Converting carbon dioxide into high-value chemicals

Abstract

introducing carbon dioxide into a system comprising an electrochemical cell comprising a carbon dioxide reduction catalyst and an electrolyte under conditions suitable for converting the carbon dioxide into one or more C2 compounds; and converting at least a portion of the one or more C2 compounds into one or more C2 compounds. 2+n and introducing the carbon dioxide into a second system containing the microorganism and the medium under conditions suitable for converting the carbon dioxide into one or more C compounds (n about 1 to 100). 2+n A method for preparing a value-added chemical compound by contacting a microorganism under conditions suitable for the production of the compound.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims priority to U.S. Provisional Application No. 63 / 409,548, entitled "Compositions and Methods for Conversion of Carbon Dioxide to Higher Value Chemicals," filed September 23, 2022, which is incorporated herein by reference for all purposes.

[0002] [Federally funded research and development] Not applicable.

[0003] The present disclosure relates to compositions and systems for use in carbon dioxide sequestration. More particularly, the present disclosure relates to compositions and binding systems for converting carbon dioxide into higher carbon number chemicals. [Background technology]

[0004] The synthesis of fuels, chemicals, and materials from CO2 is fundamental to human society. In the biosphere, plants and algae convert CO2 through photosynthesis into macromolecules and diverse chemicals to sustain their own growth and to supply other heterotrophic organisms. Most chemicals, materials, foods, and fuels used daily in society are derived from photosynthesis, either directly (e.g., photosynthetic organisms) or indirectly (e.g., fossil fuels and biorefineries). However, the efficiency of photosynthesis in most terrestrial plants is limited to approximately 1% due to the inefficiency of carbon conversion by RubisCO and the energy-intensive regeneration of carbon intermediates. RubisCO is an enzyme that catalyzes the first step of carbon fixation in the C3 pathway, or Calvin cycle, producing two molecules of 3-phosphoglycerate. Although successful chemical synthesis of CO2 into specific compounds (e.g., urea) on a commercial scale has been reported, the range of diverse compounds obtainable from CO2 conversion remains limited.

[0005] In light of the increasing levels of CO2 in the environment due to human activities, alternative CO2 conversion platforms are being developed. The goal of such platforms is twofold: carbon dioxide capture and commercial use of carbon dioxide. Achieving both goals would have important implications for society, as they could mitigate the extent of global climate change and / or produce high-value chemicals and their precursors from carbon dioxide, bringing about substantial change in the global economy.

[0006] Carbon conversion platforms that integrate catalytic CO2 reduction and bioconversion could be a carbon dioxide conversion platform that achieves the aforementioned goals. However, the state-of-the-art technologies available for building such platforms are limited by inefficient electron and mass transfer, low metabolic rates, and a lack of molecular building blocks. Therefore, there remains a need to identify and utilize compositions, systems, and methods for capturing and converting carbon dioxide into value-added chemicals. [Brief explanation of the drawings]

[0007] For details of process and system aspects of the present disclosure, please refer to the accompanying drawings.

[0008] [Figure 1] Schematic diagram of a carbon dioxide capture and conversion system. [Figure 2] 1 is a graph showing the results of comparing theoretical fatty acid yields when the sole carbon source of Rhodococcus jostii RHA1 is ethanol, acetate, or glucose. [Figure 3A] 1 is a graph of stimulated fatty acid biosynthesis flux at various carbon uptake rates for ethanol and acetate in a genome-scale metabolism (GSM) model of Rhodococcus josti RHA1. [Figure 3B]This figure shows that the difference between ethanol and acetate fluxes in a simulated fatty acid biosynthesis experiment was greater than 3 mmol / g DCW / h. "rxn" represents the reaction, and the number in each well represents the magnitude of the flux for the corresponding reaction. A negative sign indicates the reverse direction of the reaction. OAA is oxaloacetate, PEP is phosphoenolpyruvate, and PP is pentose phosphate. [Figure 3C] 1 is a graph showing the dry cell weight (DCW) measured for the indicated samples. [Figure 3D] 1 is a graph showing lipid content on a dry cell weight basis for the indicated samples. [Figure 3E] 1 is a graph showing carbon consumption for the indicated samples. [Figure 3F] 1 is a graph showing cellular ATP levels for the indicated samples. [Figure 3G] 1 is a graph showing the pH of the cultures for the samples shown. [Figure 3H] 1 is a graph showing intracellular NAD(P)H levels for the indicated samples. [Figure 4]Classification and comparison of complex lipid species accumulated in Rhodococcus josti RHA1 under conditions with ethanol or acetate as the sole carbon source. 1) Comparison of WT strains under ethanol and acetate conditions (WT_ethnoal vs WT_acetate), 2) Comparison of WT and AsF strains under ethanol conditions (WT_ethanol vs AsF_ethanol), 3) Comparison of WT and AsF strains under acetate conditions (WT_acetate vs AsF_acetate), and 4) Comparison of AsF strains under ethanol and acetate conditions (AsF_ethanol vs AsF_acetate). The lipid categories are indicated on the left side of each plot. TAG: triacylglycerol, FA: fatty acids and conjugates, GPE: glycerophosphoethanolamine, GPI: glycerophosphoinositol, GroG: glycerophosphoglycerol, DAG: diradicylglycerol, GroGroG: glycerophosphoglycerophosphoglycerol, FAcyl: fatty acyl, FAE: fatty ester, GPCho: glycerophosphocholine, Cer: ceramide, GSL: glycosphingolipid, GPL: glycerophospholipid, GL: glycerolipid. [Figure 5A] Schematic diagram of the lipid biosynthesis pathway from ethanol. The ACDH, sthA, and FASI genes were overexpressed using recombinant plasmids. ACDH: acetaldehyde dehydrogenase, sthA: soluble pyridine nucleotide transhydrogenase, FASI: type I fatty acid synthase. [Figure 5B] 1 is a graph showing the experimental results of lipid fermentation using a wild-type strain (WT strain) and a genetically modified (engineered) Rhodococcus josti RHA1 strain using ethanol as the sole carbon source, expressed as lipid content in dry cell weight. [Figure 5C] 1 is a graph showing carbon consumption for the indicated samples. [Figure 5D] 1 is a graph showing intracellular ATP levels for the indicated samples. [Figure 5E] 1 is a graph showing intracellular NADPH levels for the indicated samples. [Figure 6]This graph shows the change in culture media pH of the modified AsF strain when ethanol and a mixture of ethanol and acetate were used as the sole carbon source. Mix_4:1 is a mixed C2 carbon source with a molar ratio of ethanol to acetate of 4:1, and Mix_2:1 is a mixed C2 carbon source with a molar ratio of ethanol to acetate of 2:1. [Figure 7A] Schematic diagram of the integrated electrobiofuel system. SSF represents the single-stage fermentation mode, in which Rhodococcus josti RHA1 is inoculated into the system to achieve simultaneous cell growth and lipid accumulation in a single-stage process. WWC represents the whole-cell catalytic fermentation mode, in which the RHA1 strain acts as a whole-cell catalyst for lipid production while limiting cell growth. WCC fermentation was performed for 24 hours, with only the first 15 hours being concurrent with CO2 electroreduction. [Figure 7B] Graph of single-stage fermentation (SSF) mode for biomass / lipid production using wild-type Rhodococcus josti RHA1 in an integrated system. [Figure 7C] Figure 1 shows the lipid production of the wild-type and engineered strain FASI-ACDH3-sthA(AsF) in WCC mode in an integrated system. Cell density is expressed as dry cell weight, and lipid production was calculated by subtracting the initial lipid accumulation amount from the final lipid titer. [Figure 7D] 1 is a plot of the lipid production of an electric biofuel system using highly lipid-producing algae and microalgae. Summary of the Invention

[0009] Disclosed herein is a method for producing high-value chemicals, the method comprising the steps of introducing carbon dioxide into a system comprising an electrochemical cell including a carbon dioxide reduction catalyst and an electrolyte under conditions suitable for converting the carbon dioxide into one or more C2 compounds; 2+nand introducing at least a portion of the one or more C2 compounds into a second system comprising the microorganism and the medium under conditions suitable for converting the compounds to a compound (n: from about 1 to about 100).

