References of "Francis, Frédéric"
     in
Bookmark and Share    
Full Text
See detailBelgian Grasshoppers: A Nutritious Food Source
Paul, Aman ULg; Frederich, Michel ULg; Blecker, Christophe ULg et al

Poster (2014, May 14)

Rapid urbanization and rising economies are creating shifts in the composition of global food demand, so it is necessary to explore new sources of food with better nutritional profile. Among the ... [more ▼]

Rapid urbanization and rising economies are creating shifts in the composition of global food demand, so it is necessary to explore new sources of food with better nutritional profile. Among the alternative food that exists are the grasshoppers, about 80 species of which are consumed worldwide. Grasshoppers are not only rich source of proteins and lipids but also some important minor component like vitamins and minerals. Edible species of grasshopper in Belgium were identified and attempts were made for the lab rearing of meadow grasshopper (Chorthippus parallelus). The lipids as well as protein contents of meadow grasshopper (Chorthippus parallelus) & long winged conehead (Conocephalus discolor) were investigated. The fatty acid compositions of these two species were determined by gas chromatography. Some of the physicochemical properties of the lipids extracted were also analyzed. These two grasshopper species could be really nutritious source of food. [less ▲]

Detailed reference viewed: 49 (10 ULg)
Full Text
See detailLocusts and Grasshoppers: Future Foods?
Paul, Aman ULg; Frederich, Michel ULg; Uyttenbroeck, Roel ULg et al

Scientific conference (2014, May 08)

Consuming locusts and grasshoppers as food is not a new concept, because some people have been doing it for a long time and there are many references in the religious literature to support this. About 80 ... [more ▼]

Consuming locusts and grasshoppers as food is not a new concept, because some people have been doing it for a long time and there are many references in the religious literature to support this. About 80 locust and grasshopper species are consumed worldwide, and the large majority of grasshopper species are edible. From the nutritional point of view they are an excellent source of proteins, lipids and other minor components like vitamins and minerals. They are an excellent source of amino acids and their lipids contain a large majority of unsaturated fatty acids. Environmentalists have supported human consumption of grasshoppers owing to the facts that they usually appear as pests. Using them as food could help reduce their population and result in limited application of harmful pesticides. Their production usually generates lesser amount of greenhouse gases & ammonia; a lower amount of water is required for their production in comparison to conventional proteins sources. Some species of grasshoppers usually feed on dead organic matter, this reduces the environmental load. In the developing world, catching of grasshoppers and selling them for human consumption has played a key role in improving the livelihood of women and underprivileged children. Eating grasshopper and locust is not a very common practice in temperate areas. However it is a very common practice in the tropical areas of world because of the higher density, bigger size of the insect and yearlong availability in such areas. To encourage their consumption in temperate areas, it is now necessary to perform accurate research regarding food safety (minor components, toxicity, allergens,…) but also to develop value added products to make it easier for people to adapt with entomophagy. Furthermore we have to develop methods for commercial production and organize awareness campaigns to explain about the nutritional and other benefits related to locust & grasshopper consumption as food to people. [less ▲]

Detailed reference viewed: 30 (7 ULg)
Full Text
Peer Reviewed
See detailPhylogenetic study of Aedes albopictus and Aedes koreicus (Diptera, Culicidae) origin, two invasive mosquito species in Belgium
Raharimalala, Fara Nantenaina ULg; Boukraa, Slimane ULg; Bawin, Thomas ULg et al

Poster (2014, April 10)

The main ways of the introduction of invasive mosquito species in Europe were greatly facilitated by the importation of used tires and plants from the South of China (Dracaena sanderiana, called "Lucky ... [more ▼]

