DNA-guided assembly of a five-component enzyme cascade for enhanced conversion of cellulose to gluconic acid and H2O2.

Enzymatic fuel cells have received considerable attention because of their potential for direct conversion of abundant raw materials such as cellulose to electricity. The use of multi-enzyme cascades is particularly attractive as they offer the possibility of achieving a series of complex reactions at higher efficiencies. Here we reported the use of a DNA-guided approach to assemble a five-component enzyme cascade for direct conversion of cellulose to gluconic acid and H2O2. Site-specific co-localization of β-glucosidase and glucose oxidase resulted in over 11-fold improvement in H2O2 production from cellobiose, highlighting the benefit of substrate channeling. Although a more modest 1.5-fold improvement in H2O2 production was observed using a five-enzyme cascade, due to H2O2 inhibition on enzyme activity, these results demonstrated the possibility to enhance the production of gluconic acid and H2O2 directly from cellulose by DNA-guided enzyme assembly.