[0010] The present specification also describes a method for converting carbon dioxide into one or more C2 compounds and a method for producing high-value chemicals comprising a microorganism, the method comprising converting carbon dioxide into one or more C2 compounds. 2+n Also disclosed is a method of contacting a C2 compound with a microorganism under conditions suitable for producing the compound. DETAILED DESCRIPTION OF THE INVENTION

[0011] Disclosed herein are compositions, methods, and systems for capturing carbon dioxide and converting the captured carbon dioxide into higher value chemicals, higher carbon atom chemicals, or precursors thereof. In one embodiment, the disclosed method includes (i) sequestering carbon dioxide, (ii) converting the carbon dioxide into two carbon atom (C2) compounds of the type disclosed herein, and (iii) converting the C2 compounds into C 2+n and introducing into a microorganism capable of converting the compound into a microbial organism, wherein n is greater than 1, alternatively n is about 1-100, alternatively n is about 1-50, alternatively n is about 1-25, alternatively n is about 1-10. A system for practicing the methods of the disclosure in one or more embodiments is shown generally in FIG.

[0012] In one or more embodiments, the methods and compositions disclosed herein are used in conjunction with a carbon dioxide capture and conversion system, referred to as a CO2-CCS. As shown in FIG. 1 , the CO2-CCS 100 of the present disclosure includes a unit 150, another unit 160, and a conduit 155. The unit 150 and the other unit 160 are in fluid communication via the conduit 155. The conduit 155 is a linkage that allows at least a portion of the output of the unit 150 to be transferred to the unit 160 in accordance with a user's instructions. The unit 160 can produce a product that is then removed from the unit 160 and processed to meet one or more user and / or process goals. In one or more embodiments, the unit 150 is fed with carbon dioxide.

[0013] In one or more embodiments, disposed within unit 150 are electrochemical cells and compositions suitable for reducing carbon dioxide to one or more C2 compounds. Several half-reactions for the reduction of carbon dioxide are shown in Equations 1-6. One or more C2 compounds can be utilized as input to unit 160. TIFF2025532829000002.tif44129

[0014] In one or more embodiments, within unit 160, one or more C2 compounds are 2+n where n is greater than or equal to about 1, alternatively about 1-100, alternatively about 1-50, alternatively about 1-25, alternatively about 1-10, alternatively 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or combinations thereof. Each of these units (150, 160) and the configurations, apparatus, and methods associated with these units and CO2-CCS are described in further detail below.

[0015] In one embodiment, the carbon dioxide used in the present disclosure can be obtained from any suitable source. Non-limiting examples of carbon dioxide sources include fossil fuel combustion, large-scale point sources such as chemical factories, direct air capture, and combinations thereof. In one or more embodiments, the carbon dioxide introduced into the CO2-CCS is supplied from one or more materials and / or devices designed to capture CO2 from any suitable source. The captured CO2 is subjected to one or more purification techniques, such as scrubbing the gas through a catalyst to remove residual hydrocarbons or other impurities that may affect the composition and / or other components of the CO2-CCS. In one or more embodiments, the captured CO2 is pressurized and / or liquefied and / or purified before being introduced into the CO2-CCS. Therefore, the CO2 introduced into the CO2-CCS will be referred to hereinafter as purified CO2.

[0016] In one or more embodiments, the purified CO2 is introduced into a unit (FIG. 1 unit 150) in which an electrochemical cell operating under conditions suitable for carbon dioxide reduction is located. In one or more embodiments, the electrochemical cell comprises a cathode section and an anode section. Without being limited by theory, in the cathode section, CO2 molecules are directly reduced to other chemicals (e.g., CO, CH3OH, and C2H4) by an electrochemical CO2 reduction reaction catalyst referred to as CO2RR. In one or more embodiments, the CO2-CCS further features a unit in which microorganisms are located that incorporates an asymmetric double-chamber configuration design for separation and bioconversion of CO2RR. In such embodiments, the unit comprises a C2 + The invention is further characterized by comprising a first chamber having one or more chambers that can be placed within a larger unit to maintain the diffusion force of the product, and a second chamber in which microbial fermentation takes place and which is larger in at least one dimension than the first chamber.

[0017] In one or more embodiments, the CO2RR comprises a transition metal such as Ag, Au, Cu, Zn, or a combination thereof. In some embodiments, the CO2RR further comprises a support material such as carbon, silica, or alumina, and at least a portion of the transition metal is bound to the surface of the support material. In one or more embodiments, the support material is porous. In one embodiment, the CO2RR catalyst comprises a supported copper catalyst, or a supported sputtered copper catalyst, or sputtered copper on a porous support (e.g., a carbon support), or a combination thereof. In other embodiments, the CO2RR catalyst comprises a nanoporous Cu catalyst, a nanoporous Cu-M catalyst, or a combination thereof, where M is a metal selected from the group consisting of Pt, Ir, Pd, Ag, Au, Rh, Ru, Zn, Sn, Ni, Fe, Re, Ga, In, Cd, Tl, Ti, and combinations thereof.

[0018] Without intending to be limited by theory, a reverse oxidation reaction (e.g., oxidation of water in an aqueous system) occurs in the anode portion of the electrochemical cell. In one or more embodiments, the cathode portion and the anode portion of the electrochemical cell coexist in the same reaction medium. In other embodiments, the cathode portion and the anode portion are separated by a membrane. Non-limiting examples of membranes suitable for use in electrochemistry include proton membranes, anion membranes, bipolar membranes, and the like.

[0019] In one or more embodiments, purified CO (e.g., CO introduced in gaseous form) is subjected to electrochemical reduction using an electrochemical cell of the type disclosed herein. CO reduction products after electrochemical reduction include, for example, C2-C3 alkanes, C2-C3 alkenes, C2-C3 alcohols, or combinations thereof. Non-limiting examples of CO reduction products include carbon monoxide (CO), formic acid (HCOOH), methanol (CH3OH), formaldehyde (HCHO), methane (CH4), ethylene (C2H4), ethanol (CH3CH2OH), acetate (C2H2O2), and the like. -), formaldehyde (HCHO), methane (CH), ethylene (C2H4), and combinations thereof. In one or more embodiments, the electrochemical reduction is - ) or a combination thereof.

