Compositions and methods for production of fermentable sugars

• US 8,236,551 B2
• Filed: 11/01/2011
• Issued: 08/07/2012
• Est. Priority Date: 11/02/2010
• Status: Active Grant

• Current Assignee: Codexis, Inc.
• Original Assignee: Codexis, Inc.
• Inventors: Dhawan, Ish Kumar, Baidyaroy, Dipnath, Shaw, Andrew, Tanchak, Oleh, Hill, Christopher, Liu, Chengsong, Chokshi, Amala, Scott, Brian R.
• Primary Examiner(s): Pak, Yong
• Application Number:
  US13/286,972
• Publication Number:
  US 20120107881A1
• Time in Patent Office: 280 Days
• Field of Search: None
• US Class Current: 435/254.1
• CPC Class Codes: C12N 9/0006 acting on CH-OH groups as donors (1.1)
• 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 19/12 Disaccharides
• 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 2203/00 Fermentation products obtained from optionally pretreated or hydrolyzed cellulosic or lignocellulosic material as the carbon source
• CPC Class Codes: C12P 7/10 substrate containing cellulosic material
• CPC Class Codes: C12Y 101/99018 Cellobiose oxidase (1.1.99.18)
• CPC Class Codes: C13K 1/02 obtained by saccharification of cellulosic materials manufacture of fodder A23K10/32
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

The present application provides genetically modified fungal organisms that produce enzyme mixtures exhibiting enhanced hydrolysis of cellulosic material to glucose, enzyme mixtures produced by the genetically modified fungal organisms, and processes for producing glucose from cellulose using such enzyme mixtures.

Claims

1. A Myceliophthora thermophile fungal cell that has been genetically modified to reduce the amount of endogenous cellobiose oxidizing enzyme activity that is produced by the fungal cell, wherein the fungal cell has been genetically modified by deleting endogenous cellobiose dehydrogenase enzymes having at least about 90% or at least about 95% sequence identity to the sequences of SEQ ID NOS:

6 and 8.

2. The fungal cell of claim 1, wherein the fungal cell has been genetically modified to reduce the amount of endogenous cellobiose dehydrogenase produced by the fungal cell and to increase the production of at least one saccharide hydrolyzing enzyme, wherein said at least one saccharide hydrolyzing enzyme is selected from beta-glucosidases, endoglucanases, cellobiohydrolases, esterases, beta-xylosidases, xylanases, arabinofuranosidases, alpha-glucuronidases, acetylxylan esterases, feruloyl esterases, alpha-glucuronyl esterases, and GH61 enzymes.

3. The fungal cell of claim 2, wherein said at least one saccharide hydrolyzing enzyme is a Myceliophthora thermophila enzyme.

4. The fungal cell of claim 2, wherein said at least one saccharide hydrolyzing enzyme is overexpressed by said fungal cell.

5. The fungal cell of claim 2, wherein said overexpressed saccharide hydrolyzing enzyme is beta-glucosidase.