Procedure for the production of ethanol from lignocellulosic biomass using a new heat-tolerant yeast

• US 20020164730A1
• Filed: 02/20/2001
• Published: 11/07/2002
• Est. Priority Date: 02/24/2000
• Status: Abandoned Application

• Current Assignee: Centro De Investigaciones Energeticas Medioambientales Y Tecnologicas
• Original Assignee: Centro De Investigaciones Energeticas Medioambientales Y Tecnologicas
• Inventors: Ballesteros Perdices, Ignacio, Ballesteros Perdices, Mercedes, Oliva Dominguez, Jose Miguel, Carrasco Garcia, Juan
• Application Number:
  US09/788,908
• Publication Number:
  US 20020164730A1
• Time in Patent Office: Days
• US Class Current: 435/163
• CPC Class Codes: C12M 21/16 Solid state fermenters, e.g. for koji production
• CPC Class Codes: C12M 45/02 by mechanical forces; Stirring; Trituration; Comminuting crushing, pulverizing, disintegrating in general B02C
• CPC Class Codes: C12M 45/04 Phase separators; Separation of non fermentable material; Fractionation
• CPC Class Codes: C12M 45/20 Heating; Cooling heating or cooling apparatus for laboratory uses B01L7/00
• CPC Class Codes: C12P 7/10 substrate containing cellulosic material
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

It includes the stages of grinding the lignocellulosic biomass to a size of 15-30 mm, subjecting the product obtained to steam explosion pre-treatment at a temperature of 190-230° C. for between 1 and 10 minutes in a reactor (2), collecting the pre-treated material in a cyclone (3) and separating the liquid and solid fractions by filtration in a filter press (9), introducing the solid fraction in a fermentation deposit (10), adding a cellulase at a concentration of 15 UFP per gram of cellulose and 12.6 International Units of β-glucosidase enzyme dissolved in citrate buffer pH 4.8, inoculating the fermentation deposit (10) with a culture of the heat-tolerant bacteria Kluyveromyces marxianus CECT 10875, obtained by chemical mutagenesis from strain DER-26 of Kluyveromyces marxianus and shaking the mixture for 72 hours at 42° C.

Claims

1. Procedure for the production of ethanol from lignocellulosic biomass characterised in that it includes the stages of:

Grinding the lignocellulosic biomass Subjecting the ground lignocellulosic biomass to steam explosion pre-treatment, maintaining at a pressure of between 1 and 3 MPa and a temperature between 190 and 230°

C., for a period of time of between 1 and 10 minutes, depending on the type of material used and later provoking rapid de-pressurisation.

Collecting the pre-treated material and separating the liquid and solid fractions by filtration, and introducing the solid fraction in the fermentation deposit (10).

Adding a cellulase to the fermentation deposit (10) in a concentration of 15 UFP per gram of cellulose and 12.6 International Units of β

-glucosidase enzyme. Inoculating the fermentation deposit (10) with a suspension of a culture of the heat-tolerant yeast Kluyveromyces marxianus CECT 10875. Shaking the mixture for 72 h at 42°

C. Determining the concentration of ethanol and residual sugars in the mix, once the reaction is complete.

2. Procedure for the production of ethanol from lignocellulosic biomass, in accordance with claim 1, characterised in that the particle size of the lignocellulosic biomass after grinding is between 15 and 30 mm.

3. Procedure for the production of ethanol from lignocellulosic biomass, in accordance with claim 1, characterised in that the culture of Kluyveromyces marxianus CECT 10875 is obtained by chemical mutagenesis from the DER-26 strain of Kluyveromyces marxianus.

4. Procedure for the production of ethanol from lignocellulosic biomass, in accordance with claim 1, characterised in that the humidity content of the lignocellulosic biomass is between 10 and 15%.

5. Procedure for the production of ethanol from lignocellulosic biomass, in accordance with claim 1, characterised in that the solid fraction that is introduced into the fermentation deposit has a solid/liquid ratio that varies between 8 and 15% (w/v).

6. Procedure for the production of ethanol from lignocellulosic biomass, in accordance with claim 1, characterised in that the cellulase is CELLUCLAST 1.5L, from the NOVO-NORDISK company, and the β

-glucosidase enzyme is NOVOZYME 188, from the NOVO-NORDISK company.

7. Procedure for the production of ethanol from lignocellulosic biomass, in accordance with claim 1, characterised in that the cellulase and the β

-glucosidase are dissolved in citrate buffer pH 4.8.

8. Procedure for the production of ethanol from lignocellulosic biomass, in accordance with claim 1, characterised in that the Kluyveromyces marxianus CECT 10875 inoculant is at a concentration of 10 v/v.

9. Procedure for the production of ethanol from lignocellulosic biomass, in accordance with claim 1, characterised in that the mixture is shaken at 150 r.p.m.