References of "Delvigne, Frank"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailInfluence of methanol/sorbitol co-feeding rate on pAOX1 induction in a Pichia pastoris Mut+ strain in bioreactor with limited oxygen transfer rate.
Carly, F.; Niu, H.; Delvigne, Frank ULg et al

in Journal of industrial microbiology & biotechnology (2016), 43(4), 517-23

High Pichia pastoris biomass density could be obtained using high co-feeding rate of methanol and sorbitol in a fed-batch or continuous culture, while further higher feeding rate finally leads to oxygen ... [more ▼]

High Pichia pastoris biomass density could be obtained using high co-feeding rate of methanol and sorbitol in a fed-batch or continuous culture, while further higher feeding rate finally leads to oxygen limitation in bioreactor. In the literature, there is lack of report about AOX1 promoter regulation with regard to dissolved oxygen level (DO). Therefore, in this work, chemostat cultures were performed to investigate the cell growth, metabolism and regulation of the AOX1 promoter (pAOX1) regarding co-feeding rate of optimized methanol/sorbitol mixture (methanol fraction 0.60 C-mol/C-mol) using a P. pastoris Mut+/pAOX1-lacZ strain. The oxygen transfer rates (OTR) in bioreactor were kept in the range of typical values of large bioreactor, i.e., 4-8 g/(L h) if DO equals 30 % saturation or 5-10 g/(L h) if DO nears zero. For DO >0, an increase of the carbon fed led to an increase of pAOX1 induction. By contrast, when dissolved oxygen was completely depleted, methanol accumulated, causing a 30 % decrease of pAOX1 induction. However, this decrease is more likely to be lined to methanol accumulation than to low level of dissolved oxygen (<4 % DO). Methanol/sorbitol co-feeding allowed cells to adapt to oxygen transient limitations that often occur at industrial scale with reduced effect on pAOX1 induction. The optimal feeding rate tested here was 6.6 mmol C (DCW h)(-1) at an OTR of 8.28 g O2(L h)(-1) with over fivefold pAOX1 induction (probably directly associated with target protein productivity) compared with previous work. [less ▲]

Detailed reference viewed: 23 (2 ULg)
Full Text
See detailTechniques for nutrient recovery from manure and slurry
Camargo-Valero, Miller; De Clercq, Lies; Delvigne, Frank ULg et al

Report (2015)

Detailed reference viewed: 31 (1 ULg)
Full Text
See detailTechniques for nutrient recovery from digestate derivatives
Bamelis, Lies; Blancke, Stieven; Camargo-Valero, Miller et al

Report (2015)

Detailed reference viewed: 17 (0 ULg)
Full Text
See detailTechniques for nutrient recovery from household and industrial wastes
Camargo-Valero, Miller; Bamelis, Lies; De Clercq, Lies et al

Report (2015)

Detailed reference viewed: 15 (3 ULg)
Full Text
Peer Reviewed
See detailFungal biofilm reactor improves the quality of a fusion protein GLA::GFP produced by Aspergillus oryzae
Zune, Quentin ULg; Delepierre, Anissa ULg; Bauwens, Julien ULg et al

Poster (2015, October)

Fungal biofilm is known to promote the excretion of secondary metabolites, in accordance with solid-state related physiological mechanisms. In this work, the potentialities of fungal biofilm will be ... [more ▼]

Fungal biofilm is known to promote the excretion of secondary metabolites, in accordance with solid-state related physiological mechanisms. In this work, the potentialities of fungal biofilm will be investigated in the context of the production of a Gla::GFP fusion protein by Aspergillus oryzae. Since the production of this protein is under the control of the promoter glaB, specifically induced in solid-state fermentation, biofilm mode of culture is expected to enhance the global productivity. However, we found that the glaB promoter is also activated in submerged bioreactor and the fusion protein production is higher in this mode of culture. This result is related to the high shear stress leading to biomass autolysis and leakage of intracellular fusion protein into the extracellular medium. Moreover, 2D-gel electrophoresis highlights preservation of the fusion protein integrity produced in biofilm conditions whereas proteolysis strongly affects fusion protein recovery in the submerged cultures performed at high stirring rate. Fungal biofilm reactor design was then further investigated and the scale-up potentialities were evaluated. Indeed, the specific design investigated in this work involves the use of metal structured packing exhibiting a high specific area and that can be easily expanded to large-scale bioprocessing conditions. [less ▲]

