Screening for new antimicrobial activities in a forest soil by functional metagenomics

Poster (2011, June)

Identification of new enzymatic activities from Gram-positive bacteria isolated from termite gut (Reticulitermes santonensis)

in 4th Congress of European Microbiologists (2011, June)

Multicopy suppression screen in a Saccharomyces cerevisiae strain lacking the Rab GTPase-activating protein Msb3p.

in Biotechnology Letters (2011), 33(1), 123-9

Screening of a soil metatranscriptomic library by functional complementation of Saccharomyces cerevisiae mutants.

in Microbiological Research (2011), 166(5), 360368

Metatranscriptomics applied to environmental transcripts provides unique opportunities to reveal microbial activity in the environment and to discover novel enzymes of potential use in biotechnological ... [more ▼]

Metatranscriptomics applied to environmental transcripts provides unique opportunities to reveal microbial activity in the environment and to discover novel enzymes of potential use in biotechnological applications. Here, by functional complementation of a pho5(-) mutation (affecting a repressible acid phosphatase) and a his3(-) mutation in Saccharomyces cerevisiae, we identified fungal genes encoding an acid phosphatase and an imidazoleglycerol-phosphate dehydratase in a metatranscriptomic library, which was obtained by reverse-transcribed polyA fraction of total RNA extracted from the organic layer of a sugar maple forest soil, constructed in the modified yeast secretion vector pTEF-MF-SfiI A/B. Yeast transformants exhibiting phosphatase activity were identified in a colony-staining assay and transformants with his3(-)-complementing genes were detected by plating on histidine-deficient medium. In each screen one DNA insert was found and sequenced. The sequenced his3(-)-complementing gene showed strong similarity to a basidiomycete imidazoleglycerol-phosphate dehydratase (76% identity to a Phaffia rhodozyma enzyme). The candidate showing phosphatase activity was found to produce phosphatase extracellularly, the enzyme showing highest activity at pH 4 and between 40 and 50°C when 4-nitrophenyl phosphate was used as substrate. The sequenced insert showed strong similarity to a basidiomycete acid phosphatase (60% identity to Postia placenta). [less ▲]

Purification of a new fungal mannose-specific lectin from Penicillium chrysogenum and its aphicidal properties

in Fungal Biology (2011)

Keep bacteria under control: Dietary modulation of gut microflora in farm animals by use of hen egg yolk antibodies

E-print/Working paper (2010)

This review article focuses on the use of IgY in therapy or prophylaxis of diseases in veterinary medicine as well as in the context of functional foods to modulate microflora in animal.

Les outils moléculaires à la découverte des symbiontes de termites

Poster (2010, November 06)

Antibodies Dynamics in the Broiler Digestive Tract after Salmonella Typhimurium Oral Challenge

in Duclos, Michel; Nys, Yves (Eds.) XIIIth European Poultry Conference: Program & Book of Abstracts, World's Poultry Science Journal, Volume 66, Supplement (2010, August)

This study aimed to provide directions for Salmonella challenge experiment conception by offering a better understanding of the relationship between age and mucosal immune responsiveness of chicken ... [more ▼]

This study aimed to provide directions for Salmonella challenge experiment conception by offering a better understanding of the relationship between age and mucosal immune responsiveness of chicken. Intestinal maternal immunity of Salmonella-free chicks was monitored by ELISA analyses at 2, 9 and 16 days of age. At 21 days of age, chicks were orally inoculated with Salmonella Typhimurium. Three inoculum doses (3 x 10E3, 3 x 10E6, 3 x 10E9 cfu/bird) and an uninfected control were then compared concerning mucosal immune status of the small intestine and cecum. Results suggest that difficulties encountered to infect very young chicks can be related, at least partly, to maternal immunity. The relatively low level of intestinal immune defences observed thereafter could indicate a right time to perform an experimental infection of birds and to maximize the spreading of the pathogen during challenge experiment. After infection of 3-week-old chickens, the mucosal immune response was rapid with increased anti-Salmonella Typhimurium IgA titers. There was a linear relationship between specific IgA levels in intestinal and cecal secretions and the challenge dose initially inoculated. [less ▲]

DNA cytosine methylation in the Bovine Leukemia Virus promoter is associated with latency in a lymphoma-derived B-cell line potential involvement of direct inhibition of cAMP-responsive element (cre)-binding protein/cre modulator/activation transcription factor binding

in Journal of Biological Chemistry (2010), 285(25), 19434-19449

Identification of multicopy suppressors of the yeast msb3- mutation

Poster (2010, May 21)