The main ways of the introduction of invasive mosquito species in Europe were greatly facilitated by the importation of used tires and plants from the South of China (Dracaena sanderiana, called "Lucky bamboo"), which are a very good breeding sites of these mosquitoes (www.eidatlantique.eu). For Belgium, several species of exotic mosquitoes have already been listed such as Ochlerotatus japonicus japonicus, Aedes albopictus and A. koreicus. We have captured one male of A. albopictus in Belgium in July 2013 (Boukraa et al, 2013), and teams from other entomologist have been able to find several individuals in the months that have followed our discovery (personal communication). However, his presence was reported first in 2000 (Schaffner et al. 2004) but until 2012, no individuals have been found (Versteirt et al., 2013). We also could find larvae of A. koreicus in abundance. These discovery suggest that these two invasive species are being established in Belgium. Methods: Adult mosquitoes were collected by CO2-baited traps Mosquito Magnet Liberty Plus (MMLP) and immature stages by the dipping method from 8 sites of Belgium. Each individual was then determined morphologically. For A. albopictus and A. koreicus, reconfirmation by molecular method was performed with COI and ND5 mitochondrial primers and sequences were then aligned with those of mosquitoes available in databases by using BioEdit and Multialn softwares. The two gene sequences were concatenated to improve the reliability of the phylogenetic analysis and were carried out by using the Seaview software based on maximum likelihood (ML) methods. Trees were then constructed with the general time reversible (GTR) model, and branch supports were estimated by bootstrapping with 1000 replicates. Result: The aim of this work will focus on the study of the probable origin of these two species of Aedes, which are for the moment safe yet, but that might become dangerous in the event of massive outbreak. The knowledge of the probably origin of the two invasive mosquitoes allow take more protection against their way to enter in the country. [less ▲]

Detailed reference viewed: 56 (3 ULg)
Full Text
See detailBiological control of aphids in wheat and vegetable crops : a multi-approach case study in Shandong province (China)
Chevalier Mendes Lopes, Thomas ULg; Bosquée, Emilie ULg; Chen, Julian et al

Poster (2014, April 02)

This multi-approach study was conducted in the Shandong province (China) to assess the effectiveness of different biological control methods against aphids in wheat and vegetable crops. Three approaches ... [more ▼]

This multi-approach study was conducted in the Shandong province (China) to assess the effectiveness of different biological control methods against aphids in wheat and vegetable crops. Three approaches were tested: (1) wheat/oilseed rape and wheat/pea associations, (2) potatoes/peas association, and (3) E-β-farnesene (aphid alarm pheromone) releasers in squashes under plastic tunnels. Aphids and aphidophagous beneficials were monitored by observations on plants. Wheat associations and E-β-farnesene reduced aphid infestations compared with control treatments, while no effect was observed in the potatoes/peas association. Moreover, aphidophagous beneficials were significantly more abundant in the three kinds of associations compared with control treatments. Few individuals were observed on squashes. Additionally, adult aphidophagous beneficials were monitored using yellow pan traps. The parasitoid species Aphidius gifuensis (Ashmead) was prevalent, while Propylea japonica (Thunberg) and Harmonia axyridis (Pallas) were the most abundant species among predators. Globally, wheat associations were more efficient to reduce aphid infestations and attract aphidophagous beneficials to promote biological control. The trapping of natural enemies allowed to assess the diversity and abundance of aphidophagous species in this region. This study shows a beneficial effect of crop associations and E-β-farnesene on the control of aphid populations and contributes to assess the potentialities of these alternative methods to the use of insecticides. [less ▲]

Detailed reference viewed: 20 (4 ULg)
Peer Reviewed
See detailConservatoire entomologique de Gembloux Agro-Bio Tech: les coccinelles de Wallonie et de Bruxelles de 2001 à 2009
Vandereycken, Axel ULg; Fassotte, Bérénice ULg; Durieux, Delphine ULg et al

Poster (2014, April 02)

Un inventaire des Coccinellidae présents au sein de la collection de l’unité d’Entomologie fonctionnelle et évolutive (ULg - Gembloux Agro-Bio Tech) a été réalisé sur la période s’étendant de 2001 à 2009 ... [more ▼]

