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See detailIntegrated farming systems in Kinshasa (DRC) Diversity of agricultural practices
Mafwila Kinkela, Patrick ULg; BINDELLE, Jérôme; WILLEMS, E, Emilie et al

Poster (2014, February 07)

In Kinshasa in the Democratic Republic of Congo, integrated farming of livestock and fish farming is little documented while it is an interesting way of ecological intensification systems. After ... [more ▼]

In Kinshasa in the Democratic Republic of Congo, integrated farming of livestock and fish farming is little documented while it is an interesting way of ecological intensification systems. After identifying the density of fish ponds in the territory of the city using satellite images, about 200 farms with at least one pond and located in 2 in peri-urban and rural areas were surveyed to characterize the practical integration of the agricultural system. The preliminary results in one of the valleys indicate that the practice of agriculture in synergy with the pig and fish farming is a common practice although flow of components are still insufficiently integrated and some of them are not optimized . The fish - pig farming associations with or without vegetable production are 44 % of the sample. The identification of flow on farms showed that the manure of pigs is mainly used for crops (51%) or sold (28%), while a small part is used to fertilize the ponds. This may be explained by the predominant share of income (67%) devoted to vegetable production while sludge of ponds is rarely used to fertilize area of vegetable production. Residues of vegetable crops are rarely used to feed pigs and fish because of their limited availability. Feeding pigs and fish is based primarily on agro-industrial by-products such as wheat bran (81%) and the spent brewery grains (62%) and forages (62%). The presentation will analyze the results obtained in the three sites visited and outline opportunities for improvement. [less ▲]

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See detailSreening of essential oils against rice pathogens isolated from Madagascar
Mamiharisoa Razanakoto, Léa ULg; De Clerck, Caroline ULg; Massart, Sébastien ULg et al

Poster (2014, February 07)

Four predominant isolated pathogens have been identified during survey of rice diseases in three regions in Madagascar. These pathogens were the bacteria Xanthomonas oryzae pv. oryzae and Pseudomonas ... [more ▼]

Four predominant isolated pathogens have been identified during survey of rice diseases in three regions in Madagascar. These pathogens were the bacteria Xanthomonas oryzae pv. oryzae and Pseudomonas fuscovaginae and the fungi Alternaria sp. and Curvularia lunata. These pathogens are causing significant yield reduction on rice, which is the staple food in this country. After the identification of those pathogens, the objective of this work was to identify appropriate control measures against them. Plants extracts has been traditionally used to control diseases in other plant species. Nowadays, the problem of residues of phytopharmaceutical product, reinforce the need for research on the development of natural plant extracts to control plant diseases. Madagascar has many endemic plant of interest and we have evaluated the antimicrobial properties of essential oils from Malagasy plants. The main object of this study is the in-vitro screening of essential oils to control the pathogens isolated on rice in Madagascar. Thirty nine essentials oils from Madagascar had been tested. Activity of essentials oils on Pseudomonas fuscovaginae, Alternaria sp. and Curvularia lunata had been tested using broth media and on agar medium for Xanthomonas oryzae pv. oryzae. The growth of the pathogen (bacteria and conidia) in the presence of the essential oil was evaluated and compared to a control. Nine of the 39 essentials oils showed interesting antimicrobial activity with an efficiency more than 70% against at least one bacterial pathogen. One essential oil inhibited the growth of the two pathogens tested. For fungal pathogens, three essential oils presented an efficiency of more than 70% against at least one fungal pathogen. These results confirm that some essential oils present an interesting antimicrobial activity. The in-situ confirmation on plant of this activity is currently ongoing. [less ▲]

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See detailEfficient computation of genomically-enhanced inbreeding coefficients
Faux, Pierre ULg; Gengler, Nicolas ULg

Poster (2014, February 07)

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See detailUse of on-line flow cytometry for the characterization of microbial stress dynamics during the bioprocess
Brognaux, Alison ULg; Han, Shanshan; Sorensen, Soren et al

