(Re)-thinking the bio-prospect of lignin biomass recycling to meet Sustainable Development Goals and circular economy aspects

Lignin, as an abundant natural polymer with interesting mechanical, antimicrobial, and antioxidant properties, has the possibility to produce numerous chemicals and biofuels of current interest. However, the structural recalcitrance, heterogeneity, and complex extraction methods of lignin can hinder its transformation into value-added materials. Therefore, the research community is exploring innovative bioconversion technologies capable of effectively valorizing lignin. Thus, effective bioconversion and deconstruction methods have been recently studied. In this review, we first define lignin as a versatile raw material considering its characteristics, properties, and abundance. Then, lignin valorization is described in terms of the current opportunities and technical challenges. Finally, we discuss the industrial potential of lignin-derived products such as biofuels, biopolymers, biopesticides, and fertilizers. Those lignin-derived products are highly valuable for the energy and food industries, which are two main sectors challenged by the rapid growth of population, urbanization, and consumption. Thus, progress on lignin valorization would represent significant advancements in the Sustainable Development Goals (SDGs) and circular economy aspects.