Fungi provide a non-enzyme answer to breaking down biomass

New insights have been gained into a unique system some fungi use to digest and recycle wood.

Remarkably, a new study suggests that this unusual mechanism does not involve the use of enzymes, the usual accelerators of chemical reactions.

Microbiologist Barry Goodell first discovered the unique system twenty years ago. However, although three orders of ‘brown rot’ fungi have since been identified, details of the mechanism they use to break down wood have remained unknown, until now.

Published in the journal Biotechnology for Biofuels, the latest research by Goodell shows Basidiomycota brown rot fungi use a non-enzymatic, chelator-mediated biocatalysis method that is, according to Goodell, “very different than that used by any other microorganism studied.”

Chelators are organic compounds that bind metal ions, and in this case, they also generate “hydroxyl radicals” to break wood down and produce simple building-block chemicals.

Goodell’s collaborators at Oak Ridge National Laboratory describe the findings as a “paradigm shift” in the understanding of fungal biocatalysis for biomass conversion.

"Our research on fungal bioconversion systems looks at a novel mechanism that has potential use in bio-refineries to 'deconstruct' woody biomass for conversion into platform chemicals for biopolymers or energy products,” Goodell explains, in a statement from University Massachusetts Amherst.