Determining the Mechanism of Fungal Growth and Deconstruction of Alkali Lignins

Lignocellulosic materials such as wood are made of three key components, cellulose, hemicellulose and lignins [1]. The lignocellulosic biomass constitutes the most abundant material on earth and its degradation is essential for carbon recycling [2]. Both its abundance and composition makes it also an important raw material for biotechnological applications. However, today only plant carbohydrates are efficiently exploited and lignins remain a major by-product due to their resistance to chemical and biological degradation. The valorization of lignins remains today challenging but highly required in the biorefineries concept to make the process more cost effective and help diversify produced materials. The enzymatic degradation of lignins was found to be a specific characteristic of wood-decaying filamentous fungi and especially the basidiomycetes. To be able to degrade lignins, fungi produce a wide variety of extracellular oxidases out of which some were widely characterized. However, the whole fungal enzymatic system is far more complex and new functional proteins need to be identified and studied. In addition, the mechanistic action and the pattern of expression of these enzymes varies between different fungi and new model organisms still need to be studied. This poster presents the screening of eleven fungal strains on unmodified and fractionated alkali lignins as sole carbo