Un inventaire des Coccinellidae présents au sein de la collection de l’unité d’Entomologie fonctionnelle et évolutive (ULg - Gembloux Agro-Bio Tech) a été réalisé sur la période s’étendant de 2001 à 2009. Cette collection est essentiellement constituée par les récoltes des étudiants de première Bachelier de Gembloux Agro-Bio Tech. A travers ce recensement, nous avons étudié l’évolution des espèces récoltées au sein de cette famille en termes d’effectif relatif et de richesse spécifique. Notre étude s’est focalisée sur les données issues de Wallonie et de la Région de Bruxelles-Capitale, trop peu de collectes ayant été réalisées en Flandre. Parmi les individus identifiés, 27 espèces ont été observées, dont 21 appartiennent à la sous-famille des Coccinellinae, 2 à celle des Epilachninae et 4 à celle des Chilocorinae. La plupart des espèces sont communes à la Belgique. Cependant, Harmonia axyridis (Pallas 1773), espèce originaire du sud-est de l’Asie, a été introduite sur le territoire belge en 1997. Cette coccinelle exotique fait son apparition dans les récoltes de 2002 et son effectif ne cesse d’augmenter au fil des années prospectées. En parallèle à cette augmentation, une diminution de la richesse spécifique, ainsi que de l’effectif relatif d’Adalia bipunctata (L. 1758), de Propylea quatuordecimpunctata (L. 1758) et de Psyllobora vigintiduopunctata (L. 1758), est observée. [less ▲]

Detailed reference viewed: 11 (0 ULg)
Peer Reviewed
See detailStudy of sex ratio and morphotypes of the Multicoloured Asian Ladybird, Harmonia axyridis Pallas in Belgian corn
Vandereycken, Axel ULg; Fassotte, Bérénice ULg; Barsics, Fanny ULg et al

Poster (2014, April 02)

Several insect species are known to have different morphotypes, an adaptation to heterogeneities in changing environments. This phenotypic plasticity could be a factor used by the Multicoloured Asian ... [more ▼]

Several insect species are known to have different morphotypes, an adaptation to heterogeneities in changing environments. This phenotypic plasticity could be a factor used by the Multicoloured Asian Ladybird, which is considered as an invasive species in Europe since its introduction in the 80’s. Harmonia axyridis has four major morphotypes: 2 melanic forms, conspicua and spectabilis; and 2 non-melanic, succinea and axyridis. In Belgium, only the three first are observed. Literature reports variations in morphotype frequencies, across native and introduced strains. These variations seem to be linked to climate (geographical and seasonal variation), with non-melanic forms being the most abundant in hot and arid climate. This study focused on the variation of morphotype abundance in H. axyridis according to season, field and gender. Adult ladybirds were caught from mid-July to mid-October 2012 into 5 corn fields. The proportions of observed morphotypes were compared according to the sampling season. The abundance of morphotypes was not significantly different through the fields; the observed ratios were 81.6%, 15% and 3.4% for succinea, spectabilis and conspicua respectively. Succinea was the most observed morphotype (χ2=755.8; P<0.001). The total number of collected males and females was the same with ratios of 48.2% and 51.8%: (χ2=0.93; P=0.33). The sex ratio was also not significantly different for each morphotype. There was no evolution of melanic and non-melanic form ratio according to the season, with 25.6% of melanic form in summer and 20.6% in autumn (χ2=1.22; P=0.27). Our results seem to show that morphotype adaptation according to the climate is not observed for Belgian ladybirds. We discuss these results according to all environmental data available. [less ▲]

Detailed reference viewed: 15 (1 ULg)
Full Text
See detailWill top-down interactions be affacted by climate change?
Boullis, Antoine ULg; Verheggen, François ULg; Francis, Frédéric ULg

Poster (2014, April 02)

Greenhouse gas emissions are rising since the beginning of the industrial era: atmospheric carbon dioxide now exceeds 400 ppm (30% increase since the mid-1800s) and tropospheric ozone has reached 40 ppb ... [more ▼]

Greenhouse gas emissions are rising since the beginning of the industrial era: atmospheric carbon dioxide now exceeds 400 ppm (30% increase since the mid-1800s) and tropospheric ozone has reached 40 ppb in industrialized areas. According to forecasting models, these concentrations are expected to double by the end of the 21st century. To date, impacts of elevated greenhouse gases have been extensively studied in plant-insect interactions, whereas interactions between herbivores and their natural enemies have been neglected. Because most interactions between herbivorous insects and their natural enemies are orchestrated by natural molecules produced as semiochemicals, we hypothesize that modification in atmospheric gas composition will alter chemical communication in insects, and affect the performance of natural enemies to locate their prey. In this project, we shall attempt to analyze the effect of increase in greenhouse gas concentrations on insect communication, particularly in top-down interactions. The study model will consist in the interactions between the pea aphids (Acyrthosiphon pisum (Harris)) and their natural enemies Harmonia axyridis (Pallas) and Episyrphus balteatus (DeGeer). Under elevated CO2 and/or O3 concentrations, we will quantify the production of several aphid semiochemicals that are currently used as kairomones by natural enemies, including the aphid alarm pheromone E-β-farnesene and honeydew volatile compounds. Olfactometry assays will then be set up to examine the ability of natural enemies to locate their prey in the predicted atmospheric conditions of the end of the 21st century. Finally, using an Ecotron structure to be built in Gembloux Agro-Bio Tech, we will simulate a future ecosystem with the possibility to control additional biotic and abiotic parameters. [less ▲]

