NREL researchers find white-rot fungi use carbon captured from lignin as carbon source

In Colorado, a foundational study conducted by scientists at the National Renewable Energy Laboratory (NREL) shows for the first time that white-rot fungi are able to use carbon captured from lignin as a carbon source. 

The research confirms a hypothesis the senior author of a newly published paper. Until now, scientists were unsure whether white-rot fungi—the most efficient lignin-degrading organisms in nature—actually consume the products generated from breaking down lignin. 

The researchers examined two species of white-rot fungi: Trametes versicolor and Gelatoporia subvermispora. Through the use of genomic analysis, isotopic labeling, and systems biology approaches, the researchers determined the ability of these organisms to incorporate carbon from lignin-derived aromatic compounds into central metabolism and were able to map out the potential aromatic catabolic pathways for that conversion process. Further, in vitro enzyme analyses enable validation of some of the proposed steps. The researchers also highlight that this work is just the beginning of a broad area towards discovering new enzymes and pathways and better understanding carbon flux in these organisms. 

Scientists have demonstrated the ability of some bacterial strains to break down lignin as well, but not as effectively as white-rot fungi. The lead researcher said bacteria are easier to work with than fungi because they grow more quickly, and many are genetically tractable, contrary to white-rot fungi.