Hydrogen oxygen device and method of use

Abstract

The present invention is concerned with device that is configured to be administered to the gut digestate of a ruminant animal, which device is capable of generating electrical energy from a gut digestate and / or measuring the concentration of hydrogen (H2) and / or oxygen (O2) that is present in the gut digestate. Further, the device according to the present invention may be modified to include an electrical load adjustment means (e.g. resistor, variable resistor etc) which may be used to adjust the electrical load of the device sufficient to cause the prescribed removal of H2, and in particular dissolved hydrogen (dH2), from the gut digestate. As such the device according to the present invention may be employed to adjust the amount of dH2 available to methanogenic archaea while at least not compromising animal productivity, thereby reducing the amount of methane released in the atmosphere which has an important environmental impact in terms of reducing greenhouse gas emissions.

Description

[0001] HYDROGEN OXYGEN DEVICE AND METHOD OF USE

[0002] TECHNICAL FIELD

[0003] The present invention relates to a hydrogen (H2) oxygen (O2) device, and the use of the device in heterogeneous materials containing H2 molecules and / or O2 molecules, for combining H2 and O2 molecules to form water, for generating electrical energy, and for monitoring H2 and / or O2 in heterogenous materials, for example the digestive materials from an animal gut, for example, a ruminant animal gut.

[0004] BACKGROUND OF THE INVENTION

[0005] Farmed ruminant animals are a substantial source of methane (CF ), which is a potent greenhouse gas and contributor to global climate change. There is a recognized environmental need to reduce CF emissions from farmed ruminant animals.

[0006] The CH4 from ruminant animals is produced in the gut and is called enteric CH4, which is predominantly produced by microorganisms in the foregut organs of the reticulum and rumen, sometimes called the reticulorumen, referred to herein as the rumen. Solid and liquid materials consumed by the animal passage via the mouth and oesophagus and enter the rumen and combine with the microorganisms to form a digestate. Complex plant carbohydrates introduced into the digestate by feeding are subjected to a microbiological fermentation process and molecules are biochemically transformed into metabolites, carbon dioxide (CO2), water (H2O) and energy. Key transformations include the production of molecules collectively called volatile fatty acids (VFAs), comprising predominantly acetate, propionate, and butyrate, which are absorbed through the rumen wall into the bloodstream of the animal and used as an energy source by the animal. The microorganisms in the rumen also multiply their biomass, which is passaged to gut organs anterior to the rumen, particularly the acid-secreting abomasum where they are broken down and then further disassembled into their constituent biochemicals and absorbed from the small intestine for use by the animal.

[0007] The biochemical reactions in the rumen generate and utilize hydrogen (H2), which is predominantly dissolved in the digestate and maintained at very low concentrations. The amount of dissolved hydrogen (db ) thermodynamically modulates chemical reactions in the digestate and many features of the rumen microorganism assemblage and its biochemistry.

[0008] The concentration of dH2 in the rumen is kept at low levels by removal via thermodynamic sinks for dH2, predominantly in the form of dH2 consuming microorganisms called hydrogenotrophs. Excess levels of dH2 in the rumen can detrimentally change microorganism activity, the breakdown of carbohydrates, and the proportions of VFAs produced. Ruminant animals have adapted to use methanogenic archaea, herein called methanogens, to remove excess detrimental dH2 in the rumen by the enzymic reduction of carbon dioxide (CO2) using dH2 to form methane (CH4), according to the irreversible reaction: [Equation I]

[0009] The CH4provides a volatile, non-metabolizable thermodynamic sink for dH2. The CH4, together with CO2 and other dissolved ruminal gases, partition from the digestate and accumulate in the rumen in a region called the gas cap, where they are physically emitted from the animal by a process called eructation.

[0010] However, there is an environmental need to measure and control the amount of CH4produced by a ruminant animal.

[0011] Methods being tested to reduce CH4emissions from farmed ruminant animals include the administration of methanogen inhibiters which include, for example, 3 nitrooxypropanol (3-NOP), organohalogen compounds, organonsulfur compounds and plant polyphenols.

[0012] Other methods being tested to reduce CH4emissions from farmed ruminant animals include modifying the content of feeds which are fed to animals to reduce CH4emissions.

[0013] Yet further methods being tested to reduce CH4emissions from farmed ruminant animals include modification of the rumen microbiota by selection or genetic engineering techniques to create alternative biological dH2 sinks.

[0014] However, some methods being tested to control CH4have caused H2 to be detected in the eructation gases, indicating very high dH2 levels in the digestate and in some examples more propionate and / or butyrate to be produced. The increased production of propionate can reduce animal feed intake and ultimately animal productivity.

[0015] Reducing animal productivity is detrimental to farming practices.

[0016] Accordingly, there is a need to monitor dH2 in the digestate from a ruminant animal to

[0017] (i) monitor the effects of different feeds on dH2 and the potential for reducing CH4emissions,

[0018] (ii) monitor the effect of methanogen inhibitors on dH2, and (iii) monitor the effects of alternative dH2 sinks.

[0019] There is also a need to reduce dH2 in the digestate from a ruminant animal to compete with methanogens for dH2 to reduce CH4emissions.

[0020] There is a further need to reduce dH2 in the digestate from a ruminant animal treated with methanogen inhibitors to prevent the detrimental effects of high levels of dH2.

[0021] It would also be desirable to adjust the reduction of dH2 so that the level of dH2 in the digestate can be optimised for animal health and productivity.

[0022] The present invention addresses these unmet needs through the provision of devices and methods which monitor and / or adjust the concentration of dH2, for example, in the rumen of an animal or in rumen model (e.g. culturing device) configured to detect physiological effects produced by (e.g.) animal feeds and the like.

[0023] SUMMARY OF THE INVENTION

[0024] The inventions described and claimed herein have many attributes and embodiments including, but not limited to, those set forth or described or referenced in this Summary of the Invention. It is not intended to be all inclusive and the inventions described and claimed herein are not limited to or by the features or embodiments identified in this Summary of the Invention, which is included for purposes of illustration only and not restriction.

[0025] In an aspect of the present invention there is provided a device for combining oxygen (O2) and hydrogen (H2) to form water (H2O) from at least one heterogeneous material comprising:

[0026] (i) at least one catalyst that is capable of combining O2 and H2 to form H2O;

[0027] (ii) a semi-permeable membrane which is in fluid communication with the catalyst and is selectively permeable to O2 over H2; and / or

[0028] (iii) a semi-permeable membrane which is in fluid communication with the second electrode and is selectively permeable to H2 over O2, wherein the semi-permeable membrane (ii) and / or the semi-permeable membrane (iii) is configured to contact the at least one heterogeneous material.

[0029] In another aspect of the present invention there is provided a device configured for administration to the gut of an animal which device is capable of combining oxygen (O2) and hydrogen (H2) to form water (H2O), wherein the device comprises:

[0030] (i) at least one catalyst that is capable of combining O2 and H2 to form H2O;

[0031] (ii) a semi-permeable membrane which is in fluid communication with the catalyst and is selectively permeable to O2 over H2; and / or

[0032] (iii) a semi-permeable membrane which is in fluid communication with the second electrode and is selectively permeable to H2 over O2, wherein the semi-permeable membrane (ii) and / or the semi-permeable membrane (iii) is configured to contact the digestive content of the gut of the animal.

[0033] In another aspect of the present invention there is provided a device configured for use in an in vitro model of an animal gut comprising a gut digestate which device is capable of combining oxygen (O2) and hydrogen (H2) to form water (H2O), wherein the device comprises:

[0034] (i) at least one catalyst that is capable of combining O2 and H2 to form H2O;

[0035] (ii) a semi-permeable membrane which is in fluid communication with the catalyst and is selectively permeable to O2 over H2; and / or

[0036] (iii) a semi-permeable membrane which is in fluid communication with the second electrode and is selectively permeable to H2 over O2, wherein the semi-permeable membrane (ii) and / or the semi-permeable membrane (iii) is configured to contact the gut digestate of the in vitro model of the animal gut.

[0037] In another aspect of the present invention there is provided a device for combining oxygen (O2) and hydrogen (H2) to form water (H2O) from at least one heterogeneous material which device is capable of generating electrical energy from the heterogeneous material and / or measuring the concentration of H2 or O2 that is present in the heterogeneous material, the device comprising:

[0038] (i) at least one electrochemical cell comprising a first electrode and at least one second electrode, which electrochemical cell is capable of combining O2 and hydrogen H2 to form H2O; and

[0039] (ii) at least one electrical circuit which is connected to the first and second electrodes of the electrochemical cell (i) and is capable of measuring and reporting an amount of an electrical current generated by the electrochemical cell when O2 and H2 are combined to form H2O; and

[0040] (iii) a semi-permeable membrane which is in fluid communication with the first electrode and is selectively permeable to O2 over H2; and / or

[0041] (iv) a semi-permeable membrane which is in fluid communication with the second electrode and is selectively permeable to H2 over O2, wherein the semi-permeable membrane (iii) and / or the semi-permeable membrane (iv) is configured to contact the at least one heterogeneous material, and wherein the amount of electrical current is directly proportional to the concentration of H2 and / or O2 present in the heterogeneous material, and wherein the electrical current may be used to generate electrical energy.

[0042] In another aspect of the present invention there is provided a device for combining oxygen (O2) and hydrogen (H2) to form water (H2O) in the gut digestate of an animal which device is capable of generating electrical energy from the gut digestate and / or measuring the concentration of H2 or O2 that is present in the gut digestate, the device comprising:

[0043] (i) at least one electrochemical cell comprising a first electrode and at least one second electrode, which electrochemical cell is capable of combining O2 and hydrogen H2 to form H2O; and

[0044] (ii) at least one electrical circuit which is connected to the first and second electrodes of the electrochemical cell (i) and is capable of measuring and reporting an amount of an electrical current generated by the electrochemical cell when O2 and H2 are combined to form H2O; and

[0045] (iii) a semi-permeable membrane which is in fluid communication with the first electrode and is selectively permeable to O2 over H2; and / or (iv) a semi-permeable membrane which is in fluid communication with the second electrode and is selectively permeable to H2 over O2, wherein the semi-permeable membrane (iii) and / or the semi-permeable membrane (iv) is configured to contact the gut digestate, and wherein the amount of electrical current is directly proportional to the concentration of H2 and / or O2 in the gut digestate, and wherein the electrical current may be used to generate electrical energy.

[0046] In another aspect of the present invention there is provided a device for combining oxygen (O2) and hydrogen (H2) to form water (H2O) in an in vitro model of an animal gut comprising a gut digestate which device is capable of generating electrical energy from the gut digestate and / or measuring the concentration of H2 or O2 that is present in the gut digestate, the device comprising:

[0047] (i) at least one electrochemical cell comprising a first electrode and at least one second electrode, which electrochemical cell is capable of combining O2 and hydrogen H2 to form H2O; and

[0048] (ii) at least one electrical circuit which is connected to the first and second electrodes of the electrochemical cell (i) and is capable of measuring and reporting an amount of an electrical current generated by the electrochemical cell when O2 and H2 are combined to form H2O; and

[0049] (iii) a semi-permeable membrane which is in fluid communication with the first electrode and is selectively permeable to O2 over H2; and / or

[0050] (iv) a semi-permeable membrane which is in fluid communication with the second electrode and is selectively permeable to H2 over O2. wherein the semi-permeable membrane (iii) and / or the semi-permeable membrane (iv) is configured to contact the gut digestate, and wherein the amount of electrical current is directly proportional to the concentration of H2 and / or O2 in the gut digestate, and wherein the electrical current may be used to generate electrical energy.