Detailed reference viewed: 80 (23 ULg)
Full Text
Peer Reviewed
See detailEuler–Lagrange approach to model heterogeneities in stirred tank bioreactors – Comparison to experimental flow characterization and particle tracking
Delafosse, Angélique ULg; Calvo, Sébastien ULg; Collignon, Marie-Laure ULg et al

in Chemical Engineering Science (2015), 134

The aim of this work is the validation of an Euler–Lagrange modeling approach coupling a CFD-based compartment model (Eulerian approach) and a stochastic model based on a Continuous-Time Markov Chain ... [more ▼]

The aim of this work is the validation of an Euler–Lagrange modeling approach coupling a CFD-based compartment model (Eulerian approach) and a stochastic model based on a Continuous-Time Markov Chain (Lagrangian approach). The turbulent flow structure and the mixing process in a bioreactor stirred by an axial Mixel TT impeller is characterized by PIV and tracer experiments. Comparison between experimental and numerical data shows that the CFD-based compartment model is able to reproduce accurately the spatial heterogeneities inside the bioreactor. The trajectory of a small tracer particle which perfectly follows the fluid flow is measured by optical trajectography. It is then simulated by a stochastic model which is either based on an homogeneous or on an inhomogeneous Continuous Time Markov Chain (CTMC). Comparison of residence and circulation time distributions in three zones defined inside the bioreactor shows that the inhomogeneous CTMC model predicts with an excellent accuracy the particle trajectories inside the bioreactor. The modeling approach proposed here could be an useful tool to design scale-down bioreactors in order to reproduce at lab-scale the stress levels encountered in large-scale production bioreactors and to characterize and compare different bioreactor configurations. [less ▲]

Detailed reference viewed: 57 (26 ULg)
Full Text
Peer Reviewed
See detailFluorescent reporter libraries as useful tools for optimizing microbial cell factories: a review of the current methods and applications
Delvigne, Frank ULg; Pêcheux, Hélène; Tarayre, Cédric ULg

in Frontiers in Bioengineering and Biotechnology (2015), 3

The use of genetically encoded fluorescent reporters allows speeding up the initial optimization steps of microbial bioprocesses. These reporters can be used for determining the expression level of a ... [more ▼]

The use of genetically encoded fluorescent reporters allows speeding up the initial optimization steps of microbial bioprocesses. These reporters can be used for determining the expression level of a particular promoter, not only the synthesis of a specific protein but also the content of intracellular metabolites. The level of protein/metabolite is thus proportional to a fluorescence signal. By this way, mean expression profiles of protein/ metabolites can be determined non-invasively at a high-throughput rate, allowing the rapid identification of the best producers. Actually, different kinds of reporter systems are available, as well as specific cultivation devices allowing the on-line recording of the fluorescent signal. Cell-to-cell variability is another important phenomenon that can be integrated into the screening procedures for the selection of more efficient microbial cell factories. [less ▲]

Detailed reference viewed: 23 (1 ULg)
Full Text
Peer Reviewed
See detailLa lutte contre les moustiques (Diptera: Culicidae): diversité des approches et application du contrôle biologique
Bawin, Thomas ULg; Seye, Fawrou; Boukraa, Slimane ULg et al

in Canadian Entomologist (2015), 147(4), 476-500

Many mosquito (Diptera: Culicidae) species are zoonotic vectors responsible for numerous infectious diseases of medical and veterinary importance. Currently, changes in the vectors’ geographical ... [more ▼]

Many mosquito (Diptera: Culicidae) species are zoonotic vectors responsible for numerous infectious diseases of medical and veterinary importance. Currently, changes in the vectors’ geographical distribution induced chiefly by anthropogenic factors are accompanied by emerging and reemerging infectious diseases in Europe and North America. Since the advent of synthetic insecticides during the Second World War, mosquitoes are the object of considerably expanded and deepened research. In an integrated pest management context, means of control are now mainly classified as: (1) environmental management and physical control, (2) chemical control, (3) genetic control, and (4) biological control by means of entomophagous predators and entomopathogenic microorganisms. In this context, these last have significant potential because of their ability to infect and kill their host with more or less targeted selectivity. This article proposes to emphasize biological control among other techniques in mosquito control, and to assess the potential and the opportunities offered by entomopathogenic bacteria, viruses and fungi. Finally, their use as biopesticides is discussed. [less ▲]

