Methods for preventing a chytrid infection in a culture of Haematococcus pluvialis using hydrogen peroxide

Patent metadata

Field	Value
Publication number	US-9447374-B1
Application number	US-201514795770-A
Country	US
Kind code	B1
Filing date	Jul 9, 2015
Priority date	Mar 25, 2015
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

Methods of treating contamination, particularly fungal contamination, in cultures of Haematococcus pluvialis with hydrogen peroxide are described herein. The method comprises detecting the contamination and then dosing the culture with a concentration of hydrogen peroxide based on the stage of the cells in the culturing process and at a frequency to increase the likelihood of the cells surviving until the process of accumulating carotenoids, such as astaxanthin, is complete.

First claim

What is claimed is:

1. A method of preventing a chytrid infection in a culture of Haematococcus pluvialis , comprising:
a. Culturing a population of Haematococcus pluvialis cells in a liquid culture medium;
b. Determining a number of Haematococcus pluvialis cells infected with chytrids in the culture;
c. Contacting the culture with hydrogen peroxide when the percentage of Haematococcus pluvialis cells infected with chytrids is less than 10% of the total cells;
d. Continuing to culture the Haematococcus pluvialis cells; and
e. Verifying that a percentage of Haematococcus pluvialis cells infected with chytrids is maintained at a level less than 10% of the total cells after contact with the hydrogen peroxide.

2. The method of claim 1 , wherein the culture is contacted with hydrogen peroxide to form a calculated concentration in the range of 0.005-0.020 mL of hydrogen peroxide per L of culture medium (mL/L).

3. The method of claim 2 , wherein the calculated concentration of hydrogen peroxide is in the range of 0.005-0.010 mL/L.

4. The method of claim 2 , wherein the calculated concentration of hydrogen peroxide is in the range of 0.010-0.015 mL/L.

5. The method of claim 2 , wherein the calculated concentration of hydrogen peroxide is in the range of 0.015-0.020 mL/L.

6. The method of claim 1 , wherein the cells are contacted with the hydrogen peroxide multiple times.

7. The method of claim 6 , wherein the cells are contacted with the hydrogen peroxide every 6-24 hours.

8. The method of claim 7 , wherein the cells are contacted with the hydrogen peroxide every 6-12 hours.

9. The method of claim 8 , wherein the cells are contacted with the hydrogen peroxide every 6-8 hours.

10. The method of claim 6 , wherein the cells are contacted with the hydrogen peroxide every day over the course of 1-14 days.

11. The method of claim 6 , wherein the cells are contacted with hydrogen peroxide every other day over the course of 3-15 days.

12. The method of claim 1 , wherein the biomass yield of the Haematococcus pluvialis cells contacted with the hydrogen peroxide is equivalent to or greater than a control culture not receiving treatment with hydrogen peroxide.

13. The method of claim 12 , wherein the biomass yield of the Haematococcus pluvialis cells contacted with the hydrogen peroxide is 0.01-0.25 g/L greater than a control culture not receiving treatment with hydrogen peroxide.

14. The method of claim 1 , wherein the carotenoid yield of the Haematococcus pluvialis cells contacted with the hydrogen peroxide is equivalent to or greater than a control culture not receiving treatment with hydrogen peroxide.

15. The method of claim 14 , wherein the carotenoid yield of the Haematococcus pluvialis cells contacted with the hydrogen peroxide is 0.10-1.50% greater than a control culture not receiving treatment with hydrogen peroxide.

16. The method of claim 1 , wherein the Haematococcus pluvialis cells are primarily in a green swimmer stage.

17. The method of claim 1 , wherein the Haematococcus pluvialis cells are primarily in a cyst stage.

18. The method of claim 17 , wherein the cyst stage comprises primarily of green cysts.

19. The method of claim 17 , wherein the cyst stage comprises primarily of red cysts.

20. The method of claim 1 , wherein the method further comprises transferring the culture of Haematococcus pluvialis cells to a new culturing vessel after contacting the culture with the hydrogen peroxide.

Assignees

• Heliae Dev Llc

Inventors

• Carney Laura
• Sorensen Kristine

Classifications

• C12N1/12 Primary

  Unicellular algae; Culture media therefor (as new plants A01H13/00) · CPC title

• C12P33/00

  Preparation of steroids · CPC title

• C12N1/38

  Chemical stimulation of growth or activity by addition of chemical compounds which are not essential growth factors; Stimulation of growth by removal of a chemical compound (C12N1/34 takes precedence) · CPC title

• C12P23/00

  Preparation of compounds containing a cyclohexene ring having an unsaturated side chain containing at least ten carbon atoms bound by conjugated double bonds, e.g. carotenes (containing heterorings C12P17/00) · CPC title

• A01N59/08

  Alkali metal chlorides; Alkaline earth metal chlorides · CPC title