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US-20260125716-A1 - Optimised Fermentation of Anaerobic Bacteria

US20260125716A1US 20260125716 A1US20260125716 A1US 20260125716A1US-20260125716-A1

Abstract

The present invention provides a method for increasing the growth efficiency in an anaerobic microbial fermentation of a microorganism capable of converting CO 2 , CO or a mixture thereof into at least one organic compound, the method comprising growing the microorganisms in a cultivation medium comprising selenium in a concentration which is at least 1.2 μM.

Inventors

  • Andreea-Cristina DOBRESCU
  • Carolina SANTOS GIORDANI BENEVENUTI
  • Stephanie Redl
  • Torbjørn Ølshøj Jensen

Assignees

  • AGAIN BIO APS

Dates

Publication Date
20260507
Application Date
20231006
Priority Date
20221006

Claims (20)

  1. 1 . A method for increasing the growth efficiency in an anaerobic microbial fermentation of a microorganism capable of converting CO 2 , CO or a mixture thereof into at least one organic compound, the method comprising growing the microorganisms in a cultivation medium comprising selenium in a concentration which is at least 1.2 μM.
  2. 2 . A method for increasing the growth efficiency in an anaerobic microbial fermentation of a microorganism converting CO 2 , CO or a mixture thereof into at least one organic compound, the method comprising growing the microorganisms in a cultivation medium comprising nickel in a concentration which is in the range from 3.0 μM to 8.5 μM.
  3. 3 . A method for increasing the growth efficiency in an anaerobic microbial fermentation of a microorganism converting CO 2 , CO or a mixture thereof into at least one organic compound, the method comprising growing the microorganisms in a cultivation medium comprising molybdenum in a concentration which is at least 1.5 μM.
  4. 4 . The method according to claim 1 , wherein said cultivation medium comprises selenium in a concentration which is at least 1.3 μM, at least 2 μM, at least 3 μM, or at least 4 μM.
  5. 5 . The method according to claim 1 , wherein said cultivation medium comprises selenium in a concentration which is in the range from 2.0 μM to 8 μM, in the range from 3.0 μM to 7 μM, in the range from 4 μM to 6 μM or in the range from 4.4 μM to 5.6 μM.
  6. 6 . The method according to claim 2 , wherein said cultivation medium comprises nickel in a concentration which is in the range from 4.0 μM to 8.0 μM, in the range from 5.0 μM to 7.0 μM or in the range from 5.5 μM to 7.0 μM.
  7. 7 . The method according to claim 3 , wherein said cultivation medium comprises molybdenum in a concentration which is at least 1.7 μM, at least 2.0 μM, or at least 2.2 μM.
  8. 8 . The method according to claim 1 , wherein said microorganism is capable of converting CO 2 into at least one organic compound.
  9. 9 . The method according to claim 1 , wherein said microorganism is capable of converting CO into at least one organic compound.
  10. 10 . The method according to claim 1 , wherein said microorganism is an acetogen.
  11. 11 . The method according to claim 10 , wherein said microorganism is selected from Clostridium, Moorella, Thermoanaerobacter, Thermoanaerobacterium, Acetogenium, Acetobacterium, Acetoanaerobium, Butyribacterium, Eubacterium, Pyrococcus, Desulfobacterium and Carboxydothermus.
  12. 12 . The method according to claim 1 , wherein said at least one organic compound comprises acetate.
  13. 13 . The method according to claim 1 , wherein said anaerobic microbial fermentation is a production of said at least one organic compound from said cultivation medium and a gas comprising CO 2 , CO or a mixture thereof.
  14. 14 . Use of the method as defined in claim 1 for the industrial manufacture of at least one organic compound from CO 2 , CO or a mixture thereof.
  15. 15 . The use according to claim 14 , wherein said at least one organic compound comprises acetate.
  16. 16 . The method according to claim 3 , wherein said microorganism is capable of converting CO 2 into at least one organic compound.
  17. 17 . The method according to claim 3 , wherein said microorganism is capable of converting CO into at least one organic compound.
  18. 18 . The method according to claim 3 , wherein said microorganism is an acetogen.
  19. 19 . The method according to claim 18 , wherein said microorganism is selected from Clostridium, Moorella, Thermoanaerobacter, Thermoanaerobacterium, Acetogenium, Acetobacterium, Acetoanaerobium, Butyribacterium, Eubacterium, Pyrococcus, Desulfobacterium and Carboxydothermus.
