Ethanol production by simultaneous saccharification and fermentation (SSF)

• US 20050026261A1
• Filed: 11/14/2003
• Published: 02/03/2005
• Est. Priority Date: 11/15/2002
• Status: Abandoned Application

• Current Assignee: Novozymes North America Incorporated (Novozymes)
• Original Assignee: Novozymes North America Incorporated (Novozymes)
• Inventors: Otto, Eric, Escovar-Kousen, Jose
• Application Number:
  US10/713,182
• Publication Number:
  US 20050026261A1
• Time in Patent Office: Days
• US Class Current: 435/161
• CPC Class Codes: C12P 7/06 Ethanol, i.e. non-beverage
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

The invention relates to a process of producing ethanol by fermentation, said process comprising a simultaneous saccharification and fermentation (SSF) step conducted at a temperature of above 34° C. in the presence of a glucoamylase and a thermo-tolerant yeast.

Claims

1. A process for producing ethanol by fermentation, said process comprising a simultaneous saccharification and fermentation (SSF) step conducted at a temperature of above 34°

C. in the presence of a glucoamylase and a thermo-tolerant yeast.

2. The process of claim 1, wherein the temperature is at least 34.5°

C., or preferably at least 35°

C.

3. The process of claim 1, wherein the glucoamylase is derived from Talaromyces emersonii, preferably from Talaromyces emersonii CBS 793.97.

4. The process of claim 1, wherein the glucoamylase has an amino acid sequence comprising one or more of the partial sequences shown in SEQ ID NOS:

1-6.

5. The process of claim 1, wherein the glucoamylase has an amino acid sequence with an identity of at least 60% with SEQ ID NO:

7, or is a variant of the glucoamylase shown in SEQ ID NO;

7.

6. The process of claim 1, further comprising recovery of the ethanol.

7. The process of claim 1, further comprising a step of distillation to obtain the ethanol, wherein the SSF step and the distillation is carried out simultaneously or sequentially.

8. The process of claim 1, wherein the thermo-tolerant yeast is a yeast which when fermenting at 35°

C. maintains at least 90% of the ethanol yields and 90% of the ethanol productivity during the first 70 hours of fermentation, as compared to when fermenting at 32°

C. under otherwise similar conditions.

9. The process of claim 1, wherein the thermo-tolerant yeast is a yeast which when fermenting at 35°

C. is capable of producing at least 15% V/V alcohol from a corn mash comprising 34.5% (w/v) solids.

10. The process of claim 1, wherein the thermo-tolerant yeast is Red Star®

/Lesaffre Ethanol Red (commercially available from Red Star®

/Lesaffre, USA, Product no;

     42138).

11. The process of claim 1, wherein the SSF step is carried out in the presence of a protease and/or a phytase.

12. The process of claim 11, wherein the protease is a microbial protease, preferably a fungal protease, more preferably an acid fungal protease, even more preferably an acid fungal protease derived from a strain of Aspergillus, preferably A. niger.

13. The process of claim 11, wherein the protease is a neutral or alkaline protease, such as a protease derived from a strain of Bacillus.

14. The process of claim 11, wherein the phytase is microbial, preferably the phytase is derived from a strain of Peniophra lycii or Aspergillus oryzae.

15. An ethanol produced by a process as defined in claim 1.