Skip to Main content Skip to Navigation
Theses

Recherche et caractérisation de nouvelles enzymes de bactéries marines actives sur les polysaccharides algaux par une approche biochimique et structurale

Abstract : Algal polysaccharides are marine resources valorization of which is hindered by the lack of proper tools to modify their structure. Marine bacteria living associated to macroalgae synthesize enzymes acting on these polysaccharides. They represent a great opportunity for the development of bleu biotechnology. This thesis project resulted in the successful cloning and soluble protein production of several dozen new bacterial enzymes active on algal polysaccharides. Four of them have been studied in detail. The first two are involved in carrageenan degradation pathways. The first one, ZgCgkA, is a κ-carrageenase from family 16 of glycoside hydrolases (GH), synthesized by Zobellia galactanivorans. Its biochemical and structural study, by X-ray crystallography, provided a link between structural features and different interaction modes with the substrate in this GH16 sub-family. The second enzyme, a β-carrabiose hydrolase from Pseudoalteromonas carrageenovora, is active on hybrid oligosaccharides of β/κ-carrageenan. Its biochemical and phylogenetic study suggests the creation of a new GH family, distantly related to the GH42 family. The last two enzymes, a GH29 and a non-classified GH, are encoded in a locus of Z. galactanivorans probably dedicated to the degradation of sulfated fucans. GH29 was biochemically characterized on synthetic substrate, and its structural study is ongoing. These results raise the possibility to use these enzymes as tools for the valorization of algal polysaccharides, particularly carrageenans.
Complete list of metadata

https://tel.archives-ouvertes.fr/tel-03465174
Contributor : Abes Star :  Contact
Submitted on : Friday, December 3, 2021 - 4:54:09 PM
Last modification on : Friday, January 21, 2022 - 3:29:37 AM

File

MATARD_MANN_Maria_these_2017.p...
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-03465174, version 1

Citation

Maria Matard-Mann. Recherche et caractérisation de nouvelles enzymes de bactéries marines actives sur les polysaccharides algaux par une approche biochimique et structurale. Biochimie [q-bio.BM]. Université Pierre et Marie Curie - Paris VI, 2017. Français. ⟨NNT : 2017PA066659⟩. ⟨tel-03465174⟩

Share

Metrics

Les métriques sont temporairement indisponibles