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Etude du rôle des microorganismes dans les modifications biochimiques intervenant lors de la maturation des coagulums de latex d’Hevea brasiliensis : impact sur les propriétés du caoutchouc naturel sec.

Abstract : The overall objective of this thesis was to study the microbial mechanisms involved in the evolution of the structure and the properties of the natural rubber from Hevea brasiliensis during the maturation of latex and cup-coagula. For this, three levels of analyses were performed on maturation experiments under controlled conditions: dry rubber structure and properties, biochemistry and microbial flora. After a methodology development phase aiming at (i) optimizing maturation conditions in a controlled chamber and (ii) defining suitable DNA extraction methods, samples of serum and dry rubber coagulum were produced at different times and under different maturation treatments varying three parameters: the presence of microorganisms, the presence of oxygen, and the latex coagulation method. Dry rubber analyses concerned macrostructure (P0, P30 and PRI) and mesostructure (Mw, Mn and total gel). The microbial flora was analyzed using several complementary methods: plate-counts, total DNA determination, cloning / sequencing and 454 pyrosequencing. The objective was to assess microbial diversity on field and in latex, and to follow the dynamics of their evolution during maturation in a controlled environment. Various biochemical investigations were performed on latex, serum and dry rubber (nitrogen content, proteins, lipids, sugars, quebrachitol, organic acids). The results were then analyzed for correlations to propose mechanisms linking changes in dry rubber properties, latex and coagula biochemistry, and their evolution under the action of microorganisms and enzymes. Some ideas for improving technical routes in the process are also proposed.
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https://hal-montpellier-supagro.archives-ouvertes.fr/tel-02019722
Contributor : Melanie Salomez <>
Submitted on : Monday, March 4, 2019 - 12:07:24 PM
Last modification on : Monday, October 19, 2020 - 11:12:01 AM
Long-term archiving on: : Wednesday, June 5, 2019 - 1:08:06 PM

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  • HAL Id : tel-02019722, version 1

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Mélanie Salomez. Etude du rôle des microorganismes dans les modifications biochimiques intervenant lors de la maturation des coagulums de latex d’Hevea brasiliensis : impact sur les propriétés du caoutchouc naturel sec.. Sciences du Vivant [q-bio]. Montpellier SupAgro, 2014. Français. ⟨tel-02019722⟩

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