Detailed reference viewed: 20 (7 ULg)
Peer Reviewed
See detailDiversité et abondance entomologique en cultures maraîchères à Libreville et à Owendo (Gabon)
Bayendi-Loudit, Sandrine ULg; Poligui, René Noël ULg; Ndoutoume Ndong, Auguste et al

Conference (2014, April 02)

In order to improve knowledge of the diversity and abundances of the entomofauna occurring within market gardenings in Gabon, this study was conducted in three localities in Libreville and Owendo, from ... [more ▼]

In order to improve knowledge of the diversity and abundances of the entomofauna occurring within market gardenings in Gabon, this study was conducted in three localities in Libreville and Owendo, from July1st to August 31st, 2012. Insect collections from yellow traps and visual observations were performed weekly within plots in which grow Amaranth (Amaranthus sp., Amaranthaceae), red sorrel (Hibiscus sabdariffa L, Malavaceae), Tomato (Lycopersicon esculentum Mill, Solanaceae) and Cabbage (Brassica oleracea L, Brassicaceae). A total of 7119 insects were assessed and taxonomically classified in 8 distinct orders comprising 81 families. The study highlighted some entomologic families with agronomic interest. The main pests were represented by Aphididae (31,0%), Cecidomyiidae (5,1%), Chrysomelidae (4,0%) and Thripidae (2,0%), the useful insects (pollinators and predators) by Dolichopodidae (5,4%), Andrenidae (2,6%) Coccinellidae (1,7%), Syrphidae (0,6%), Braconidae (0,5%) and Hemerobiidae (0,1%) and the associated insects were Psychodidae (7,4%), Muscidae (5,9%), Formicidae (4,4%) and Anthomyiidae (4,2%). Entomological diversity is discussed according to the local conditions and potential for sustainable pest control encountered. [less ▲]

Detailed reference viewed: 35 (2 ULg)
Peer Reviewed
See detailFirst evidence of a volatile sex pheromone in the invasive Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae)
Fassotte, Bérénice ULg; Fischer, Christophe ULg; Durieux, Delphine ULg et al

Conference (2014, April 02)

Data about sex pheromones, or any semiochemicals that play a role in Coccinellid mating, remain limited. Since years, various studies and behavioral observations have hypothesized that such molecules are ... [more ▼]

Data about sex pheromones, or any semiochemicals that play a role in Coccinellid mating, remain limited. Since years, various studies and behavioral observations have hypothesized that such molecules are involved in sexual communication of ladybeetles. In this study, we collected volatile organic compounds released by virgin females of the multicolored Asian ladybeetle, Harmonia axyridis (Pallas), which were either allowed or not allowed to feed on aphids. In the presence of aphids, virgin females exhibited “calling behavior”, which has been associated with the emission of a sex pheromone in several Coleoptera species. Bioassays showed that these females released a blend of volatile compounds that is involved in the attraction of males. Gas Chromatography-Mass Spectrometry analyses highlighted specific volatile cues emanating from females, whereas males did not produce these compounds. Five components were identified: (–)-β-caryophyllene, β elemene, methyl-eugenol, α humulene, and α bulnesene. All compounds were produced after virgin females were fed aphids, and their quantity increased across the experimental period. The results confirm that female H. axyridis produce a volatile sex pheromone. Therefore, this study provides important biological information that could promote the development of efficient pest control management methods to manipulate the movements of this invasive ladybeetle, and to reduce its negative impacts on biodiversity. [less ▲]

Detailed reference viewed: 22 (4 ULg)
Peer Reviewed
See detailA pheromone-based formulation against phytophagous pests
Fassotte, Bérénice ULg; Vandereycken, Axel ULg; Heuskin, Stéphanie ULg et al