Poster (2014, February 07)

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See detailRhizobacterial volatile organic compounds implication in Brachypodium distachyon response to phosphorus deficiency
Baudson, Caroline ULg; Saunier de Cazenave-Mendaluk, Magdalena ULg; du Jardin, Patrick ULg et al

Poster (2014, February 07)

In agriculture, phosphorus (P) is considered as the second most growth-limiting macronutrient after nitrogen. However, P fertilizers are produced from non-renewable resources. In this context, sustainable ... [more ▼]

In agriculture, phosphorus (P) is considered as the second most growth-limiting macronutrient after nitrogen. However, P fertilizers are produced from non-renewable resources. In this context, sustainable production strategies have to be developed to enhance P use efficiency of crops, e.g. based on naturally occurring biotic interactions that limit the negative impacts of P deficiency in soils. Plant growth-promoting rhizobacteria (PGPR) have already revealed their ability to promote plant growth and tolerance to abiotic stresses through many mechanisms. Among them, the bacterial volatile organic compounds-mediated communication between plants and PGPR is still poorly documented. Our research project aims at studying the capacity of a model cereal plant (Brachypodium distachyon (L.) Beauv. Bd21) to face P deficiency in interaction with PGPR. The prerequisite of this project consists in characterizing Bd21 response to P deficiency by measuring plant biomass production and allocation, root system architecture, total phosphorus content, root-secreted and intracellular acid phosphatase activity under various P concentrations. Those results will allow us to define P-limiting conditions, in order to assess PGPR volatiles influence on plant response to P deficiency. This approach will use an ex-vitro co-cultivation system allowing volatiles-mediated interaction and should help us to unravel the ability of rhizobacterial volatiles to enhance plant tolerance to P deficiency. [less ▲]

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See detailEffect of sun-drying on flavonoïd composition and antioxidant activity of three dark fig varieties
Bachir Bey, M.; Richard, Gaetan ULg; Fauconnier, Marie-Laure ULg et al

Poster (2014, February 07)

The aim of the study was to investigate the effect of sun-drying on individual flavonoïd and antioxidant activities of three dark fig varieties (Azenjar, Bouankik, and Aberkane). Flavonoïd compounds were ... [more ▼]

The aim of the study was to investigate the effect of sun-drying on individual flavonoïd and antioxidant activities of three dark fig varieties (Azenjar, Bouankik, and Aberkane). Flavonoïd compounds were identified and quantified using high-performance liquid chromatography. The results showed that all samples significantly differed in their flavonoïd compositions. [less ▲]

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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

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See detailarchiDART: a R package allowing root system architecture analysis using Data Analysis of Root Tracings (DART) output files
Delory, Benjamin ULg; Baudson, Caroline ULg; Brostaux, Yves ULg et al

Poster (2014, February 07)

In 2010, Le Bot et al presented a free and open-access software (Data Analysis of Root Tracings - DART) allowing the analysis of complex root system architectures from captured images, particularly across ... [more ▼]

In 2010, Le Bot et al presented a free and open-access software (Data Analysis of Root Tracings - DART) allowing the analysis of complex root system architectures from captured images, particularly across time series. Using this software, a user has to manually identify roots as a set of links. After vectorization of a root system, three final data sets (RAC, TPS and LIE) can be exported as table files containing several attributes for (a) each individual root (e.g. root length), (b) each observation day or (c) each point used to construct the vectorized root system respectively. These data sets can finally be used either to calculate derived root system architecture (RSA) parameters or to draw the root system architecture at selected observation dates. However when an experiment involves the analysis and comparison of many root systems, the calculation of RSA parameters for each data set and the drawing of the corresponding vectorized root systems become time-consuming. In this context, we developed a R package, called archiDART, allowing both the automatic calculation of common root architecture parameters and the X-Y plotting of vectorized root systems for selected observation dates. [less ▲]

