Fungal strains

• US 9,528,098 B2
• Filed: 05/20/2015
• Issued: 12/27/2016
• Est. Priority Date: 11/02/2010
• Status: Active Grant

• Current Assignee: Codexis, Inc.
• Original Assignee: Codexis, Inc.
• Inventors: Baidyaroy, Dipnath, Dhawan, Ish K.
• Primary Examiner(s): PAK, YONG D
• Application Number:
  US14/717,447
• Publication Number:
  US 20150252342A1
• Time in Patent Office: 587 Days
• Field of Search: None
• US Class Current: 1/1
• 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: C12N 9/2445 Beta-glucosidase (3.2.1.21)
• 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 ethanol C12P7/10
• 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: C12Y 302/01021 Beta-glucosidase (3.2.1.21)
• 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
• CPC Class Codes: Y02P 20/52 using catalysts, e.g. selective catalysts

Abstract

The present invention provides improved fungal strains. In some embodiments, the improved fungal strains find use in hydrolyzing cellulosic material to glucose.

Claims

1. A method for generating glucose, comprising contacting a lignocellulose substrate with an enzyme mixture comprising two or more M. thermophila cellulose hydrolyzing enzymes selected from endoglucanases (EGs), beta-glucosidases (BGLs), Type 1 cellobiohydrolases (CBH1s), Type 2 cellobiohydrolases (CBH2s), and/or glycoside hydrolase 61s (GH61s), to generate glucose and/or cellobiose, wherein at least one of the cellulose hydrolyzing enzymes is endogenous to an M. thermophila fungal cell and wherein the enzyme mixture is characterized in that, when the enzyme mixture is contacted with cellobiose and/or glucose, no more than about 10%, about 15%, or about 20% of the cellobiose and/or glucose produced using the method is oxidized after 10 hours, the method further comprising the step of subjecting the enzyme mixture to a purification process to selectively remove at least one glucose and/or cellobiose oxidizing enzyme from the enzyme mixture.

3. The method of claim 1, wherein the enzyme mixture is produced by a fungal cell that has been genetically modified to reduce the amount of one or more endogenous glucose and/or cellobiose oxidizing enzymes that is secreted by the fungal cell.

2. A method for generating glucose comprising contacting a lignocellulose substrate with an enzyme mixture comprising two or more M. thermophila cellulose hydrolyzing enzymes selected from endoglucanases (EGs), beta-glucosidases (BGLs), Type 1 cellobiohydrolases (CBH1s), Type 2 cellobiohydrolases (CBH2s), and/or glycoside hydrolase 61s (GH61s), to generate glucose and/or cellobiose, wherein at least one of the cellulose hydrolyzing enzymes is endogenous to an M. thermophila fungal cell and wherein, of the lignocellulose hydrolyzed by the enzyme mixture, at least about 80%, about 85%, or about 90% is present in the form of glucose, the method further comprising the step of subjecting the enzyme mixture to a purification process to selectively remove at least one glucose and/or cellobiose oxidizing enzyme from the enzyme mixture.