Microbial electrochemical cells and methods for producing electricity and bioproducts therein

Patent metadata

Field	Value
Publication number	US-10074867-B2
Application number	US-201514705766-A
Country	US
Kind code	B2
Filing date	May 6, 2015
Priority date	Mar 17, 2010
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

Bioelectrochemical systems comprising a microbial fuel cell (MFC) or a microbial electrolysis cell (MEC) are provided. Either type of system is capable of fermenting insoluble or soluble biomass, with the MFC capable of using a consolidated bioprocessing (CBP) organism to also hydrolyze an insoluble biomass, and an electricigen to produce electricity. In contrast, the MEC relies on electricity input into the system, a fermentative organism and an electricigen to produce fermentative products such as ethanol and 1,3-propanediol from a polyol biomass (e.g., containing glycerol). Related methods are also provided.

First claim

What is claimed is:

1. A method of using a microbial electrolysis cell comprising:
setting a potential in the microbial electrolysis cell between an anode electrode and a cathode electrode;
performing a fermentation step comprising fermentation only or fermentation and hydrolysis in the microbial electrolysis cell with one or more mesophilic consolidated bioprocessing organisms to convert a polyol-containing product located in the microbial electrolysis cell to a bioproduct, wherein the fermentation step also produces one or more fermentation byproducts which contain electrons and protons, wherein the one or more mesophilic consolidated bioprocessing organisms also anaerobically co-ferment six- and five-carbon sugars and comprise one or more cellulomonads, or one or more clostridial strains, not including Clostridium cellulolyticum ; and
in the presence of the potential, allowing a second organism comprising an electricigen cultured at a temperature not greater than 40° C. to convert substantially all the fermentation byproducts to electricity by first transferring substantially all the electrons present in the one or more fermentation byproducts to the anode electrode to produce a film which catalytically splits the electrons and the protons, wherein the electrons thereafter flow from the anode electrode towards the cathode electrode to produce the electricity, further wherein the electrons and the protons react at the cathode electrode to produce hydrogen gas.

2. The method of claim 1 wherein at least one of the one or more cellulomonads is an alcohol-tolerant cellulomonad.

3. The method of claim 1 wherein at least one of the one or more cellulomonads is Cellulomonas uda (Cuda).

4. The method of claim 3 wherein the Cuda is an alcohol tolerant strain.

5. The method of claim 1 wherein the polyol-containing product is glycerol-containing water.

6. The method of claim 1 wherein the one or more fermentation products comprise ethanol and/or 1,3-propanediol.

7. The method of claim 1 wherein the anode electrode has a buffering capacity which is adjustable through use of a buffering system.

8. The method of claim 1 wherein the cathode electrode and the anode electrode are co-located in a single chamber, wherein the single chamber further comprises a reference electrode.

9. The method of claim 8 wherein the anode electrode, the cathode electrode and the reference electrode are electronically connected to each other and to an external electric current which sets the potential between the anode electrode and the cathode electrode.

10. The method of claim 1 wherein the anode electrode is in an anode chamber and the cathode electrode is in an cathode chamber, wherein the anode chamber and cathode chamber are separated by a proton exchange membrane, wherein the anode chamber further comprises a reference electrode.

11. The method of claim 10 wherein the anode electrode, the cathode electrode and the reference electrode are electronically connected to each other via the proton exchange membrane and to an external electric current which sets the potential between the anode electrode and the cathode electrode.

12. The method of claim 11 wherein the protons in the one or more fermentation byproducts permeate the proton exchange membrane.

13. The method of claim 1 wherein at least one of the one or more clostridial strains is a clostridial-strain variant selected from an alcohol-tolerant strain, a glycerol-tolerant strain, a heat-tolerant strain and combinations thereof.

14. The method of claim 1 wherein the one or more clostridial strains are selected from Clostridium lentocellum (Clen), Acetivibrio celluloyticus, Clostridium cellobioparum (Ccel or Cce) and combinations thereof.

15. The method of claim 14 wherein the Cce is a glycerol-tolerant strain (CceG), an alcohol-tolerant strain (CceA), a heat-tolerant strain, or a combination thereof.

16. The method of claim 1 wherein the electricigen is Geobacter sulfurreducens (Gsu) or an alcohol-tolerant strain of Gsu (GsuA).

17. The method of claim 1 wherein the one or more mesophilic consolidated bioprocessing organisms and the electricigen are present in the microbial electrolysis cell as a co-culture.

18. The method of claim 17 wherein the co-culture is Cce-Gsu, CceA-GsuA or any combination thereof, with or without additional Cce.

19. The method of claim 1 wherein the microbial electrolysis cell can yield at least 80% of a theoretical maximum of ethanol.

20. The method of claim 1 further comprising connecting a computer system to the microbial electrolysis cell for monitoring and controlling fuel cell activity.

21. The method of claim 1 wherein the bioproduct comprises a biofuel.

22. The method of claim 1 wherein the fermentation byproducts include acetate, formate and/or lactate.

Assignees

• Univ Michigan State

Inventors

• Reguera Gemma
• Speers Allison M
• Young Jenna M
• Awate Bhushan

Classifications

• C12P7/08

  produced as by-product or from waste or cellulosic material substrate · CPC title

• C12P7/18

  polyhydric · CPC title

• C12P7/10

  substrate containing cellulosic material · CPC title

• C25B1/02 Primary

  Hydrogen or oxygen · CPC title

• C12P7/065 Primary

  with microorganisms other than yeasts · CPC title