Efficient light harvesting

• US 9,187,778 B2
• Filed: 02/11/2010
• Issued: 11/17/2015
• Est. Priority Date: 05/04/2009
• Status: Active Grant

• Current Assignee: Aurora Algae, Incorporated (Reliance Industries Limited)
• Original Assignee: Aurora Algae, Incorporated (Reliance Industries Limited)
• Inventors: Bailey, Shaun, Tam, Yuen Yee, Vick, Bertrand
• Primary Examiner(s): Kallis, Russell
• Application Number:
  US12/704,035
• Publication Number:
  US 20110197306A1
• Time in Patent Office: 2,105 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: A01H 1/06 Processes for producing mutations, e.g. treatment with chemicals or with radiation specific mutations prepared by genetic engineering on plant cell or plant tissues C12N15/00 ; process for producing transgenic plants C12N15/82
• CPC Class Codes: C12N 1/12 Unicellular algae; Culture media therefor as new plants A01H13/00
• CPC Class Codes: C12N 15/01 Preparation of mutants without inserting foreign genetic material therein; Screening processes therefor
• CPC Class Codes: C12N 5/04 Plant cells or tissues culture media C12N5/0025
• CPC Class Codes: C12Q 1/02 involving viable microorganisms
• CPC Class Codes: G01N 2333/405 from algae

Abstract

Various aspects provide for genetically modifying photosynthetic cells. In some cases, an integrated light harvesting efficiency of photosynthetic cells may be increased by reducing the amount of incident light that is absorbed but not used for photosynthesis. In some cases, an increased transparency may be associated with an increased light harvesting efficiency when absorption due to non-photosynthetic processes is reduced. A reduced capacity of various light-harvesting antenna apparatus may increase transparency. In some cases, a capacity of an organism to adapt to varying light levels may be reduced, and in certain cases, a modified organism may have a reduced ability to acclimate to a low light irradiance.

Claims

1. A method for increasing cell density of photosynthetic organisms, the method comprising:

choosing a first photosynthetic organism having a first transparency and a first cell density associated with light transmission through the first photosynthetic organism;

subjecting the first photosynthetic organism to mutagenesis to create one or more second photosynthetic organisms;

determining a second transparency associated with light transmission through at least one of the second photosynthetic organisms; and

selecting one or more second photosynthetic organisms for which the second transparency is greater than the first transparency;

the first photosynthetic organism being a member of genus Nannochloropsis and the selected one or more second photosynthetic organisms having a second cell density greater than the first cell density by at least 5%.

2. The method of claim 1, further comprising:

determining a first growth rate of the first photosynthetic organism;

determining a second growth rate of at least one of the second photosynthetic organisms; and

selecting one or more second photosynthetic organisms having the second growth rate larger than the first growth rate.

3. The method of claim 2, wherein at least one of the second photosynthetic organisms has the second growth rate larger than the first growth rate and has the second transparency greater than the first transparency.

4. The method of claim 2, wherein one or more growth rates include a measurement of total biomass.

5. The method of claim 2, wherein one or more growth rates include a measurement of lipid production.

6. The method of claim 1, wherein the first transparency and the second transparency are determined in the visible light regime.

7. The method of claim 1, wherein a color of the first photosynthetic organism is a first green, and at least one of the selected second photosynthetic organisms is a paler green than the first green.

8. The method of claim 1, wherein at least one of the selected second photosynthetic organisms has a less effective light harvesting antenna than does the first photosynthetic organism.

9. The method of claim 1, wherein at least one of the second photosynthetic organisms has a higher PSII electron transport rate than the first photosynthetic organism at a first irradiance.

10. The method of claim 9, wherein the first irradiance is associated with a saturation regime of the first photosynthetic organism.

11. The method of claim 1, wherein at least one of the second photosynthetic organisms has a lower value associated with nonphotochemical quenching than does the first photosynthetic organism at a first irradiance.

12. The method of claim 1, wherein at least one of the second photosynthetic organisms has a higher threshold irradiance than does the first photosynthetic organism.

13. The method of claim 1, wherein at least one of the second photosynthetic organisms has a higher maximum photosynthetic rate than does the first photosynthetic organism.