References of "Delvigne, Frank"
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See detailDynamic analysis of microbial behaviour face to envrionmental heterogeneities encountered in large-scale bioreactors
Sunya, Sirichai; Bideaux, Carine; Uribellarea, Jean-Louis et al

in Delvigne, Frank (Ed.) BASE (2011)

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See detailE.coli prpoS::gfp strain as biosensor of glucose heterogeneity inside industrial bioreactors
Brognaux, Alison ULg; Delvigne, Frank ULg; Thonart, Philippe ULg

Poster (2010, December 08)

• OBJECTIVE: Escherichia coli is a microorganism widely used in the industry for the production of recombinant proteins. The performances obtained at the laboratory level are not reproducible at a large ... [more ▼]

• OBJECTIVE: Escherichia coli is a microorganism widely used in the industry for the production of recombinant proteins. The performances obtained at the laboratory level are not reproducible at a large scale. Actually, the mixing operation is not efficient enough: gradients of glucose and oxygen appear when operating in fed-batch mode (addition of glucose during the culture). These gradients cause adverse impacts on the production of biomass and recombinant protein. The aim of this work is to use the microbial population as biocaptor of the encoutered stress inside heterogeneous industrial bioreactors to better scale-up and regulate these reactors. • MATERIALS AND METHODS: A plasmid carrying a stress promoter followed by the coding sequence of the Green Fluorescent Protein (GFP) is introduced in the bacterial host (in our case, the strain E. coli K12 will be considered as a model organism). When the cell is submitted to given stress condition, GFP synthesis is induced and accumulated into the cytoplasm, leading to the increase of the cell's fluorescence. Flow cytometry detection is used in order to quantify the fluorescence at the single cell level. Obtained results are frequency histograms of fluorescenceintensity in the microbial population • RESULTS: The rpoS gene is a gene of the general stress response, mainly induced at the entrance to stationary phase (during a lack of glucose). The tracking of the GFP fluorescence linked to the activation / repression of the rpoS promoter gives good results. Indeed, there is appearance of a segregation at the level of the GFP content among the microbial population. The intensity of the segregation, as well as its time of appearance during the culture can be related to the bioreactor mixing efficiency. • CONCLUSION: prpoS::gfp strains can be used as biosensors of the heterogeneity of glucose encountered inside industrial reactors. • POTENTIAL APPLICATIONS & KEY BENEFITS: These strains could be used to validate a fed-batch regulation (addition of glucose) at the industrial level. [less ▲]

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See detailBioprocesses scale-up : Interactions between physico-chemical and biological parameters
Delvigne, Frank ULg

Scientific conference (2010, March 15)

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See detailEvaluation of a set of E. coli reporter strains as physiological tracer for estimating bioreactor hydrodynamic efficiency
Delvigne, Frank ULg; Ingels, Sophie; Thonart, Philippe ULg

in Process Biochemistry (2010), 45(11), 1769-1778

A set of different green fluorescent protein (GFP) Escherichia coli reporter strains have been evaluated in mini- and stirred bioreactors operating in fed-batch mode with different degrees of ... [more ▼]

A set of different green fluorescent protein (GFP) Escherichia coli reporter strains have been evaluated in mini- and stirred bioreactors operating in fed-batch mode with different degrees of perturbations in order to estimate their potential use as process-related stress biosensor. The mini-bioreactor platform comprises a set of parallel shake flasks operating in fed-batch mode. The advantage of this system is its high experimental throughput for the evaluation of the GFP synthesis capacity of our reporter strains. In the case of classical shake flask system, no significant evolution of GFP synthesis have been observed, considering the reduced microbial growth period allowed by the system, whereas in the case of fed-batch operated mini-bioreactors, evolution of GFP synthesis, as well as GFP distribution among the microbial population, has been observed for three preselected strains (prpoS, puspA and posmC::gfp). More interestingly, a binary mode of expression has been observed in the case of the cultures carried out with the reporter strains for which GFP synthesis is under the control of the rpoS promoter which is induced under carbon limitation conditions. However, the generation of controlled glucose perturbations is relatively limited in this system and, in a second step fully automated bioreactor with a sclae-down strategy has been used to correlate the response of a prpoS::gfp strains with extracellular glucose perturbations. In the case of the culture performed in perturbed bioreactor (glucose intermittent feeding or glucose addition at the level of the recycle loop of a two-compartment scale-down bioreactor), the slowdown of the GFP synthesis resulting in the observation of a binary repartition of GFP content among the microbial population, has been observed. This observation led to the conclusion that the prpoS::gfp can be used as a biosensor for the validation of a fed-batch profile in industrial-scale bioreactors. [less ▲]