Poster (2014, April 02)

Innovative integrated pest management methods are needed to overcome market withdrawal of synthetic pesticides. Therefore, the identification of environment-friendly bio-products carrying direct or ... [more ▼]

Innovative integrated pest management methods are needed to overcome market withdrawal of synthetic pesticides. Therefore, the identification of environment-friendly bio-products carrying direct or indirect biocide activity is one promising alternative option. Our researches focus on the identification of appropriate formulations releasing volatile organic compounds that are attractive for natural enemies of insect pests. However, the elaboration of slow-release devices that ensure stable and controlled release of active volatile compounds is quite challenging. Here, we developed a formulation based on E-β-farnesene and (–)-β-caryophyllene, these two semiochemicals having strong attractive potential on aphid natural enemies including ladybeetles and hoverflies. Both compounds were encapsulated together in alginate gel beads. The blend efficiency is currently being evaluated through laboratory and field assays. [less ▲]

Detailed reference viewed: 20 (3 ULg)
Full Text
See detailWildflower strips: a help for crop protection ?
Hatt, Séverin ULg; Uyttenbroeck, Roel ULg; Bodson, Bernard ULg et al

Poster (2014, March 05)

Detailed reference viewed: 20 (1 ULg)
Full Text
See detailWildflower strips: a help for crop protection ?
Hatt, Séverin ULg; Uyttenbroeck, Roel ULg; Bodson, Bernard ULg et al

Conference (2014, March 05)

Detailed reference viewed: 20 (5 ULg)
Full Text
Peer Reviewed
See detailImpacts of earthworms on soil components and dynamics. A review
Lemtiri, Aboulkacem ULg; Colinet, Gilles ULg; Alabi, Taofic ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2014), 18

Earthworm populations are important decomposers contributing to aggregate formation and nutrient cycling processes involving nitrogen cycles, phosphorus and carbon. They are known to influence soil ... [more ▼]

Earthworm populations are important decomposers contributing to aggregate formation and nutrient cycling processes involving nitrogen cycles, phosphorus and carbon. They are known to influence soil fertility by participating to important processes in soil such as soil structure regulation and organic matter dynamics. Earthworms also modify the microbial communities through digestion, stimulation and dispersion in casts. Consequently, changes in the activities of earthworm communities, as a result of soil management practices, can also be used as indicators of soil fertility and quality. It is therefore important to understand how earthworm communities affect soil dynamics. This review adresses the current state of knowledge on earthworm’s impacts on soil structure and soil organic matter (carbon, nitrogen, and phosphorus) dynamics, with special emphasis on the effects of land management practices on earthworm communities. [less ▲]

Detailed reference viewed: 84 (4 ULg)
Full Text
Peer Reviewed
See detailComparaison des populations de Culicoides Latreille 1809 (Diptera: Ceratopogonidae) présentes au sein d’une bergerie belge et d’une prairie ovine associée
Zimmer, Jean-Yves ULg; Losson, Bertrand ULg; Saegerman, Claude et al

in Annales de la Société Entomologique de France (2014), 49(4), 446-459

Culicoides biting midges (Diptera: Ceratopogonidae) serve as biological vectors for several pathogens, including the Bluetongue virus and the recently described Schmallenberg virus in northern Europe ... [more ▼]

Culicoides biting midges (Diptera: Ceratopogonidae) serve as biological vectors for several pathogens, including the Bluetongue virus and the recently described Schmallenberg virus in northern Europe. These diseases have caused considerable direct and indirect economic losses to the sheep and cattle industries. This study undertaken between August and December 2007 on a sheep farm in the Namur province (Belgium) aims to evaluate Culicoides populations present inside a partially opened sheepfold and in a nearby sheep meadow, using light traps. The comparative analysis of insects trapped at 18 dates at regular intervals showed that Culicoides were most abundant Inside this livestock building (17,450 midges) than in surrounding meadow (1,121 midges); this meadow had however a greater species diversity. The two species C. obsoletus and C. scoticus constituting the Obsoletus complex predominated for all trappings and females were much more numerous than males. Important capture of engorged females of the Obsoletus complex inside the sheepfold seems to reflect the possibility of an opportunistic endophagous behavior. Maintaining sheep inside livestock buildings in order to reduce the risk of Culicoides bites – and thus of pathogens transmission – however requires to limit biting midge populations which are likely to enter or to develop inside these buildings. Implementation of effective sanitation and hygiene measures against midges present inside farms, as well as establishing of measures to protect livestock against intrusion and improvement of “midge-proofing” of animal housing are therefore highly recommended. [less ▲]

