Stabilized chlorine dioxide for contamination control in zymomonas fermentation

• US 9,522,203 B2
• Filed: 08/26/2014
• Issued: 12/20/2016
• Est. Priority Date: 12/20/2012
• Status: Active Grant

• Current Assignee: Sustainable Technology Corporation
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Leana, Maria C, Lefebvre, Brian G
• Primary Examiner(s): Kosson, Rosanne
• Application Number:
  US14/468,364
• Publication Number:
  US 20150359916A1
• Time in Patent Office: 847 Days
• US Class Current: 1/1
• CPC Class Codes: A61L 2/18 Liquid substances or solutions comprising solids or dissolved gases
• CPC Class Codes: C08H 8/00 Macromolecular compounds derived from lignocellulosic materials pretreatment thereof B27N
• CPC Class Codes: C08L 97/02 Lignocellulosic material, e.g. wood, straw or bagasse manufacture of articles made from lignocellulosic material by dry processes B27N
• CPC Class Codes: C12H 1/00 Pasteurisation, sterilisation, preservation, purification, clarification, or ageing of alcoholic beverages simulating ageing by flavouring C12G3/06
• CPC Class Codes: C12N 1/20 Bacteria; Culture media therefor
• CPC Class Codes: C12N 1/22 Processes using, or culture media containing, cellulose or hydrolysates thereof
• CPC Class Codes: C12N 1/36 Adaptation or attenuation of cells
• CPC Class Codes: C12N 2500/05 Inorganic components
• CPC Class Codes: C12N 9/2437 Cellulases (3.2.1.4; 3.2.1.74; 3.2.1.91; 3.2.1.150)
• CPC Class Codes: C12P 7/065 with microorganisms other than yeasts
• CPC Class Codes: C12P 7/10 substrate containing cellulosic material
• CPC Class Codes: C12Y 302/01004 Cellulase (3.2.1.4), i.e. endo-1,4-beta-glucanase
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

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.

Claims

1. A composition comprising:

a) fermentation medium comprising cellulosic biomass hydrolysate;

b) stabilized chlorine dioxide; and

c) 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.

2. A composition comprising:

a) cellulosic biomass;

b) at least one cellulase enzyme;

c) stabilized chlorine dioxide;

d) fermentation medium; and

e) Zymomonas cells.