PROCESS FOR THE PRODUCTION OF CELLULOLYTIC AND/OR HEMICELLULOLYTIC ENZYMES

• US 20170349888A1
• Filed: 08/23/2017
• Published: 12/07/2017
• Est. Priority Date: 07/12/2010
• Status: Active Grant

• Current Assignee: IFP Energies Nouvelles
• Original Assignee: IFP Energies Nouvelles
• Inventors: BEN CHAABANE, Fadhel, MONOT, Frederic
• Granted Patent: US 10,457,925 B2
• Time in Patent Office: Days
• 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

(a) growing the microorganism in the presence of a source of carbon;

(b) inducing the production of the enzymes by the microorganism in the presence of an inducing substrate, wherein said inducing substrate is a mixture of cellulosic hydrolysates, lactose and xylose or a solution of hemicellulosic hydrolysates, the quantities of each of the constituents of the mixture being defined by the following limits;

40% to 65% by weight of 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%, and wherein the microorganism belongs to the species Trichoderma reesei which is deleted for catabolic repression by glucose,

and wherein both the source of carbon and the inducing substrate comprise sugar.

3. The process according to claim 1, in which the inducing substrate is supplied in solution having a concentration of 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. The process according to claim 1, wherein the inducing substrate comprises 50% to 65% by weight of 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. The process according to claim 5, in which the inducing substrate is a mixture constituted by 60% by weight of cellulosic hydrolysates, 23% by weight of lactose and 17% by weight of xylose or hemicellulosic hydrolysates.

7. The process according to claim 1, in which the carbon source in (a) 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. The process according to claim 1, wherein growth (a) is conducted at a pH of 3.5 to 6 and the temperature is 20°

C. to 35°

C.

9. The process according to claim 1, wherein in (b) induction solution is introduced at a flow rate of 30 to 45 mg per gram of cells per hour.

10. The 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.

11. The process of claim 1, wherein the residual concentration of sugar in the culture medium during induction step b) is less than 0.5 g/L.

12. The process of claim 1, wherein the residual concentration of sugar in the culture medium during induction step b) is less than 0.1 g/L.

13. The process of claim 1, wherein the constituent of the inducing substrate that is 10% to 39% by weight of xylose or a solution of hemicellulosic hydrolysates consists essentially of xylose.

2. (canceled)

14. A process for the production of cellulolytic and/or hemicellulolytic enzymes by a cellulolytic and/or hemicellulolytic microorganism, comprising

a) growing the microorganism in the presence of a source of carbon;

and

b) inducing the production of the enzymes by the microorganism in the presence of an inducing substrate supplied in solution having a concentration of 450-600 g/l, wherein said inducing substrate is 50% to 65% by weight of 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%,

and wherein the microorganism belongs to the species Trichoderma reesei which is deleted for catabolic repression by glucose, and

wherein both the source of carbon and the inducing substrate comprise sugar such that the residual concentration of sugar in eh culture medium during (b) is less than 0.1 g/l.