References of "Massart, Sébastien"
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See detailA "external" StandPoint on QMS
Massart, Sébastien ULg

Conference (2016, March)

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See detailEarly life programming of pigs' intestinal microbiota, intestinal functioning and hepatic metabolism by maternal wheat bran supplementation
Leblois, Julie ULg; Bindelle, Jérôme ULg; Dehareng, Frédéric et al

Poster (2016, February 05)

The gastrointestinal (GI) microbiota plays many roles on the host’s health, acting as a barrier against pathogens and influencing the development and maturation of the mucosa, important for host’s ... [more ▼]

The gastrointestinal (GI) microbiota plays many roles on the host’s health, acting as a barrier against pathogens and influencing the development and maturation of the mucosa, important for host’s immunity. Microbial colonization occurs pre- and postnatally, via maternal transfer i.e. by milk and by the contact with sows faeces. Hence, the early establishment of a beneficial gastrointestinal microbiota in piglets was investigated by supplementing the sows with wheat bran that we consider as a prebiotic (rich in non-starch polysaccharides). Sows were fed either a wheat bran-enriched diet (25% in gestation, 14% in lactation) either a control diet. Piglets were suckling during 4 weeks, receiving a standard creep feed containing no pre- or probiotic from the second week until weaning. The direct effect of wheat bran on the fecal microbial composition of the sow has been analyzed as well as the chemical composition and immunoglobulins content of the colostrum and milk. Sows and piglets growth performances have been recorded at different time points to verify that wheat bran doesn’t impair performances. At weaning, piglets have been euthanized and the impact of the maternal treatment was investigated at different levels: growth performances, ileal and colonic microbiota, intestinal physiology and immunological response and metabolism. A second animal experiment will be performed next year including a metabolic challenge by giving half of the piglets a high-energy diet post-weaning. [less ▲]

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See detailA metagenomic approach from aphid’s hemolymph sheds light on the potential roles of co-existing endosymbionts
De Clerck, Caroline ULg; Fujiwara, Akiko; Joncour, Pauline et al

in Microbiome (2015), 3(63),

Background: Aphids are known to live in symbiosis with specific bacteria, called endosymbionts which can be classified as obligate or accessory. Buchnera aphidicola is generally the only obligatory ... [more ▼]

Background: Aphids are known to live in symbiosis with specific bacteria, called endosymbionts which can be classified as obligate or accessory. Buchnera aphidicola is generally the only obligatory symbiont present in aphids, supplying essential nutrients that are missing in the plants phloem to its host. Pentalonia nigronervosa is the main vector of the banana bunchy top virus, one of the most damageable viruses in banana. This aphid is carrying two symbionts: B. aphidicola (BPn) and Wolbachia sp. (wPn). The high occurrence of Wolbachia in the banana aphid raises questions about the role it plays in this insect. The goal of this study was to go further in the understanding of the role played by the two symbionts in P. nigronervosa. To do so, microinjection tests were made to see the effect of wPn elimination on the host, and then, high-throughput sequencing of the haemolymph was used to analyze the gene content of the symbionts. Results: We observed that the elimination of wPn systematically led to the death of aphids, suggesting that the bacterium could play a mutualistic role. In addition, we identify and annotate 587 and 250 genes for wPn and BPn, respectively, through high-throughput sequencing. Analysis of these genes suggests that the two bacteria are working together for the production of several essential nutrients. The most striking cases are for lysin and riboflavin which are usually provided by B. aphidicola alone to the host. In the banana aphid, the genes involved in the production pathways of these metabolites are shared between the two bacteria making them both essential for the survival of the aphid host. Conclusions: Our results suggest that a co-obligatory symbiosis between B. aphidicola and Wolbachia occurs in the banana aphid, the two bacteria acting together to supply essential nutrients to the host. This is, to our knowledge, the first time Wolbachia is reported to play an essential role in aphids. [less ▲]

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See detailPractical training session on virus discovery from High Throughput Sequencing data
Massart, Sébastien ULg

Conference (2015, September 09)

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See detailEffect of Volatile Organic Compounds against fungal and bacterial plant pathogens
Kaddes, Amine ULg; Massart, Sébastien ULg; Fauconnier, Marie-Laure ULg et al

