Skip to Main content Skip to Navigation
Theses

Exploration de sécrétomes d'Aspergillus spp. en vue de la complémentation du cocktail cellulolytique de Trichoderma reesei

Abstract : Lignocellulosic biomass is considered as a promising alternative to fossil resources. This abundant and renewable feedstock, derived from plant cell wall, is composed of polysaccharides and aromatic polymers linked together to form a highly resistant structure. Its transformation into bioethanol or other products requires the degradation of polysaccharides into fermentable sugars, using enzymes such as cellulases, hemicellulases and lytic polysaccharide monooxygenases (LPMOs). These enzymes are secreted by biomass-degrading microorganisms, such as bacteria and filamentous fungi. The most commonly used is Trichoderma reesei, a fungal species that is known for its efficient secretion of cellulases, but has a low diversity of other enzymes. Enzymatic hydrolysis is still a bottleneck for the cost-effective utilization of lignocellulosic biomass, and needs to be optimized. Providing activities that are missing in T. reesei using enzymes produced by other fungal organisms is a promising approach, which has been implemented during this PhD project.Using a proteomic approach, different Aspergillus strains were studied in order to find enzymatic activities that could improve the hydrolysis of pretreated biomass. For this purpose, 5 strains were grown on 3 inducers, and the protein content of these different secretomes was determined by mass spectrometry. The secretomes were then tested for their ability to improve hydrolysis yields by supplementing a T. reesei cocktail. Analysis of the protein content of some of the best-performing secretomes revealed the presence of a protein belonging to a putative family of LPMO. Several proteins of this family were recombinantly produced and tested on different substrates in the presence of redox partners. Oxidative cleavage of cellulose was demonstrated, leading to the creation of a new LPMO family, called AA16. The pretreatment of cellulosic substrates by AA16 LPMOs resulted in a significant improvement of their hydrolysis by a cellulase from T. reesei, demonstrating their potential interest for biotechnological applications in biorefineries.
Document type :
Theses
Complete list of metadata

Cited literature [243 references]  Display  Hide  Download

https://hal.inrae.fr/tel-02790951
Contributor : Abes Star :  Contact
Submitted on : Thursday, November 5, 2020 - 1:02:04 AM
Last modification on : Thursday, November 19, 2020 - 3:17:43 AM
Long-term archiving on: : Saturday, February 6, 2021 - 6:20:46 PM

File

82665_FILIATRAULT_CHASTEL_2019...
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-02790951, version 1
  • PRODINRA : 496450

Collections

Citation

Camille Filiatrault Chastel. Exploration de sécrétomes d'Aspergillus spp. en vue de la complémentation du cocktail cellulolytique de Trichoderma reesei. Biotechnologie. Institut agronomique, vétérinaire et forestier de France, 2019. Français. ⟨NNT : 2019IAVF0021⟩. ⟨tel-02790951⟩

Share

Metrics

Record views

184

Files downloads

157