METHOD FOR PRODUCING CELLULOLYTIC AND/OR HEMICELLULOLYTIC ENZYMES

• US 20130210119A1
• Filed: 06/16/2011
• Published: 08/15/2013
• Est. Priority Date: 07/12/2010
• Status: Abandoned Application

• Current Assignee: Agro industrie Recherches et Développements, Institut National de La Recherche Agronomique
• Original Assignee: IFP Energies Nouvelles
• Inventors: Monot, Frederic, Ben Chaabane, Fadhel
• Application Number:
  US13/809,734
• Publication Number:
  US 20130210119A1
• Time in Patent Office: Days
• US Class Current: 435/209
• CPC Class Codes: C12N 1/14 Fungi culture of mushrooms A01G18/00; as new plants A01H15/00; Culture media therefor
• CPC Class Codes: C12N 9/2434 acting on beta-1,4-glucosidic bonds
• 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 9/248 Xylanases
• CPC Class Codes: C12P 21/02 having a known sequence of two or more amino acids, e.g. glutathione
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

The process for the production of cellulolytic and/or hemicellulolytic enzymes by a cellulolytic and/or hemicellulolytic microorganism according to the present invention comprises at least one phase for growth in the presence of a source of carbon and at least one phase for production in the presence of an inducing substrate, in which said inducing substrate is a mixture comprising 40% to 65% by weight of glucose or cellulosic hydrolysates, 21% to 25% by weight of lactose and 10% to 39% by weight of xylose or a solution of a lignocellulosic hemicellulosic hydrolysate, the sum of these three constituents being equal to 100%.

Claims

1. A process for the production of cellulolytic and/or hemicellulolytic enzymes by a cellulolytic and/or hemicellulolytic microorganism, comprising at least one phase for growth in the presence of a source of carbon and at least one phase for production in the presence of an inducing substrate, in which said inducing substrate is a mixture of glucose or cellulosic hydrolysates, lactose and xylose or a solution of hemicellulolytic hydrolysates, the quantities of each of the constituents of the mixture being defined by the following limits:

40% to 65% by weight of glucose or cellulosic hydrolysates;

21% to 25% by weight of lactose; and

10% to 39% by weight of xylose or a solution of hemicellulosic hydrolysates;

the sum of these three constituents being equal to 100%.

2. A process according to claim 1, in which the microorganism belongs to the species Trichoderma reesei and is deleted for catabolic repression by glucose.

3. A process according to claim 1, in which the inducing substrate is supplied in solution, the concentration of inducing substrate in the supply solution used during the production phase being 350 to 600 g/L.

4. A process according to claim 3, in which the concentration is in the range 450 to 550 g/L.

5. A process according to claim 1, in which the mixture constituting the inducing substrate comprises 50% to 65% by weight of glucose or cellulosic hydrolysates, 22% to 24% by weight of lactose and 15% to 25% by weight of xylose or a solution of hemicellulosic hydrolysates, the sum of the constituents being equal to 100%.

6. A process according to claim 5, in which the inducing substrate is a mixture constituted by 60% by weight of glucose or cellulosic hydrolysates, 23% by weight of lactose and 17% by weight of xylose or hemicellulosic hydrolysates.

7. A process according to claim 1, in which the carbonaceous substrate used during the growth phase is selected from glucose, xylose, lactose, residues obtained after ethanolic fermentation of monomeric sugars of the enzymatic hydrolysates of cellulosic biomass and/or an unrefined extract of hydrosoluble pentoses possibly derived from the pre-treatment of a cellulosic biomass.

8. A process according to claim 1, in which the pH is adjusted to between 3.5 and 6 and the temperature is in the range 20°

C. to 35°

C.

9. A process according to claim 1, in which the flow rate for introduction of the supply solution is 30 to 45 mg per gram of cells per hour.

10. A process according to claim 1, in which the residual concentration of sugar in the culture medium during the production phase is less than 1 g/L, preferably less than 0.5 g/L and highly preferably less than 0.1 g/L.