[0051] In another aspect of the present invention there is provided a device configured to adjust the amount of hydrogen (H2) and / or oxygen (O2) from at least one heterogenous material, the device comprising:

[0052] (i) at least one electrochemical cell comprising a first electrode and a second electrode, which electrochemical cell is capable of combining O2 and H2 to form water (H2O);

[0053] (ii) at least one electrical circuit which:

[0054] (1) is connected to the first and second electrodes of the electrochemical cell

[0055] (i); and (2) comprises an electrical load adjustment means which is capable of adjusting the load of the electrical circuit sufficient to cause adjustment in the amount of H2 and / or O2 from the at least one heterogenous material; and optionally

[0056] (3) is capable of reporting an amount of electrical current generated by the electrochemical cell when the O2 and H2 is combined to form H2O; and

[0057] (iii) a semi-permeable membrane which is in fluid communication with the first electrode and is selectively permeable to O2 over H2; and / or

[0058] (iv) a semi-permeable membrane which is in fluid communication with the second electrode and is selectively permeable to H2 over O2; and wherein the semi-permeable membrane (iii) and / or the semi-permeable membrane (iv) is configured to contact the at least one heterogeneous material, and wherein the amount of electrical current is directly proportional to the concentration of H2 and / or O2 in the at least one heterogenous material.

[0059] In another aspect of the present invention there is provided a device configured to adjust the amount of hydrogen (H2) and / or oxygen (O2) in the gut digestate of an animal, the device comprising:

[0060] (i) at least one electrochemical cell comprising a first electrode and a second electrode, which electrochemical cell is capable of combining O2 and H2 to form water (H2O); and

[0061] (ii) at least one electrical circuit which:

[0062] (a) is connected to the first and second electrodes of the electrochemical cell (i); and

[0063] (b) comprises an electrical load adjustment means which is capable of adjusting the load of the electrical circuit sufficient to cause adjustment in the amount of H2 and / or O2 from the gut digestate; and optionally

[0064] (c) is capable of reporting an amount of electrical current generated by the electrochemical cell when the O2 and H2 is combined to form H2O; and

[0065] (iii) a semi-permeable membrane which is in fluid communication with the first electrode and is selectively permeable to O2 over H2; and / or

[0066] (iv) a semi-permeable membrane which is in fluid communication with the second electrode and is selectively permeable to H2 over O2; and wherein the semi-permeable membrane (iii) and / or the semi-permeable membrane (iv) is configured to contact the gut digestate, and wherein the amount of electrical current is directly proportional to the concentration of H2 and / or O2 in the gut digestate. In another aspect of the present invention there is provided a device configured to adjust the amount of hydrogen (H2) and / or oxygen (O2) in an in vitro model of an animal gut comprising a gut digestate, the device comprising:

[0067] (i) at least one electrochemical cell comprising a first electrode and a second electrode, which electrochemical cell is capable of combining O2 and H2 to form water (H2O); and

[0068] (ii) at least one electrical circuit which:

[0069] (a) is connected to the first and second electrodes of the electrochemical cell (i); and

[0070] (b) comprises an electrical load adjustment means which is capable of adjusting the load of the electrical circuit sufficient to cause adjustment in the amount of H2 and / or O2 from the gut digestate; and optionally

[0071] (c) is capable of reporting an amount of electrical current generated by the electrochemical cell when the O2 and H2 is combined to form H2O; and

[0072] (iii) a semi-permeable membrane which is in fluid communication with the first electrode and is selectively permeable to O2 over H2; and / or

[0073] (iv) a semi-permeable membrane which is in fluid communication with the second electrode and is selectively permeable to H2 over O2; and wherein the semi-permeable membrane (iii) and / or the semi-permeable membrane (iv) is configured to contact the gut digestate, and wherein the amount of electrical current is directly proportional to the concentration of H2 and / or O2 in the gut digestate.

[0074] In another aspect of the present invention there is provided a method for generating electrical energy from at least one heterogenous material comprising oxygen (O2) and / or hydrogen (H2), the method comprising the steps of:

[0075] (i) contacting a device comprising at least one electrical circuit as described herein with a heterogenous material comprising O2 and / or H2; and

[0076] (ii) generating an electrical current in the electrical circuit of the device through a disequilibrium that exists between the concentration of O2 and the concentration of H2 at the first and second electrodes, thereby generating electrical energy from the at least one heterogenous material comprising O2 and / or H2.

[0077] In another aspect of the present invention there is provided a method for generating electrical energy in the gut digestate of an animal comprising oxygen (O2) and / or hydrogen (H2), the method comprising the steps of:

[0078] (i) administering at least one device comprising at least one electrical circuit as described herein to the gut of an animal which comprises O2 and / or H2; and (ii) generating an electrical current in the electrical circuit of the device through a disequilibrium that exists between the concentration of O2 and the concentration of H2 at the first and second electrodes, thereby generating electrical energy from the gut digestate of the animal comprising O2 and / or H2.

[0079] In another aspect of the present invention there is provided a method for generating electrical energy in an in vitro model of an animal gut comprising a gut digestate, which gut digestate comprises oxygen (O2) and / or hydrogen (H2), the method comprising the steps of:

[0080] (i) introducing a device comprising at least one electrical circuit as described herein to the gut digestate of the in vitro model;

[0081] (ii) generating an electrical current in the electrical circuit of the device through a disequilibrium that exists between the concentration of O2 and the concentration of H2 at the first and second electrodes, thereby generating electrical energy in the gut digestate of the in vitro model of the animal gut comprising O2 and / or H2.

[0082] In another aspect of the present invention there is provided a method for measuring the concentration of oxygen (O2) and / or hydrogen (H2) in at least one heterogenous material, the method comprising the steps of:

[0083] (i) contacting a device comprising at least one electrical circuit as described herein with at least one heterogenous material comprising O2 and / or H2; and

[0084] (ii) measuring an amount of electrical current generated in the electrical circuit of the device after it has been contacted with the at least one heterogenous material (i) through a disequilibrium that exists between the concentration of O2 and the concentration of H2 at the first and second electrodes; and

[0085] (iii) comparing the amount of measured electrical current (ii) against a reference standard to measure the concentration of O2 and / or H2 in the at least one heterogenous material.

[0086] In another aspect of the present invention there is provided a method for measuring the concentration of oxygen (O2) and / or hydrogen (H2) in the gut digestate of an animal, the method comprising the steps of:

[0087] (i) administering at least one device comprising at least one electrical circuit as described herein to the gut of the animal which comprises O2 and / or H2;

[0088] (ii) measuring an amount of electrical current generated in the electrical circuit of the device after it has been administered to the animal (i) through a disequilibrium that exists between the concentration of O2 and the concentration of H2 at the first and second electrodes; and (iii) comparing the amount of measured electrical current (ii) against a reference standard to measure the concentration of O2 and / or H2 in the gut digestate of the animal.

[0089] In another aspect of the present invention there is provided a method for measuring the concentration of oxygen (O2) and / or hydrogen (H2) in an in vitro model of an animal gut comprising a gut digestate, the method comprising the steps of:

[0090] (i) introducing a device comprising at least one electrical circuit as described herein to the gut digestate which comprises O2 and / or H2; and

[0091] (ii) measuring an amount of electrical current generated in the electrical circuit of the device after it has been introduced to the gut digestate (i) through a disequilibrium that exists between the concentration of O2 and the concentration of H2 at the first and second electrodes; and

[0092] (iii) comparing the amount of measured electrical current (ii) against a reference standard to measure the concentration of O2 and / or H2 in the gut digestate of the in vitro model of the animal gut.

[0093] In another aspect of the present invention there is provided a method for adjusting the concentration of oxygen (O2) and / or hydrogen (H2) in at least one heterogenous material, the method comprising the steps of:

[0094] (i) contacting a device comprising at least one electrical circuit and an electrical load adjustment means as described herein with the at least one heterogenous material comprising O2 and / or H2;

[0095] (ii) measuring an amount of electrical current generated in the electrical circuit of the device after it has been contacted with the at least one heterogenous material (i) through a disequilibrium that exists between the concentration of O2 and the concentration of H2 at the first and second electrodes;

[0096] (iii) comparing the amount of measured electrical current (iii) against a reference standard to establish the concentration of O2 and / or hydrogen H2 that exists in the at least one heterogenous material; and

[0097] (iv) adjusting the concentration of O2 and / or H2 in the heterogenous material by adjusting the electrical load of the circuit.

[0098] In another aspect of the present invention there is provided a method for adjusting the concentration of oxygen (O2) and / or hydrogen (H2) in a gut digestate of an animal, the method comprising the steps of:

[0099] (i) administering at least one device comprising at least one electrical circuit and an electrical load adjustment means as described herein to the gut of the animal; (ii) measuring an amount of electrical current generated in the electrical circuit of the device after it has been administered to the gut of the animal (i) through a disequilibrium that exists between the concentration of O2 and the concentration of H2 at the first and second electrodes;

[0100] (iii) comparing the amount of measured electrical current (ii) against a reference standard to establish the concentration of O2 and / or hydrogen H2 that exists in the gut digestate; and

[0101] (iv) adjusting the concentration of O2 and / or H2 in the gut digestate by adjusting the electrical load of the circuit.

[0102] In another aspect of the present invention there is provided a method for adjusting the concentration of oxygen (O2) and / or hydrogen (H2) in an in vitro model of an animal gut comprising a gut digestate, the method comprising the steps of:

[0103] (i) introducing a device comprising at least one electrical circuit and an electrical load adjustment means as described herein to the gut digestate;

[0104] (ii) measuring an amount of electrical current generated in the electrical circuit of the device after it has been introduced to the gut digestate (i) through a disequilibrium that exists between the concentration of O2 and the concentration of H2 at the first and second electrodes;

[0105] (iii) comparing the amount of measured electrical current (ii) against a reference standard to establish the concentration of O2 and / or hydrogen H2 that exists in the gut digestate; and

[0106] (iv) adjusting the concentration of O2 and / or H2 in the gut digestate by adjusting the electrical load of the circuit.

[0107] BRIEF DESCRIPTION OF THE FIGURES

[0108] Figure 1 depicts an overview of an exemplary device 100 according to the present invention shown in schematic transverse cross-section.

[0109] Figure 2 depicts a graph of voltage versus time trace using prototype devices described in Example 2.

[0110] Figure 3 shows an example of data from microorganism feeding and administration of methanogenesis inhibitor to an in vitro animal gut model according to the present invention. DETAILED DESCRIPTION

[0111] General Definitions

[0112] Unless specifically defined otherwise, all technical and scientific terms used herein shall be taken to have the same meaning as commonly understood by one of ordinary skill in the art to which the inventions belong (for example, in immunology, immunohistochemistry, protein chemistry, and biochemistry).

[0113] The term "and / or", e.g., "X and / or Y" shall be understood to mean either "X and Y" or "X or Y" and shall be taken to provide explicit support for both meanings or for either meaning.

[0114] The term "a" or "an" refers to one or more than one of the entity specified; for example, "a pressure adjustment means" or may refer to one or more pressure adjustment means. As such, the terms "a" or "an", "one or more" and "at least one" can be used interchangeably herein.

[0115] Throughout this specification, unless specifically stated otherwise or the context requires otherwise, reference to a single step, composition of matter, group of steps or group of compositions of matter shall be taken to encompass one and a plurality (i.e. one or more) of those steps, compositions of matter, groups of steps or group of compositions of matter.

[0116] It is intended that reference to a range of numbers disclosed herein (for example 1 to 10) also incorporates reference to all related numbers within that range (for example, 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10) and also any range of rational numbers within that range (for example 2 to 8, 1.5 to 5.5 and 3.1 to 4.7) and, therefore, all sub-ranges of all ranges expressly disclosed herein are expressly disclosed. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner.

[0117] Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0118] Those skilled in the art will appreciate that the invention described herein is amenable to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications. The invention also includes all of the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations or any two or more of said steps or features.

[0119] The present invention is not to be limited in scope by the specific embodiments described herein, which are intended for the purpose of exemplification only. Functionally equivalent products, compositions and methods are clearly within the scope of the invention, as described herein.

[0120] Any example or embodiment described herein shall be taken to apply mutatis mutandis to any other example or embodiment unless specifically stated otherwise.

[0121] Selected Definitions

[0122] The term "connected" as used herein is intended to mean a connection which is a direct connection or an indirect connection. When used in the context of (e.g.) "electrical circuit connected to the first and second electrodes" this term contemplates a connection between the electrical circuit and the first / second electrodes which is either direct or indirect.

