Paper-based electrodes as a tool for detecting ligninolytic enzymatic activities.

[Display omitted] • Paper-based electrodes coated with polymers, mimick the lignocellulosic biomass. • Lignin penetrates deeply in the paper as shown by SEM and CV analyses. • The presence of lignin forms a barrier, avoiding a redox probe to reach the electrode. • Ligninolytic enzymes degraded this biomimetic substrate and allowed to recover the signal. Lignin is the most important natural source of aromatic compounds. The valorisation of lignin into aromatics requires fractionation steps that can be catalysed by ligninolytic enzymes. However, one of the main limitations of biological lignin fractionation is the low efficiency of biocatalysts; it is therefore crucial to enhance or to identify new ligninolytic enzymes. Currently, the screening of ligninolytic activities on lignin polymers represents a technological bottenleck and hinders the characterization and the discovery of efficient ligninolytic biocatalysts. An efficient and fast method for the measurement of such enzymatic activities is therefore required. In this work, we present a new electrochemical tool based on lignin-coated paper electrodes for the detection and the characterization of ligninolytic activity. The suitability of this method is demonstrated using a catalase-peroxidase isolated from Thermobacillus xylanilyticus. [ABSTRACT FROM AUTHOR]