[0020] In one or more embodiments, at least a portion of the C2 products (e.g., ethanol, acetate) obtained by CO2 reduction are converted to C2 products. 2n+1 The C2 product is transferred to a unit (FIG. 1, unit 160) having disposed therein a suitable medium and microorganisms capable of converting the C2 product into a product. In one embodiment, a method for transferring the C2 product includes passing the C2 product unidirectionally from unit 150 to unit 160.

[0021] In one embodiment, the suitable medium comprises one or more of the electrolyte solutions of the reactor to which the C2 product is transferred. 2n+1 Any microorganism capable of converting a C2 product into a C2 product can be used. Microorganisms suitable for use can be characterized as wild-type or engineered microorganisms that use acetyl-CoA as a central metabolite. In one embodiment, the microorganism is a bacterium, a fungus, or a yeast. In one or more embodiments, the microorganism is wild-type. Alternatively, the microorganism can convert a C2 product into one or more C2 products. 2n+1 The microorganisms are genetically engineered to more efficiently convert the product into a desired product. Genetic engineering of microorganisms to achieve one or more process and / or user goals can be carried out using any suitable technique known to those skilled in the art for microbial mutation. Non-limiting examples of microorganisms suitable for use in the present disclosure include Tetraselmis sp., Chaetoceros sp., Pseudomonas putida, Rhodococcus josti, or combinations thereof.

[0022] In one embodiment, the method of the present disclosure comprises one or more C 2+n The method comprises fermenting the mixture of C2 products with a microorganism under conditions suitable for producing the C2 products. 2+n The product is selected from the group consisting of polymers, fuels, lipids, light olefins, gluconic acid, lactic acid, malonic acid, propionic acid, tricarboxylic acid, citric acid, aconitic acid, xylonic acid, acetoin, furfural, levoglucosan, lysine, serine, threonine, 1,4 succinic acid, fumaric acid, malic acid, 2,5 furandicarboxylic acid, 3-hydroxypropionic acid, aspartic acid, glucaric acid, glutamic acid, itaconic acid, levulinic acid, 3-hydroxybutyrolactone, glycerol, sorbitol, xylitol, arabinitol, 5-hydroxymethylfurfural, ferulic acid, terpenoids, polyketides, carotenoids, polyphenols, alkaloids, and combinations thereof.

[0023] In one or more embodiments, an exemplary CO2-CCS involves electromicrobial conversion (EMC2) with C2. An efficient EMC2 system can include a four-stage design for integrating electrochemical CO2 reduction reaction (CO2RR) with microbial conversion of C2 products. The first stage can focus on electrocatalysis, where the design and selection of the electrolyzer (electrochemical cell), catalyst, and electrolyte ensure efficient electrocatalysis to C2 products promoted by CO2RR under biocompatible conditions. The electrochemical cell, catalyst, and electrolyte can be of the type disclosed herein.

[0024] The second step is the design of a chemical-biological interface to ensure that microbial conversion does not inhibit CO2RR. The third step is the design of an integrated EMC2 system to achieve efficient mass transfer of C2 products between electrocatalysis and fermentation. The fourth step is the design of microorganisms to efficiently direct C2 compounds into the microbial tricarboxylic acid (TCA) cycle and increase carbon flux to the target bioproducts. The fourth step design can achieve complete and efficient electrothermal microbial conversion of CO2. As the starting point for converting CO2 to C2 intermediates, the electrocatalyst placed in the electrochemical cell is designed to provide sufficient C2 products for microbial conversion under bioavailable conditions.

[0025] These criteria can be met, at a minimum, by the integrated design and selection of the electrolyzer, electrolyte, and catalyst. First, given the potentially high yield of C2 products, a flow electrolyzer equipped with a gas diffusion electrode (GDE) can be used for C2 production. While not intending to be limited by theory, the GDE configuration can achieve much higher current densities and C2 product contents than conventional electrocatalysis using an H-cell because the CO2 supply to the GDE is not limited.

[0026] In another exemplary embodiment, the ECM2 operates when CO is introduced into a first reactor containing a flow electrolyzer equipped with a GDE. The first reactor may further include an electrolyte (e.g., a salt solution) flowing between a first electrocatalytic reactor and a second reactor in which one or more bioconversion reactions occur. In one or more embodiments, the first and second reactors are in fluid communication with each other via a unidirectional membrane that allows transfer from the first reactor to the second reactor while restricting flow from the second reactor to the first reactor. The electrolyte used in this system is suitable for both electrocatalysis and cell culture. In one embodiment, the electrolyte is a "basal" solution containing a phosphate buffer (e.g., NaHPO + KHPO + NaCl) at a pH of approximately 7.

[0027] In one embodiment, disposed within the first reactor are one or more CORR catalysts that promote the production of C2 products, such as ethanol, acetate, or a combination thereof. The C2 products are produced by reacting the salt solution of the first reactor with the C2 products in a C 2+n and one or more microorganisms capable of converting the C2 products to C3 compounds. In one embodiment, the microorganisms are wild-type species of the microorganisms. In other embodiments, the microorganisms are capable of converting the C2 products to C4 compounds to achieve one or more user and / or process goals. 2+n The microorganisms are genetically modified to promote the production of compounds. Non-limiting examples of microorganisms suitable for use in the present disclosure include Pseudomonas putida. In one embodiment, the methods of the present disclosure involve the use of one or more C 2+n It involves fermenting a mixture of C2 products with a microorganism under conditions suitable for the production of the product.

[0028] The methods and processes disclosed herein overcome traditional barriers associated with electrocatalysis, chemical-biological interfaces, and systematic design of microorganisms, enabling efficient production of EMC2 intermediates. The soluble C2 intermediates disclosed herein facilitate rapid mass transfer, readily transition to primary metabolism, are less toxic, transport more energy and electrons, and function as superior molecular building blocks for many microorganisms. Through multi-step chemical-biological interface design, the EMC2 system achieved approximately 2- to 10-fold improvements in microbial biomass productivity compared to the C1 intermediate and hydrogen-driven routes, respectively. Alternatively, improvements of approximately 2- to 5-fold or approximately 5-fold were achieved.

[0029] In one aspect, the disclosed method functions as a multi-modular synthetic biology design capable of producing medium-chain-length PHA (polyhydroxyalkanoate), biodegradable polymers, which exhibit much higher productivity and molecular chain length than platforms based on C1 intermediates, hydrogen, or electrons.

[0030] The following aspects of the present disclosure are given by way of non-limiting example.

[0031] The first aspect involves introducing carbon dioxide into a system including an electrochemical cell including a carbon dioxide reduction catalyst and an electrolyte under conditions suitable for converting the carbon dioxide into one or more C compounds; 2+n and introducing at least a portion of the one or more C2 compounds into a second system comprising a microorganism and a medium under conditions suitable for converting the C2 compounds into a compound (n about 1 to 100).

[0032] In a second aspect, the one or more C2 compounds are ethylene (C2H4), ethanol (CH3CH2OH), acetate (C2H2O2 - ), ethylene (C2H4), or a combination thereof.

[0033] A third aspect is a method according to the first or second aspect, wherein the C2 compound comprises ethanol, acetate or a combination thereof.

[0034] A fourth aspect is the method of any of the first to third aspects, wherein the catalyst comprises Ag, Au, Cu, Zn, or a combination thereof.