Detailed reference viewed: 43 (4 ULg)
Full Text
See detailEffects of Eisenia fetida on metal uptake of heavy metals from polluted soils by Vicia faba and Zea Mays
Lemtiri, Aboulkacem ULg; Liénard, Amandine ULg; Francis, Frédéric ULg et al

Poster (2014, February 26)

Earthworms are known to increase availability of heavy metals in soils and also play an important role in maintaining the structure and quality of soil. The introduction of earthworms into soils ... [more ▼]

Earthworms are known to increase availability of heavy metals in soils and also play an important role in maintaining the structure and quality of soil. The introduction of earthworms into soils contaminated with metals has been suggested as an aid for phytoremediation processes. In Belgium (Wallonia), a century of industrial metallurgic activities produced significant heavy metal soil pollution. A large q u a n t i t y o f s m e l t e r w a s t e c r e a t e d a g r a d i e n t o f zi n c, lead and cadmium c o n c e n t r a t i o n . The objectives of our study were to evaluate : (i) the potential toxicity of heavy metal elements on the epigeic earthworms Eisenia fetida and on two plants Zea mays and Vicia faba and (ii) to determine the effects of the earthworms on the growth and contaminants phytoextraction process. The combination of behavioural factor measurements (survival, growth, reproduction of earthworms), physico-chemical parameters such as metal absorption, bioaccumulation by earthworms, soil physico-chemical changes, and plant responses (root and shoot elongation, dried biomass,…) provided a valuable indication of pollutant bioavailability and ecotoxicity. After 56-days exposure, the results suggest that adult earthworms have a strong tolerance for heavy metals exposure, but the responses depend on metal elements. Earthworms modify the bioavailable heavy metals in root and shoot in the contaminated soils and their activities alter shoot and root biomass of V. faba and Z. mays. The presence of earthworms led to a change in physico-chemical caracteristics in contaminated soils. These results show that the ecological context for phytoremediation should be broadened by considering earthwom – plant – soil interactions as they influence both plant health and absorption of heavy metals. [less ▲]

Detailed reference viewed: 14 (1 ULg)
Full Text
Peer Reviewed
See detailScale-down effect on the extracellular proteome of Escherichia coli: correlation with membrane permeability and modulation according substrate heterogeneities
Brognaux, Alison ULg; Francis, Frédéric ULg; Twizere, Jean-Claude ULg et al

in Bioprocess and Biosystems Engineering (2014)

Protein leakage is induced in well-mixed fed-batch bioreactor by comparison with cultures carried out in scale-down conditions. This effect is attributed to a progressive increase of cell membrane ... [more ▼]

Protein leakage is induced in well-mixed fed-batch bioreactor by comparison with cultures carried out in scale-down conditions. This effect is attributed to a progressive increase of cell membrane permeability and the synthesis of several outer-membrane components allowing to cope with substrate limitation commonly found in high-cell density culture. A comparative analysis of protein leakage has thus been performed in well-mixed bioreactors and in scale-down devices. The extracellular proteome of E.coli has been investigated by 2D-gel electrophoresis and identified by subsequent MALDI-TOF analysis. On 110 picked spots, 67 proteins have been identified and the sub-localisation and the molecular function of these proteins have been determined. A majority of the extracellular proteome was composed of outer-membrane and periplasmic proteins (64%) confirming the fact that leakage is involved in high-cell density cultures. About 50% of this extracellular proteome was composed of transport and binding proteins. Furthermore, the more abundant spots on the gel corresponded to porin proteins and periplasmic transporters. In particular, the OmpC porin was found to be very abundant. Moreover, the scale-down effect on this extracellular proteome has been investigated by 2D-DIGE analysis (2-Dimensional Differential in-Gel Electrophoresis) and significant differences have been observed by comparison with culture carried out in well-mixed systems. Indeed, since substrate limitation signal is alleviated in this kind of apparatus, cell permeability was lowered as shown by flow cytometry. In scale-down conditions, protein leakage was thus less abundant. [less ▲]

