Enzymatic upgrading of nanochitin using an ancient lytic polysaccharide monooxygenase

Enzymes are effective at chemically converting low-value biomass to technological materials. Here, an ancestral lytic polysaccharide monooxygenase enzyme is used to synthesize chitin nanocrystals, which are used as a matrix for cell growth and to create conducting graphene oxide bioinks. Numerous enzymes have the potential to upgrade biomass, converting it into high-tech materials for new applications. However, the features of natural enzymes often limit their use beyond chemical conversion of the substrate. The development of strategies for the enzymatic conversion of biomass into high-value materials may broaden the range of applications of enzymes and enzyme design techniques. A relevant case is lytic polysaccharide monooxygenase (LPMO), a class of enzymes that catalyzes the oxidative cleavage of glycosidic bonds. Here, we show that an ancestral LPMO can generate chitin nanocrystals. Physicochemical characterization of the chitin nanocrystals demonstrates modifications that make it superior compared to chitin obtained by chemical treatments. We show that the nanocrystals are suitable for controlled 2D and 3D cell cultures, as well as for engineering a biomatrix that combines with graphene oxide, forming a hybrid conductive bioink.

Automated summary

Enzymes are capable of converting low-value biomass into high-tech materials, with one particular enzyme being able to synthesize chitin nanocrystals for cell growth and conducting bioinks. The development of strategies for enzymatic conversion of biomass into high-value materials has the potential to expand the applications of enzymes and enzyme design techniques.