[0035] A fifth aspect is the method of any of the first to fourth aspects, wherein the catalyst comprises a support material.

[0036] A sixth aspect is the method of any of the first to fifth aspects, wherein the support material is porous.

[0037] A seventh aspect is the method of any of the first to sixth aspects, wherein the catalyst comprises a supported copper catalyst.

[0038] An eighth aspect is the method of any of the first to seventh aspects, wherein the catalyst comprises a nanoporous Cu-M catalyst, where M is a metal selected from the group consisting of Pt, Ir, Pd, Ag, Au, Rh, Ru, Zn, Sn, Ni, Fe, Re, Ga, In, Cd, Tl, Ti, and combinations thereof.

[0039] A ninth aspect is the method of any of the first to eighth aspects, wherein the medium and the electrolyte are compositionally identical.

[0040] A tenth aspect is the method of any of the first to ninth aspects, wherein the microorganism is a wild-type strain.

[0041] An eleventh aspect is the method of any of the first to ninth aspects, wherein the microorganism is a mutant strain.

[0042] The 12th aspect is one or more C 2+n 12. The method of any of the first to 11 aspects, wherein the compound is selected from the group consisting of polymers, fuels, lipids, light olefins, gluconic acid, lactic acid, malonic acid, propionic acid, tricarboxylic acid, citric acid, aconitic acid, xylonic acid, acetoin, furfural, levoglucosan, lysine, serine, threonine, 1,4 succinic acid, fumaric acid, malic acid, 2,5 furandicarboxylic acid, 3-hydroxypropionic acid, aspartic acid, glucaric acid, glutamic acid, itaconic acid levulinic acid, 3-hydroxybutyrolactone, glycerol, sorbitol, xylitol, arabinitol, 5-hydroxymethylfurfural, ferulic acid, terpenoids, polyketides, carotenoids, polyphenols, alkaloids, and combinations thereof.

[0043] The 13th aspect is one or more C 2+n Aspect 12. The method of any of aspects 1 to 12, wherein the compound comprises a lipid.

[0044] A fourteenth aspect is a method for preparing a value-added chemical, the method comprising converting carbon dioxide into one or more C2 compounds and a microorganism, wherein the C2 compound is contacted with the microorganism under conditions suitable for producing the one or more C2 compounds.

[0045] A fifteenth aspect is the method of the fourteenth aspect, wherein the means for converting carbon dioxide to one or more C2 compounds is an electrochemical cell comprising a nanoporous Cu-M catalyst, where M is a metal selected from the group consisting of Pt, Ir, Pd, Ag, Au, Rh, Ru, Zn, Sn, Ni, Fe, Re, Ga, In, Cd, Tl, Ti, and combinations thereof.

[0046] A sixteenth aspect is the method of any of the fourteenth to fifteenth aspects, wherein the C2 compound comprises ethanol, acetate, or a combination thereof.

[0047] A seventeenth aspect is the method of any of the fourteenth to sixteenth aspects, wherein the microorganism comprises a bacterium.

[0048] An eighteenth aspect is the method of any of the fourteenth to seventeenth aspects, wherein the microorganism is mutated.

[0049] The 19th aspect is one or more C 2+n 19. The method of any of aspects 14 to 18, wherein the compound is selected from the group consisting of polymers, fuels, lipids, light olefins, gluconic acid, lactic acid, malonic acid, propionic acid, tricarboxylic acid, citric acid, aconitic acid, xylonic acid, acetoin, furfural, levoglucosan, lysine, serine, threonine, 1,4 succinic acid, fumaric acid, malic acid, 2,5 furandicarboxylic acid, 3-hydroxypropionic acid, aspartic acid, glucaric acid, glutamic acid, itaconic acid, levulinic acid, 3-hydroxybutyrolactone, glycerol, sorbitol, xylitol, arabinitol, 5-hydroxymethylfurfural, ferulic acid, terpenoids, polyketides, carotenoids, polyphenols, alkaloids, and combinations thereof.

[0050] The 20th aspect is one or more C 2+n The method of any of aspects 14 to 19, wherein the compound comprises a lipid. [Example]

[0051] In the following examples, RLU means relative luminescence units and RAU means relative absorbance units. All data were collected in biological triplicates. All values ​​are presented as mean ± SEM (standard error of the mean).

[0052] [Example 1] C2 compounds as precursors for lipid biosynthesis We investigated the potential limitations of oleaginous organisms in the production of electrobiofuels (EBFs). These experiments used ethanol and acetate as C2 carbon sources. Fatty acids (FAs) are lipid precursors and serve as building blocks for the synthesis of triacylglycerol, the main component of lipids used in biodiesel production, via the Kennedy pathway. Theoretical calculations suggest that the theoretical FA yield from acetate is 0.29 g FA / g acetate, which, based on the energy content of the substrates, is comparable to that of glucose (37 g FA / g glucose). The theoretical fatty acid yield from ethanol is even higher, reaching 0.62 g FAs / g ethanol based on the same calculations (Figure 2).

[0053] This comparison suggests that C2 compounds, especially ethanol, have great energy potential as feedstocks for microbial fuel production. Considering that FA biosynthesis is influenced not only by the energy content of the substrate but also by microbial specificity and metabolic processes, we further investigated the influence of C2 metabolism on FA biosynthesis.

[0054] [Example 2] We used a widely used genome-scale metabolic (GSM) model to describe metabolism under various conditions and simulate the metabolic flux of target bioproducts. To study C2 metabolism in FA biosynthesis, we used the KBase platform to build a draft GSM model for the model oleaginous bacterium Rhodococcus jostii RHA1 grown in a customized minimal medium with ethanol or acetate as the sole carbon source. The draft metabolic model consisted of 1,284 compounds and 1,328 reactions. To ensure biomass production in the specified medium, 56 reactions were added using the default gap-filling approach. Next, we performed a flux balance analysis (FBA) with FA biosynthesis as the objective function under a range of carbon uptake rates to simulate FA biosynthesis at different carbon input levels. The simulation results showed that fatty acid biosynthesis increased with increasing carbon input levels in both ethanol and acetate (see Figure 2).

[0055] Furthermore, at carbon uptake rates in the range of 15–50 mmol / g dry cell weight (DCW) / h, ethanol was able to support higher fatty acid synthesis rates compared to acetate, consistent with the theoretical prediction of higher fatty acid uptake rates from ethanol than from acetate.

[0056] To identify metabolic pathways contributing to the difference in FA biosynthesis between the two carbon sources, we compared the fluxes of all reactions in each FBA. Reactions with flux differences exceeding 3 mmol / gDCW / h were identified because this threshold was considered significant compared to most reactions with fluxes below 10 mmol / gDCW / h. Our investigations showed that when ethanol was used, acetyl-CoA was supplied by ethanol oxidation, whereas when acetate was used as the carbon input, acetyl-CoA was produced by acetate phosphorylation (Figure 3). The notable difference between these two carbon assimilation pathways is that the former generates significant amounts of reducing equivalents (e.g., NADH) that can be utilized in various biosynthetic processes, including fatty acid (FA) synthesis. In contrast, the latter does not generate reducing equivalents and consumes one ATP. Consistently, under acetate conditions, the flow of acetyl-CoA into the tricarboxylic acid (TCA) cycle increased to support the generation of reducing equivalents and ATP compared to ethanol conditions. Furthermore, ATP production by ATPase was also higher under acetate conditions than under ethanol conditions. These higher levels of energy metabolism, including the TCA cycle and oxidative phosphorylation, could explain the increased CO2 output and potentially lead to a diversion of carbon flux away from FA biosynthesis. Furthermore, acetate also led to increased carbon flux in the glyoxylate shunt and the phosphoenolpyruvate / pyruvate / oxaloacetate node. These nodes are known to be capable of utilizing acetyl-CoA obtained by FA oxidation for gluconeogenesis. This carbon flux distribution may result in a lower flux of acetyl-CoA, which enters the initial reaction of FA biosynthesis, where acetyl-CoA is converted to malonyl-CoA and then further converted to malonyl-ACP.