Detailed reference viewed: 139 (39 ULg)
Full Text
Peer Reviewed
See detailImpact of phenotypic heterogeneity and metabolic specialisation on metabolic engineering strategies: case of study of E.coli as a representative microbial cell factory
Brognaux, Alison ULg; Delepierre, Anissa ULg; Pecheux, Hélène ULg et al

Conference (2015, July 21)

The goal of this research is to directly highlight the simultaneous occurrence of several phenotypes with distinct metabolic function among clonal population of E. coli., often used for recombinant ... [more ▼]

The goal of this research is to directly highlight the simultaneous occurrence of several phenotypes with distinct metabolic function among clonal population of E. coli., often used for recombinant protein and pDNA production in bioprocesses. This phenotypic heterogeneity, first due to the noise, is reinforced by environmental heterogeneities occurring at large scale during fed-batch processes. This phenotypic heterogeneity has been tracked according to GFP reporter strains (biosensors) that circulate in the bioreactor and encounter environmental heterogeneities. First, we have highlighted the simultaneous occurrence of several phenotypes with distinct metabolic functions. Indeed, a diversity of glucose uptake strategies has recently been noticed with the PtsG and MglABC transporters. Moreover, when E.coli encounters zones of glucose excess, acetate is produced through the overflow metabolism. Only the sub-population with high acs expression (acetate transporter) could consume this acetate. GFP reporter strains have thus been constructed for PtsG, MgIABC and acs genes. In addition of the stable GFP, two destabilized GFP variants for each gene have been used to obtain more instantaneous responses. The response of these biosensors have been followed by on-line flow cytometry. In the end, this experimental strategy for direct phenotyping at the single cell level will also be used to investigate the impact of metabolic engineering strategies on phenotypic heterogeneity, robustness and fitness of microbial population in industrial conditions. [less ▲]

Detailed reference viewed: 91 (13 ULg)
Full Text
Peer Reviewed
See detailBIOREFINE Project – Recovery of useful nutrients from organic wastes produced in five European countries (3AV.3.55)
Tarayre, Cédric ULg; De Clercq, Lies; Michels, Evi et al

Poster (2015, June 01)

At this time, many wastes are used or eliminated through processes that do not really consider their potential applications. Such wastes contain useful nutrients (nitrogen, phosphorus and potassium), the ... [more ▼]

At this time, many wastes are used or eliminated through processes that do not really consider their potential applications. Such wastes contain useful nutrients (nitrogen, phosphorus and potassium), the importance of which has been demonstrated in agriculture for many years. The composition of wastes is highly heterogeneous, which makes treatment techniques more difficult to apply on a large scale. Sewage sludge is usually used as a fertilizer in agriculture, in energy production or in the field of construction. The main use of manure is agriculture, although considerable amounts of nutrients are lost and cause pollution. Digestate is also used in agriculture, but other alternatives have been proposed. Ashes should also be highlighted, although they do not contain nitrogen, which is lost into the atmosphere during the combustion process. Finally, household and industrial wastes are resources that should be considered as well. Those different types of wastes could be recycled to produce environment-friendly fertilizers. Here, we propose to investigate these opportunities inside five European countries (Belgium, France, Germany, United Kingdom and The Netherlands) through five work packages with the BioRefine Project. [less ▲]

Detailed reference viewed: 40 (7 ULg)
Full Text
Peer Reviewed
See detailMultiple analyses of microbial communities applied to the gut of the wood-feeding termite Reticulitermes flavipes fed on artificial diets
Tarayre, Cédric ULg; Bauwens, Julien ULg; Mattéotti, Christel et al

in Symbiosis (2015)

The purpose of this work was the observation of the differences between the microbial communities living in the gut of the termite Reticulitermes flavipes fed on different diets. The termites were fed on ... [more ▼]

