Ethanol production from lignocellulose

• US 6,333,181 B1
• Filed: 04/07/1997
• Issued: 12/25/2001
• Est. Priority Date: 04/07/1997
• Status: Expired due to Fees

• Current Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Original Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Inventors: Ingram, Lonnie O., Wood, Brent E.
• Primary Examiner(s): PRATS, FRANCISCO CHANDLER
• Application Number:
  US08/833,435
• Time in Patent Office: 1,723 Days
• Field of Search: 435/99, 435/165, 435/163, 435/278, 435/277, 435/170, 435/72, 435/173.2, 435/173.8
• US Class Current: 435/165
• CPC Class Codes: C12N 13/00 Treatment of microorganisms or enzymes with electrical or wave energy, e.g. magnetism, sonic waves
• CPC Class Codes: C12P 19/14 produced by the action of a carbohydrase (EC 3.2.x), e.g. by alpha-amylase , e.g. by cellulase, hemicellulase
• CPC Class Codes: C12P 7/10 substrate containing cellulosic material
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

This invention presents a method of improving enzymatic degradation of lignocellulose, as in the production of ethanol from lignocellulosic material, through the use of ultrasonic treatment. The invention shows that ultrasonic treatment reduces cellulase requirements by ⅓ to ½. With the cost of enzymes being a major problem in the cost-effective production of ethanol from lignocellulosic material, this invention presents a significant improvement over presently available methods.

Claims

1. A method for producing ethanol from lignocellulose comprising discontinuously treating an aqueous mixture containing lignocellulose, a cellulase and an ethanologenic microorganism with ultrasound under conditions sufficient for hydrolysis of said lignocellulose to occur, to thereby produce ethanol.

2. The method according to claim 1 wherein said cellulase is provided by a cellulase-producing microorganism in said aqueous mixture.

3. The method according to claim 1 wherein said aqueous mixture is treated with ultrasound at a frequency of between about 2 and 200 kHz.

4. The method according to claim 1 wherein said ethanologenic microorganism is an ethanologenic bacteria or yeast.

5. The method according to claim 4 wherein said ethanologenic microorganism is a bacteria or yeast which expresses one or more enzymes which, individually or together, convert a sugar to ethanol.

6. The method according to claim 4 wherein said ethanologenic microorganism expresses enzymes which, individually or together, convert pentose and hexose to ethanol.

7. The method according to claim 4 wherein said ethanologenic microorganism expresses alcohol dehydrogenase and pyruvate decarboxylase.

8. The method according to claim 7 wherein said alcohol dehydrogenase and pyruvate decarboxylase are from Zymomonas mobilis.

9. The method according to claim 4 wherein said ethanologenic microorganism expresses xylose isomerase, xylulokinase, transaldolase, and transketolase.

10. The method according to claim 9 wherein said xylose isomerase, xylulokinase, transaldolase, and transketolase are from Escherichia coli.

11. The method according to claim 9 wherein said xylose isomerase, xylulokinase, transaldolase, and transketolase are from Klebsiella oxytoca.

12. The method according to claim 9 wherein said xylose isomerase, xylulokinase, transaldolase, and transketolase are from Erwinia species.

13. The method according to claim 4 wherein said ethanologenic microorganism expresses alcohol dehydrogenase, pyruvate decarboxylase, xylose isomerase, xylulokinase, transaldolase, and transketolase.

14. The method according to claim 13 wherein said ethanologenic microorganism is a recombinant microorganism expressing Zymomonas mobilis alcohol dehydrogenase and pyruvate decarboxylase wherein said microorganism is selected from the group consisting of Escherichia coli, Klebsiella oxytoca, and Erwinia species.

15. The method according to claim 14 wherein said ethanologenic microorganism is Klebsiella oxytoca P2.

16. The method according to claim 14, wherein said ethanologenic microorganism is Escherichia coli KO11.