Towards an Enzymatic Approach to Valorize Wood Residues for Industrial Production in a Circular Bioeconomy

To limit the global temperature increase to a maximum of two degrees by mid-century, as stated in the Paris Agreement, the concept of circular bioeconomy is becoming increasingly relevant. For a sustainable, circular design of production systems, which is decisive for industry's future viability, the valorization of residual and side-streams is urgently needed. One of the most promising bio-based recyclables is wood, especially lignin. About 50 million tons are produced worldwide per year as a waste product from the pulp and paper industry. To date, most lignin recycling processes require high energy inputs and the use of chemicals with potentially harmful environmental effects. Furthermore, wood-based products often contain substances that prevent their biodegradability. In nature, enzymatic mechanisms are applied to synthesize and decompose wood components. Inspired by this, enzymatic processes could lead to the production of bio-based and biodegradable materials. This paper describes enzymes from plants and organisms involved in wood synthesis and degradation, regarding their technical implementation in production processes such as additive manufacturing. By integrating biological systems into technical production processes, the transformation of the industry towards a biointelligent circular economy is supported.