{"id":9289,"date":"2018-10-19T15:29:04","date_gmt":"2018-10-19T15:29:04","guid":{"rendered":"https:\/\/mycor.iam.inrae.fr\/IAM\/?p=9289"},"modified":"2018-10-19T15:30:27","modified_gmt":"2018-10-19T15:30:27","slug":"9289","status":"publish","type":"post","link":"https:\/\/mycor.iam.inrae.fr\/IAM\/?p=9289","title":{"rendered":"PhD Defense : Fran\u00e7ois Maillard"},"content":{"rendered":"
\n
\n
Fran\u00e7ois Maillard\u00a0soutiendra publiquement ses travaux de th\u00e8se portant sur :<\/div>\n
Le r\u00f4le des communaut\u00e9s microbiennes dans la d\u00e9gradation de la mati\u00e8re organique en for\u00eat dans un contexte d’exportation intense de biomasse<\/strong>\u00a0<\/strong><\/div>\n
\u00a0<\/strong><\/div>\n
Dirig\u00e9s par Marc Bu\u00e9e et Dominique G\u00e9rant\u00a0le 26 octobre\u00a0\u00e0 9h00
Salle de conf\u00e9rence
Centre INRA Grand Est – Nancy
Champenoux<\/div>\n
<\/div>\n
Jury<\/strong><\/span><\/div>\n
Patricia Luis<\/strong>, Ma\u00eetre de Conf\u00e9rences, Universit\u00e9 de Lyon (Rapporteur)
Fran\u00e7ois Busco<\/strong>t, Prof. Dr., Helmholtz Centre for Environmental Research (Rapporteur)
Daniel Epron<\/strong>, Professeur des Universit\u00e9s, Universit\u00e9 de Lorraine (Examinateur)
Fran\u00e7ois Rineau<\/strong>, Prof. Dr., University of Hasselt (Examinateur)<\/div>\n
\u00a0
R\u00e9sum\u00e9\u00a0:<\/strong>
En Europe, le bois est la premi\u00e8re source d\u2019\u00e9nergie renouvelable. La transition \u00e9nerg\u00e9tique se traduit par une intensification de l\u2019exploitation des for\u00eats. L\u2019effet de ces pratiques sylvicoles sur les communaut\u00e9s microbiennes du sol est encore peu \u00e9tudi\u00e9. Au cours de ma th\u00e8se, j\u2019ai \u00e9valu\u00e9 les cons\u00e9quences d\u2019une manipulation artificielle de mati\u00e8re organique en for\u00eat temp\u00e9r\u00e9e sur la diversit\u00e9 fonctionnelle et taxonomique des communaut\u00e9s bact\u00e9riennes et fongiques telluriques dans six sites exp\u00e9rimentaux (r\u00e9seau exp\u00e9rimental MOS). Parall\u00e8lement, une caract\u00e9risation fonctionnelle des communaut\u00e9s microbiennes a \u00e9galement \u00e9t\u00e9 r\u00e9alis\u00e9e dans un contexte proche des r\u00e9alit\u00e9s de l\u2019intensification des pratiques sylvicoles sous climat tropical en plantation d\u2019Eucalyptus. Si certains descripteurs fonctionnels de la d\u00e9gradation de la mati\u00e8re organique sont particuli\u00e8rement informatifs, les activit\u00e9s microbiennes de d\u00e9gradation de la chitine, polym\u00e8re azot\u00e9 des arthropodes et champignons, sont apparues tr\u00e8s sensibles au retrait de mati\u00e8re organique. C\u2019est pourquoi, par des approches de g\u00e9nomiques comparatives, nous avons cherch\u00e9 \u00e0 estimer le potentiel chitinolytique des diff\u00e9rentes guildes fongiques des sols. En conditions contr\u00f4l\u00e9es, nous avons ensuite quantifi\u00e9 les capacit\u00e9s potentielles de mobilisation et de transfert du carbone et de l\u2019azote, \u00e0 partir d\u2019une mati\u00e8re organique microbienne riche en chitine, par un champignon ectomycorhizien en symbiose avec son h\u00f4te. Enfin, la g\u00e9n\u00e9ricit\u00e9 des fonctions chitinolytiques d\u2019un plus large spectre d\u2019esp\u00e8ces fongiques ectomycorhiziennes a \u00e9t\u00e9 \u00e9valu\u00e9e par le couplage d\u2019approches enzymatiques et isotopiques. L\u2019ensemble de nos r\u00e9sultats met en lumi\u00e8re le r\u00f4le significatif des champignons ectomycorhiziens dans la mobilisation du carbone et de l\u2019azote \u00e0 partir de certaines formes de mati\u00e8re organique, et la n\u00e9cessit\u00e9 de prendre en compte le compartiment microbien dans les \u00e9tudes d\u2019impact des pratiques sylvicoles.<\/div>\n
\u00a0
Abstract:<\/strong><\/div>\n
One of the main usages of wood in Europe is renewable energy supply that implies intensification of forest management to respond to this increasing demand. However, the impact of intense forestry practices on soil microbial communities remains poorly investigated. In the frame of my PhD thesis, I evaluated effects of artificial organic matter removal on functional and taxonomical diversity of soil bacterial and fungal communities in temperate forest, using six experimental sites across France (INRA MOS experimental network). In parallel, I also characterised impact of intensified forest management practices on functional microbial communities in tropical plantation of Eucalyptus trees. This work permitted to identify several sensitive functional indicators of organic matter degradation. Notably, the degradation of chitin \u2013 a nitrogen polymer main component of arthropods and fungal cell walls \u2013 was revealed to be particularly sensitive to organic matter removal. Genomics and enzymatic approaches were then used to estimate chitinolytic potentials of the different genera of soil fungi. In controlled conditions, we were able to quantify ectomycorrhizal fungus carbon and nitrogen mobilisation and transfer capacities from chitin enriched organic matter to its host during symbiotic interaction. Finally, we evaluated chitinolytic functions of ectomycorrhizal fungi at large scale by combining enzymatic and isotopic approaches. Taken together, the results acquired in the frame of my PhD thesis, illustrate the significant role of ectomycorrhizal fungi in carbon and nitrogen mobilisation from organic matter. We particularly highlight that microbial compartment in soil must be considered in studies of forest management practices.<\/div>\n<\/div>\n<\/blockquote>\n
<\/div>\n","protected":false},"excerpt":{"rendered":"

Fran\u00e7ois Maillard\u00a0soutiendra publiquement ses travaux de th\u00e8se portant sur : Le r\u00f4le des communaut\u00e9s microbiennes dans la d\u00e9gradation de la mati\u00e8re organique en for\u00eat dans un contexte d’exportation intense de biomasse\u00a0 \u00a0 Dirig\u00e9s par Marc Bu\u00e9e et Dominique G\u00e9rant\u00a0le 26 … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,8],"tags":[],"class_list":["post-9289","post","type-post","status-publish","format-standard","hentry","category-seminarmeeting","category-thesis"],"_links":{"self":[{"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/posts\/9289","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=9289"}],"version-history":[{"count":0,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=\/wp\/v2\/posts\/9289\/revisions"}],"wp:attachment":[{"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=9289"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=9289"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/IAM\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=9289"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}