Stabilized chlorine dioxide for contamination control in zymomonas fermentation

Patent metadata

Field	Value
Publication number	US-9522203-B2
Application number	US-201414468364-A
Country	US
Kind code	B2
Filing date	Aug 26, 2014
Priority date	Dec 20, 2012
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

Though chlorine dioxide is generally used to control bacterial contamination, a method was developed which allows the use of stabilized chlorine dioxide (SCD) for controlling contamination during fermentation that uses the bacteria Zymomonas as the biocatalyst, even though Zymomonas is sensitive to chlorine dioxide. Parameters were identified for inoculating a composition for fermentation with Zymomonas cells after a time period has elapsed following SCD addition.

First claim

What is claimed is:

1. A composition comprising:
a) fermentation medium comprising cellulosic biomass hydrolysate;
b) stabilized chlorine dioxide; and
c) Zymomonas cells.

2. A composition comprising:
a) cellulosic biomass;
b) at least one cellulase enzyme;
c) stabilized chlorine dioxide;
d) fermentation medium; and
e) Zymomonas cells.

3. The composition of claim 1 or 2 , wherein the concentration of the stabilized chlorine dioxide is initially at least 10 mg/kg±10%, with the amount of the stabilized chlorine dioxide given in terms of the amount of chlorine dioxide that can be released upon complete activation of the stabilized chlorine dioxide by acid.

4. The composition of claim 1 or 2 , wherein the composition contains at least 10% solids based on dry weight of biomass to total composition weight.

5. The composition of claim 1 or 2 , wherein the cellulosic biomass is selected from the group consisting of corn cobs, corn husks, corn stover, grasses, wheat, wheat straw, barley straw, hay, rice straw, switchgrass, waste paper, sugar cane bagasse, sorghum, and woody plant cellulosic components.

6. The composition of claim 1 , wherein the cellulosic biomass hydrolysate comprises at least one cellulase enzyme.

7. The composition of claim 1 or 2 , wherein the Zymomonas cells are Zymomonas mobilis cells.

8. The composition of claim 1 or 2 , wherein the composition further comprises ethanol.

9. The composition of claim 1 or 2 , wherein the composition comprises less than 1 g/L of lactic acid.

10. The composition of claim 4 , wherein the composition contains at least 20% solids based on dry weight of biomass to total composition weight.

Assignees

• Du Pont

Inventors

• Leana Maria C
• Lefebvre Brian G

Classifications

• C12P7/10

  substrate containing cellulosic material · CPC title

• C12N1/20 Primary

  Bacteria; Culture media therefor · CPC title

• C12N1/22

  Processes using, or culture media containing, cellulose or hydrolysates thereof · CPC title

• C12N1/36

  Adaptation or attenuation of cells · CPC title

• A61L2/18 Primary

  Liquid substances · CPC title