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See detailScreening of two agricultural genomic DNA libraries to seek new glycoside hydrolases
Stroobants, Aurore ULg; Portetelle, Daniel ULg; Vandenbol, Micheline ULg

Poster (2014, February 07)

Soils are very rich environments where the diversity of microorganisms is very high. These microorganisms play an important role in the degradation of organic matter with enzymes able to degrade it. This ... [more ▼]

Soils are very rich environments where the diversity of microorganisms is very high. These microorganisms play an important role in the degradation of organic matter with enzymes able to degrade it. This work aims to discover, by functional screening, new microbial glycoside hydrolases from soils collected in winter and spring in a winter wheat crop. The genomic DNA was extracted from both soils to construct two libraries in Escherichia coli. These libraries were then screened for beta-glucosidase activities on 2YT agar media containing 0.5% esculin and 0.1% ammonium iron (III) citrate. At this time, about 250.000 clones from each library have been screened. Two beta-glucosidases have already been found in the winter library while five beta-glucosidases and two glycosyltransferases were identified in the spring library. Sequence analyses with the BLASTX program revealed putative enzymes showing between 25% and 72% sequence identity with known enzymes and belonging to three glycoside hydrolase families (GH1, GH3 and GH20) and to two probably new glycosyltransferase families. Biochemical characterisation of the candidates at several pH values and temperatures, and with four substrates, is in progress. [less ▲]

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See detailQuantitative gas chromatography - mass spectrometry profiling of volatile organic compounds produced by barley (Hordeum distichon L.) roots according to plant age
Delory, Benjamin ULg; Delaplace, Pierre ULg; du Jardin, Patrick ULg et al

Poster (2014, February 07)

In chemical ecology, the roles played by root-emitted volatile organic compounds (VOCs) in biotic interactions and the quantitative analysis of such chemicals in root tissues remain poorly documented. In ... [more ▼]

In chemical ecology, the roles played by root-emitted volatile organic compounds (VOCs) in biotic interactions and the quantitative analysis of such chemicals in root tissues remain poorly documented. In this context, this study aims at developing a fully automated analytical methodology allowing both identification and accurate quantification of VOCs produced by roots of a monocotyledon plant species. Briefly, VOC emitted by crushed barley roots are successively trapped by dynamic headspace sampling on Tenax TA adsorbents, thermally desorbed and cryofocused, separated by gas chromatography (GC) and finally analysed by mass spectrometry (MS) in both SCAN and selected ion monitoring modes. Results show that barley roots mainly produce four volatile aldehydes, namely hexanal, (E)-hex-2-enal, (E)-non-2-enal and (E,Z)-nona-2,6-dienal. These molecules are well-known linoleic (C18:2) and linolenic (C18:3) acid derivatives produced via the lipoxygenase and the hydroperoxide lyase pathways of higher plants. Our findings contrast with analyses documented on aboveground barley tissues that mainly emit C6 aldehydes, alcohols and their derivative esters. Moreover, preliminary results indicate quantitative changes in the volatile profile contained in barley roots according to plant age. Multivariate statistical analyses are currently underway to quantitatively assess these changes using plants at five selected developmental stages ranging from germination to the end of tillering. [less ▲]

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See detailIMPLEMENTATION OF A METAL STRUCTURED PACKING IN A FUNGAL BIOFILM REACTOR FOR THE PRODUCTION OF A RECOMBINANT PROTEIN BY ASPERGILLUS ORYZAE
Zune, Quentin ULg; Delepierre, Anissa; Toye, Dominique ULg et al

in Communications in Agricultural and Applied Biological Sciences (2014, February 07)

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See detailCan phytoestrogen-rich plants restore the image of livestock in terms of human health? Do they promise a differentiated quality products chain?
Daems, Frédéric ULg; Jasselette, Christophe; Lognay, Georges ULg et al

Poster (2014, February 07)