[0123] The term "fluid communication" when used (e.g.) in the context of "semi-permeable membrane which is in fluid communication with the "electrode" is intended to mean that a path exists between the membrane and the electrode to allow fluid to diffuse substantially unobstructed from the membrane to the electrode, wherein fluid includes gas and particularly O2 and H2.

[0124] The term "gut organ" as used herein includes, but is not limited to, the foregut, hindgut, oesophagus, rumen, reticulum, pseudo-rumen, reticulo-rumen, omasum, abomasum, stomach, true stomach, caecum, small intestine, large intestine, bowel, and colon.

[0125] The term "gut content" as used herein should be understood as meaning the liquid phase and gaseous phase interior contents of a gut organ of a live or dead animal including but not limited to, a gut organ derived fluid, a gut organ derived gas, a gut organ derived liquid, a gut organ derived solid, a gut organ derived semisolid, an oesophageal sample, a sample procured from a fistula.

[0126] The term "gut content" as used herein may further comprise: microorganisms, for example, archaea, bacteria, fungi, viruses, protozoa and probiotics; organic and inorganic material, for example, fluid, liquid, gas, dissolved gas, hydrogen (H), molecular hydrogen (H2), gaseous hydrogen (gH2), dissolved hydrogen (dH2) cationic hydrogen (H+), oxygen (O), molecular oxygen (O2), gaseous oxygen (gC ), dissolved hydrogen (dH2), carbon dioxide (CO2), gaseous carbon dioxide (gCC ), dissolved carbon dioxide (dCC ), nitrogen (N), molecular nitrogen (N2), ammonia (NH3), ammonium (NH4+), hydrogen sulfide (H2S), methane (CF ), gaseous methane (gCF ), dissolved methane (dCF ) water, mineral salts, ions, bicarbonate, buffers; biomolecules, for example, amino acids, peptides, proteins, nucleic acids, carbohydrates, fatty acids, volatile fatty acids including but not limited to acetic acid, acetate, propionic acid, propionate, butyric acid, butyrate, isobutyric acid, isobutyrate, valeric acid, valerate, iso valeric acid, isovalerate, hexanoic acid, hexanoate, heptanoic acid and heptanoate, enzyme co-factors nicotinamide adenine dinucleotide (NAD), oxidised NAD (NAD+) reduced NAD (NADH), Flavin adenine dinucleotide (FAD), FAD oxidised (FAD), FAD reduced (FADH2), Flavin mononucleotide (FMN), FMN fully oxidised (FMN), FMN semiquinone (FMNH*), FMN reduced (FMNH2), all of the materials introduce into the gut including feeds, fibres, supplements, prebiotics and treatments, for example forage, pasture, grass, Gramineae, legume, Leguminosae, clover, lucerne, fodder, preserved, straw, hay, silage, baleage, brassica, herb, chicory, plantain, grains, oats, barley, maize; and feed supplements, drug, inhibitor, methanogenesis inhibitor, organohalogen, haloform, chloroform, bromoform, iodoform, seaweed, Asparagopsis sp., Asparagopsis extract, Asparagopsis matter, polyphenols, alliin, iso-alliin, allicin, Mootral™, garlic extract, garlic matter, 3- Nitrooxypropanol (3-NOP), Bovaer™, device, bolus, and electronic bolus.

[0127] The term gut digestate as used herein is intended to mean the digestate of an animal gut that is derived from an animal gut content or has been created synthetically (e.g.) via a bioreactor.

[0128] The term "heterogeneous material" should be understood as meaning a material comprising one or more liquid, gas or solid of two or more different type of particle comprising molecule and ion.

[0129] The term "membrane" as used herein should be understood as meaning a thin solid material including for example crystalline, semicrystalline, liquid crystalline and polymeric material, that may be organic, or inorganic, of pure composition or heterogeneous composition that can be formed to create a boundary between two volumes.

[0130] The term "methanogenesis" as used herein should be understood to mean CF production by methanogenic organisms. Example methanogenic organisms may be selected from the group consisting of: Archaea, ruminal archaea, the order Methanomicrobiales, the order Methanobacteriales, the order Methanosarcinales, the genus Methanobrevibacter, the genus Methanosphaera, the genus Methanomicrobium, the genus Methanobacterium, and the genus Methanosarcina.

[0131] The terms "permeable", "semi-permeable", "permeability", "semi-permeability" and "differential permeability" in the context of a membrane should be understood as meaning the propensity and selectivity of a membrane to permit at least one particle, comprising (e.g.) a molecule and / or an ion, to translocate through the membrane from one volume to another volume. It will be appreciated that the permeability of a membrane by a specific particle may arise from many factors selected from intrinsic properties of the membrane, geometry of the membrane, area of the membrane, thickness of the membrane, crystallinity of the membrane, polarizability of the membrane, voids in the membrane, extrinsic properties of the membrane, temperature, pressure, osmotic pressure, chemical potential, diffusivity and solubility.

[0132] The term "rumen" should be understood as meaning the foregut organs of ruminant and pseudo-ruminant animals, where the fermentation of consumed feed predominantly occurs. Specifically, "rumen" may refer to the first and largest stomach chamber, or alternatively a combination of the first and second stomach chambers in the alimentary canal of animals, including adult, juvenile, and neonate animals from the suborder Ruminantia (ruminants) including wild and domesticated animals, for example cattle, goats, sheep, bison, buffalo, yaks, deer. The term "rumen" may also refer to the first stomach chamber in the alimentary canal of animals, including adult, juvenile, and neonate animals from the suborder Tylopoda (pseudo-ruminants) including antelope, camels, alpacas, and llamas.

[0133] Invention Area

[0134] Dissolved hydrogen (dHz) in the gut of a ruminant animal is an important by-product of gut fermentation but excess dH2 is problematic i.e., it has the potential to alter microorganism breakdown of carbohydrates and the proportions of VFAs produced e.g., increased propionate due to excess dH2 appears to reduce feed intake and may be detrimental to animal productivity.

[0135] While ruminant animals have evolved to use Cl- as a sink for dH2 through methanogenic archaea, this ultimately leads to unwanted Cl- production and emissions.

[0136] Targeting methanogenic archaea using methanogen inhibitors is a possible solution but when uncontrolled it causes excessive dH2 in the digestate which exacerbates the primary problem of elevated dH2.

[0137] Despite conventionally held dogma that the rumen is anaerobic there is evidence that the gut of ruminant animals contains dissolved oxygen (dC ) i.e., aerobic microenvironments exist in the gut of ruminant animals. The Applicant has therefore conceived to use this dO2 and combine it with dH2 to form water in an electrochemical reaction in the gut of a ruminant animal. The invention may also be used in a model of an animal gut e.g., a rumen or any other environment where H2 and O2 might co-exist.

[0138] Devices

[0139] The present invention is predicated on the surprising discovery that a hydrogen fuel cell with its anode and cathode gas inlets each separately coupled to polymer membranes of different gas permeability with respect to H2 and O2 generate an electrical current when both polymer membranes contact an environment containing H2 and O2.

[0140] This unexpected finding led to the conception of a device incorporating an electrochemical cell in which the anode and / or cathode of an electrochemical cell is coupled to at least one membrane which permits the preferential permeation and diffusion of molecular oxygen (O2) and / or molecular hydrogen (H2) to an electrode surface. When the device according to the present invention is placed within a heterogenous material containing O2 and H2, the differential permeation and diffusion of gas across the membrane(s) creates a disequilibrium in terms of the concentration of O2 (e.g. at the cathode) and the concentration of H2 (e.g. at the anode) sufficient for conversion of O2 and H2 to water (H2O) according to the following reactions:

[0141] H2+ V2O2 2H2O [Equation II] which is comprised of the two half reactions:

[0142] H22H++ 2e- [Equation III]

[0143] 2H++ 2e- + V2O2 2H2O [Equation IV]

[0144] The electrons that are generated as a consequence of the oxidation of H2 at the anode may optionally be harnessed via an electrochemical circuit which is connected across the electrodes of the device so as to generate an electrical current. As such, not only does the differential diffusion of O2 and H2 from the heterogenous material across the semi-permeable membrane(s) coupled to the electrochemical cell provide a source of electrical energy that may be harnessed or stored, but the amount of electrical energy generated by the device is directly proportional to the relative concentration(s) of O2 and H2 present within the heterogenous material.

[0145] The present invention relies on the properties of semi-permeable materials that are differentially permeable to H2 and / or O2, which are configured to contact an animal digestive material and sorb H2 and / or O2 from the animal digestive material and for the sorbed H2 and / or O2 to permeate the semipermeable material and for the permeated H2 and / or O2 to diffuse or otherwise move through the semipermeable material, and then for the H2 and / or O2 to desorb from the semi-permeable material and contact the catalytic electrode of an electrochemical cell.

[0146] The semi-permeable materials of the present invention can facilitate selective permeation of H2 and / or O2 molecules through a microporous structure, comprising a network of small pores through which large molecules are separated from smaller molecules by a pressure-driven mechanism akin to filtration. Microporous materials have pores with diameters of 1-200 nm distributed along the material surface. Microporous materials can have pores as part of their intrinsic structure and can include for example natural and synthetic zeolites, and metal oxide framework (MOF) compounds. However, microporous materials generally have low selectivity for specific gases and the pore filtration models are insufficient for describing dense polymer materials where the pore diameter is less than 1 nm and their properties are affected by the thermal motion of the polymer chains. Permeation through such small pores is a molecular diffusion process and so permeability of molecules through such polymer materials is dependent on the material properties e.g., physical and chemical properties, the properties of the permeate molecules e.g., size shape and polarity, and the interactions between the polymer chains and permeate molecules.

[0147] The properties of the dissolved and gaseous molecules found in the animal digestate material have physical and chemical properties comprising kinetic diameter, being the average distance between the centre of two colliding molecules, and polarizability, being a measure of the volume of the molecular electron cloud distortion by an external electric field. Although the kinetic diameters of the ruminal gases are similar, their polarizabilities differ considerably.

[0148] The permeation of molecules through dense polymer materials has been modelled by the solution-diffusion mechanism where molecular separation is achieved by both their diffusion through the matrix of polymers and their solubility of the molecules within the material. The permeability coefficient (P, in mol / m / s / Pa) of a penetrant molecule is the product of the diffusion coefficient (D, in m2 / s) a kinetic parameter and the solubility coefficient (S, in mol / m3 / Pa) a thermodynamic parameter given by:

[0149] P = DS [Equation V]

[0150] Dense polymer materials can be classified as glassy or rubbery on account of their arrangement of polymer packing and is dependent on the glass transition temperature (Tg). Below the Tgpolymer materials are rigid and brittle due to constrained molecular motion, whereas above the Tgpolymer materials are flexible due to elastic behavior.

[0151] In rubbery materials, solubility of the permeate molecule in the polymer generally matrix dominates the molecular selectivity and generally follows Henry's law where the concentration of the permeate molecule (CD, in mol / m3) is linearly proportional to the partial pressure or fugacity (f, in Pa) via the Henry's law constant (KD) given by:

[0152] CD= KDf [Equation VI] In glassy materials, below Tg, the polymer chains are not energy minimised and exhibit inefficient packing and excess free volume in the polymer matrix. Langmuir type adsorption occurs due to the presence of microvoids. The total concentration of a sorbed molecule within a glassy material can be approximated by combining Henry's law concentration (CD) with Langmuir type adsorption (CH) in a dual-mode-sorption model given by: [Equation VII]

[0153] Where CH is the Langmuir relationship, C'H is the maximum adsorption capacity and b is the ratio of rate constants for adsorption and desorption.

[0154] The maximum adsorption capacity is linked to the proportion and distribution of the free volume elements not occupied by polymer chains. Typically, the occupied volume is estimated as the van der Waals volume multiplied by 1.3, based on the packing and density of a molecular crystal at 0° K. The concept quantifies the disruption in polymer chain packing by the fractional free volume (FFV) by the expressions:

[0155] Vf= Vsp- 1.3Vw[Equation VIII] [Equation IX]

[0156] Where Vf is the free volume, Vspis the specific volume and Vw is the specific van der Waals volume.