The purpose of this work was the observation of the differences between the microbial communities living in the gut of the termite Reticulitermes flavipes fed on different diets. The termites were fed on poplar wood (original diet) and artificial diets consisting of crystalline cellulose (with and without lignin), α-cellulose (with and without lignin) and xylan. The termites were then dissected and the protist communities were analyzed through microscopy, leading to the conclusion that protist species are strongly influenced by diets. BIOLOG ECO Microplates® were used to assess the metabolic properties of the different types of consortia, highlighting strong differences on the basis of principal component analysis and calculation of similarity rates. The microorganisms were cultivated in liquid media corresponding to the artificial diets before being characterized through a metagenetic analysis of gut microbiota (16S ribosomal DNA). This analysis identified several phyla: Acidobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, Fibrobacteres, Firmicutes, Nitrospirae, OP9, Planctomycetes, Proteobacteria, Spirochaetes, TM6, Tenericutes, Verrucomicrobia and WS3. The OTUs were also determined and confirmed the abundance of Proteobacteria, Bacteroidetes, Firmicutes and Verrucomicrobia. It was possible to isolate several strains from the liquid media, and one bacterium and several fungi were found to produce interesting enzymatic activities. The bacterium Chryseobacterium sp. XAvLW produced α-amylase, β-glucosidase, endo-1,4-β-D-glucanase, endo-1,4-β-D-xylanase and filter paper-cellulase, while the fungi Sarocladium kiliense CTGxxyl and Trichoderma virens CTGxAviL generated the same activities added with endo-1,3-β-D-glucanase. [less ▲]

Detailed reference viewed: 61 (21 ULg)
Full Text
Peer Reviewed
See detailA fungal biofilm reactor based on metal structured packing improves the quality of a Gla::GFP fusion protein produced by Aspergillus oryzae
Zune, Quentin ULg; Delepierre, Anissa ULg; Gofflot, Sebastien et al

in Applied Microbiology and Biotechnology (2015)

Fungal biofilm is known to promote the excretion of secondary metabolites in accordance with solid-state related physiological mechanisms. This work is based on the comparative analysis of classical ... [more ▼]

Fungal biofilm is known to promote the excretion of secondary metabolites in accordance with solid-state related physiological mechanisms. This work is based on the comparative analysis of classical submerged fermentation with a fungal biofilm reactor for the production of a Gla::GFP fusion protein by Aspergillus oryzae. The biofilm reactor comprises a metal structured packing allowing the attachment of the fungal biomass. Since the production of the target protein is under the control of the promoter glaB, specifically induced in solid-state fermentation, the biofilm mode of culture is expected to enhance the global productivity. Although production of the target protein was enhanced by using the biofilm mode of culture, we also found that fusion protein production is also significant when the submerged mode of culture is used. This result is related to high shear stress leading to biomass autolysis and leakage of intracellular fusion protein into the extracellular medium. Moreover, 2D-gel electrophoresis highlights the preservation of fusion protein integrity produced in biofilm conditions. Two fungal biofilm reactor designs were then investigated further, i.e. with full immersion of the packing or with medium recirculation on the packing, and the scale-up potentialities were evaluated. In this context, it has been shown that full immersion of the metal packing in the liquid medium during cultivation allows for a uniform colonization of the packing by the fungal biomass and leads to a better quality of the fusion protein. [less ▲]

Detailed reference viewed: 103 (39 ULg)
Full Text
Peer Reviewed
See detailDetermination of Zinc, Cadmium and Lead Bioavailability in Contaminated Soils at the Single-Cell Level by a Combination of Whole-Cell Biosensors and Flow Cytometry
Hurdebise, Quentin ULg; Tarayre, Cédric ULg; Fischer, Christophe ULg et al

in Sensors (2015)

Zinc, lead and cadmium are metallic trace elements (MTEs) that are widespread in the environment and tend to accumulate in soils because of their low mobility and non-degradability. The purpose of this ... [more ▼]

Zinc, lead and cadmium are metallic trace elements (MTEs) that are widespread in the environment and tend to accumulate in soils because of their low mobility and non-degradability. The purpose of this work is to evaluate the applicability of biosensors as tools able to provide data about the bioavailability of such MTEs in contaminated soils. Here, we tested the genetically-engineered strain Escherichia coli pPZntAgfp as a biosensor applicable to the detection of zinc, lead and cadmium by the biosynthesis of green fluorescent protein (GFP) accumulating inside the cells. Flow cytometry was used to investigate the fluorescence induced by the MTEs. A curvilinear response to zinc between 0 and 25 mg/L and another curvilinear response to cadmium between 0 and 1.5 mg/L were highlighted in liquid media, while lead did not produce exploitable results. The response relating to a Zn2+/Cd2+ ratio of 10 was further investigated. In these conditions, E. coli pPZntAgfp responded to cadmium only. Several contaminated soils with a Zn2+/Cd2+ ratio of 10 were analyzed with the biosensor, and the metallic concentrations were also measured by atomic absorption spectroscopy. Our results showed that E. coli pPZntAgfp could be used as a monitoring tool for contaminated soils being processed. [less ▲]

