Stellate MSN-based Dual-enzyme Nano-Biocatalyst for the Cascade Conversion of Non-Food Feedstocks to Food Products

Abstract

The successful demonstration of a tandem enzymatic catalyst which utilizes stellate macroporous silica nanospheres (Stellate MSN) platform as dual-enzyme host is reported herein. Upon simultaneous loading of beta-glucosidase and glucose isomerase inside their porous structure, Stellate MSNs-featuring a hierarchical pore arrangement and large surface area, show capability to perform a cascade reaction that converts cellobiose, a cellulosic hydrolysis product, into glucose and further to fructose. The silica platform provides a modality for substrate channelling which involves the transfer of the cascade intermediate, glucose, to the next enzyme without first diffusing to the bulk. A key aspect to this proof-of-concept is the two-enzyme system working in an optimized pH domain to fit the modus operandi for both enzymes. The concept could be extrapolated to other enzyme tandems, with potential to impact dramatically enzymatic processes which require multi-catalyst, one-pot transformations.