  20. 20 . The method according to claim 3 , wherein said at least one organic compound comprises acetate.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to the fields of biotechnology, microbiology, fermentations and microbial growth and conversion of carbon dioxide or carbon monoxide into organic compounds. BACKGROUND OF THE INVENTION Carbon emission gasses such as carbon dioxide (CO2) and carbon monoxide (CO) form during many industrial processes, mainly manufacturing, raw material mining, energy and transportation. CO2 and CO have traditionally been emitted to the atmosphere as rather harmless compounds entering the global carbon cycle while environmental and health safety focus was on limiting emissions of other gasses, including toxic gasses, such as NOx, SO2, methane etc. Due to increasing global population, the ongoing global warming and climate changes there is an urgent need for industrial processes which are more circular in nature, i.e. leaving little footprints and not causing large emissions disturbing global balances. No doubt, this undertaking will require many different efforts in order to timely intervene in the ongoing developments which are very fast compared to the rate of fundamentally changing the industrial processes which support man kind and our present population. Examples being substituting combustion of fossil fuels for electricity made from wind, solar, water and nuclear power, and being minimizing the emission of CO2 and CO from industrial processes by alternative processes or by capturing the CO2 and CO. The capture of CO2 and CO from industrial processes may fundamentally be carried out in two different ways. Firstly, CO2 may be collected for the industrial process and stored so that it does not enter the atmosphere. Attempts have been made to pump the CO2 into underground cavities such as in areas where oil and gas exploration have taken place. There are also large scale processes where CO2 is liquefied and transported to a suitable site for long term storage. However, the concept of storing CO2 does point to a less than optimal solution from a sustainability point of view. Secondly, CO2 may be collected from the industrial process where it is produced and then used in another process where it is converted into some carbon-containing product which has commercial value. WO 98/37179 discloses chemically defined media for the fermentative production of valuable compounds on an industrial scale. WO 2010/064932 discloses optimized fermentation media for the production of alcohols by microbial fermentation of substrates comprising CO. US 2015/0024449 discloses a process and medium for fermenting syngas wherein the selenium levels in biomass are reduced. Redl et al., Frontiers in Microbiology (2020), Vol 10, pp 1-15 discloses a medium for the cultivation of species of Moorella. Hence, there is a great need for new effective processes for converting CO2 or CO from emissions from industrial processes into products having commercial value, thus serving dual purposes of eliminating CO2 or CO from emissions and manufacturing a product which can ensure the process to be commercially viable. SUMMARY OF THE INVENTION It is an object of the present invention to provide processes for the conversion of CO2 and CO from emissions into an organic compound. It is in particular an object of the present invention to provide an improved fermentation medium useful in a microbial process that converts CO2 or CO into at least one organic compound. It is a further object of the present invention to provide an improved fermentation medium which facilitates a cost-effective process, e.g. low cost of medium and low cooling requirements. It is also an object of the present invention to overcome some of the disadvantages of the processes known in the art. The inventors have surprisingly found that a medium having a high concentrations of selenium and molybdenum facilitates a high growth rate and high biomass yields of an acetogenic microorganism. The inventors has also found that the nickel concentration and the magnesium concentration in contrast to some prior teachings have novel and optimal intervals with respect to growth rate and yield of an acetogenic microorganism In a first aspect the present invention provides a method for increasing the growth efficiency in an anaerobic microbial fermentation of a microorganism capable of converting CO2, CO or a mixture thereof into at least one organic compound, the method comprising growing the microorganisms in a cultivation medium comprising selenium in a concentration which is at least 1.2 μM. In a second aspect the present invention provides a method for increasing the growth efficiency in an anaerobic microbial fermentation of a microorganism converting CO2, CO or a mixture thereof into at least one organic compound, the method comprising growing the microorganisms in a cultivation medium comprising nickel in a concentration which is in the range from 3.0 μM to 8.5 μM. In a third aspect the present invention provides a method for increasing the g