[0157] Semipermeable materials suitable for the present invention have attributes that include a FFV sufficient for the task of permeating H2 and / or O2 and include for example fluoropolymers, which have the advantage of high chemical stability, resistance to biofouling and include for example dense polymers with FFV > 0.1 and include for example polymers of intrinsic microporosity (PIM), fluoropolymers, fluorinated ethylene polypropylene (FEP), perfluoroalkoxy polymer (PFA), polytetrafluoroethylene (PTFE, Teflon®), ethylenetetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE, CTFE, Kel-F®), ethylenechlorotrifluoroethylene (ECTFE, Halar®), 2,2-bis-trifluoromethyl-4,5-difluoro-l ,3- dioxide and PTFE copolymer, and amorphous fluoropolymer Teflon® AF, Teflon® AF1600, Teflon® AF2400, Aciplex F, Aciplex S, Algoflon D60, Aquivion E87-03, Aquivion E87-12S, Flemion S, Hyflon AD60, Hyflon AD80, Nation 112, Nation 117 perfluoro polyvinylether sulphonate, Perfluorosulfonic acid (PFSA), poly a, trifluorostyrene, perfluoro polyvinylether sulphonate, expanded (microporous) polytetrafluoroethylene (e-PTFE) matrix, amorphous perfluorinated copolymers of tetrafluoroethylene (TFE) and 2,2,4-trifluoro-5- trifluoromethoxy-l,3-dioxole (TTD), Polytetrafluoroethylene (PTFE), perflourinated carboxylic acid, perfluorinated polyvinylether sulphonate.

[0158] In an aspect of the present invention there is provided a device configured to be administered to the gut of an animal comprising a gut digestate, which device is capable of generating electrical energy from the gut digestate and / or measuring the concentration of H2 and / or O2 that is present in the gut digestate, the device comprising:

[0159] (i) at least one electrochemical cell comprising a first electrode and a second electrode, which electrochemical cell is capable of combining O2 and hydrogen H2 to form water (H2O);

[0160] (ii) at least one electrical circuit which is connected to the first and second electrodes of the electrochemical cell (i) and is capable of housing and reporting an amount of an electrical current generated by the electrochemical cell when O2 and H2 is combined to form H2O;

[0161] (iii) a semi-permeable membrane which is in fluid communication with the first electrode and is selectively permeable to O2 over H2; and / or

[0162] (iv) a semi-permeable membrane which is in fluid communication with the second electrode and is selectively permeable to H2 over O2, wherein the semi-permeable membrane (iii) and / or the semi-permeable membrane (iv) is configured to contact the gut digestate, and wherein the amount of electrical current is directly proportional to the concentration of H2 and / or O2.

[0163] In another aspect of the present invention the devices described herein are configured to be introduced to an in vitro model of an animal gut comprising a gut digestate, which device is capable of generating electrical energy from the gut digestate and / or measuring the concentration of hydrogen (H2) and / or oxygen (O2) that is present in the gut digestate.

[0164] In an example according to these and other aspects of the present invention, the devices described herein are configured for inclusion in an in vitro model of an animal gut, such as the culturing device described in WO 2024 / 177514 the disclosure of which is incorporated herein by reference.

[0165] In an example according to the devices and methods of the present invention, the semi- permeable membrane(s) is intended to separate the catalytic electrodes of at least one electrochemical cell from at least one heterogeneous material when the device is in fluid communication with the at least one heterogenous material.

[0166] In another example according to the devices and methods of the present invention, the first electrode is comparatively depleted of H2 and comparatively enriched with O2, whereas the second electrode is comparatively enriched with H2 and comparatively depleted of O2 thereby creating a thermodynamic disequilibrium across both electrodes. When the first and second electrodes are connected to an electrical circuit the disequilibrium permits the H2 to be chemically oxidized (e.g. at second electrode) and O2 to be chemically reduced (e.g. at the first electrode) thereby allowing electrical energy to be generated. The comparative enrichment of H2 and depletion of O2 at one electrode and the comparative enrichment of O2 and depletion of H2 at the opposing electrode is caused by one or more differences including:

[0167] (1) differences in the composition of semi-permeable membranes wherein one membrane composition has a greater permeability to H2 and / or O2 compared to a different membrane composition with a lesser permeability to H2 and / or O2;

[0168] (2) differences in the surface area of semi-permeable membranes contacting the heterogeneous material wherein a membrane with larger surface area permits greater permeation of H2 and / or O2 compared to a membrane with a smaller surface area;

[0169] (3) differences in the cross-sectional thicknesses of semi-permeable membranes wherein a membrane with a smaller cross-sectional thickness permits greater permeation of H2 and / or O2 compared to a membrane with a larger cross-sectional thickness;

[0170] (4) differences in the pressure applied to semi-permeable membranes wherein a membrane with a greater applied pressure causes a greater permeation of H2 and / or O2 compared a membrane with a lesser applied pressure; and

[0171] (5) differences in the amounts of H2 and / or O2 contacting the membranes wherein a membrane contacting a larger amount of H2 and / or O2 will cause greater permeation of H2 and / or O2 compared to a different membrane, wherein such differences may occur due to concentration gradients of H2 and / or O2 in the heterogeneous material.

[0172] In another example according to the devices and methods of the present invention, the electrical energy is selected from current, amperes, potential difference, Volts, power and Watts.

[0173] In another example according to the devices and methods of the present invention, the heterogeneous material is selected from fluidic material, gaseous material, liquid material, solid material, fermentation material, gastrointestinal material, faecal material, plant material, animal material, decomposing material, compost, hydrothermal material, geological material, and volcanic material.

[0174] In another example according to the devices and methods of the present invention, the electrochemical cell is selected from a fuel cell, a proton exchange fuel cell, a hydrogen fuel cell, a hydrogen electrode, an oxygen electrode, an anode and a cathode.

[0175] In another example according to the devices and methods of the present invention, the electrical circuit is selected from an analog circuit, a digital circuit, a logic circuit, an integrated circuit, a clock circuit, a microprocessor circuit, a communication circuit, a bus circuit, a sensor circuit, a pressure sensor circuit, a temperature sensor circuit, an actuator controller circuit, a regulator circuit, a power regulator circuit, a temperature regulator circuit, a transmitter circuit, a radio frequency circuit, a radio frequency identification (RFID) circuit, a receiver circuit, a transceiver circuit.

[0176] In another example according to the devices and methods of the present invention, the electrical circuit contains electronic components selected from a conductor, an inductor, a variable inductor, a regulator, a resistor, a variable resistor, a capacitor, a variable capacitor, a diode, a light emitting diode, a photodiode, a transistor, an actuator, a valve, a sensor, a pressure sensor and a temperature sensor.

[0177] In another example according to the devices and methods of the present invention, the semi-permeable membrane comprises a geometry selected from a tube, a capillary, a conduit, a hose, a pipe and a sheet.

[0178] In another example according to the devices and methods of the present invention, the semi-permeable membrane comprises a composition selected from a polymer, a natural polymer, a synthetic polymer, a copolymer, a blended polymer, an acrylic styrene acrylonitrile, an acrylonitrile butadiene styrene, cellulose acetate, ethyl cellulose, ethylene vinyl alcohol, polyalylsiloxane, polyamide, polydimethylsiloxane, polybenzimidazole, polybenzoxazole, polycarbonate, polychloroprene, polylactic acid, polypropylene, polyetherimide, polyethylene high density, polyethylene low density, polyethylene terephthalate, polyethyl methacrylate, polyimide, polyisoprene, polynorbonene, polyolefin, polymethyl methacrylate, polymethyl pentene, polyphenyleneoxide, polystyrene, polysulfone, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, fluoropolymer, fluorinated ethylene polypropylene (FEP), perfluoroalkoxy polymer (PFA), polytetrafluoroethylene (PTFE, Teflon®), ethylenetetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE, CTFE, Kel- F®), ethylenechlorotrifluoroethylene (ECTFE, Halar®), 2,2-bis-trifluoromethyl-4,5-difluoro- 1 ,3-dioxide and PTFE copolymer (amorphous fluoropolymer (Teflon® AF)), ceramic, silica, zeolite, aluminosilicate, metalorganic framework, perovskite, palladium, palladium alloy, palladium silver alloy.

[0179] In another example according to the devices and methods of the present invention, the semi-permeable membrane comprises fluorinated ethylene polypropylene (FEP).

[0180] In another example according to the devices and methods of the present invention, the semi-permeable membrane comprises a perfluoroalkoxy polymer (PFA).

[0181] In another example according to the devices and methods of the present invention, the first semi-permeable membrane comprises FEP and / or the second semi-permeable membrane comprises PFA.

[0182] In another example according to the devices and methods of the present invention, the first semi-permeable membrane comprises FEP and the second semi-permeable membrane comprises PFA. In another example according to the devices and methods of the present invention, the hydrogen is selected from gaseous hydrogen (H2) and dissolved hydrogen (dHz).

[0183] In another example according to the devices and methods of the present invention, the oxygen molecule is selected from gaseous oxygen (O2) and dissolved oxygen (dC ).

[0184] By way of illustration only, Figure 1 depicts an overview of an exemplary device according to the present invention 100 shown in schematic transverse cross-section. The device 100 is configured to generate electrical energy in heterogeneous material 101 comprising a mixture including H2 102 and O2 103.

[0185] In some examples, the heterogeneous material 101 may be any fluid, a liquid, a gas, or a combination thereof, that contains at least one H2 molecule 102 and at least one O2 molecule 103. The heterogeneous material 101 may be manufactured or occur by natural processes. The heterogeneous material 101 may include material from any environment containing H2 102 and O2 103. The heterogeneous material 101 may contain various proportions of H2 102 and / or O2 103, which levels of may be static, or changing, or manipulated by adjustment, or occur naturally and manifest as chemical gradients of H2 102 and / or O2 103.

[0186] In some examples, the heterogeneous material 101 may have H2 102 and / or O2 103 present in trace or undetectable amounts and the function of the device 100 to generate electrical energy is contingent the presence of the H2 102 and / or O2 103 reaching a threshold level.

[0187] In some examples, the heterogeneous material 101 may include part of the atmosphere or hydrosphere at any elevation or depth.

[0188] In some examples, the heterogeneous material 101 may be static, moving, turbulent, laminar flow, pressurized, or de-pressurized.

[0189] In some examples, the heterogeneous material 101 may include a material from an animal including man selected from the group comprising digestive material, excretory material, inhaled respiratory material, and exhaled respiratory material.

[0190] In some examples, the heterogeneous material 101 may include the digestive content (also referred to herein as the "gut digestate") of an animal including the content of the organs of the animal alimentary canal selected from mouth, oesophagus, omasum, abomasum, reticulum, rumen, stomach, small intestine, large intestine, ileum, duodenum, bowel, caecum, colon, rectum and anus.

[0191] In some examples, the heterogeneous material 101 may include the contents of the animal alimentary canal fluid, solid, semi-solid, liquor, liquid, vapor, faeces, gas, headspace, dissolved gas, hydrogen (H), molecular hydrogen (H2), oxygen (O), molecular oxygen (O2), carbon dioxide (CO2), nitrogen (N), molecular nitrogen (N2), hydrogen sulfide (H2S), methane (CH4), water, mineral salt, ion, bicarbonate, buffer, protein, nucleic acid, carbohydrate, fatty acid, volatile fatty acid, acetic acid, acetate, propionic acid, propionate, butyric acid, butyrate, isobutyrate, isobutyric acid, valerate, valeric acid, co-factor, flavin co-factor, co-factor F420, polyphenol, microorganism, archaea, methanogen, bacteria, mycobacterium, fungus, virus, protozoa, organic material, inorganic material, feed, food, feed supplement, forage, pasture, grass, Gramineae, legume, Leguminosae, clover, lucerne, fodder, preserved, straw, hay, silage, baleage, brassica, herb, chicory, plantain, grains, oats, barley, maize, methanogenesis inhibitor, organohalogen, haloform, chloroform (CHCI3), bromoform (CHB ), Iodoform (CHI3) seaweed, Asparagopsis sp., Asparagopsis extract, Asparagopsis matter, polyphenols, alliin, iso-alliin, allicin, Mootral™, garlic extract, garlic matter, 3-Nitrooxypropanol (3-NOP), Bovaer™, device, bolus, and electronic bolus.

