Groundbreaking research into white-rot fungi proves its value in carbon sequestration from lignin

In Colorado, a 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, which could be further exploited to simultaneously convert the biopolymer into value-added compounds.

The research confirms a hypothesis from Davinia Salvachúa Rodriguez, 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.

“What we have demonstrated here is that white-rot fungi can actually utilize lignin-derived aromatic compounds as a carbon source, which means they can eat them and utilize them to grow,” Salvachúa said. “That is another strategy for carbon sequestration in nature and has not been reported before.”

Salvachúa’s work forms the foundation of a new research area based on lignin being broken down by white-rot fungi, which could be further exploited to simultaneously convert the biopolymer into value-added compounds.

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.