[0057] In contrast to acetate, flux distributions using ethanol as a carbon source showed a higher flux through the pentose phosphate (PP) pathway, which is known to provide NADPH in Rhodococcus. Furthermore, under ethanol conditions, reversible reactions in the glyoxylate cycle increased in both the forward and reverse directions, resulting in the consumption of NADH and the production of NADPH. Because FA biosynthesis requires NADPH, but not NADH, these reactions likely contributed to the increased FA biosynthesis from ethanol by providing the necessary NADPH. Meanwhile, simulation results indicated that optimal FA biosynthesis from ethanol occurs via the direct conversion of acetaldehyde to acetyl-CoA, bypassing the acetaldehyde-acetate-acetyl phosphate-acetyl-CoA pathway. This pathway requires one additional ATP consumption. Interestingly, under ethanol conditions, a significant flux from acetyl-CoA to acetyl phosphate was observed, suggesting an excess of ethanol-derived acetyl-CoA. These results suggest that enhancing the ethanol-acetaldehyde-acetyl-CoA-FA pathway may be a key factor in FA biosynthesis from ethanol. Overall, metabolic simulations suggest that ethanol, due to its high energy content, may enhance acetyl-CoA flux, increase reducing power for FA biosynthesis, and reduce carbon loss compared to acetate. To experimentally verify the potential of ethanol as a carbon source for FA biosynthesis and lipid production, we performed lipid fermentation experiments using ethanol or acetate as the sole carbon source using Rhodococcus josti RHA1 as a model bacterium. Surprisingly, at the same total carbon supply of 225 mmol / L, acetate could provide 1.162 ± 0.043 g DCW / L of RHA1 dry cell weight, while ethanol could only provide 0.830 ± 0.031 g DCW / L (Figures 3C-3H). Furthermore, the lipid content, quantified in the form of fatty acid methyl esters, was 0.241±0.013 g lipid / g DCW under acetate conditions, whereas it was only 0.194±0.002 g lipid / g DCW under ethanol conditions.This observation is in contrast to the results of theoretical calculations and metabolic simulations, which indicate the existence of metabolic factors that limit the conversion of ethanol to lipids.

[0058] To identify limiting factors, we analyzed carbon flux, ATP, and NAD(P)H levels, which are known to affect lipid biosynthesis. First, the carbon consumption rate of strain RHA1 with ethanol was significantly lower (84.4 ± 14.7 mmol / L) than with acetate (139.7 ± 15.8 mmol / L). This lower ethanol intake may limit the carbon flux into FA and lipid biosynthesis. Second, the intracellular ATP level of R. josti RHA1 was also significantly lower when ethanol was used as the sole carbon source compared with acetate. This may be due to the lower carbon intake of ethanol, which limits the level of ATP production. During ethanol fermentation, acetate appeared in the culture medium at 8.27 ± 0.71 mmol / L, and the pH was significantly lower compared to acetate fermentation. These results suggest that acetate accumulates during ethanol metabolism in Rhodococcus josti RHA1, which causes cytoplasmic acidification and further affects ATP synthase activity on the plasma membrane. In response to intracellular acidification, Rhodococcus josti RHA1 can expel protons by consuming ATP. This typical microbial response to acid stress explains the pH drop from 7.5±0.0 to 6.8±0.1 during ethanol fermentation and contributes to a decrease in intracellular ATP levels. Third, the NAD(P)H levels of Rhodococcus josti RHA1 under ethanol conditions are approximately 2.2-fold higher than those under acetate conditions, supporting ethanol assimilation in metabolic simulations and generating large amounts of reducing equivalents. Particularly interesting is the imbalance between high NAD(P)H levels and low ATP levels when ethanol is used as a carbon source. This suggests that the conversion of NAD(P)H to ATP is inefficient. This phenomenon represents a "saturation" of the respiratory chain and is probably due to cytoplasmic acidification, which affects the efficiency of electron transport.Overall, in Rhodococcus josti RHA1, ethanol promoted higher reducing power generation compared with acetate, but ethanol metabolism caused cellular acidification stress, which significantly affected carbon uptake and ATP production, and also affected lipogenesis.

[0059] [Example 3] Although the FBA simulation showed that ethanol is more favorable than acetate for FA biosynthesis, the observed difference in lipid accumulation compared to the simulation suggests that the actual metabolic flux distribution when these two C2 substrates are used may differ from the simulated scenario. Therefore, we conducted a comprehensive metabolomics study measuring both primary metabolites and complex lipid species to investigate the actual metabolic distribution when ethanol or acetate is used as the sole carbon source in Rhodococcus josti RHA1. Of the 127 primary metabolites identified in Rhodococcus josti RH1, 79 showed significant differences in levels (Abslog2(FC) > 1) between ethanol and acetate conditions. Of these 79 metabolites, 88.6% showed higher levels under ethanol compared to acetate conditions, and many of them belonged to categories such as amino acids, monosaccharides, disaccharides, and fatty acids. To visualize the pathways involved, we mapped all these differential metabolites to the metabolic pathways of R. josti RHA1 using the cellular overview tool of the BioCyc database. The results showed that these differential metabolites were mainly involved in glycolysis, the pentose phosphate pathway, trehalose biosynthesis, and the biosynthesis of nucleosides and amino acids.

[0060] The significant difference in metabolic flux distribution of primary metabolism between ethanol and acetate conditions is likely due to the acidification phenomenon observed during ethanol metabolism. First, increased trehalose concentrations, which are known to protect microorganisms from acidification stress, were observed under ethanol conditions. Second, increased nicotinamide concentrations were observed under ethanol conditions, suggesting upregulation of the nicotinamide adenine dinucleotide (NAD) salvage pathway. Furthermore, aspartate, a precursor for NAD biosynthesis, also showed significantly higher levels under ethanol conditions. These two observations suggest that the requirement for NAD increases when ethanol is used as the primary carbon source. This can be explained by the metabolic requirement for NAD during the metabolism of aldehydes and alcohols. Furthermore, upregulation of the NAD salvage pathway may increase cellular tolerance to aldehydes and acetate. Third, a broad increase in the levels of various amino acids was observed under ethanol conditions compared to acetate conditions. On the one hand, increased amino acid levels are involved in tRNA charging reactions and promote protein synthesis, which is important for acid tolerance. On the other hand, these amino acids undergo decarboxylation, consuming intracellular protons and enhancing the acid tolerance of microbial cells. Overall, these results demonstrate that primary metabolic reactions in RHA1 differ between ethanol and acetate carbon sources, highlighting a significantly increased carbon flux to primary metabolic pathways under ethanol conditions compared to acetate conditions.