In a project named PhytoHealth, the development of analytical methods for studying the impact of phytoestrogens rich diet on the «health value» of animal products is in progress. Despite the ambiguous ... [more ▼]

In a project named PhytoHealth, the development of analytical methods for studying the impact of phytoestrogens rich diet on the «health value» of animal products is in progress. Despite the ambiguous image that have phytoestrogens, some of their metabolites seemed to have potentially beneficial effects to human health. In a first time, a microbial metabolite (equol) was selected and its metabolism in dairy cow is studied. A first method using the UPLC®-MS/MS technology has been validated and has achieved a screening of equol content in milk consumed in Wallonia. Equol was found in all milk samples analyzed and a significant difference between farming methods has been highlighted. A second analytical method to quantify the equol precursors was then developed and a study of forage plants consumed by Belgian dairy cows will be conducted to select the richest fodder varieties. Other methods will be developed to better understand the metabolism in the cow and estimate the impact of enriched milk on human health. An original approach involving the use of minipigs will be considered. In the end, creating of a differentiated quality animal products chain could be interesting for the consumer, but also recoverable for the producer. [less ▲]

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See detailGold nanorods coated with a thermo-responsive poly(ethylene glycol)-b-poly(N-vinylcaprolactam) corona as drug delivery systems for remotely near infrared-triggered release
Liu, Ji ULg; Detrembleur, Christophe ULg; De Pauw, Marie-Claire ULg et al

in Polymer Chemistry (2014), 5(3), 799-813

Poly(ethylene glycol)-b-poly(N-vinylcaprolactam) (PEG-b-PNVCL) copolymers are prepared from a PEG macro-chain transfer agent in DMF at 65 °C via reversible addition-fragmentation chain transfer (RAFT ... [more ▼]

Poly(ethylene glycol)-b-poly(N-vinylcaprolactam) (PEG-b-PNVCL) copolymers are prepared from a PEG macro-chain transfer agent in DMF at 65 °C via reversible addition-fragmentation chain transfer (RAFT) polymerization. The well-defined PEG114-b-PNVCL237 copolymer with a cloud point temperature of 39 °C is used for the formation of a thermo-responsive polymer corona on the surface of gold nanorods (GNRs) via a “grafting-to” approach. Thermo-responsiveness and thermo-dependent optical properties of the as-obtained GNR@PEG-b-PNVCL nanoparticles are studied with dynamic light scattering and UV/vis spectroscopy techniques. Near infrared (NIR)-induced heating of GNR@PEG-b-PNVCL is also explored in aqueous suspension under NIR laser irradiation (802 nm, up to 250 mW). The potential of these GNR@PEG-b-PNVCL nanoparticles to be used as smart drug delivery systems (DDS) is then studied. A hydrophilic drug model, Rhodamine ® B, is used to assess the guest loading capacity, and triggered release behaviours are then evaluated under conventional external heating or internal heating induced by remote NIR irradiation. Cytotoxicity evaluation of the GNR@PEG-b-PNVCL against the fibroblast-like L929 cell line is carried out via the MTS assay in order to confirm the improved biocompatibility of the GNRs after polymer coating. These thermo-responsive GNR@PEG-b-PNVCL nanoparticles are promising DDS that combine the chemotherapeutic and phototherapeutic functions. [less ▲]

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See detailFrom wood charcoals to trees: pitfalls and successes of the taxonomic identification in tropical contexts
Morin-Rivat, Julie ULg; De Weerdt, Joëlle; Hubau, Wannes et al

Poster (2014, February 07)

So as to document the past history of tropical forests, several palaeoenvironmental proxies have been used. For instance, charcoals from soil deposits provide a local signal of the evolution of the ... [more ▼]

