ABSTRACT
We report herein the use of nanofibrillated cellulose (NFC) for development of enzyme assemblies in an oriented manner for biotransformation with in situ cofactor regeneration. This is achieved by developing fusion protein enzymes with cellulose-specific binding domains. Specifically, lactate dehydrogenase and NADH oxidase were fused with a cellulose binding domain, which enabled both enzyme recovery and assembling in essentially one single step by using NFC. Results showed that the binding capacity of the enzymes was as high as 0.9 µmol-enzyme/g-NFC. Compared to native parent free enzymes, NFC-enzyme assemblies improved the catalytic efficiency of the coupled reaction system by over 100%. The lifetime of enzymes was also improved by as high as 27 folds. The work demonstrates promising potential of using biocompatible and environmentally benign bio-based nanomaterials for construction of efficient catalysts for intensified bioprocessing and biotransformation applications.
Subject(s)
Cellulose/chemistry , L-Lactate Dehydrogenase/metabolism , Multienzyme Complexes/metabolism , NADH, NADPH Oxidoreductases/metabolism , Biotransformation , Clostridium thermocellum/enzymology , Industrial Microbiology , Lacticaseibacillus casei/enzymology , Nanofibers/chemistry , Nanostructures/chemistry , Protein Domains , Recombinant Proteins/metabolism , TemperatureABSTRACT
Renewable biobased carbon fibers are promising materials for large-scale electrochemical applications including chemical processing, energy storage, and biofuel cells. Their performance is, however, often limited by low activity. Herein we report that branching carbon nanotubes can enhance the activity of carbonized cellulosic fibers, such that the oxidation potential of NAD(H) was reduced to 0.55 V from 0.9 V when applied for bioprocessing. Coordinating with enzyme catalysts, such hierarchical carbon materials effectively facilitated the biotransformation of glycerol, with the total turnover number of NAD(H) over 3500 within 5 h of reaction.