Detailed reference viewed: 31 (10 ULg)
Full Text
Peer Reviewed
See detailScale-down effect on the extracellular proteome of Escherichia coli: correlation with membrane permeability and modulation according substrate heterogeneities
Brognaux, Alison ULg; Francis, Frédéric ULg; Twizere, Jean-Claude ULg et al

in Bioprocess and Biosystems Engineering (2014)

Protein leakage is induced in well-mixed fed-batch bioreactor by comparison with cultures carried out in scale-down conditions. This effect is attributed to a progressive increase of cell membrane ... [more ▼]

Protein leakage is induced in well-mixed fed-batch bioreactor by comparison with cultures carried out in scale-down conditions. This effect is attributed to a progressive increase of cell membrane permeability and the synthesis of several outer-membrane components allowing to cope with substrate limitation commonly found in high-cell density culture. A comparative analysis of protein leakage has thus been performed in well-mixed bioreactors and in scale-down devices. The extracellular proteome of E.coli has been investigated by 2D-gel electrophoresis and identified by subsequent MALDI-TOF analysis. On 110 picked spots, 67 proteins have been identified and the sub-localisation and the molecular function of these proteins have been determined. A majority of the extracellular proteome was composed of outer-membrane and periplasmic proteins (64%) confirming the fact that leakage is involved in high-cell density cultures. About 50% of this extracellular proteome was composed of transport and binding proteins. Furthermore, the more abundant spots on the gel corresponded to porin proteins and periplasmic transporters. In particular, the OmpC porin was found to be very abundant. Moreover, the scale-down effect on this extracellular proteome has been investigated by 2D-DIGE analysis (2-Dimensional Differential in-Gel Electrophoresis) and significant differences have been observed by comparison with culture carried out in well-mixed systems. Indeed, since substrate limitation signal is alleviated in this kind of apparatus, cell permeability was lowered as shown by flow cytometry. In scale-down conditions, protein leakage was thus less abundant. [less ▲]

Detailed reference viewed: 31 (10 ULg)
Full Text
Peer Reviewed
See detailPhysico-chemical properties and aroma profile of Acacia Honey produced in Romania
Madas, Mariana-Niculina ULg; Francis, Frédéric ULg; Marghitas, L.A. et al

in Communications in Agricultural and Applied Biological Sciences (2014, February 07), 79(1), 133-135

Detailed reference viewed: 39 (1 ULg)
Full Text
See detailThree aspects, One concept: Agroecology. Agroecological practices and human interactions for a new approach for science. An example at the Univeristy of Liege.
Hatt, Séverin ULg; Artru, Sidonie ULg; Boeraeve, Fanny et al

Poster (2014, February 07)

Critics are raising about conventional farming and its consequences on biodiversity, human health and society. As alternatives, novel models for agriculture are proposed, and among them Agroecology. Quite ... [more ▼]

Critics are raising about conventional farming and its consequences on biodiversity, human health and society. As alternatives, novel models for agriculture are proposed, and among them Agroecology. Quite often, Agroecology is seen as the application of ecological knowledge to the agricultural production. Indeed, this helps to develop more ecological farming practices favoring biodiversity to provide ecosystem services at multiple scales. Agroecology goes further in considering that the agricultural production is integrated in a food system guided by human interactions. This latter one takes into account socio-economic and political dimensions to develop new production systems. Doing so, it assures food security worldwide while preserving resources for future generations. Facing these ambitious objectives, academics are invited to elaborate a new approach for science in developing participatory and action-oriented approaches as well as multidisciplinarity. AgricultureIsLife is a research platform built up at the University of Liège (ULg). In 2013, 40 researchers (including 18 young researchers) from 16 research units of ULg were working in a multidisciplinary approach. About twenty research topics have been divided in four research axes of which objectives are to develop a more sustainable agriculture. The platform has the ambition to discuss its results to a large comity gathering the actors of the agricultural development. The aim of our work is firstly to present Agrocology as a concept made of three interrelated aspects. To illustrate it, the organization and objectives of the research platform AgricultureIsLife will be discussed in a second part. [less ▲]

Detailed reference viewed: 78 (12 ULg)