Scientific conference (2015, August 25)

Barley is threatened by various edaphic fungal diseases. Common root rot, caused by Fusarium culmorum and Cochliobolus sativus , is one of the major fungal diseases of barley, causing between 9 and 23 ... [more ▼]

Barley is threatened by various edaphic fungal diseases. Common root rot, caused by Fusarium culmorum and Cochliobolus sativus , is one of the major fungal diseases of barley, causing between 9 and 23 % of yield losses. Since several chemicals used for crop protection are being forbidden, new ways of protection are needed. In a previous study, we have shown that barley roots infected by common root rot emitted 23 Volatile Organic Compounds (VOCs) that were not emitted by healthy barley roots. Among VOCs methyl propionate and methyl acrylate applied alone reduced significantly the development of both barley pathogens. The main objective of this study is to evaluate the antifungal and antibacterial activity of both VOCs on a wider range of plant pathogens: Fusarium culmorum , Fusarium graminiurum, Penicillium expansum, Penicilium digitatum and Penicilium itallicum as fungal pathogens ) and Pectobacterium carotovorum carotovorum and Pectobacterium atrosepticum as bacterial pathogens. The evaluation has been made through ELISA microplates with PDB or V8 media. The growth of the pathogen (bacteria and conidia) in the presence of the VOCs was evaluated and compared to a control (same media without VOCs). Methylpropionate showed interesting antibacterial activity with 40% and 96%of inhibition against Pectobacterium carotovorum carotovorum and Pectobacterium atrosepticum, respectively. An inhibition of 77 and 97 % was observed in presence of methylacrylate against Pectobacterium carotovorum carotovorum and Pectobacterium atrosepticum, respectively. Concerning antifungal activity, the results showed that the methyl acrylate inhibted the growth of all tested fungi (the least was P.digitatum by 70%), similarly to methylpropionate (with 50% found in F.culmorum). [less ▲]

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See detailApplication of next generation sequencing for study and diagnosis of plant viral diseases in agriculture
van der Vlugt, René; Minafra, Angelanotio; Olmos, Antonio et al

Poster (2015, August)

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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 ▲]

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See detailEmpowering NGS technologies for the study and diagnostic of plant viruses - European COST Action FA1407
Massart, Sébastien ULg; Gentit, Pascal; Olmos, Antonio et al

Poster (2015, June)

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See detailStudy of essential oil activity on Curvularia sp. a rice leaf spot pathogen in Madagascar
Mamiharisoa Razanakoto, Léa ULg; Parisi, Olivier ULg; Massart, Sébastien ULg et al

Poster (2015, May 19)

Rice leaf spot have been observed on many fields during survey of rice diseases in three regions in Madagascar. Curvularia sp. was the most frequently isolated pathogen from the most severe diseased ... [more ▼]

Rice leaf spot have been observed on many fields during survey of rice diseases in three regions in Madagascar. Curvularia sp. was the most frequently isolated pathogen from the most severe diseased samples. This pathogen has been reported worldwide to cause important losses. Then in this work, we study the possibility to develop an alternative method to control Curvularia sp. Plants or plant extracts have been traditionally used to control human and plant diseases. Nowadays, the problem of residues of phytopharmaceutical products, reinforce the need for research on the development of natural plant extracts to control plant diseases. Madagascar has many endemic plants of interest. The antimicrobial properties of essential oils from Malagasy aromatic plants were evaluated. The main steps of this study are (i) the in-vitro screening of 39 Malagasy essential oils to control this pathogen, (ii) the evaluation of the phytotoxicity (on rice plants) of the efficient essential oils and (iii) the in vivo test of the activity of these non phytotoxic essential oils on Curvularia sp. on rice seedlings. The activity of essentials oils on Curvularia sp. has been tested in vitro during a microscale ELISA plate bioassay using optical density for a rapid evaluation of the biofungicidal activity of the extracts. Essential oils that showed interesting antifungal effect on this pathogen were tested for their phytotoxicity on rice plants. Briefly, one to two drop(s) of essential oils were applied on 3 leaves leaves of three weeks rice seedling. Six essential oils over the 39 tested showed an interesting antifungal activity with a percentage of growth inhibition greater than 70%. Three essential oils tested were phytotoxic as they induced necrotic spots on rice leaves after 48 h. Among three essential oils left, one of them showed an important effect when applied on rice seedling inoculated with a conidial suspension of Curvularia sp. These results confirmed that some essential oils present an antifungal activity. And even some of them are phytotoxic on rice plants, some essential oils show interesting potential to be an alternative method against rice diseases. [less ▲]