Detailed reference viewed: 62 (22 ULg)
Full Text
See detailAmélioration de la biodégradation du biphényle par Rhodococcus erythropolis t902.1 en présence de Fe2O3 et de nanoparticules de fer encapsulées dans un xérogel de silice
Wannoussa, Wissal ULg; Hiligsmann, Serge ULg; Tasseroul, Ludivine ULg et al

in Déchets Sciences et Techniques (2015), 69

In this work, the effect of iron oxide particles Fe2O3 and iron nanoparticles encapsulated in a porous silica matrix (xerogel Fe/SiO2) was investigated on biphenyl biodegradation by the strain Rhodococcus ... [more ▼]

In this work, the effect of iron oxide particles Fe2O3 and iron nanoparticles encapsulated in a porous silica matrix (xerogel Fe/SiO2) was investigated on biphenyl biodegradation by the strain Rhodococcus erythropolis T902.1. After 18 days of incubation biodegradation yields of 75% and 85% were achieved respectively in presence of non-autoclaved or autoclaved xerogel Fe/SiO2 at 10-5 M iron. These results are 42 and 60 % higher than in standard conditions without nanoparticles. They suggest that the autoclave procedure lead to the release of some iron less anchored in the silica matrix. This study highlights that siderophore production by Rhodococcus erythropolis T902.1 would be related to the presence of iron nanoparticles in the culture. It suggests that the production of these strong chelating compounds decreases with increase of iron release from xerogel Fe/SiO2. Moreover, most of the surfactants synthesized by Rhodococcus erythropolis T902.1 which are glycolipids containing trehalose (hexose), would be linked to cell surface and not excreted in the culture medium; the biomass hexose content also increased by 85% in presence of iron nanoparticles. [less ▲]

Detailed reference viewed: 100 (24 ULg)
Full Text
Peer Reviewed
See detailApplication of Steam Explosion as Pretreatment on Lignocellulosic Material: A Review
Jacquet, Nicolas ULg; Maniet, Guillaume ULg; Vanderghem, Caroline ULg et al

in Industrial & Engineering Chemistry Research (2015), 54(10), 2593-2598

Steam explosion is a thermo-mechanicochemical pretreatment which allows the breakdown of lignocellulosic structural components by the action of heating, formation of organic acids during the process, and ... [more ▼]

Steam explosion is a thermo-mechanicochemical pretreatment which allows the breakdown of lignocellulosic structural components by the action of heating, formation of organic acids during the process, and shearing forces resulting in the expansion of the moisture. Two distinct stages compose the steam-explosion process: vapocracking and explosive decompression which include modification of the material components: hydrolysis of hemicellulosic components (mono- and oligosaccharides released), modification of the chemical structure of lignin, and modification of the cellulose crystallinity index, etc. These effects allow the opening of lignocellulosic structures and influence the enzymatic hydrolysis yield of the material. [less ▲]

Detailed reference viewed: 54 (15 ULg)
Full Text
Peer Reviewed
See detailThermophilic and cellulolytic consortium isolated from composting plants improves anaerobic digestion of cellulosic biomass: toward a microbial resource management approach
Kinet, Romain ULg; Destain, Jacqueline ULg; Hiligsmann, Serge ULg et al

in Bioresource Technology (2015)

A cellulolytic consortium was isolated from a composting plant in order to boost the initial hydrolysis step encountered in anaerobic digestion. Improvement of the cellulose degradation, as well as biogas ... [more ▼]

A cellulolytic consortium was isolated from a composting plant in order to boost the initial hydrolysis step encountered in anaerobic digestion. Improvement of the cellulose degradation, as well as biogas production, was observed for the cultures inoculated with the exogenous consortium. Metagenomics analyses pointed out a weak richness (related to the number of OTUs) of the exogenous consortium induced by the selective pressure (cellulose as sole carbon source) met during the initial isolation steps. Main microbial strains determined were strictly anaerobic and belong to the Clostridia class. During cellulose anaerobic degradation, pH drop induced a strong modification of the microbial population. Despite the fact that richness and evenness were very weak, the exogenous consortium was able to adapt and to maintain the cellulolytic degradation potential. This important result point out the fact that simplified microbial communities could be used in order to increase the robustness of mixed cultures involved in environmental biotechnology. [less ▲]

Detailed reference viewed: 70 (22 ULg)