Activité
- Thèmes de recherches :
- Symbioses mycorhiziennes
- Dégradation de la matière organique du sol par les champignons
Parcours scientifique
- DUT Génie Biologique 2002
- Master 2R "Ecosciences Microbiologie" 2014
Publications
2019
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Alonso L, et al. 2019. Anthropization level of Lascaux Cave microbiome shown by regional-scale comparisons of pristine and anthropized caves. Molecular Ecology. 28:3383-3394. doi: 10.1111/mec.15144.Résumé : Limestone areas across the world develop karstic caves, which are populated by a wide range of macro- and microorganisms. Many of these caves display Paleolithic art or outstanding speleothems, and in the last century they have been subjected to anthropization due to touristic management and intense human frequentation. Despite their cultural importance and associated conservation issues, the impact of anthropization on cave biodiversity is not known. Here, we show that anthropization is associated with specific cave biota modifications. We compared diversity in four pristine caves, four anthropized show caves, and the iconic Lascaux Cave with even stronger anthropization. The predominant microbial higher taxa were the same in all caves, but the most anthropized cave (Lascaux) was unique as it differed from the eight others by a higher proportion of Bacteroidetes bacteria and the absence of Euryarchaeota and Woesearchaeota archaea. Anthropization resulted in lower diversity and altered community structure for bacteria and archaea on cave walls, especially in Lascaux, but with a more limited effect on microeukaryotes and arthropods. Our findings fill a key gap in our understanding of the response of karstic communities to anthropization, by revealing that tourism-related anthropization impacts on the prokaryotic microbiome rather than on eukaryotic residents, and that it shapes cave biota irrespective of cave natural features.
2017
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Doré J, et al. 2017. The ectomycorrhizal basidiomycete Hebeloma cylindrosporum undergoes early waves of transcriptional reprogramming prior to symbiotic structures differentiation. Environmental Microbiology. 19:1338–1354. doi: 10.1111/1462-2920.13670.Résumé : To clarify the early molecular interaction between ectomycorrhizal partners, we performed a RNA-Seq study of transcriptome reprogramming of the basidiomycete Hebeloma cylindrosporum before symbiotic structure differentiation with Pinus pinaster. Mycorrhiza transcriptome was studied for comparison. By reference to asymbiotic mycelium, 47 and 46 genes were specifically up-regulated over five-fold (p≤0.05) upon rhizosphere colonization and root adhesion respectively. Other 45 were up-regulated throughout the symbiotic interaction, from rhizosphere colonization to differentiated mycorrhizas, whereas 274 were specifically up-regulated in mycorrhizas. Although exoproteome represents 5.6% of H. cylindrosporum proteome, 38.5% of the genes up-regulated upon pre-infectious root colonization encoded extracellular proteins. The proportion decreased to 23.5% in mycorrhizas. At all studied time points, mycorrhiza-induced small secreted proteins (MiSSPs), representing potential effectors, were over-represented among up-regulated genes. This was also the case for carbohydrate-active enzymes (CAZymes). Several CAZymes were up-regulated at all studied stages of the interaction. Consistent with a role in fungal morphogenesis and symbiotic interface differentiation, CAZymes over-expressed before and upon root attachment targeted fungal and both fungal and plant polysaccharides respectively. Different hydrophobins were up-regulated upon early root adhesion, in mycorrhizas or throughout interaction. The functional classification of genes up-regulated only in mycorrhizas pointed to intense metabolic activity and nutritional exchanges. This article is protected by copyright. All rights reserved.
2015
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Kohler A, et al. 2015. Convergent losses of decay mechanisms and rapid turnover of symbiosis genes in mycorrhizal mutualists. Nature Genetics. advance online publication:410. doi: 10.1038/ng.3223.Résumé : To elucidate the genetic bases of mycorrhizal lifestyle evolution, we sequenced new fungal genomes, including 13 ectomycorrhizal (ECM), orchid (ORM) and ericoid (ERM) species, and five saprotrophs, which we analyzed along with other fungal genomes. Ectomycorrhizal fungi have a reduced complement of genes encoding plant cell wall–degrading enzymes (PCWDEs), as compared to their ancestral wood decayers. Nevertheless, they have retained a unique array of PCWDEs, thus suggesting that they possess diverse abilities to decompose lignocellulose. Similar functional categories of nonorthologous genes are induced in symbiosis. Of induced genes, 7–38% are orphan genes, including genes that encode secreted effector-like proteins. Convergent evolution of the mycorrhizal habit in fungi occurred via the repeated evolution of a 'symbiosis toolkit', with reduced numbers of PCWDEs and lineage-specific suites of mycorrhiza-induced genes.
