An ultrasensitive nanofiber-based assay for enzymatic hydrolysis and deep-sea microbial degradation of cellulose

Substrates for enzymatic reactions, such as cellulose and chitin, are often insoluble in water. The enzymatic degradation of these abundant organic polymers plays a dominant role in the global carbon cycle and has tremendous technological importance in the production of bio-based chemicals. In addition, biodegradation of plastics is gaining wide attention. However, despite the significance, assaying these degradation reactions remains technically challenging owing to the low reaction rate, because only the surface of the substrate is accessible to the enzymes. We developed a nanofiber-based assay for the enzymatic hydrolysis of cellulose. This assay facilitated the quantification of the enzymatic hydrolysis of <1 ng crystalline cellulose. Utilization of the assay for the functional screening of cellulolytic microorganisms revealed an unprecedented genetic diversity underlying the production of deep-sea cellulase. This study reiterates that interdisciplinary efforts, such as from nanotechnology to microbiology, are critical for solving sustainability challenges.