Etude et réduction des interactions hémicellulases-lignine pour le développement de procédés de prétraitement et de fractionnement enzymatiques performants de la lignocellulose – HémiLi
Interactions lignins-enzymes : impact on the plant cell wall recalcitrance to hydrolysis ?
Which are the parameters governing the interactions between lignins and enzymes ?
Lignocellulose recalcitrance to bioprocessing represents the core problem and remains the limiting factor in creating an economy base on lignocellulosic ethanol production. The project is aimed to understand and subsequently to reduce the non productive interactions between xylanases and lignin during bioconversion of lignocellulosic feedstocks to produce bioethanol. The objective of the Hémili project is to indentify the impact of lignin during the enzymatic fractionation of different lignocellulosic biomass by xylanases. Use of xylanases, which hydrolyze xylans (representing 20-40% of the lignocellulosic biomass), would improve the interest for the production of second generation bioethanol as it would decrease the drasticity of physico-chemical pretreatments and lead to the valorization of pentoses. Scientific goal of this project is to better understand molecular parameters inherent to enzymes and to lignin governing enzyme-lignin interactions. Such understanding will facilitate biological deconstruction of lignocellulose by rationally design of biocatalysts, lignocellulose feedstocks or reactional media for improved catalysis.
Our approach is based on the study of interactions between various lignins differing by their chemical and structural complexity and various xylanases (with different 3D structures and surface properties). A second part of the project is to reduce interactions xylanases-lignins by modulating the reactional media. Due to the high hydrophobicity of lignins, development of methodologies to investigate interactions with enzymes represents a major challenge. The approach developed in the project is Surface Plasmon Resonance Spectroscopy (SPR).
The main challenge for the development of the SPR methodology was to prepare stable lignin layer on the sensors surfaces. Among the various chemical and physico-chemical approaches tested, two approaches led to stable lignin layers which allowed studying interactions with xylanases in the liquid phase. All results indicate that numerous parameters favor or limit the xylanases-lignins interactions: nature of xylanases and lignins and media composition
Results obtained in the Hémili project are currently under valorization: 3 scientific articles will be submitted during 2012 and results will be presented during international meetings.
Madame Caroline REMOND (Organisme de recherche)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
Help of the ANR 373,161 euros
Beginning and duration of the scientific project: - 36 Months