Endophytic yeast strains, methods for ethanol and xylitol production, methods for biological nitrogen fixation, and a genetic source for improvement of industrial strains

Patent metadata

Field	Value
Publication number	US-9487451-B2
Application number	US-201414209709-A
Country	US
Kind code	B2
Filing date	Mar 13, 2014
Priority date	Mar 13, 2009
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

The present invention provides novel endophytic yeast strains capable of metabolizing both pentose and hexose sugars. Methods of producing ethanol and xylitol using the novel endophytic yeast are provided herein. Also provided are methods of fixing nitrogen and fertilizing a crop using the novel endophytic yeast strains provided herein.

First claim

What is claimed is:

1. An isolated yeast strain capable of fixing nitrogen, wherein the strain of yeast is heterologous gene from an endophytic yeast strain selected from the group consisting of Rhodotorula graminis strain WP1, Rhodotorula mucilaginosa strain PTD2, Rhodotorula mucilaginosa strain PTD3, and Rhodotorula mucilaginosa strain Ad1 wherein said strain is identified by sequencing an rRNA gene sequence comprising SEQ ID NO:7.

2. The isolated yeast strain of claim 1 , wherein the yeast strain is Rhodotorula graminis strain WP1, identified by an rRNA gene sequence of SEQ ID NO:7.

3. The isolated yeast strain of claim 2 , deposited under deposit number ATCC-PTA-120764.

4. A culture comprising one or more isolated yeast strains of claim 1 .

5. A method for fertilizing a crop, the method comprising inoculating the crop with a strain of yeast of claim 1 capable of fixing nitrogen.

6. The method of claim 5 , wherein the step of inoculating the crop comprises colonizing the soil the crop is planted in with the yeast.

7. The method of claim 5 , wherein the strain of yeast is an endophytic strain of yeast selected from the group consisting of Rhodotorula graminis strain WP1, Rhodotorula mucilaginosa strain PTD2, Rhodotorula mucilaginosa strain PTD3, and Rhodotorula mucilaginosa strain Ad1 wherein said strain is identified by an rRNA gene sequence comprising SEQ ID NO: 7.

8. The method of claim 5 , wherein the strain of yeast is a recombinant yeast harboring a heterologous gene sequence from an endophytic yeast strain selected from the group consisting of Rhodotorula graminis strain WP1, Rhodotorula mucilaginosa strain PTD2, Rhodotorula mucilaginosa strain PTD3, and Rhodotorula mucilaginosa strain Ad1, wherein said endophytic strain is identified by an rRNA gene sequence comprising SEQ ID NO: 7.

9. The method of claim 5 , wherein the crop is a food crop.

10. The method of claim 9 , wherein the food crop is selected from the group consisting of sugar cane, maize, wheat, rice, potatoes, sugar beets, soybean, oil palm fruit, barley, tomato, coffee, and cocoa.

11. The method of claim 5 , wherein the crop is a non-food crop.

12. The method of claim 11 , wherein the non-food crop is selected from the group consisting of cottonwood, willow, a woody plant, cotton, a grass, hemp, and bamboo.

13. A method of producing ethanol, xylitol or a mixture thereof, the method comprising fermenting a carbon source with an endophytic strain of yeast selected from the group consisting of Rhodotorula graminis strain WP1, Rhodotorula mucilaginosa strain PTD2, Rhodotorula mucilaginosa strain PTD3, and Rhodotorula mucilaginosa strain Ad1 wherein said strain is identified by an rRNA gene sequence comprising SEQ ID NO: 7.

14. The isolated yeast strain of claim 1 , wherein the yeast strain comprises the nifH gene.

Assignees

• Univ Washington Through Its Center For Commercialization

Inventors

• Doty Sharon L
• Staley James Trotter
• Su Michael
• Vajzovic Azra
• Bura Renata
• Redman Regina
• Khan Zareen

Classifications

• C12P7/06

  Ethanol, i.e. non-beverage · CPC title

• C12P7/10

  substrate containing cellulosic material · CPC title

• C12P7/18

  polyhydric · CPC title

• Y02E50/16

  Cross-Sectional Technologies · mapped topic

• C05F11/08 Primary

  Organic fertilisers containing added bacterial cultures, mycelia or the like · CPC title