2014
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Doré J, Marmeisse R, Combier J-P, Gay G. 2014. A fungal conserved gene from the basidiomycete Hebeloma cylindrosporum is essential for efficient ectomycorrhiza formation. Molecular Plant-Microbe Interactions. doi: 10.1094/MPMI-03-14-0087-R.Résumé : We used Agrobacterium-mediate insertional mutagenesis to identify genes in the ectomycorrhizal fungus Hebeloma cylindrosporum that are essential for efficient mycorrhiza formation. One of the mutants presented a dramatically reduced ability to form ectomycorrhizas when grown in the presence of Pinus pinaster. It failed to form mycorrhizas in the presence of 0.5 g l-1 glucose, a condition favourable for mycorrhiza formation by the wild-type strain. It however formed few mycorrhizas when glucose was replaced by fructose or when glucose concentration was increased to 1 g l-1. Scanning electron microscopy examination of these mycorrhizas revealed that this mutant was unable to differentiate true fungal sheath and Hartig net. Molecular analyses showed that the single-copy disrupting T-DNA was integrated 6884 bp downstream the start codon, of an ORF potentially encoding a 3096 amino acid-long protein. This gene, which we named HcMycE1 has orthologs in numerous fungi as well as different other eukaryotic microorganisms. RNAi inactivation of HcMycE1 in wild-type strain also led to a mycorrhizal defect, demonstrating that the non-mycorrhizal phenotype of the mutant was due to mutagenic T-DNA integration in HcMycE1. In the wild-type strain colonizing P. pinaster roots, HcMycE1 was transiently up-regulated before symbiotic structures differentiation. Together with the inability of the mutant to differentiate these structures, this suggests that HcMycE1 plays a crucial role upstream fungal sheath and Hartig net differentiation. This study provides the first characterization of a fungal mutant altered in mycorrhizal ability. -
Maury F, et al. 2014. Comparative Study of Antibacterial Efficiency of M-TiO<sub>2</sub> (M = Ag, Cu) Thin Films Grown by CVD. Key Engineering Materials. 617:127-130. doi: 10.4028/www.scientific.net/KEM.617.127.
2010
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Mungkalasiri J, et al. 2010. CVD Elaboration of Nanostructured TiO <sub>2</sub> -Ag Thin Films with Efficient Antibacterial Properties. Chemical Vapor Deposition. 16:35-41. doi: 10.1002/cvde.200906764.
2009
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Mungkalasiri J, et al. 2009. DLI-CVD of TiO2–Cu antibacterial thin films: Growth and characterization. Surface and Coatings Technology. 204:887-892. doi: 10.1016/j.surfcoat.2009.07.015. -
Ngari C, et al. 2009. The dominant Hc. Sdh R carboxin-resistance gene of the ectomycorrhizal fungus <i>Hebeloma cylindrosporum</i> as a selectable marker for transformation. Current genetics. 55:223–231. http://www.springerlink.com/index/F707413681P11487.pdf. -
Ngari C, et al. 2009. The dominant Hc. Sdh R carboxin-resistance gene of the ectomycorrhizal fungus <i>Hebeloma</i> cylindrosporum as a selectable marker for transformation. Current genetics. 55:223–231. http://www.springerlink.com/index/F707413681P11487.pdf (Consulté octobre 20, 2012).
2007
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Forest P, et al. 2007. Validation of a viral and bacterial inactivation step during the extraction and purification process of porcine collagen. Bio-Medical Materials and Engineering. 17:199-208. http://iospress.metapress.com/content/M1355572L13TQ575.Résumé : In the last few years, regulations for biomolecule production, and especially for extraction and purification of animal molecules such as collagen, have been reinforced to ensure the sanitary safety of the materials. To be authorized to market biomaterials based on collagen, manufacturers now have to prove that at least one step of their process is described in guidelines to inactivate prion, viruses, and bacteria. The present study focuses on the inactivation step performed during the extraction and purification of porcine type I atelocollagen. We chose to determine the reduction factor of a 1 M NaOH step on porcine parvovirus and four bacterial strains inactivation. During the extraction step, we deliberately inoculated the collagen suspension with the different microorganisms tested. Then, 1 M NaOH was added to the suspension for 1 hour at 20°C. We demonstrated that this treatment totally inactivated S. aureus, P. aeruginosa, C. albicans and A. niger which are bacterial strains responsible of severe human pathology. The reduction factors reached more than 4 logs for B. cereus spores and 4 logs for the porcine parvovirus. are encouraging as those two microorganisms are known to be very resistant to inactivation.
2006
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Comina E, et al. 2006. Pacifiers: A microbial reservoir. Nursing and Health Sciences. 8:216-223. doi: 10.1111/j.1442-2018.2006.00282.x. -
Renaud FNR, Doré J, Freney HJ, Coronel B, Dusseau J-Y. 2006. Evaluation of Antibacterial Properties of a Textile Product with Antimicrobial Finish in a Hospital Environment. Journal of Industrial Textiles. 36:89-94. doi: 10.1177/1528083706066438.Résumé : The objective of this study is to evaluate the antibacterial activity of a textile product with an antimicrobial finish in real-life hospital conditions. Sixty antibacterial samples and nonactive controls are tested on garments worn by nurses during their working day. The number of colony forming units (CFU) is significantly lower on antibacterial textiles than on the nonactive ones. Moreover, the higher the contamination, the more this contamination was reduced, up to 50% reduction.
Chapitres d’ouvrages
Vulgarisation
Communications Orales
Posters
