Microbial oil production from biomass hydrolysate by oleaginous yeast strains

• US 8,802,409 B2
• Filed: 09/06/2011
• Issued: 08/12/2014
• Est. Priority Date: 09/06/2010
• Status: Expired due to Fees

• Current Assignee: Washington State University
• Original Assignee: Washington State University
• Inventors: Zheng, Yubin, Chen, Shulin, Yu, Xiaochen
• Primary Examiner(s): Noakes, Suzanne M
• Assistant Examiner(s): CHONG, STEPHEN M
• Application Number:
  US13/225,656
• Publication Number:
  US 20120083023A1
• Time in Patent Office: 1,071 Days
• Field of Search: None
• US Class Current: 435/171
• CPC Class Codes: C10G 2300/1014 of vegetal origin
• CPC Class Codes: C10L 1/02 essentially based on components consisting of carbon, hydrogen, and oxygen only
• CPC Class Codes: C10L 1/026 for compression ignition
• CPC Class Codes: C12N 1/22 Processes using, or culture media containing, cellulose or hydrolysates thereof
• CPC Class Codes: C12P 7/6409 Fatty acids
• CPC Class Codes: C12P 7/649 Biodiesel, i.e. fatty acid alkyl esters
• CPC Class Codes: C13K 1/02 obtained by saccharification of cellulosic materials manufacture of fodder A23K10/32
• CPC Class Codes: C13K 13/002 Xylose
• CPC Class Codes: C13K 13/007 Separation of sugars provided for in subclass C13K C13K3/00 takes precedence
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel
• CPC Class Codes: Y02P 30/20 using bio-feedstock

Abstract

Oleaginous yeast strains are used to hydrolyze biomass (e.g. wheat straw) that has been pretreated using dilute acid, in order to produce lipids. The lipids may be used as feedstock for producing biofuels.

Claims

1. A method of producing lipids, comprising the steps of

hydrolyzing biomass with dilute acid to faun a hydrolysate containing sugars;

culturing at least one species of oleaginous yeast in the hydrolysate under conditions that allow said oleaginous yeast to produce and accumulate lipids; and

extracting said lipids from said oleaginous yeast,

wherein said dilute acid is present at a concentration of 0.05% w/v to 2% w/v.

2. The method of claim 1, wherein said oleaginous yeast is selected from the group consisting of Cryptococcus curvatus, Rhodotorula glutinis, Lipomyces starkeyi and Yarrowia lipolytica.

3. The method of claim 1, wherein said method further comprises the step of detoxifying said hydrolysate prior to said step of culturing.

4. The method of claim 3, wherein said oleaginous yeast is Rhodosporidium toruloides.

5. The method of claim 1, wherein said biomass is lignocellulosic biomass selected from the group consisting of wheat straw, grass straw, barley straw, corn stover and sugarcane bagasse.

6. The method of claim 1, wherein said dilute acid is dilute sulfuric acid.

7. The method of claim 1, further comprising the step of harvesting said oleaginous yeast prior to said step of extracting.

8. The method of claim 1, wherein said oleaginous yeast is Cryptococcus curvatus.

15. The method of claim 1, wherein said step of hydrolyzing is carried out for a period of time ranging from seconds to minutes.

9. A method of producing biofuel, comprising the steps of

hydrolyzing biomass with dilute acid to form a hydrolysate containing sugars;

culturing at least one species of oleaginous yeast in said hydrolysate under conditions that allow said oleaginous yeast to produce and accumulate lipids;

extracting said lipids from said oleaginous yeast; and

producing biofuel from said lipids extracted in said extracting step,

wherein said dilute acid is present at a concentration of 0.05% w/v to 2% w/v.

10. The method of claim 9, wherein said oleaginous yeast is selected from the group consisting of Cryptococcus curvatus, Rhodotorula glutinis, Lipomyces starkeyi and Yarrowia lipolytica.

11. The method of claim 9, wherein said method further comprises the step of detoxifying said hydrolysate prior to said step of culturing.

12. The method of claim 9, wherein said biofuel is renewable gasoline, diesel, jet fuel, and biodiesel.

13. The method of claim 9, further comprising the step of harvesting said oleaginous yeast prior to said step of extracting.

14. The method of claim 9, wherein said oleaginous yeast is Cryptococcus curvatus.

16. A method of producing lipids, comprising the steps of

hydrolyzing biomass with dilute acid to form a hydrolysate, wherein the step of hydrolyzing produces at least 4 g/l of acetic acid in the hydrolysate;

culturing at least one species of oleaginous yeast in the hydrolysate under conditions that allow said oleaginous yeast to produce and accumulate lipids; and

extracting said lipids from said oleaginous yeast,

wherein said dilute acid is present at a concentration of 0.05% w/v to 2% w/v.