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See detailPasseport santé pour bananier
Massart, Sébastien ULg

E-print/Working paper (2015)

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See detailEquipements remarquable: Passeport santé pour bananier
Massart, Sébastien ULg

in 15e Jour du Mois (Le) (2015), (242),

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See detailA novel sub-phylum method discriminates better the impact of crop management on soil microbial community
Degrune, Florine ULg; Dufrêne, Marc ULg; Colinet, Gilles ULg et al

in Agronomy for Sustainable Development (2015)

Soil microorganisms such as mycorrhizae and plant-growth-promoting rhizobacteria have beneficial effects on crop productivity. Agricultural practices are known to impact soil microbial communities, but ... [more ▼]

Soil microorganisms such as mycorrhizae and plant-growth-promoting rhizobacteria have beneficial effects on crop productivity. Agricultural practices are known to impact soil microbial communities, but past studies examining this impact have focused mostly on one or two taxonomic levels, such as phylum and class, thus missing potentially relevant information from lower levels. Therefore we propose here an original, sub-phylum method for studying how agricultural practices modify microbial communities. This method involves exploiting the available sequence information at the lowest taxonomic level attainable for each operational taxonomic unit. In order to validate this novel method we assessed microbial community composition using 454 pyrosequencing of 16S and 28S rRNA genes, then we compared the results with results of a phylum-level analysis. Agricultural practices included conventional tillage, reduced tillage, residue removal and residue retention. Results show that, at the lowest taxonomic level attainable, tillage is the main factor influencing both bacterial community composition, accounting for 13% of the variation, and fungal community composition, accounting for 18% of the variation. Whereas phylum-level analysis failed to reveal any effect of soil practice on bacterial community composition, and missed the fact that different members of the same phylum responded differently to tillage practice. For instance, the fungal phylum Chytridiomycota showed no impact of soil treatment, while sub-phylum-level analysis revealed an impact of tillage practice on the Chytridiomycota sub-groups Gibberella, which includes a notorious wheat pathogen, and Trichocomaceae. This clearly demonstrates the necessity of exploiting the information obtainable at sub-phylum level when assessing the effects of agricultural practice on microbial communities. [less ▲]

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See detailBiological control in the microbiome era: Challenges and opportunities
Massart, Sébastien ULg; Martinez-Medina, Margarita; Jijakli, Haissam ULg

in Biological Control (2015), 89

Biocontrol research has long been focused on the study of single strains of biocontrol agents (BCAs) and on their interaction with pathogens and host plants. Further focus on plant-associated microbial ... [more ▼]

Biocontrol research has long been focused on the study of single strains of biocontrol agents (BCAs) and on their interaction with pathogens and host plants. Further focus on plant-associated microbial communities was suggested several years ago, but significant advances only occurred recently. The advent of high-throughput sequencing (or next-generation sequencing – NGS) technologies is now driving a paradigm change that allows researchers to integrate microbial community studies into the traditional biocontrol approach. This integration could answer old scientific questions, and will raise new biocontrol hypotheses. Microbial communities could impact disease control through their interaction with host plants, pathogens, and BCAs. A better understanding of these interactions will provide unexpected opportunities to develop innovative biocontrol methods against plant pathogens. For example, formulation or timing of BCA application can be improved, ‘‘helper’’ microbial strains can be selected, or molecules driving the microbiota to a pathogen-resistant composition (‘‘prebiotic’’ approach) can be developed. The five main challenges of microbiome implementation in biocontrol research are also described, i.e. (i) the management of technical errors and biases, (ii) the growing importance of bioinformatics, (iii) the adaptation of experimental schemes, (iv) the appropriate interplay between NGS and other technologies, and (v) the need to complete current genome databases [less ▲]

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