The main objectives of my research work, carried out in partnership and in an interdisciplinary framework, are to understand the enzymatic and chemical mechanisms that govern the establishment of lignins within plant cell walls, to understand the specificities of lignocellulosic biomass, to estimate its potential in a process of recovery and use of lignins or wood residues from biomass processing industries, for the functionalization of materials or the production of biosourced molecules for the chemical industry.