An Oxidative Enzyme Boosting the Enzymatic Conversion of Recalcitrant Polysaccharides

TLDR

Efficient enzymatic conversion of crystalline polysaccharides is crucial for a sustainable bioeconomy yet remains inefficient, and evidence suggests analogous enzymes may act on cellulose. The study describes an enzyme that acts on crystalline chitin surfaces, introducing chain breaks and oxidized ends to promote chitinase‑mediated degradation. The enzyme’s activity was identified and characterized using mass spectrometry and chromatographic separation to detect oxidized products with or without H₂(¹⁸)O or (¹⁸)O₂. The study demonstrates a previously unknown enzyme activity and opens new avenues for more efficient biomass conversion.

Abstract

Efficient enzymatic conversion of crystalline polysaccharides is crucial for an economically and environmentally sustainable bioeconomy but remains unfavorably inefficient. We describe an enzyme that acts on the surface of crystalline chitin, where it introduces chain breaks and generates oxidized chain ends, thus promoting further degradation by chitinases. This enzymatic activity was discovered and further characterized by using mass spectrometry and chromatographic separation methods to detect oxidized products generated in the absence or presence of H(2)(18)O or (18)O(2). There are strong indications that similar enzymes exist that work on cellulose. Our findings not only demonstrate the existence of a hitherto unknown enzyme activity but also provide new avenues toward more efficient enzymatic conversion of biomass.