Use of RVF technology to achieve rough beer clarification and cold-sterilisation of beer. . 28. Congress of the European Brewery Conventio

Identification of critical cell concentrations with in-situ and ex-situ characterization of physico-chemical properties of broth during oxidative axenic cultures of Yarrowia lipolytica in fed-batch mode

Identification of critical cell concentrations with in-situ and ex-situ characterization of physico-chemical properties of broth during oxidative axenic cultures of Yarrowia lipolytica in fed-batch mod