[0061] On the other hand, lipid composition analysis revealed that of the 253 lipid compounds identified, 197 were significantly higher under acetate conditions, compared with only two under ethanol conditions (t-test, p<0.05). This result suggests that lipid synthesis is significantly and extensively reduced when ethanol is used as a carbon source compared to acetate. Specifically, of these 197 compounds, 86 were triradicylglycerols (TAGs), 23 were fatty acids (FAs), 3 were glycerolipids (GLs), and 1 was a fatty ester (FAE) (Figure 4). These lipid types are essential for microbial energy storage and serve as key components for biofuel production. Furthermore, levels of phospholipids, including glycerophosphoethanolamine (GPE), glycerophosphoinositol (GPI), glycerophosphoglycerol (GroG), diradicylglycerol (DAG), and glycerophospholipids (GPL), were dramatically reduced, potentially compromising cell membrane biosynthesis and structural integrity. These results indicate that lipid metabolic homeostasis is disrupted when ethanol is used as the sole carbon source, further supporting the acidifying effects of ethanol. Integrating findings from lipid composition analysis and primary metabolism revealed that ethanol supports higher metabolic fluxes in diverse primary metabolic pathways that generate energy and building blocks compared to acetate.

[0062] [Example 4] Metabolic engineering to promote lipid production from C2 compounds To improve lipid conversion from C2 substrates using genetic engineering, we performed a comparative analysis of metabolic simulations and metabolome analysis results. First, the simulations did not consider the metabolic impact of acidification stress during ethanol metabolism, which significantly increases the biosynthesis of amino acids, nucleosides, and trehalose, potentially diverting carbon flux from FA and lipid biosynthesis. Second, the simulations suggested an ethanol-acetaldehyde-acetyl-CoA ethanol assimilation pathway that does not require ATP consumption. However, in the actual scenario, significant acetate accumulation was observed when ethanol was the sole carbon source. This indicates that ethanol was rapidly oxidized to acetate and then converted to acetyl-CoA by acetyl-CoA synthase, consuming two units of ATP. Third, ethanol exhibited significantly higher reducing power than acetate. The simulations showed that although a portion of NADH was converted to NADPH, providing NADPH for FA biosynthesis, a large amount of NADH was dissipated by the reduction and excretion of iron ions, resulting in insufficient energy utilization from ethanol to FAs. Based on this comparative analysis, we investigated genetic engineering approaches to redirect carbon flux from other biosynthetic pathways to fatty acid biosynthesis, reduce acetate accumulation from ethanol oxidation, improve ATP supply, and improve the utilization of reducing power for lipid biosynthesis.Based on this comparative analysis, we investigated genetic engineering approaches to redirect carbon flux from other biosynthetic pathways to fatty acid biosynthesis, reduce acetate accumulation from ethanol oxidation, improve ATP supply, and improve the utilization of reducing power for lipid biosynthesis.

[0063] First, to reduce ATP costs and acetate accumulation during ethanol assimilation, we overexpressed the ACDH3 gene, encoding acetaldehyde dehydrogenase, to convert acetaldehyde to acetyl-CoA and avoid acetate production (Figure 5). Upregulation of this reaction competes with the rapid oxidation of acetaldehyde to acetate, generating acetyl-CoA without consuming extra ATP and alleviating acetate accumulation. Second, because Rhodococcus josti RHA1 uses NADPH instead of NADH for fatty acid biosynthesis, we simultaneously overexpressed sthA, a soluble pyridine nucleotide transhydrogenase that converts NADH to NADPH, to direct reducing power toward fatty acid biosynthesis. Coexpression of ACDH and sthA significantly improved intracellular ATP levels by 78.4% ± 25.8%. However, NADPH levels did not improve significantly. This is likely due to the relatively high NADPH levels when ethanol is used as a carbon source. Furthermore, this coexpression increased lipid content by 21.6% ± 0.7% compared to wild-type (WT) Rhodococcus josti RHA1. Meanwhile, ethanol consumption in the ACDH-sthA strain was comparable to that in the WT strain, indicating that overexpression of ACDH-sthA improved the efficiency of carbon-to-lipid conversion. Third, taking advantage of previous observations that FASI is significantly upregulated during lipid accumulation in Rhodococcus, we overexpressed the FASI gene encoding type I fatty acid synthase (FASI) to direct more carbon flux toward FA biosynthesis. FASI is a single, large, multifunctional enzyme complex capable of highly efficient fatty acid condensation and elongation. Compared to the WT strain, the FASI strain increased ethanol uptake by 45.1% ± 18.7% and lipid accumulation by 18.0% ± 4.1%. These results indicate that overexpression of FASI not only improves lipid biosynthesis but also enhances the ethanol assimilation capacity of Rhodococcus josti RHA1. Furthermore, the FASI-overexpressing strain had significantly lower levels of both ATP and NADPH compared with the wild-type strain, likely due to the intense consumption of these two factors in lipid biosynthesis.Based on these observations, we overexpressed ACDH and sthA together with FASI in the WT strain to enhance ATP and NADPH production and further promote lipid production. The ATP and NADPH levels of the ACDH-sthA-FASI (AsF) strain were significantly improved by 47.6% ± 3.5% and 48.0% ± 20%, respectively, compared with the FASI strain. At the same time, the ethanol uptake rate was also significantly improved by 27.5% ± 14.8% compared with the ACDH-sthA strain. Furthermore, the ACDH-sthA-FASI strain accumulated 33.1% ± 1.0% of the total biomass, representing a 39.4% ± 1.5% increase in lipid content compared with the WT strain. These results demonstrate that coexpression of ACDH, sthA, and FASI in Rhodococcus josti RHA1 significantly improved the carbon and energy utilization efficiency of ethanol, which is required for lipid biosynthesis.

[0064] [Example 5] To investigate whether overexpression of the ACDH-sthA-FASI strain redirects metabolic flux from other synthetic biosynthetic pathways to the lipid biosynthetic pathway, we compared the AsF and WT strains under ethanol and acetate conditions and examined the levels of primary metabolites and complex lipid species. Comparison of primary metabolism revealed that almost all primary metabolites involved in carbohydrate metabolism, amino acid biosynthesis, and nucleoside biosynthesis were reduced in the ACDH-sthA-FASI strain under ethanol and acetate conditions, indicating a significant reduction in metabolic flux distribution in these metabolisms. In particular, the high concentrations of trehalose and amino acids, which are important for WT cells to counteract acidification stress during ethanol utilization, were significantly reduced by ACDH-sthA-FASI overexpression, suggesting that the acidification stress caused by ethanol utilization was alleviated in the AsF strain. This alleviating effect of ACDH-sthA-FASI overexpression was also evident from the reduced pH decrease and acetate accumulation in the culture medium of the AsF strain compared to the WT strain. Overall, the results suggest that overexpression of ACDH-sthA-FASI significantly alleviated acidification stress and reduced carbon partitioning in energy metabolism and other synthetic pathways (Fig. 6).