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See detailBioprocédés et biotechnologies
Delvigne, Frank ULg

Scientific conference (2010)

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See detailDevelopment of an original approach to evaluate effects of surfactants, biomass and pollutants on the scaling-up of a two-phase partitioning bioreactor
Aldric, Jean-Marc ULg; Gillet, Sébastien ULg; Delvigne, Frank ULg et al

in Journal of Chemical Technology & Biotechnology (2010), 84

BACKGROUND: Two-phase partitioning bioreactors (TPPBs) are considered as a new technology for xenobiotic degradation in gaseous effluents. However, there is still a need for more knowledge on how to ... [more ▼]

BACKGROUND: Two-phase partitioning bioreactors (TPPBs) are considered as a new technology for xenobiotic degradation in gaseous effluents. However, there is still a need for more knowledge on how to design and scale-up TPPBs. The partitioning of the two phases remains a misunderstood way of research. In particular, the impact of pollutant (isopropylbenzene), biomass and surfactant extract needs to be better evaluated. RESULTS:. An adaptated scale-down apparatus has been developed in order to quantify the speed of phase partitioning (SPP) into a plug flow section. Firstly, it was shown that isopropylbenzene (IPB) doesn’t destabilize more significantly the system. Secondly, respectively 0.5 g.L-1 and 0.05 g.L-1 of biomass and surfactant extract, separately or in mixture, were sufficient to ensure the stability of the two-phase system. Finally, a 100 m3 limit of scaling-up was suggested on the basis of the circulation time comparison. CONCLUSION: The scaling-up of an aqueous/silicone-oil TPPB was found to be definitely conceivable when the presence of biotic compounds were considered. However, further considerations are needed to verify our assumptions, in particular by taking into account the velocity field pattern in full-scale bioreactors and reproduce it in lab-scale apparatus. [less ▲]

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See detailL'extrapolation des bioréacteurs : un problème de génie des procédés ou de physiologie microbienne ?
Delvigne, Frank ULg; Destain, Jacqueline ULg; Brognaux, Alison ULg et al

in Chimie Nouvelle (2010), 104

Bioreactor scale-up often pose a serious issue during the industrial development of a bioprocess considering the numerous physical and biological phenomena occurring in the reacting volume. The basic ... [more ▼]

Bioreactor scale-up often pose a serious issue during the industrial development of a bioprocess considering the numerous physical and biological phenomena occurring in the reacting volume. The basic principles of scale-up coming from the traditional chemical and process engineering approaches will be first reviewed and will be then compared to a new one involving recent development at the level of microbial strain manipulation. This "physiological" approach of scale-up involves directly a biological component of the system (by comparison with the traditional approach for scaling-up involving physical parameters indirectly linked to the physiological phenomena occurring in the bioreactor), i.e. the synthesis of a reporter fluorescent protein when microbial cells are exposed to stress. It will be shown how this principle can be used for a better understanding of the relationship between bioreactor hydrodynamics and microbial stress. [less ▲]

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See detailFoam formation and control in bioreactors
Delvigne, Frank ULg; Lecomte, Jean-Paul

in Michael C. (Ed.) Encyclopedia of Industrial Biotechnology: Bioprocess, Bioseparation, and Cell Technology (2010)

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See detailMicrobial bioprocesses : current state and future prospect
Delvigne, Frank ULg