So as to document the past history of tropical forests, several palaeoenvironmental proxies have been used. For instance, charcoals from soil deposits provide a local signal of the evolution of the vegetation together with snapshots of human interactions with the environment. As charcoal analyses are rare in tropical contexts, here we aim at presenting the different aspects of charcoal studies through their pitfalls and successes as well as the needs for further research. Charcoal analysis (anthracology) is a discipline initially from archaeobotany that consists in the analysis of pieces of charred wood primarily found in archaeological contexts but also in natural soil layers. Its goal is to identified the species that burnt during the past through the observation of the charred wood structure. Indeed carbonization, as the incomplete combustion of the ligneous material, preserves the wood structure. The identifications obtained through microscopic observations allow assessing past uses of wood and human impacts on the forest landscape. However, issues typically tropical exist: difficulties related to fieldwork accessibility, to sampling, to soil processing so as to collect the charcoals, difficulties related to the taxonomic identification because of the huge number of species and of the limited number of anatomical descriptions. New developments are nonetheless emerging for Central Africa with original anatomical descriptions, identification protocols and visual keys. [less ▲]

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See detailUsing micro-injection technique to assess fungal toxicity in mosquito control
Bawin, Thomas ULg; Boukraa, Slimane; Seye, Fawrou et al

in Communications in Agricultural and Applied Biological Sciences (2014, February 07), 79(1), 181-185

Topical application of insecticidal compounds allows directly exposing these substances on insect tissues and measuring their toxicity while ignoring many factors. However, this technique remains ... [more ▼]

Topical application of insecticidal compounds allows directly exposing these substances on insect tissues and measuring their toxicity while ignoring many factors. However, this technique remains difficult to apply on mosquito larvae considering their aquatic lifestyle. Micro-injection could be used for the direct deposition of toxic compounds in the larvae. Capillaries exhibiting an injection tip with an external diameter of 0.5 mm have been designed from silica tubes. For each treatment, a capillary is mounted on a pump connected to a flow rate regulator. Culex quinquefasciatus larvae were injected with 10^7 spores/ml of entomopathogenic fungi (Aspergillus clavatus, Metarhizium anisopliae, Metarhizium sp.). Mortalities were recorded daily during 72h. The distribution of spores stained with methylene blue and injected into the body of larvae was also observed according to the system described. Results showed that spores were distributed over the whole body. The injection of Aspergillus clavatus, Metarhizium anisopliae and Metarhizium sp spores induced corrected mortalities of 62%, 53% and 57% after 72h, and differed statistically from control groups. Finally, post-mortem emergences of filaments from dead larvae were observed in the case of the three fungal strains confirming spore viability. Injection of inactivated spores (or inert bodies of similar size) could help to reject the hypothesis of a response due to the presence of foreign bodies. [less ▲]

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See detailField bordering flower strips as source of lipids
Paul, Aman ULg; Danthine, Sabine ULg; Stephanie, Heuskin et al

Poster (2014, February 07)

Field bordering flower strips not just only improves the biodiversity but also serves as a source of beneficial compounds. Some of the plants in these strips can be really interesting source of lipids ... [more ▼]

Field bordering flower strips not just only improves the biodiversity but also serves as a source of beneficial compounds. Some of the plants in these strips can be really interesting source of lipids, the oils extracted from their seeds can be important for food, pharmaceutical and cosmetics industries. Six species of plants from flowering strips in Belgium were investigated for their seed oil content. The oil from seeds was extracted by cold extraction technique using chloroform/methanol in 2:1 ratio as solvent. Oil extraction from seeds of Red Clover (Trifolium pratense), Rough Hawkbit (Leontodon hispidus), Cow Parsley (Anthriscus sylvestris), St John’s Wort (Hypericum perforatum), Common Yarrow (Achillea millefollium) and Birdsfoot Trefoil (Lotus corniculatus) plant species was done on wet weight which came out to be 7.89±0.11%, 11.86±0.07%, 14.78±0.31%, 24.20±0.02%, 20.08±0.15% and 7.04±0.12% respectively. The physicochemical properties of the extracted oils were analyzed. Some of these oils can be of great commercial value. [less ▲]

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