Separation of Proteins from Grasses Integrated with Ammonia Fiber Explosion (AFEX) Pretreatment and Cellulose Hydrolysis

• US 20090318670A1
• Filed: 04/30/2007
• Published: 12/24/2009
• Est. Priority Date: 05/01/2006
• Status: Abandoned Application

• Current Assignee: The Board of Trustees of Michigan State University (Michigan State University)
• Original Assignee: The Board of Trustees of Michigan State University (Michigan State University)
• Inventors: Bals, Bryan, Dale, Bruce E., Balan, Venkatesh
• Application Number:
  US12/226,850
• Publication Number:
  US 20090318670A1
• Time in Patent Office: Days
• US Class Current: 530/344
• CPC Class Codes: A23J 1/006 from vegetable materials A23J1/005, A23J1/12 and A23J1/14 take precedence
• CPC Class Codes: A23K 20/10 Organic substances
• CPC Class Codes: A23K 20/147 Polymeric derivatives, e.g. peptides or proteins
• CPC Class Codes: A23K 50/10 for ruminants
• CPC Class Codes: A23K 50/75 for poultry
• CPC Class Codes: C07K 14/415 from plants
• CPC Class Codes: C12P 19/02 Monosaccharides 2-ketogulonic acid C12P7/60
• 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 2201/00 Pretreatment of cellulosic or lignocellulosic material for subsequent enzymatic treatment or hydrolysis

Abstract

A process for extracting an aqueous ammonium hydroxide solution from a plant biomass after an Ammonia Fiber Explosion (AFEX) process step, is described. The proteins can be separated before or after a hydrolysis of sugar precursors (carbohydrates) from the biomass to produce sugars for fermentation to produce ethanol. The proteins are useful as animal feeds because of their amino acid food values.

Claims

1. A process for extracting plant proteins from a lignocellulosic plant biomass comprising:

(a) providing a harvested lignocellulosic plant biomass;

(b) treating the plant biomass with an Ammonia Fiber Explosion (AFEX) process to provide a treated plant biomass; and

(c) extracting proteins in the treated plant biomass with an aqueous alkaline ammonium hydroxide solution comprising up to about 3% by weight NH₄OH to provide the extracted proteins in the solution.

2. The process of claim 1 wherein the plant is a monocot.

3. The process of claim 2 wherein the monocot is rice or maize.

4. The process of claim 1 wherein the plant material is switchgrass.

5. The process of any one of claims 1, 2, 3 or 4 wherein the pH is above about 8.

6. The process of any one of claims 1, 2, 3 or 4 wherein the proteins are separated from the solution by precipitation or ultrafiltration.

7. The process of any one of claims 1, 2, 3 or 4 wherein the extracting is after a hydrolysis step in the plant biomass, after step (b), to produce sugars from sugar precursors in the biomass.

8. The process of any one of claims 1, 2, 3 or 4 wherein the extracting of the proteins is before a hydrolysis step in the plant biomass, after step (b), to produce sugars from sugar precursors in the biomass and optionally in addition after the hydrolysis step.

9. A process for isolating plant proteins from a lignocellulosic plant biomass comprising:

(a) providing a harvested lignocellulosic plant biomass;

(b) treating the plant biomass with an Ammonia Fiber Explosion (AFEX) process to provide a treated plant biomass;

(c) soaking the treated plant biomass in an alkaline aqueous solution of ammonium hydroxide at 25°

to 70°

C. to provide a soaked plant biomass in the solution;

(d) extracting the solution from the soaked plant biomass in step (c); and

(e) separating crude proteins from the solution of step (d) so as to provide isolated plant proteins from the plant biomass.

10. The method of claim 9 wherein the plant is a monocot.

11. The method of claim 10 wherein the monocot is switchgrass, rice or maize.

12. The process of claim 9 wherein the plant biomass is switchgrass.

13. The process of any one of claims 10, 11, 12 or 13 wherein the pH is above about 8.

14. The process of any one of claims 9, 10, 11 or 12 wherein the proteins are separated from the solution by precipitation or ultrafiltration.

15. The process of any one of claims 9, 10, 11 or 12 wherein the proteins are separated after a hydrolysis step in the plant biomass, after step (b), to produce sugars from structural carbohydrates in the biomass.

16. The process of any one of claims 9, 10, 11, 12 or 13 wherein the proteins are separated before a hydrolysis step in the biomass, after step (b), to produce sugars from structural carbohydrates and optionally in addition after the hydrolysis step.