Scientific conference (2010)

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See detailInfluence of bioreactor hydraulic characteristics on a Saccharomyces cerevisiae fed-batch culture: hydrodynamic modelling and scale-down investigations.
Lejeune, Annick ULg; Delvigne, Frank ULg; Thonart, Philippe ULg

in Journal of Industrial Microbiology & Biotechnology (2010), 37

Yeast is a widely used microorganism at the industrial level because of its biomass and metabolite production capabilities. However, due to its sensitivity to the glucose effect, problems occur during ... [more ▼]

Yeast is a widely used microorganism at the industrial level because of its biomass and metabolite production capabilities. However, due to its sensitivity to the glucose effect, problems occur during scale-up to the industrial scale. Hydrodynamic conditions are not ideal in large-scale bioreactors, and glucose concentration gradients can arise when these bioreactors are operating in fed-batch mode. We have studied the effects of such gradients in a scale-down reactor, which consists of a mixed part linked to a non-mixed part by a recirculation pump, in order to mimic the hydrodynamic conditions encountered at the large scale. During the fermentation tests in the scale-down reactor, there was a drop in both biomass yield (ratio between the biomass produced and the glucose added) and trehalose production and an increase in both fermentation time (time between inoculation and beginning of stationary phase) and ethanol production. We have developed a stochastic model which explains these effects as the result of an induction process determined mainly by the hydrodynamic conditions. The concentration profiles experienced by the microorganisms during the scale-down tests were expressed and linked to the biomass yields of the scale-down tests. [less ▲]

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See detailDevelopment of a compartment model based on CFD simulations for mixing description in bioreactors
Delafosse, Angélique ULg; Delvigne, Frank ULg; Collignon, Marie-Laure ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2010), 14(2), 517-522

Understanding and modelling the complex interactions between biological reaction and hydrodynamics is a key problem when dealing with bioprocesses. It is fundamental to be able to accurately predict the ... [more ▼]

Understanding and modelling the complex interactions between biological reaction and hydrodynamics is a key problem when dealing with bioprocesses. It is fundamental to be able to accurately predict the hydrodynamics behaviour of bioreactors of different size and its interaction with the biological reaction. CFD can provide detailed modelling about hydrodynamics and mixing. However, it is computationally intensive, especially when reactions are taken into account. Another way to predict hydrodynamics is the use of "Compartment" or "Multi-zone" model which are much less demanding in computation time than CFD. However, compartments and fluxes between them are often defined by considering global quantities not representative of the flow. To overcome the limitations of these two methods, a solution is to combine compartment modelling and CFD simulations. Therefore, the aim of this study is to develop a methodology in order to propose a compartment model based on CFD simulations of a bioreactor. The flow rate between two compartments can be easily computed from the velocity fields obtained by CFD. The difficulty lies in the definition of the zones in such a way they can be considered as perfectly mixed. The creation of the model compartments from CFD cells can be achieved manually or automatically. The manual zoning consists in aggregating CFD cells according to the user's wish. The automatic zoning defines compartments as regions within which the value of one or several properties are uniform with respect to a given tolerance. Both manual and automatic zoning methods have been developed and compared by simulating the mixing of an inert scalar. For the automatic zoning, several algorithms and different flow properties have been tested as criteria for the compartment creation. [less ▲]

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See detail80 years of industrial dry hopping knowledge
Derdelinckx, Guy; Daenen, Luk; Rock, Jean-Marie et al

in EBC hop symposium 2010 (2010)

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See detailTrehalose as a stress marker of the physiological impact of mixing on yeast production: scale-down reactors and mini-bioreactors investigations
Lejeune, Annick ULg; Delvigne, Frank ULg; Thonart, Philippe ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2010), 14

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See detailImpact of scaled-down dissolved oxygen fluctuations at different levels of the lipase synthesis pathway of Yarrowia lipolytica
Kar, Tambi ULg; Destain, Jacqueline ULg; Thonart, Philippe ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2010), 14

Detailed reference viewed: 33 (12 ULg)