System for converting sucrose to, beta -D-glucose; a reservoir, pump, porous packed column of invertase, porous packed column of glucose isomerase, porous packed column of mutarotase; biofuels
Inventors
Simmons, Blake A. • Volponi, Joanne V. • Ingersoll, David • Walker, Andrew
Assignees
National Technology and Engineering Solutions of Sandia LLC • Sandia National Laboratories
Publication Number
US-7264962-B1
Publication Date
2007-09-04
Expiration Date
2025-03-14
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Abstract
Disclosed is an apparatus and method for continuously converting sucrose to β-D-glucose. The method comprises a three stage enzymatic reactor in which an aqueous solution of sucrose is first converted into a solution of fructose and α-D-glucose by passing it through a porous, packed column containing an inert media on which invertase is immobilized. This solution is then sent through a second packed column containing glucose isomerase and finally a third packed column containing mutarotase. Solution temperature and pH are adjusted to maximize glucose output.
Core Innovation
The invention discloses a system and method for continuously converting sucrose to β-D-glucose using a three-stage enzymatic reactor with flow-through packed columns. An aqueous sucrose solution first passes through a column with immobilized invertase, converting sucrose to fructose and α-D-glucose. This solution then passes through a second column with immobilized glucose isomerase, converting fructose to β-D-glucose. The final step involves a third column with immobilized mutarotase, which converts α-D-glucose to β-D-glucose, producing the glucose product. The system incorporates control of temperature and pH to maximize glucose output.
The problem addressed is the limitation in biologically inspired fuel cells arising from insufficient quality and quantity of glucose fuel feedstock in environments where only complex sugars like sucrose or fructose are available. Existing implanted medical devices and fuel cells require glucose, but such environments may lack glucose. Therefore, the invention provides an efficient enzymatic cascade for converting sucrose and fructose to glucose to supply a fuel stream suitable for powering mechanical or electrical devices.
The invention utilizes immobilized enzymes on porous silica beads within packed chromatography columns. The enzymatic cascade reactor design enables conversion of complex sugars to simple sugars by linking invertase, glucose isomerase, and mutarotase in series. Enzymes are immobilized on aminated silica surfaces using cross-linking chemistry such as glutaraldehyde attachment. Conditions such as pH, temperature, and magnesium ion stabilization are optimized to maximize reaction efficiency and enzyme activity retention. This approach also has relevance to other biofuels and carbon sequestration applications where efficient enzymatic reformation is desired.
Claims Coverage
The patent contains one main independent claim defining a system comprising multiple enzymatic packed columns and associated components. The claim covers inventive features related to the configuration and composition of the reactor system for converting sucrose to β-D-glucose.
System comprising sequential enzymatic packed columns for conversion
The system includes a reservoir containing a sucrose solution, pumping means in fluid communication with the reservoir, and three porous packed columns containing immobilized enzymes invertase, glucose isomerase, and mutarotase arranged in series for sequential enzymatic conversion of sucrose to β-D-glucose.
Use of Mg+ stabilizer in glucose isomerase packed column
The glucose isomerase packed column includes an Mg+ stabilizer, specifically MgCl2 at about 20 mM concentration, to activate and stabilize the enzyme during conversion.
Heating means for controlling temperature of enzymatic columns
The system incorporates means for heating the first, second, and third porous packed columns, which may be electrically heating via heating tape wrapping or heated jackets containing circulating heated liquids, maintaining temperatures between about 43° C. and 47° C.
Immobilization of enzymes on aminated silica beads in glass chromatography columns
Each packed column comprises a glass chromatography column filled with silica beads whose surfaces are modified by attachment of amine functional groups through amino-functional silanes and further cross-linked with amine group cross-linkers such as glutaraldehyde to provide binding sites for immobilizing the enzymes.
Fluid communication configuration of components
The columns are connected so that the outlet of one column feeds the inlet of the next, establishing a continuous fluid flow from the pump through the invertase column, then glucose isomerase column, followed by the mutarotase column.
Use of pumps compatible with controlled fluid flow
The pumping means can be positive displacement or dynamic pumps including peristaltic, reciprocating piston, rotary gear, helical screw, rotary lobe, gear-within-gear, diaphragm, progressing cavity, or vane pumps.
Buffer solution pH control for optimal enzyme activity
The sucrose solution reservoir comprises a buffer fluid with pH controlled between about 4.6 and 5.8 to accommodate the enzymatic conversion process.
The claims cover a flow-through system for enzymatic conversion of sucrose to β-D-glucose, featuring a series of immobilized enzyme-packed columns, controlled heating, enzymatic bead functionalization chemistry, fluidic layout, pump selection, stabilizing additives, and solution pH control, collectively forming an integrated reactor system for efficient sugar conversion.
Stated Advantages
Provides an efficient means for converting complex sugars like sucrose and fructose into glucose suitable as fuel feedstock for biofuel cells.
Enables deployment of glucose-based fuel cells in environments with abundant sucrose or fructose but minimal glucose.
The enzymatic cascade approach can increase process efficiency, cost benefit, and may be applicable in alternative fuel production and carbon sequestration.
Immobilization of enzymes on silica beads ensures enzyme stability and activity retention throughout multiple conversion cycles.
Documented Applications
Powering mechanical and electrical implanted medical devices such as cardiac and brain pacemakers, insulin and chemotherapy pumps, LVADs, and blood sensors by providing a glucose fuel stream for biofuel cells.
Deployment of glucose-based fuel cells in environments containing sucrose and fructose (e.g., plants and trees) with minimal glucose.
Application in alternative biofuel production processes including ethanol production and in carbon sequestration contexts.
General bio-reformation of complex sugars to simple sugars, and extended applicability to enzymatic conversion of fatty acids, triglycerides, cholesterols, urea, lactates, pyruvate, and similar substrates.
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