[0192] In some examples, the heterogeneous material 101 may include digestive contents of an animal selected from a live animal, adult, juvenile, or neonate from the suborder Ruminantia (ruminant) including domesticated animal, cattle, goat, sheep, bison, buffalo, yak, deer, antelope, from the suborder Tylopoda (pseudo-ruminant) including camel, alpaca, and lama, from the suborder Haplorhini including monkey, ape, and human.

[0193] In some examples, the heterogeneous material 101 may be derived from an in vitro system configured for research, or for waste remediation, or for energy generation selected from the group comprising, animal model, animal gut organ model, mechanical rumen, artificial rumen, artificial gut, and a bioreactor.

[0194] In some examples, the heterogeneous material 101 may include a fluid derived from a biological process selected from fermentation, decomposition, metabolism and respiration.

[0195] In some examples, the heterogeneous material 101 may include a fluid derived from a geological process selected from a hydrothermal, geothermal, tectonic and volcanic process.

[0196] In some examples, the heterogeneous material 101 may include a fluid derived from a man-made physical or chemical process selected from combustion, propulsion, mixing, synthesis and manufacturing.

[0197] In some examples, the heterogeneous material 101 may include a preparation selected from filtering, pressurizing, depressurizing, heating, cooling, evaporation, sublimation, condensation, combusting, decanting and fractionating,

[0198] The device 100 comprises at least one membrane 104A permeable to at least one H2 molecule 102 and at least one membrane 104C permeable to at least one O2 molecule 103.

[0199] The device 100 further comprises an electrochemical cell 105 enclosed by the dashed line 105 depicted in Figure 1.

[0200] The electrochemical cell 105 comprises an electrolyte 106 and an electrode called the anode 107A and an electrode called the cathode 107C.

[0201] On the surface of the anode 107A is an anode catalyst 108A and on the surface of the cathode 107C is a cathode catalyst 108C. A void 109A provides a substantially unobstructed a path to allow H2 102 to diffuse from the membrane 104A to the anode 107A and contact the anode catalyst 108A. A void 109C provides a substantially unobstructed a path to allow O2 103 to diffuse from the membrane 104C to the cathode 107C and contact the cathode catalyst 108C. In general terms the electrochemical cell 105 comprises a composite apparatus of two halves comprising the anode half and the cathode half.

[0202] The electrochemical cell 105 is configured with an anode terminal 110A electrically connected to the anode 107A, which by convention has a negative polarity as depicted by the minus (-) symbol 111, and a cathode terminal HOC electrically connected to the cathode 107C, which by convention has a positive polarity as depicted by the plus (+) symbol 112.

[0203] The anode terminal 110A and the cathode terminal HOC are conductors that provide a path for electrical current. The anode terminal 110A and the cathode terminal HOC are both electrically connected to an electrical circuit 113 and so the electrochemical cell 105 is part of the electrical circuit 113 which permits the flow of electrical current.

[0204] In some examples H2 102 in the heterogeneous material 101 preferentially permeates the membrane 104A and is then oxidized by the removal of electrons from its molecular structure at the anode 107A by interacting with the anode catalyst 108A. A preferred example of hydrogen 102 is molecular hydrogen (H2), which can be gaseous H2 in a gaseous heterogeneous fluid 101 or can be dissolved H2 in a liquid heterogeneous fluid 101, or a combination thereof.

[0205] It will be appreciated by the skilled person that the membrane 104A being preferentially permeable to H2 102 may be preferentially impermeable to other particles in the heterogeneous fluid 101 including (e.g.) O2 103.

[0206] In some examples the O2 103 in the heterogeneous material 101 preferentially permeates the membrane 104C and then is reduced by the addition of electrons to its chemical structure at the cathode 107C by interacting with the cathode catalyst 108C. A preferred example of O2 103 is molecular oxygen (O2), which can be gaseous O2 in a gaseous heterogeneous fluid 101 or can be dissolved O2 in a liquid heterogeneous fluid 101, or a combination thereof.

[0207] It will be appreciated by the skilled person that the membrane 104C being preferentially permeable to O2 103 may be preferentially impermeable to other particles in the heterogeneous fluid 101.

[0208] In some examples, the membrane 104A and membrane 104C may both be permeable to H2 102 and to O2 103. However, differences in the permeability of membrane 104A and membrane 104C to H2 102 and to O2 103 are sufficient to exhibit preferential permeability when comparing the permeabilities of membrane 104A with membrane 104C.

[0209] In some examples, the membrane 104A and membrane 104C may be a composition selected from the group comprising polymer, natural polymer, synthetic polymer, copolymer, blended polymer, acrylic styrene acrylonitrile, acrylonitrile butadiene styrene, cellulose acetate, ethyl cellulose, ethylene vinyl alcohol, polyalylsiloxane, polyamide, polydimethylsiloxane, polybenzimidazole, polybenzoxazole, polycarbonate, polychloroprene, polylactic acid, polypropylene, polyetherimide, polyethylene high density, polyethylene low density, polyethylene terephthalate, polyethyl methacrylate, polyimide, polyisoprene, polynorbonene, polyolefin, polymethyl methacrylate, polymethyl pentene, polyphenyleneoxide, polystyrene, polysulfone, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, fluoropolymer, fluorinated ethylene polypropylene (FEP), perfluoroalkoxy polymer (PFA), polytetrafluoroethylene (PTFE, Teflon®), ethylenetetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE, CTFE, Kel-F®), ethylenechlorotrifluoroethylene (ECTFE, Halar®), 2,2-bis-trifluoromethyl-4,5-difluoro-l ,3- dioxide and PTFE copolymer (amorphous fluoropolymer (Teflon® AF)), ceramic, silica, zeolite, aluminosilicate, metalorganic framework, perovskite, palladium, palladium alloy, palladium silver alloy.

[0210] In some examples, membrane 104A and membrane 104C may be of different composition.

[0211] In some examples, membrane 104A and membrane 104C may be of the same composition.

[0212] In some examples, membrane 104A and membrane 104C may be formed into any geometry, for example, formation of a capillary, a conduit, a hose, a pipe, a tube and a sheet.

[0213] In some examples, membrane 104A and membrane 104C may be of different geometry.

[0214] In some examples, membrane 104A and membrane 104C may be of the same geometry.

[0215] In some examples, membrane 104A and membrane 104C may be adjusted to increase or reduce or otherwise optimize their differential permeability to H2 102 and / or O2 103 with adjustment of one or more physical property selected from the group comprising geometry, thickness, area, temperature.

[0216] In some examples the electrochemical cell 105 is a hydrogen fuel cell herein referred to as a fuel cell, comprising an electrolyte 106 that is configured with an anode 107A on one side of the electrolyte 106 and a cathode 107C configured on the other side of the electrolyte 106 so that the electrolyte 106 is sandwiched between the anode 107A and the cathode 107C.

[0217] In some examples, the electrolyte 106 is a polymer electrolyte membrane (PEM) sometimes called a proton exchange membrane. In some examples the electrolyte 106 is a PEM that is permeable to hydrogen ions (H+) otherwise called protons and the electrolyte 106 includes materials of composition selected from the group comprising ionomer, polymer, copolymer, doped, fluoropolymer, sulfonated fluoropolymer, NafionTM, Nation doped with cerium, Nation doped with cerium oxide, BPSH-BPS, BisAF-BPSH, sulfonated polyether ether ketone (SPEEK), SPEEK / BPO4, SPEEK / PSSA-g-PVDF, AF6SPEEK, SPEEK / NIM-SiO2, C- SPAKESD / Im-MOF-801-4, SPAES50, poly(arylene ether), poly(arylene ether sulfone), sulfonated poly (arylene ether sulfone)(SPAES), polyimide, sulfonated polyimide, polybenzimidazole (PBI), polyphenylene, sulfonated polyphenylene, polyphenylene sulfide (PPS).

[0218] In some examples, the anode 107A contains or is coated with an anode catalyst 108A that comprises a composition of material selected from metals, metal alloy, binary alloy, cobalt, copper, chromium, gold, iridium, iron, manganese, molybdenum, nickel, niobium, palladium, platinum, rhodium, ruthenium, selenium, silver, sodium, tellurium, tungsten, yttrium, zinc, non-metals, bismuth, carbon, carbon, graphene, nitrogen, oxygen, fluorine, ionomer, ion, halide, polyaromatic polymer, nanoparticle, nanotube, nanowire.

[0219] In some examples, the cathode 107C contains or is coated with a cathode catalyst 108C that comprises a composition of material selected from metals, metal alloy, binary alloy, cobalt, copper, chromium, gold, iridium, iron, manganese, molybdenum, nickel, niobium, palladium, platinum, rhodium, ruthenium, selenium, silver, sodium, tellurium, tungsten, yttrium, zinc, non-metals, bismuth, carbon, carbon, graphene, nitrogen, oxygen, fluorine, ionomer, ion, halide, polyaromatic polymer, nanoparticle, nanotube, nanowire.

[0220] In some examples, the anode 107A and the anode catalyst 108A may be identical in composition and or structure to the cathode 107C and the cathode catalyst 108C.

[0221] In some examples, the anode 107A and the anode catalyst 108A may differ in composition and or structure to the cathode 107C and the cathode catalyst 108C.

[0222] In some examples, the anode catalyst 108A loading at the anode 107A may be identical to the cathode catalyst 108C loading at the cathode 107C.

[0223] In some examples, the anode catalyst 108A loading at the anode 107A may differ from the cathode catalyst 108C loading at the cathode 107C.

[0224] In some examples, the H2 is chemically oxidized by the anode catalyst 108A at the anode 107A by the removal of electrons, which causes the formation of H+ions which then pass through the electrolyte to contact the cathode catalyst 108C. The O2 is chemically reduced by the addition of electrons and H+at the cathode catalyst 108C, which causes the formation of H2O. The electrolyte 106 permits the conduction of H+from the anode catalyst 108A to the cathode catalyst 108C, where two H+recombine with one O (i.e. 72O2) to create one molecule of H2O. Electrical connectivity between the anode catalyst 108A to the cathode catalyst 108C via the anode 107A and the cathode 107C is provided via an electrical pathway comprising anode 107A, anode terminal HOC, electrical circuitry 113, cathode terminal HOC, and cathode 107C. The space between the anode catalyst 108A and the cathode catalyst 108C is bridged by the electrolyte, which permits the conduction of H+ions. In some examples, there may be an anode space 114A between the membrane 104 anode 107A for the accumulation of permeated H2 102 which space 114A fills the void 109A for H2 102 to diffuse unobstructed from the membrane 104A to the anode 107A and contact the anode catalyst 108A.

[0225] In some examples, there may be a cathode space 114C between the membrane 105 and the cathode 107C for the accumulation of permeated O2 103 which space 114C fills the void 109C for O2 103 to diffuse unobstructed from the membrane 104C to the cathode 107C and contact the cathode catalyst 108C.

[0226] In some examples, the anode space 114A includes the lumen of a tube wherein the wall of the tube comprises the membrane 104A.

[0227] In some examples, the cathode space 114C includes the lumen of a tube wherein the wall of the tube comprises the membrane 104C.

[0228] One feature of the device 100 is the separation of the H2 102 from the O2 103 and the separation of the anode space 114A from the cathode space 114C.

[0229] In some examples, the separation of the anode space 114A from the cathode space 114C is by sealing the first membrane 102 and or the second membrane 104 against the electrolyte 106 by mechanisms selected from clamping, bonding, fusing, gluing, sealing, heat sealing, stitching, stapling, welding, ultrasonic welding.

[0230] The anode terminal 110A and the cathode terminal HOC permits the electrochemical cell 105 to be connected to electrical circuitry 113.

[0231] In some examples, the device 100 may be configured to utilise the flow of electrons created by the electrochemical cell 105 with electronic circuitry 113 selected from a conductor, a resistor, a capacitor, an inductor, a diode, a light emitting diode (LED), an analog to digital converter (ADC), an amplifier, a operational amplifier, an integrated circuit, a potentiometer, a transistor, a field effect transistor (FET), a metal oxide silicon field effect transistor (MOSFET), a power supply, a battery, a voltage regulator, a microcontroller, a microcomputer and a computer.

