Process for enzymatic hydrolysis of pretreated lignocellulosic feedstocks

• US 8,017,373 B2
• Filed: 08/29/2007
• Issued: 09/13/2011
• Est. Priority Date: 08/31/2006
• Status: Active Grant

• Current Assignee: Iogen Energy Corporation (Iogen Corporation)
• Original Assignee: Iogen Energy Corporation (Iogen Corporation)
• Inventors: Scott, Brian, Hill, Christopher, Tomashek, John
• Primary Examiner(s): Ariani; Kade
• Application Number:
  US11/846,653
• Publication Number:
  US 20080057541A1
• Time in Patent Office: 1,476 Days
• Field of Search: None
• US Class Current: 435/209
• 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 19/02 Monosaccharides 2-ketogulonic acid C12P7/60
• 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: C12Y 302/01004 Cellulase (3.2.1.4), i.e. endo-1,4-beta-glucanase
• CPC Class Codes: C12Y 302/01091 Cellulose 1,4-beta-cellobiosidase (3.2.1.91)

Abstract

An enzyme mixture for the enzymatic hydrolysis of a pretreated lignocellulosic feedstock to soluble sugars is provided. Also provided is a process for hydrolyzing a pretreated lignocellulosic feedstock with an enzyme mixture. The enzymatic hydrolysis comprises adding a cellulase enzyme mixture to a pretreated lignocellulosic feedstock. The cellulase enzyme mixture comprises a primary cellulase mixture of CBH1 and CBH2, and EG1 and EG2. The CBH1 and CBH2 being present at greater than or equal to 55% and less than 85% of the primary cellulase mixture. Furthermore, CBH2 is present at a fraction relative to CBH1 and CBH2, and EG2 is present at a fraction relative to the EG1 and EG2.

Claims

1. A cellulase enzyme mixture comprising a primary cellulase mixture of CBH1 and CBH2 cellobiohydrolases and EG1 and EG2 endoglucanases, said CBH1 and CBH2 cellobiohydrolases being present at greater than or equal to 55% and less than 65% of the primary cellulase mixture, said CBH2 being present at a fraction relative to CBH1 and CBH2 cellobiohydrolases as defined by f_C2 and said EG2 being present at a fraction relative to the EG1 and EG2 endoglucanases as defined by f_E2, wherein said f_C2 is greater than or equal to 0.35 and less than 0.55, and

(i) when said f_C2 value is greater than or equal to 0.35 and less than 0.45, said f_E2 value is greater than or equal to 0.15 and less than 0.35;

and

(ii) when said f_C2 value is greater than or equal to 0.45 and less than 0.55, said f_E2 value is greater than or equal to 0.15 and less than 0.25, or greater than or equal to 0.35 and less than 0.45.

2. The cellulase enzyme mixture of claim 1, wherein the cellulase enzyme mixture is produced by expressing the primary cellulases from Trichoderma at pH values between about 2 and about 5.

13. A process for enzymatic hydrolysis of a pretreated lignocellulosic feedstock to soluble sugars, the process comprising adding the cellulase enzyme mixture as in any of claims 1-12 to the pretreated lignocellulosic feedstock and hydrolyzing under conditions suitable to convert the cellulose within said pretreated lingocellulosic feedstock to soluble sugars.

3. A cellulase enzyme mixture comprising a primary cellulase mixture of CBH1 and CBH2 cellobiohydrolases and EG1 and EG2 endoglucanases, said CBH1 and CBH2 cellobiohydrolases being present at greater than or equal to 65% and less than 75% of the primary cellulase mixture, said CBH2 being present at a fraction relative to CBH1 and CBH2 cellobiohydrolases as defined by f_C2 and said EG2 being present at a fraction relative to the EG1 and EG2 endoglucanases as defined by f_E2, wherein said f_C2 is greater than or equal to 0.25 and less than 0.75, and

(i) when said f_C2 value is greater than or equal to 0.25 and less than 0.35, said f_E2 value is greater than or equal to 0.05 and less than 0.35;

(ii) when said f_C2 value is greater than or equal to 0.35 and less than 0.45, said f_E2 value is greater than or equal to 0.05 and less than 0.55;

(iii) when said f_C2 value is greater than or equal to 0.45 and less than 0.65, said f_E2 value is greater than or equal to 0.05 and less than 0.65; and

(iv) when said f_C2 value is greater than or equal to 0.65 and less than 0.75, said f_E2 value is greater than or equal to 0.15 and less than 0.55.

4. The cellulase enzyme mixture of claim 3, wherein when said f_C2 value is greater than or equal to 0.45 and less than 0.65, said f_E2 value is greater than or equal to 0.15 and less than 0.55.

5. The cellulase enzyme mixture of claim 4, wherein when said f_C2 value is greater than or equal to 0.55 and less than 0.65, said f_E2 value is greater than or equal to 0.35 and less than 0.45.

6. The cellulase enzyme mixture of claim 4, wherein the cellulase enzyme mixture is produced by expressing the primary cellulases from Trichoderma at pH values between about 2 and about 5.

11. The cellulase enzyme mixture of claim 3, wherein the cellulase enzyme mixture is produced by expressing the primary cellulases from Trichoderma at pH values between about 2 and about 5.

12. The cellulase enzyme mixture of claim 5, wherein the cellulase enzyme mixture is produced by expressing the primary cellulases from Trichoderma at pH values between about 2 and about 5.

7. A cellulase enzyme mixture comprising a primary cellulase mixture of CBH1 and CBH2 cellobiohydrolases and EG1 and EG2 endoglucanases, said CBH1 and CBH2 cellobiohydrolases being present at greater than or equal to 75% and less than 85% of the primary cellulase mixture, said CBH2 being present at a fraction relative to CBH1 and CBH2 cellobiohydrolases as defined by f_C2 and said EG2 being present at a fraction relative to the EG1 and EG2 endoglucanases as defined by f_E2, wherein said f_C2 is greater than or equal to 0.35 and less than 0.65, and

(i) when said f_C2 value is greater than or equal to 0.35 and less than 0.45, said f_E2 value is greater than or equal to 0.05 and less than 0.25;

(ii) when said f_C2 value is greater than or equal to 0.45 and less than 0.55, said f_E2 value is greater than or equal to 0.15 and less than 0.65; and

(iii) when said f_C2 value is greater than or equal to 0.55 and less than 0.65, said f_E2 value is greater than or equal to 0.15 and less than 0.35.

8. The cellulase enzyme mixture of claim 7, wherein

(i) when said f_C2 values are greater than or equal to 0.35 and less than 0.45, said f_E2 value is greater than or equal to 0.15 and less than 0.25;

(ii) when said f_C2 values are greater than or equal to 0.45 and less than 0.55, said f_E2 value is greater than or equal to 0.15 and less than 0.55; and

(iii) when said f_C2 values are greater than or equal to 0.55 and less than 0.65, said f_E2 value is greater than or equal to 0.15 and less than 0.25.

9. The cellulase enzyme mixture of claim 8, wherein when said f_C2 values are greater than or equal to 0.45 and less than 0.55, said f_E2 values are greater than or equal to 0.15 and less than 0.25.

10. The cellulase enzyme mixture of claim 7, wherein the cellulase enzyme mixture is produced by expressing the primary cellulases from Trichoderma at pH values between about 2 and about 5.