System for simultaneous isomerization and fermentation of sugars

Patent metadata

Field	Value
Publication number	US-9856445-B2
Application number	US-201615388443-A
Country	US
Kind code	B2
Filing date	Dec 22, 2016
Priority date	Jan 4, 2008
Publication date	Jan 2, 2018
Grant date	Jan 2, 2018

Abstract

Methods and systems for the isomerization and fermentation of xylose and hexose sugars using an immobilized enzyme system capable of sustaining two different pH microenvironments in a single vessel are disclosed. Bilayer particles are dispersed in a mixture comprising an ionic borate source and xylose. The bilayer particles have a first region with a first enzymatic activity comprising xylose isomerase and a pH of 6 or above, and a second region having a second enzymatic activity at an acidic pH.

First claim

What is claimed is:

1. A system comprising:
a batch vessel comprising a confinement system having an inlet and an outlet, and comprising co-immobilized enzyme particles, the confinement system being configured to be submerged in a fermentation broth in the batch vessel, wherein the co-immobilized enzyme particles comprise a first region having a first enzymatic activity and a second region having a second enzymatic activity;
and
a hollow fiber membrane fermentor having an inlet connected in series to the outlet of the batch vessel, the hollow fiber membrane fermentor comprising a microporous hollow fiber membrane,
wherein the microporous hollow fiber membrane has a lumen side and a shell side, the lumen side defining a flow channel and the shell side defining a shell space; and,
wherein the outlet of the batch vessel is connected directly to the inlet of the hollow fiber membrane fermentor, the fermenter inlet being connected to the lumen side of the hollow fiber membrane fermentor.

2. The system of claim 1 , wherein the confinement system comprises an impellor having vanes comprising baskets packed with the co-immobilized enzyme particles.

3. The system of claim 2 , wherein the impellor is rotatable in the batch vessel.

4. The system of claim 1 , comprising a sugar-fermenting microorganism in the hollow fiber membrane fermentor.

5. The system of claim 4 , wherein the sugar-fermenting microorganism comprises yeast.

6. The system of claim 5 , wherein the yeast comprise Saccharomyces cerevisiae.

7. The system of claim 1 , wherein the co-immobilized enzyme particles comprise urease and xylose isomerase.

8. The system of claim 1 , wherein the co-immobilized enzyme particles are bilayer particles.

9. The system of claim 1 , wherein the hollow fiber membrane fermentor comprises a microporous hollow fiber membrane composed of microporous hollow fibers.

10. The system of claim 9 , wherein the microporous hollow fibers comprise polysulfone fibers.

11. The system of claim 1 , wherein the system contains an aqueous solution comprising borate.

12. The system of claim 1 , wherein the batch vessel and the hollow fiber membrane fermentor are connected in a closed loop system.

13. The system of claim 1 , wherein the batch vessel contains a mixture of glucose and xylose.

14. The system of claim 1 , wherein the hollow fiber membrane fermentor comprises at least one port configured to vent a gas from the shell space.

15. The system of claim 2 , wherein the impellor has four vanes.

Assignees

• Univ Toledo

Inventors

• Varanasi Sasidhar
• Rao Kripa
• Relue Patricia Ann
• Yuan Dawei

Classifications

• C12N11/18

  Multi-enzyme systems · CPC title

• C12P7/14

  Multiple stages of fermentation; Multiple types of microorganisms or re-use of microorganisms · CPC title

• C12M21/18 Primary

  Apparatus specially designed for the use of free, immobilized or carrier-bound enzymes · CPC title

• C12M21/12

  for producing fuels or solvents (C12M21/04 takes precedence; liquid carbonaceous fuels C10L1/00, solid fuels C10L5/00) · CPC title

• C12N1/16

  Yeasts; Culture media therefor · CPC title