[0232] It will be appreciated that the electrochemical cell 105 combines H2 102 and O2 103 in stoichiometric equivalents of two H2 molecules 102 are combined with one O2 molecule 103 to create two H2O molecules so that either the H2 or the O2 may be limiting.

[0233] In some examples the heterogeneous environment 101 can be augmented by the addition of H2 102 and / or O2 103 from external sources elected from air, sparged air, compressed air, gas, sparged gas, compressed gas, electrolysis, chemical reaction and electrochemical reaction.

[0234] In some examples the permeation of O2 103 into the anode space 114A and the permeation of H2 into the cathode space 114C causes the direction of electrical current flow to be reversed. The electrical resistance of the electronic circuitry 113, sometimes called the load resistance, dictates the size of the current that can pass through the HFC electrochemical circuit and so controls or otherwise limits the electrochemical reaction of H2and O2to form

[0235] H20.

[0236] In some examples the load resistance is fixed at a specific load.

[0237] In some examples the load resistance is adjustable across a range of loads.

[0238] In some examples the load resistance is selected from less than about 1 Ohm, less than about 10 Ohms, less than about 100 Ohms, less than about 1 kiloohms, less than about 10 kiloohoms, less than about 100 kiloohms, less than about 1 Megaohms, less than about 10

[0239] Megaohms, less than about 100 Megaohms, less than about 1 Gigaohms, less than about 10

[0240] Gigaohms.

[0241] In some examples the devices and methods according to the present invention are configured for generating electrical energy.

[0242] In some examples the devices and methods according to the present invention are configured for monitoring H2and O2by measuring the flow of electrons.

[0243] In some examples the devices and methods according to the present invention are configured for monitoring H2in a heterogeneous material.

[0244] In some examples the devices and methods according to the present invention are configured for monitoring O2in a heterogeneous material.

[0245] In some examples the devices and methods according to the present invention are configured for removing H2and O2from a heterogeneous material.

[0246] In some examples the devices and methods according to the present invention are configured for removing H2from a heterogeneous material.

[0247] In some examples the devices and methods according to the present invention are configured for removing O2from a heterogeneous material.

[0248] Methods

[0249] The dH2in the gut of animals is an important metabolic intermediary in gut fermentation but excess dH2is problematic because it has the potential to alter / inhibit microorganism activity / breakdown of carbohydrates and the proportions of VFAs produced. For example, increased propionate produced due to excess dH2may act as a satiety factor and may be detrimental to animal feed intake and productivity.

[0250] While animals have evolved to use CF as a sink for dH2through methanogenic archaea, this ultimately leads to unwanted CF production / green-house gas emissions.

[0251] Targeting methanogenic archaea using methanogen inhibitors presents one possible solution but when uncontrolled it may cause excessive dH2in the digestate which is a primary issue. Despite conventionally held dogma that the gut of animals is an anaerobic environment with a large and negative oxidation reduction potential (ORP), there is evidence that the gut of ruminant animals contains dO2. The applicant has conceived that there are aerobic microenvironments that exist in the gut of ruminant animals which contain domains with comparatively elevated dO2 and where the ORP is comparatively more positive. The Applicant has conceived to use this O2, and / or to optionally augment this O2 with administered O2, to sink excess dH2 to H2O.

[0252] The present invention is therefore concerned with creating an alternative dH2 sink (H2O) within the gut rumen (or model gut rumen) by providing a catalytic device which reacts H2 with O2to produce H2O according to the irreversible reaction: [Equation II]

[0253] The device according to the present invention is particularly adapted to use within the digestate of an animal gut. In this context, the production of H2O provides a non- metabolizable thermodynamic sink for dH2 which results in reduced CPU production by ruminant animals.

[0254] The present invention provides devices and methods which addresses these unmet needs.

[0255] The device according to the present invention is also particularly adapted for use in an in vitro model of an animal gut such as (e.g.) a culturing device described in WO 2024 / 177514, the disclosure of which is incorporated herein by reference. The application of a device according to the present invention to a gut organ model of an animal may be advantageous from the point of view that the concentration of dH2 produced by existing and new animal feeds may facilitate the identification of the most suitable animal-feeds for wider farming practices (i.e. energy efficient and with reduced methane production).

[0256] For the device according to the present invention to function within the gut, O2 must be present (i.e. refer to Equation I). However, the presence of O2 in the rumen is held to be somewhat counter-intuitive for the reason that the in vitro culturing of microorganisms from the rumen, and in particular methanogens, shows them to be obligate anaerobes and requires the fastidious exclusion of O2 from the culturing material and culturing apparatus to permit their survival and growth. This has led to the prevailing view that the digestate material of the rumen is anaerobic because of the high levels of enteric CH4 emitted from the animal by eructation.

[0257] Without being bound by theory, Applicant hypothesizes that there are compartments or pockets within the digestate of a ruminant animal gut which contain O2 and may therefore be utilized in an artificially created redox reaction within the digestate of the animal gut to measure and / or modulate (e.g. reduce) the concentration of dH2 in the digestate.

[0258] The present invention therefore provides a device which may be administered to the gut of an animal (or included within a gut model of an animal such as (e.g.) a culturing device described in WO 2024 / 177514) to combine H2 and O2 to determine the concentration of dH2 and / or dO2 as reflected by the amount of electrical energy generated. Further, the device according to the present invention may also be used to adjust (e.g. decrease) the amount of dH2 and / or dO2 in the gut of the animal by providing an alternative sink for dH2 (i.e. H2O) thereby reducing the amount of dH2 in the digestate which may otherwise result in the production of CF by methanogenic archaea. In situ, the device according to the present invention would achieve the unmet environment need of preventing methanogenic archaea from utilising H2 to synthesize CF and thereby reducing CF that is released into the atmosphere by ruminant animals.

[0259] Accordingly, in yet another aspect of the present invention there is provided a method for measuring the concentration of dH2 in gut digestate of an animal, the method comprising the steps of:

[0260] (i) administering to the gut digestate of the animal at least one device comprising : a. at least one electrochemical cell comprising a first electrode and a second electrode, which electrochemical cell is capable of combining oxygen (O2) and hydrogen (H2) to form water (H2O); b. at least one electrical circuit which is connected to the first and second electrodes of the electrochemical cell (a) which electrical circuit is capable of reporting an amount of electrical current generated by the electrochemical cell when the O2 and H2 is converted to H2O; c. a semi-permeable membrane which is in fluid communication with the first electrode and is selectively permeable to O2 over H2; and / or d. a semi-permeable membrane which is in fluid communication with the second electrode and is selectively permeable to H2 over O2,

[0261] (ii) measuring an amount of electrical current generated in the electrical circuit of the device through a disequilibrium that exists between the concentration of O2 and the concentration of H2 at the first and second electrodes of the device; and

[0262] (iii) comparing the amount of measured electrical current (ii) against a reference standard to establish the concentration of dH2 that exists in the gut digestate of the animal. Where the concentration of dH2 in the gut the animal is determined to exceed a desirable threshold, it may be advantageous to adjust the level of dH2, for example through removal of dH2 from the gut digestate. The present invention contemplates such methods.

[0263] Accordingly, in another aspect of the present invention there is provided a method for removing dissolved hydrogen (dHz) in the gut digestate of an animal, the method comprising the steps of:

[0264] (i) administering to the gut digestate of an animal at least one device comprising: a. at least one electrochemical cell comprising a first electrode and a second electrode, which electrochemical cell is capable of combining oxygen (O2) and hydrogen (H2) to form water (H2O); b. at least one electrical circuit which:

[0265] (1) is connected to the first and second electrodes of the electrochemical cell (a);

[0266] (2) comprises an electrical load adjustment means which is capable of adjusting the load of the electrical circuit sufficient to cause removal of H2 and / or O2 from the at least one heterogenous material; and optionally

[0267] (3) is capable of reporting an amount of electrical current generated by the electrochemical cell when the O2 and H2 is combined to form H2O; c. a semi-permeable membrane which is in fluid communication with the first electrode and is selectively permeable to O2 over H2; and d. a semi-permeable membrane which is in fluid communication with the second electrode and is selectively permeable to H2 over O2, wherein the semi-permeable membranes (c) and (d) are configured to contact the gut digestate of the animal; and

[0268] (ii) adjusting the load of the electrical circuit via the electrical load adjustment means, thereby removing an amount of dH2 from the gut digestate of the animal.

[0269] The skilled person would appreciate that the devices according to the present invention may be used in an in vitro model of an animal gut comprising a gut digestate to determine dH2 content (e.g.) as a function of feed cycle, to interrogate existing or new animal feeds, to determine the effects of different interventions such as methanogen inhibitors, probiotic microorganisms and plant bioactives on metabolic pathways involving dH2 and / or VFAs and / or CH4. Accordingly, the present invention is further directed to the above-described methods where the electrochemical cell is included in the gut model of an animal as opposed to be being administered to an animal per se (i.e.) the equivocal methods involving the utility of a device according to the present invention in a gut model of an animal is clearly contemplated.

[0270] In another example according to the devices and methods of the present invention, the heterogeneous material from the digestive tract of an animal includes materials cultured in a bioreactor.

[0271] In an example according to the devices and methods of the present invention, the heterogeneous material from the digestive tract of an animal includes materials from the organs of the animal alimentary canal selected from the group comprising, mouth, oesophagus, omasum, abomasum, reticulum, rumen, stomach, small intestine, large intestine, ileum, duodenum, bowel, caecum, colon, rectum, anus.

[0272] In another example according to the devices and methods of the present invention, the heterogeneous material from the digestive tract of an animal includes the contents of the animal alimentary canal selected from the group comprising fluid, solid, semi-solid, liquor, liquid, vapor, faeces, gas, dissolved gas, hydrogen (H), molecular hydrogen (H2), oxygen (O), molecular oxygen (O2), carbon dioxide (CO2), nitrogen (N), molecular nitrogen (N2), hydrogen sulfide (H2S), methane (CF ), water, mineral salt, ion, bicarbonate, buffer, protein, nucleic acid, carbohydrate, fatty acid, volatile fatty acid, short chain fatty acid, acetic acid, acetate, propionic acid, propionate, butyric acid, butyrate, isobutyrate, isobutyric acid, valerate, valeric acid, co-factor, flavin co-factor, co-factor F420, polyphenol, microorganism, archaea, methanogen, bacteria, mycobacterium, fungus, virus, protozoa, organic material, inorganic material, feed, food, feed supplement, forage, pasture, grass, Gramineae, legume, Leguminosae, clover, lucerne, fodder, preserved, straw, hay, silage, baleage, brassica, herb, chicory, plantain, grains, oats, barley, maize, , methanogenesis inhibitor, enzyme inhibitor, organohalogen, haloform, chloroform (CHCI3), bromoform (CHB ), Iodoform (CHI3). seaweed, Asparagopsis sp., Asparagopsis extract, Asparagopsis matter, polyphenols, alliin, iso-alliin, allicin, Mootral™, garlic extract, garlic matter, 3-Nitrooxypropanol (3-NOP), Bovaer™, device, bolus, and electronic bolus.