[0065] To investigate whether ACDH-sthA-FASI overexpression diverged metabolic flux toward lipid biosynthesis, we also compared the levels of complex lipid species between the AsF and WT strains. First, 195 of the 253 identified lipid compounds were significantly higher in the AsF strain than in the WT strain under ethanol conditions. Notably, these 195 lipid compounds overlapped with 99.0% of the 197 lipid compounds that were significantly lower in the WT strain under ethanol conditions compared to acetate conditions. This indicates that ACDH-sthA-FASI overexpression significantly affected lipid biosynthesis and precisely diverged metabolic flux toward increased lipid production. Notably, 53.8% of the increased lipids belonged to the energy storage lipid category, including TAG, FA, GL, and FAE. Furthermore, phospholipid species such as GPE, GPI, GPL, GroG, and DAG, accounting for 32.3%, were also restored by ACDH-sthA-FASI overexpression. These increased lipid pools may have helped RHA1 cope with stress induced during ethanol assimilation. Second, under acetate conditions, the AsF strain had significantly higher levels of 35 lipid compounds compared with the WT strain, whereas the WT strain had higher levels of only 20 lipid compounds. This suggests that overexpression of ACDH-sthA-FASI improves the lipid biosynthetic ability of RHA1 when acetate is the sole carbon source. Third, when we compared the lipid species of the AsF strain under ethanol and acetate conditions, we found that 25 lipid compounds were significantly higher under ethanol conditions, whereas only five lipids were higher under acetate conditions. This result indicates that ethanol supports lipid biosynthesis more efficiently in the AsF strain, further highlighting the effect of overexpression of ACDH-sthA-FASI on improving the ability of RHA1 to utilize ethanol for lipid production. Overall, overexpression of ACDH, sthA, and FASI in strain RHA1 effectively addressed the acidification problem associated with ethanol utilization, significantly improved carbon and energy utilization from both ethanol and acetate sources, and introduced more carbon and reductive energy into lipid biosynthesis, thereby significantly enhancing lipid production.

[0066] [Example 6] Co-substrate effects in lipid synthesis guide catalyst design to tailor C2 profiles As shown in Figure 4, genetic engineering improved the ability of Rhodococcus josti RHA1 to utilize ethanol as a carbon source to produce lipids. However, the engineered strain AsF experienced acidification stress during ethanol metabolism, resulting in the accumulation of acetate. When acetate was used as the sole carbon source, an alkalizing effect was observed, with the culture medium pH increasing from 7.5 ± 0.0 to 8.7 ± 0.1. This suggests that acetate co-produced with ethanol from CO2RR may help alleviate acidification stress and further improve lipid production. We investigated the potential co-substrate effect of ethanol and acetate in bioconversion, which could be an important element in electromicrobial conversion systems using C2 as an intermediate. Specifically, we conducted lipid fermentation experiments using the engineered AsF strain using three different C2 substrate pools: ethanol alone, ethanol:acetate = 4:1 (mol:mol), and ethanol:acetate = 2:1 (mol:mol), while keeping the total molar concentration constant. The results showed that using the C2 mixture (ethanol and acetate) as a carbon source significantly increased lipid production compared to ethanol alone. At a 4:1 ethanol to acetate molar ratio, lipid titers reached 317.9 ± 20.8 mg / L, a significant 29.5% increase compared to ethanol alone. When acetate was increased to one-third of the total carbon source, lipid titers further increased to 392.7 ± 34.7 mg / L, an approximately 60.0% increase compared to ethanol alone. Notably, the AsF strain consumed similar amounts of total carbon under the three carbon source conditions, indicating that the C2 mixture (ethanol and acetate) improved carbon and energy utilization for lipid production. This increased efficiency is likely due to the co-metabolization of acetate with ethanol, which reduced acidification stress and prevented a decrease in culture pH during cell growth and lipid accumulation. These results demonstrate that cometabolism of acetate and ethanol from CO2RR improves the lipid production performance of strain RHA1 and provides guidance for the next catalyst design to tailor the C2 production profile.

[0067] [Example 7] Integrated system for rapid lipid production from CO2 To investigate direct lipid production from CO2, we prepared an EBF system consisting of a CO2-reducing metal catalyst and a microbial cell factory. This system allowed finely tuned CO2 products from a CO2 electrolyzer to be introduced into the circulation chamber of the bioreactor, from which they diffused into the fermentation chamber, supporting lipid production by the RHA1 cell factory (Figure 7). To evaluate the performance of the EBF system in CO2 conversion and lipid production, we employed two commonly used fermentation modes, namely, single-stage fermentation (SSF) mode and whole-cell catalyst (WCC) mode, to perform lipid fermentation using the RHA1 strain in an integrated system. First, in the SSF mode, Rhodococcus josti RHA1 was inoculated into the integrated system, and cell growth and lipid accumulation were performed simultaneously. This fermentation mode was designed to achieve both biomass production and lipid production from CO2 in a single step, making it a suitable approach for evaluating the performance and potential of the EBF system in CO2 conversion and biosupport. The results showed that the EBF system could perform SSF fermentation for 42 hours while maintaining stable CO2 concentrations and rapid cell growth. Specifically, the system voltage was kept constant between 5 and 6 volts, and the concentrations of ethanol and acetate continued to increase over the first 30 hours. This indicates that the metal catalyst was producing sufficient C2 substrates to support their utilization by RHA1 cells. Indeed, under these conditions, RHA1 rapidly grew in the integrated system, as evidenced by an increase in OD600 from 0.3 to 2.2. Furthermore, lipid accumulation reached 562.1 mg / L within 42 hours, corresponding to a lipid production rate of 321.1 mg / L / day, comparable to the lipid production rates reported in many studies of highly lipid-producing algae. These results demonstrate the efficient SSF performance of the EBF system and highlight its effectiveness in CO2 conversion to support the expansion of microbial cell factories.

[0068] In contrast to the SSF mode for RHA1 swarm growth, the WCC mode was specifically designed to promote lipid production from the RHA1 microbial cell factory in an EBF system. Specifically, the RHA1 strain was inoculated at a relatively high cell density and with a limited nitrogen supply to maintain a high C / N ratio during fermentation, allowing the Rhodococcus spp. to accumulate a high lipid content within the cells. Four rounds of WCC fermentation were performed to examine the lipid production capacity of the EBF system using the WT and AsF strains. When WT RHA1 cells were inoculated into the EBF system at a biomass load of 4.0 g / L, lipid production of 820.0 mg / L from CO2 was achieved. Similarly, when AsF cells with a similar biomass load (3.9 g / L) were inoculated, the lipid titer reached 1029.6 mg / L. Increasing the biomass of the WT strain to 4.9 g / L resulted in a lipid titer of 750.4 mg / L, whereas inoculating the EBF system with 5.2 g / L of AsF cells resulted in a high lipid production of 1360.0 mg / L. These four WCC fermentation routes demonstrated the reliability of the EBF system for lipid production from CO2. Furthermore, the lipid production of the EBF system using the AsF strain reached an average of 1194.8 mg / L / day, which is comparable to the top two lipid production rates of the algae Chaetoceros gracilis and the prasinophyte Tetraselmis tetrathele. These results highlight the potential of the EBF system for rapid lipid production from CO2.

