Development of protein modules (PROTeic CARriers) for the modification of vegetable fibres

PI : Eric Gelhaye (UMR 1136 « Interactions Arbres/Micro-organismes » – IAM)

LabEx partners : Philippe Gérardin (LERMAB)

Collaboration : C. Segovia (CETELOR), N. Attenot (BIOLIE)

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Context —Detailed knowledge of the structural and chemical organization of the cell wall, is a key point for the development of different biotechnologies related to plant chemistry: biorefinery, textile, white biotechnology, biocomposites, extraction of molecules of interest, … The chemical composition and also of the three-dimensional organization of cell wall vary greatly depending on the considered species and tissues. This variability is correlated with that of the enzymatic systems secreted by microorganisms to degrade and mineralize the various constituents of the plant cell wall. Many enzymes involved in the degradation of carbohydrates (cellulose, hemicelluloses, pectins, …) are modular and have a domain mediating their substrate binding (carbohydrate binding module) and a catalytic domain. They are called CAZYmes. Concerning the other plant components (lignin, extractives, waxes, …), some Glutathione Transferases may react with some of them. The main objective of PROTCAR is to use these enzymes (or their domains) to develop tools to investigate plant cell wall.

Objectives and Approach — The main aim of this project was to validate our hypothesis producing the different studied proteins merged or not to fluorescent domains. These domains/enzymes have been chosen for their ability to bind the different components of the plant cell wall. These modules have been tested using different fluorescent microscopic and spectroscopic methods.

Key results —

• The bacterial proteins LigE, LigF, CBM3a and the fungal protein PcGSTFuA have been heterogously produced merged or not with mcherry
• In collaboration with the xyloscience platform and the microscopic devices of the ecogenomic platform, a method allowing the quantification of the adhesion of the different tested proteins to oak has been developed.
• After computer processing of the observations obtained by confocal microscopy, we quantitatively measure different binding of the tested proteins on oak. These results are in agreement with the composition of wood
• Using these protein modules, chemical modification of flax, hemp and bamboo has been demonstrated (improved hydrophobicity)

Main findings and future perspectives —

This program aims to develop enzymatic tools for both the characterization and especially modification of lignocellulosic walls. These tools are currently used in various research programs. This methodology will be used in particular in the NEWFIBRE program developed with partners which have collaborated on this program: BIOLIE, LERMAB and CETELOR. The NEWFIBRE program financed by FEDER and the Région Lorraine aims to develop a new local industry and includes most of the textile industries found in Lorraine. A valuation of these works as a patent is under consideration.