[0273] In another example according to the devices and methods of the present invention, the animal is selected from the group comprising a live animal, a dead animal, an animal from the suborder Ruminantia (ruminant) including domesticated animal, cattle, goat, sheep, bison, buffalo, yak, deer, antelope, from the suborder Tylopoda (pseudo-ruminant) including camel, alpaca, and lama, from the suborder Haplorhini including monkey, ape, and human,

[0274] In another example according to the devices and methods of the present invention, the bioreactor is selected from the group comprising model animal, mechanical rumen, artificial rumen, artificial gut, and bioreactor. EXAMPLES

[0275] Example 1: Fabricating an Exemplary HFC Device

[0276] In one example, a device according to the present invention was configured using a hydrogen fuel cell (HFC) of a type typically used for educational purposes. The HFC comprised a polymer exchange membrane (PEM) of Nation 115 polymer of thickness 127 .M. On both opposing sides of the PEM was a layer of catalyst material comprising platinum (Pt) particles embedded in a carbon (C) film with a Pt loading of 1 mg / cm2on one side to form the catalytic anode electrode and a Pt loading of 3 mg / cm2on the opposing side to form the catalytic cathode electrode. Each of catalyst layers served as catalytic electrodes and each had an active area of 25 mm2and a HFC voltage generating range of ±0.9 V at 0.1A. The three- layer composite of electrode-PEM-electrode is often called a membrane electrode assembly (MEA). Adjacent to each opposing catalytic electrode face of the MEA was a sheet of carbon paper often called a gas-diffusion layer (GDL), which allows for both the diffusion of gases and conduction of electrons. Contacting each GDL was a perforated stainless-steel plate often called the bipolar plate (BP), which functions to permit the flow of gases through the perforations and to collect electrical current. Each BP may also provide connection to an electrical circuit via an electrical terminal, which on one BP was arbitrarily coloured black for the anode terminal and on the other BP coloured red for the cathode terminal. The HFC assemblage of BP-GDL-MEA-GDL-BP was encased in a sealed plastic housing that provided gas ports to permit delivery of gas to each side of the HFC. For conventional use, H2 gas was delivered to the anode side of the HFC and O2 or air containing about 20.95% O2 was delivered to the cathode side of the HFC. An electrical circuit connected to the anode and cathode terminals could be used to measure the magnitude of electrical energy produced due to the relative amounts of H2 present at the cathode side of the HFC and the relative amounts of O2 present at the cathode side of the HFC. The combining of H2 and O2 was monitored by measuring the electrical energy generated via a voltage meter electrically connected in parallel to a resistor, sometimes called a load resistor, which electrically connected the anode to the cathode terminals. In this configuration, and in the presence of H2 at the catalytic anode and O2 at the catalytic cathode, a voltage (V in units of Volts) was measured with a positive polarity. In the alternative configuration of H2 delivered to the cathode side of the HFC and O2 delivered to the anode side of the HFC the measured voltage had a negative polarity. Knowing the electrical resistance (R in units of Ohms, sometimes called the load resistance or load) of the electrical circuit permitted the electrical current (I in units of Amps) to be determined by I=V / R and the electrical power (P in units of Watts) used by the circuit to be determined by P=VI.

[0277] To construct an exemplary device according to the present invention, semi-permeable membrane materials permeable to H2 and / or O2 were configured as closed lengths of tube of a specified composition and length and connected to fluid ports of the HFC so that each catalytic electrode was separately enclosed by the tubular membrane. The tubes, herein called tubular membranes, were the type typically used for solvent delivery in liquid chromatography with cross-sectional dimensions of 1.59 mm outer diameter and 1 mm inner diameter. Example tubular membranes were made of materials that included fluoropolymer tubes of fluorinated ethylene polypropylene (FEP), perfluoroalkoxy polymer (PFA) from Altmann Analytik GmbH & Co. KG Chromatography & Lab Supplies, Munich, Germany. The connections between the tubular membranes and the ports were via gas tight seals so that each a length of tubular membrane formed a closed loop and the lumen of each tubular membrane was in fluidic communication with anode or the cathode of the HFC respectively.

[0278] For evaluation of the exemplary device of the present invention according to this Example, the tubular membrane was plumbed through the walls of a polymethyl methacrylate (PMMA, acrylic) chamber filled with a heterogeneous material comprising water which was continuously sparged with gases pumped through an aeration stone at a rate of approximately 2 L / minute.

[0279] Sparge gases included:

[0280] 1. air which contains about 0.00005% H2 and about 20.95% O2; and

[0281] 2. mixed gas from a water electrolyser, which comprises H2 and O2 gases in the stoichiometric ratio of two H2 molecules for every O2 molecule and often called HHO gas, which corresponds to 66.7% H2 and 33.3% O2.

[0282] In operation the tubular membrane contacted sparged water allowing dissolved H2 and / or dissolved O2 present in the water to contact the tubular membrane, permeate the tubular membrane wall and then enter the lumen of the tubular membrane to be fluidically transported by diffusion via the lumen of the tubular membrane to the catalytic anode and or the catalytic cathode of the HFC. The generation of electrical energy was measured at the anode terminal and the cathode terminal of the HFC by connection to electrical circuitry comprising a load resistor electrically connected to both the anode terminal and the cathode terminal, and a potential difference measuring electrical circuit placed across the resistor and recorded using analog-to-digital converter (ADC). The current through the load resister was determined using I = V / R and the power used by the load resister was determined from P = IV, where I is current in Amperes, V is the potential difference in Volts, R is the electrical resistance of the load resister in Ohms, and P is the electrical power in Watts. The temperature was contemporaneously recorded and determined to vary less than 1 °C over the course of the measurements.

[0283] Table 1 shows the measured equilibrium voltage V for a configuration of HFC with the cathode gas port open to air and 400 mm of PFA tubular membrane fitted to the anode gas port and contacting water sparged with HHO for different load resistors R, the calculated current I, and the calculated power P.

[0284] Table 1: Voltage, current and power outputs for HFC device as a function of load resistance

[0285] These data show that the power output of the exemplary HFC device according to the present invention may be modulated by adjusting the load resistance, which in turn adjusts amount of H2 and O2 combined into H2O. A load resistance of 2 kQ maximized the power output because it yielded the largest electrical power derived from the measured voltage and the electrical current, which in turn, maximizes the removal of H2 and O2 by their chemical conversion to H2O.

[0286] Accordingly, in certain examples of the devices according to the present invention, the electrical circuit comprises a resistor.

[0287] Example 2: Evaluating Exemplary HFC Device in Response to Gas Sparging Events

[0288] Figure 2, 200 is a graph showing three traces 201, 202 and 203 of the voltage 204 versus time 205 across a 2 k load resistor placed across the anode and cathode of the exemplary HFC device configuration according to the present invention.

[0289] Trace 201 was generated from a configuration of an exemplary device comprising a 300 mm length of FEP tubular membrane enclosing the catalytic anode and a 300 mm length of FEP tubular membrane enclosing the catalytic cathode.

[0290] Trace was 202 generated from a configuration of an exemplary device comprising a 300 mm length of FEP tubular membrane enclosing the catalytic anode and a 300 mm length of PFA tubular membrane enclosing the catalytic cathode. Trace 203 was generated from a configuration of an exemplary device comprising a 300 mm length of PFA tubular membrane enclosing the catalytic anode and a 300 mm length of PFA tubular membrane enclosing the catalytic cathode.

[0291] Marked on Figure 2, 200 are vertical dotted lines 206, 207, 208, 209, and 210 which indicate events as detailed herein.

[0292] Each configuration of the device described above was initially equilibrated with water sparged with air and showed an equilibrium voltage of about 0 mV in respective voltage 204 versus time 205 traces 201, 202 and 203 indicating no detectable net electrochemical conversion of H2 to H+and, subsequently, 2H++ 72O2 to H2O in the HFC. This could be attributed to the very low percentage of H2 in air and consequently a low percentage of dissolved H2 in the water with low subsequent H2 permeation though the tubular membrane enclosing the catalytic electrodes.

[0293] At the event marked 206 the sparge gas was changed to HHO

[0294] At the event marked 207 the sparge gas was changed to air.

[0295] At the event marked 208 the membranes enclosing the anode and the cathode were reversed.

[0296] At the event marked 209 the sparge gas was changed to HHO.

[0297] At the event marked 210 the sparge gas was changed to air.

[0298] These traces 201, 202, and 203 show the surprising and unexpected generation of electrical energy by combining of H2 and O2 from a heterogeneous material containing H2 and O2 using semi-permeable membranes which may be selectively permeable to H2 and O2 which membranes enclose catalytic electrodes of the HFC and which membranes contact the heterogeneous material.

[0299] In the example 201 where FEP tubular membrane enclosed both the catalytic anode and the catalytic cathode, electrical energy was detected as a transient spike in the voltage following event 206, 207, 209 and 210.

[0300] In the example 202 where FEP tubular membrane enclosed the catalytic anode and PFA tubular membrane enclosed the catalytic cathode, electrical energy was detected as a transient spike in the voltage following event 206 and 207 and surprisingly when this configuration was reversed at event 208 so that PFA tubular membrane enclosed the catalytic anode and FEP tubular membrane enclosed the catalytic cathode, electrical energy was detected as a transient spike in the voltage following event 209, which then equilibrated and generated a continuous voltage of about 16 mV until event 210.

[0301] In the example 203 where PFA tubular membrane enclosed both the catalytic anode and catalytic cathode, electrical energy was detected as a transient spike in the voltage following event 206, which then equilibrated and generated a continuous voltage of about 16 mV until event 207. When this was reversed at event 208 electrical energy was detected as a transient spike in the voltage following event 209, which then equilibrated and generated a continuous voltage of about 16 mV until event 210.

[0302] It will be appreciated that the tubular membrane length of 300 mm was shorter than the tube length in Example 1 and this accounts in part for the difference in the voltage measured across the 2k load resistor. It will also be appreciated that the catalytic cathode in Example 1 was also open to the atmosphere and not enclosed by a semi-permeable membrane of the present example.

[0303] The differences in the voltage responses shown in 201, 202, and 203 from events 206 and 207 compared to events 209 and 210 due to event 208, the reversal of the tubular membranes, may be due to number of contributing factors including but not limited to:

[0304] (1) Differences between the membranes enclosing the catalytic electrodes which contact the heterogeneous material. The selective permeabilities of different materials likely affect the rate at which different gases permeate the tubular membranes. For example, PFA is 1.58 x more permeable to H2 than FEP (Graunke et al. (2016) Sensors, 16(10): 1605). From DuPont, the manufacturer of FEP and PFA, selected gas permeabilities are provided (103 cm3 / m2x 24 h x atm). The permeability of FEP to O2 = 11.6; the permeability of FEP to H2 = 31.4; and the permeability of PFA to O2 = 6.7. Extrapolating from these data, the permeability of PFA to H2 would be 1.58 x the permeability of FEP to H2 (i.e.) 1.58 x 31.4 = 49.6. It then follows that the ratio H2 / O2 for PFA = 49.6 / 6.7 or 7.40; and the ratio H2 / O2 for FEP = 31.4 / 11.6 or 2.71. Thus, PFA appears to be far more selective for H2 over O2 than FEP, and FEP should accumulate O2 more selectively than PFA. In other words, when the HFC tubes are both or separately exposed to H2 and / or O2, the H2 will permeate PFA comparatively faster than FEP whereas O2 will permeate FEP comparatively faster than PFA. This causes the selective enrichment of H2 and O2 at the membrane enclosed catalytic electrodes causing electrical voltage to be generated. Accordingly, any differences in the membrane composition enclosing one or more catalytic electrode of an electrochemical cell according to the present invention which, when in contact with a heterogeneous material, will cause a differential presentation of H2 and / or O2 at the respective electrodes and assist in creating the disequilibrium conditions sufficient for (i) removal of H2 and O2 from the heterogeneous material by chemical transformation into H2O and consequently (ii) for electrical energy to be generated.

[0305] (2) Differences in the catalytic capacity of the catalytic electrodes of the electrochemical cell due to the loading of catalyst on the catalytic anode electrode (1 mg / cm2) versus the loading of catalyst on the catalytic cathode electrode (3 mg / cm2). The asymmetric loading of catalyst in a HFC is often used to permit the utility of air to supply the catalytic cathode electrode of the HFC with atmospheric O2 and to compensate for the relatively low percentage of O2 in air 20.95%. (3) Differences in the rates at which H2 and O2 diffuse through the heterogeneous materials and contact the semi-permeable membranes. The diffusion coefficient of H2 in H2O is over twice that of O2 in H2O (refer (e.g.) Wise & Houghton (1966) Chemical Engineering Science, 21(ll):999-1010). This means that the replacement of H2 at a semi-permeable membrane enclosing a catalytic electrode, which removes said H2 will occur faster than the replacement of O2 at a semi-permeable membrane enclosing a catalytic electrode, which removes said O2 wherein said membranes are contacting a heterogeneous material containing water and H2 and O2.

