Assay methods and colorimetric screens for lignin-degrading microbes and lignin-oxidising enzymes

Assaying enzymes and microbes for activity for degradation of polymeric lignin is inherently challenging to do. This article describes several methods that our research group has developed for assay of lignin-oxidising enzymes and lignin-degrading microbes. The assay methods involve (1) colorimetric assays involving chemically nitrated lignin; (2) changes in molecular weight using gel filtration chromatography; (3) delignification of lignocellulose using Klason assay; (4) colorimetric assays for release of low molecular weight phenols and carbonyl compounds.