[0069] To further evaluate the energy conversion efficiency of the EBF system, we performed an analysis considering three stages: sunlight to electricity, electricity to soluble carbon source, and soluble carbon source to lipid. The conversion efficiency of the first stage was estimated using mature photovoltaic technology, which can achieve an efficiency of 25%. Second, when calculating the energy efficiency of the electrocatalytic stage, we considered that gaseous products such as ethylene and hydrogen obtained from electrocatalysis are not utilized in bioconversion. Therefore, we calculated the energy efficiency by dividing the energy content of all soluble products (energy output) by the electrical energy input used to generate these soluble products. The analysis resulted in an energy efficiency of 45.6% for the conversion from electricity to soluble products. Third, we calculated the energy efficiency of bioconversion by dividing the energy content of the produced lipids by the total energy of the soluble products consumed. As a result, the average efficiency of the AsF strain in WCC mode was 36.5%. Overall, the EBF system achieved an energy efficiency of 4.2% for the conversion of CO2 to lipids.

[0070] While aspects of the present disclosure have been illustrated and described, changes thereto can be made without departing from the spirit and teachings of the subject matter of the present disclosure. The aspects and examples described herein are illustrative only and are not intended to be limiting. Many variations and modifications of the subject matter disclosed herein are possible and are within the scope of the present disclosure.

[0071] At least one embodiment is disclosed, and variations, combinations, and / or modifications of that embodiment and / or features of that embodiment made by one skilled in the art are within the scope of the disclosure. Alternative embodiments resulting from combining, integrating, and / or omitting features of the embodiments are also within the scope of the disclosure. When numerical ranges or limits are explicitly stated, it is to be understood that such explicit ranges or limits include all iterative ranges or limits of similar magnitude that are subsumed within the explicitly stated range or limit (e.g., about 1 to about 10 includes 2, 3, 4, 5, 6, ...; greater than 0.10 includes 0.11, 0.12, 0.13, 0.14, 0.15, ...). For example, when a numerical range with a lower limit Rl and an upper limit Ru is disclosed, any number within that range is specifically disclosed. In particular, numbers within the following ranges are specifically disclosed: R=Rl+k * (Ru-Rl), where k is a variable ranging from 1 percent to 100 percent in 1 percent increments, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, 50 percent, 51 percent, 52 percent, 95 percent, 96 percent, 97 percent, 98 percent, 99 percent, or 100 percent. Additionally, any numerical range defined by two R numbers as defined above is specifically disclosed. The use of the term "optionally" with respect to any element in a claim means either that the element is required or that the element is not required, with both alternatives being within the scope of the claim. The use of broader terms such as "comprises," "includes," and "having" should be understood to support narrower terms such as "consisting of," "consisting essentially of," and "consisting substantially of."

[0072] Therefore, the scope of protection is not limited by the above description, but only by the claims, which scope includes all equivalents of the subject matter of the claims. Each claim is incorporated herein as an aspect of the present disclosure. Thus, the claims are further explanation and are attached to the detailed description of the subject matter of the present disclosure.

Claims

1. 1. A method for producing a value-added chemical, comprising: Carbon dioxide is divided into one or more C ２ introducing carbon dioxide into a system comprising an electrochemical cell comprising a carbon dioxide reduction catalyst and an electrolyte under conditions suitable for converting carbon dioxide into a compound; C ２ The compound is one or more C ２＋ｎ under conditions suitable for converting one or more C ２ introducing at least a portion of the compound into a second system containing the microorganism and the medium; A method comprising:

2. One or more C ２ The compound is ethylene (C ２ H ４ ), ethanol (CH ３ CH ２ OH), acetate (C ２ H ２ O ２ － ), ethylene (C ２ H ４ ) or a combination thereof.

3. C ２ 10. The method of claim 1, wherein the compound comprises ethanol, acetate, or a combination thereof.

4. The method of claim 1 , wherein the catalyst comprises Ag, Au, Cu, Zn, or a combination thereof.

5. The method of claim 1 , wherein the catalyst comprises a support material.

6. The method of claim 1 wherein the support material is porous.

7. The method of claim 1 , wherein the catalyst comprises a supported copper catalyst.

8. 10. The method of claim 1, wherein the catalyst comprises a nanoporous Cu-M catalyst, wherein M is a metal selected from the group consisting of Pt, Ir, Pd, Ag, Au, Rh, Ru, Zn, Sn, Ni, Fe, Re, Ga, In, Cd, Tl, Ti, and combinations thereof.

9. The method of claim 1 , wherein the medium and the electrolyte are compositionally identical.

10. The method of claim 1 , wherein the microorganism is a wild-type strain.

11. The method of claim 1 , wherein the microorganism is a mutant strain.

12. One or more C ２＋ｎ 10. The method of claim 1, wherein the compound is selected from the group consisting of polymers, fuels, lipids, light olefins, gluconic acid, lactic acid, malonic acid, propionic acid, tricarboxylic acid, citric acid, aconitic acid, xylonic acid, acetoin, furfural, levoglucosan, lysine, serine, threonine, 1,4 succinic acid, fumaric acid, malic acid, 2,5 furandicarboxylic acid, 3-hydroxypropionic acid, aspartic acid, glucaric acid, glutamic acid, itaconic acid, levulinic acid, 3-hydroxybutyrolactone, glycerol, sorbitol, xylitol, arabinitol, 5-hydroxymethylfurfural, ferulic acid, terpenoids, polyketides, carotenoids, polyphenols, alkaloids, and combinations thereof.

13. One or more C ２＋ｎ The method of claim 1 , wherein the compound comprises a lipid.

14. 1. A method for preparing a value-added chemical, comprising: Carbon dioxide is divided into one or more C ２ a means for converting the compound into a compound; and a microorganism, ２ The compound is one or more C ２＋ｎ The method comprises contacting the compound with a microorganism under conditions suitable for its production.

15. Carbon dioxide is divided into one or more C ２ 15. The method of claim 14, wherein the means for converting to the compound is an electrochemical cell comprising a nanoporous Cu-M catalyst, where M is a metal selected from the group consisting of Pt, Ir, Pd, Ag, Au, Rh, Ru, Zn, Sn, Ni, Fe, Re, Ga, In, Cd, Tl, Ti, and combinations thereof.

16. C ２ 15. The method of claim 14, wherein the compound comprises ethanol, acetate, or a combination thereof.

17. 15. The method of claim 14, wherein the microorganism comprises a bacterium.

18. 15. The method of claim 14, wherein the microorganism is mutated.

19. One or more C ２＋ｎ 15. The method of claim 14, wherein the compound is selected from the group consisting of polymers, fuels, lipids, light olefins, gluconic acid, lactic acid, malonic acid, propionic acid, tricarboxylic acid, citric acid, aconitic acid, xylonic acid, acetoin, furfural, levoglucosan, lysine, serine, threonine, 1,4 succinic acid, fumaric acid, malic acid, 2,5 furandicarboxylic acid, 3-hydroxypropionic acid, aspartic acid, glucaric acid, glutamic acid, itaconic acid, levulinic acid, 3-hydroxybutyrolactone, glycerol, sorbitol, xylitol, arabinitol, 5-hydroxymethylfurfural, ferulic acid, terpenoids, polyketides, carotenoids, polyphenols, alkaloids, and combinations thereof.

20. One or more C ２＋ｎ 15. The method of claim 14, wherein the compound comprises a lipid.

Images