[0306] Example 3: Recording of dissolved Hydrogen (dH2) in an Animal Gut Model

[0307] Figure 3 shows an example recording 300 of the temperature, CH4, and dH2 due to the experimental administration of feed material and the methanogenesis inhibitor CHB to a gut digestate of an animal gut model inoculated with a gut digestate from a ruminant animal foregut in accordance with an in vitro model of an animal gut according to the present invention (e.g. such as that described in PCT / NZ2024 / 050013; incorporated herein by reference). Figure 3 comprises a graph 301 of the measured temperature on the upper y- axis 302 shown in degrees Celsius (°C) and the measured CH4 on the middle y-axis 303 in percentage (%). The measured dH2 on the lower y-axis 304 in milli Volts (mV) versus time on the x-axis 305 measured in hours was generated from a configuration of an exemplary device of the present invention

[0308] The plot 305 of temperature is the temperature in the gut digestate recorded by a temperature sensor located in about the mid-point of the in vitro model of an animal gut according to the present invention.

[0309] The temperature was monitored and the heat generated by the gut digestate could be distinguished from the thermal energy normally applied to liquor by the heating elements of the culturing device to maintain the temperature of the liquor at the set point of 39°C.

[0310] The plot 306 of CH4 is the output of a SGX methane sensor.

[0311] The plot 306 of dH2 is the voltage generated was generated from a configuration of an exemplary device of the present invention comprising a 300 mm length of PFA tubular membrane enclosing the catalytic anode and the catalytic cathode open to the air.

[0312] The in vitro model of an animal gut (i.e. culturing device vessel such as that described in PCT / NZ2024 / 050013) was inoculated with a culture sourced from a freshly slaughtered grass-fed ewe hogget sheep of mixed breed. After resection of the reticulorumen organ, 2.5 L the rumen content was determined to have a pH Of 6.0 and then transferred to a 5 L jug and mixed with 2.5 L of rainwater. A 0.7 L aliquot of this mixture was used to inoculate the vessel of a culturing device containing 0.8 L of rainwater pre-heated to the culturing device setpoint temperature of about 39°C. After inoculation, the culturing device was prescribed a movement algorithm so as to mimic the movement of an animal gut.

[0313] It will be appreciated that the time domains for the movement, typically seconds, are substantially smaller than the time domains culturing, typically days.

[0314] At the top of the graph 301 are bars 308 to 314, indicating daily intervals delineated by abrupt downward pointing transients in the temperature plot 305. Each bar 308 to 314 corresponds to a period of 24 hours with the temperature at the start of each period, except that the temperature transient for period 308 is not shown. These temperature transients were caused by the daily feeding protocol which first extracts a volume of liquor from the vessel and then replaces that volume of liquor with an approximately equivalent volume of feed material at room temperature. The administration of the feed material at room temperature caused the abrupt change in temperature of the liquor until such time that the culturing device had caused the liquor temperature to rise to about the setpoint temperature.

[0315] The recording shown in the graph 301 shows seven consecutive days of elapsed time, which started two complete days (48 hours) after inoculation. Each consecutive day is delineated by a single feed event and its consequential downward pointing temperature transient.

[0316] In this example, the culturing device vessel has an internal volume of about 2.0 L and is typically operated with 1.5 L of liquor and 0.5 L of headspace. A feeding event starts with a decanting of liquor. In the present example the vessel was moved to 71 degrees to extract liquor material by decanting and to retain approximately two thirds (1 L) of the liquor in the vessel. The extracted volume of liquor, typically 0.5 L or less can be subjected to asynchronous analyses and / or discarded.

[0317] It will be appreciated that any fraction of liquor may be retained or extracted by prescribing the angle of movement to decant and extract liquor. In the present example, a hydraulic retention time for feed in the vessel was set to about 3 days by the daily extraction of vessel liquor of about l / 3rd of the liquor volume (0.5 L) and replacement with an equivalent volume of feed materials (0.5 L) during feeding. Other hydraulic retention times can be specified. For example, by decanting and replacing1 / 4 of the liquor daily specifies a hydraulic retention time of 4 days.

[0318] It will be appreciated that the volume of decanted liquor may be variable and / or reduced due to the conversion of liquor materials to volatile and gaseous substances thereby decreasing the liquor volume. However, by precisely decanting the liquor to a prescribed angle of movement permits retention of a known and more precise volume of liquor.

[0319] Typical analyses of the extracted liquor include for example asynchronous measurements including for example the determination of the mass, volume, pH, Eh, dry matter (DM), and VFA content. Following the extraction of liquor, a replacement material comprising feed and buffer was administered to the vessel at a prescribed angle. In the present example the vessel was moved to -25 degrees which assists in the administration method.

[0320] The administration of feed used in the present example comprised weighing a mass 12 g of dried and cut forage plant lucerne, adding to the cut forage plant a mass of 475 g of artificial saliva, a bicarbonate-based buffer comprised of rainwater, NazHPC (26 mM), NaHCO3(117.0 mM), NaCI (8.0 mM), KCI (8.0 mM), MgCI2(0.3 mM), and CaCI2(0.2 mM). The cut forage plant and the buffer were mixed to form a slurry with a volume of about 0.5 L. Any other material to be administered to the culture was added to the forage prior to the buffer and the volume adjusted and mixed.

[0321] The slurry was then administered to the vessel and then the culturing device was prescribed the movement algorithm described above.

[0322] In the experiment CHBr3together with 1 mL of canola oil and 1g of ground oats was added to the slurry to give a final CHBr3concentration of 6 pM in the 1.5 L of liquor and administered to the culturing device during the daily feeding protocol 309, 310, 311, and 312.

[0323] From the plot 306 of CF the effect of the added CHBr3, a known potent inhibitor of methanogenesis, appears to be cumulative as can be seen with decreasing Cl-h up to an including the final day of CHBr3administration 312. The recovery of methanogenesis after CHBr3administration was ceased when no CHBr3was administered with feed on 313 and 314, was rapid as shown in the plot 306 of CF . The results from the plot 306 are mirrored in the plot 307 of the dH2which is anticipated to increase due to the reduction of methanogenesis and decrease when methanogenesis is increased.

[0324] Analysis of the extracted liquor using a calibrated pH meter showed that the culturing device maintained stable pH: 308, pH 6.4; 309, pH 6.2; 310, pH 6.0; 311, pH 6.2; 312, pH 6.3; 313, pH 6.4; 314, pH 6.5 and near to pH 6.0 of the rumen from which the inoculation was sourced.

[0325] * * *

[0326] Although the invention has been described by way of example, it should be appreciated that variations and modifications may be made without departing from the scope of the invention as defined in the claims. Furthermore, where known equivalents exist to specific features, such equivalents are incorporated as if specifically referred in this specification.

Claims

CLAIMS1. A device configured to be administered to the gut digestate of a ruminant animal, which device is capable of generating electrical energy from the gut digestate and / or measuring the concentration of hydrogen (H2) and / or oxygen (O2) that is present in the gut digestate, the device comprising :(i) at least one electrochemical cell comprising a first electrode and a second electrode, which electrochemical cell is capable of combining O2 and hydrogen H2 to form water (H2O);(ii) at least one electrical circuit which is connected to the first and second electrodes of the electrochemical cell (i) and is capable of measuring and reporting an amount of an electrical current generated by the electrochemical cell when O2 and H2 is combined to form H2O;(iii) a semi-permeable membrane which is in fluid communication with the first electrode and is selectively permeable to O2 over H2; and / or(iv) a semi-permeable membrane which is in fluid communication with the second electrode and is selectively permeable to H2 over O2, wherein the semi-permeable membrane (iii) and / or the semi-permeable membrane (iv) is configured to contact the gut digestate, and wherein the amount of electrical current is directly proportional to the concentration of H2 and / or O2, and wherein the electrical current may be used to generate electrical energy.

2. The device according to claim 1, wherein the semi-permeable membrane (iii) comprises fluorinated ethylene polypropylene (FEP).

3. The device according to claim 1 or claim 2, wherein the semi-permeable membrane (iv) comprises a perfluoroalkoxy polymer (PFA).

4. The device according to any one of claims 1 to 3, wherein the semi-permeable membrane comprises a geometry selected from a tube, a capillary, a conduit, a hose, a pipe and a sheet.

5. The device according to any one of claims 1 to 4, wherein the electrical circuit comprises one or more of a conductor, an inductor, a variable inductor, a regulator, a resistor, a variable resistor, a capacitor, a variable capacitor, a diode, a light emittingdiode, a photodiode, a transistor, an actuator, a valve, a sensor, a pressure sensor and a temperature sensor.

6. The device according to any one of claims 1 to 5, wherein the electrochemical cell is a hydrogen fuel cell.

7. The device according to any one of claims 1 to 6, wherein the H2 is dissolved hydrogen (dHz) and / or the O2 is dissolved oxygen (dC ).

8. A method for measuring the concentration of dissolved hydrogen (dH2) in the gut digestate of a ruminant animal or an in vitro model of a ruminant animal gut comprising a gut digestate, the method comprising the steps of:(i) administering to the gut digestate of the ruminant animal, or introducing to the gut digestate of the ruminant animal model, at least one device comprising: a. at least one electrochemical cell comprising a first electrode and a second electrode, which electrochemical cell is capable of combining oxygen (O2) and hydrogen (H2) to form water (H2O); and b. at least one electrical circuit which is connected to the first and second electrodes of the electrochemical cell (a) which electrical circuit is capable of reporting an amount of electrical current generated by the electrochemical cell when the O2 and H2 is combined to form H2O; and c. a semi-permeable membrane which is in fluid communication with the first electrode and is selectively permeable to O2 over H2; and d. a semi-permeable membrane which is in fluid communication with the second electrode and is selectively permeable to H2 over O2,(ii) measuring an amount of electrical current generated in the electrical circuit of the device through a disequilibrium that exists between the concentration of O2 and the concentration of H2 at the first and second electrodes of the device, respectively; and(iii) comparing the amount of measured electrical current (ii) against a reference standard to establish the concentration of dH2 that exists in the gut digestate of the ruminant animal or the gut digestate of the ruminant animal model.

9. The method according to claim 8, wherein the amount of electrical current generated by the electrochemical device is directly proportional to the concentration of H2 and / or O2 in the gut digestate and may be used to determine the concentration of the H2 and / or O2.

10. A method for removing dissolved hydrogen (dHz) from the gut digestate of a ruminant animal, the method comprising the steps of:(i) administering to the gut digestate of the ruminant animal at least one device comprising: a. at least one electrochemical cell comprising a first electrode and a second electrode, which electrochemical cell is capable of combining oxygen (O2) and hydrogen (H2) to form water (H2O); b. at least one electrical circuit which:(1) is connected to the first and second electrodes of the electrochemical cell (a); and(2) comprises an electrical load adjustment means to adjust the load of the electrical circuit sufficient to cause removal of H2 and / or O2 from the at least one heterogenous material; and optionally(3) is capable of reporting an amount of electrical current generated by the electrochemical cell when the O2 and H2 is combined to form H2O; and c. a semi-permeable membrane which is in fluid communication with the first electrode and is selectively permeable to O2 over H2; and d. a semi-permeable membrane which is in fluid communication with the second electrode and is selectively permeable to H2 over O2, wherein the semi-permeable membranes (c) and (d) are configured to contact the gut contents of the ruminant animal; and(ii) adjusting the electrical load of the electrical circuit, thereby removing an amount of dissolved H2 from the gut digestate of the ruminant animal.

11. The method according to claim 10, wherein dH2 is produced by microorganisms in the gut digestate of the ruminant animal.

12. The method according to claim 10 or claim 11, wherein removal of the dH2 from the gut digestate results in reduced methane production by the ruminant animal.

13. The method according to any one of claims 10 to 12, wherein an inhibitor of methanogenic organisms is administered with the device.

4. The method according to claim 13, wherein the inhibitor of methanogenic organisms is selected from archaea, ruminal archaea, the order Methanomicrobiales, the order Methanobacteriales, the order Methanosarcinales, the genus Methanobrevibacter, the genus Methanosphaera, the genus Methanomicrobium, the genus Methanobacterium, and the genus Methanosarcina.

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