Application of film-embedded conjugated oligo-electrolyte in promoting electron transfer of non-photosynthetic bacteria and enhancing carbon sequestration capability

Abstract

The invention discloses an application of a film-embedded conjugated oligomeric electrolyte in promoting electron transfer of non-photosynthetic bacteria and enhancing carbon sequestration capability. The structural formula of the film-embedded conjugated oligomeric electrolyte is shown as a formula I in the specification. According to the invention, the conjugated oligomeric electrolyte which has photophysical activity and can be embedded into bacterial cell walls is combined with the non-photosynthetic microorganisms, and photoinduced electron or excited state energy transfer generated by the material under illumination is utilized to promote the electron transfer process in non-photosynthetic microorganism cells, so that the reducing power supply of the non-photosynthetic microorganisms is enhanced; the CO2 fixation metabolic pathway is activated or enhanced, and finally efficient and green bioconversion of CO2 into valuable chemicals is realized.

Description

Technical Field

[0001] This invention belongs to the field of carbon fixation and microbial resource utilization technology, specifically involving the application of membrane-embedded conjugated oligoelectrolytes in promoting electron transfer in non-photosynthetic bacteria and enhancing carbon fixation capacity, and more specifically involving the application of membrane-embedded conjugated oligoelectrolyte materials in promoting the conversion of carbon dioxide into organic carbon compounds by non-photosynthetic microorganisms. It can be applied to microbial metabolic engineering, bio-electron transfer regulation, non-photosynthetic carbon fixation technology, biomanufacturing, and carbon resource utilization. Background Technology

[0002] With the acceleration of global industrialization, excessive emissions of greenhouse gases such as carbon dioxide (CO2) have led to serious environmental problems and climate change. Against this backdrop, converting CO2 into valuable organic chemicals or fuels—a process known as "carbon fixation"—has become a crucial pathway to achieving sustainable development. Microbial carbon fixation is one of the most important carbon conversion mechanisms in nature. Photosynthetic microorganisms (such as cyanobacteria and photosynthetic bacteria) can use light energy through photosynthesis to reduce CO2 into organic matter, such as carbohydrates and organic acids. In addition, some non-photosynthetic microorganisms (such as chemoautotrophic bacteria) can also drive CO2 reduction and fixation by consuming chemical energy (such as hydrogen, sulfides, and iron ions), participating in the global carbon cycle in anaerobic or special habitats. In recent years, microbial electrosynthesis, biocarbon fixation, and biomanufacturing technologies that utilize microorganisms (especially non-photosynthetic bacteria) to convert CO2 into high-value-added chemicals (such as acetic acid, propionic acid, ethanol, and lactic acid) have received widespread attention. These technologies are expected to play a significant role in green chemistry, carbon resource utilization, and bioenergy.

[0003] Non-photosynthetic microorganisms face challenges in carbon fixation, including limited electron supply and difficulties in metabolic regulation. Despite their significant potential for CO2 fixation, their carbon fixation efficiency is typically limited by insufficient electron supply, low electron transfer efficiency, and complex metabolic pathway regulation. Non-photosynthetic microorganisms usually rely on external reducing equivalents (such as H2, S). 0 Fe 2+Electrons are provided by microbial substrates or other sources, but these electron donors are often costly, limited in supply, or unsustainable in practical applications. Furthermore, even when electron donors exist, the efficiency of the electron transport chain (ETC) within microbial cells, the regeneration capacity of coenzymes (such as NAD(P)H), and the ability to regulate carbon metabolic flux are often insufficient to support efficient CO2 reduction and fixation. Many non-photosynthetic microorganisms do not naturally rely on CO2 as their primary carbon source, and their carbon fixation-related enzymes (such as carbon monoxide dehydrogenase, formate dehydrogenase, and reductive acetyl-CoA synthase) have low activity, or their related metabolic pathways are not fully activated. Therefore, effectively enhancing the electron supply capacity of non-photosynthetic microorganisms, improving their intracellular electron transport efficiency, and activating or strengthening their CO2 fixation pathways are the core challenges currently facing the development of microbial carbon fixation technology.

[0004] Current technologies for enhancing the carbon fixation capacity of non-photosynthetic microorganisms mainly include: providing exogenous electron donors, metabolic engineering and synthetic biology modification, and electrochemically assisted microbial carbon fixation. However, these methods all have certain limitations, such as the instability, high cost, and safety hazards associated with using reducing agents like H2, formic acid, and sulfides as electron donors in CO2 reduction, and the difficulty in large-scale application. Genetic engineering of non-photosynthetic microorganisms to overexpress carbon fixation-related enzymes and introduce artificial metabolic pathways (such as the reverse water-gas shift pathway) can enhance their carbon fixation capacity. However, microbial genetic manipulation is complex, metabolic flow balance is difficult to control, cellular metabolic burden is high, and the stability and adaptability of the modified strains are often unsatisfactory. Electrochemically assisted carbon fixation systems that use electrodes as electron donors to transfer electrons to microorganisms by applying voltage to drive CO2 reduction require external electrical energy input, resulting in high system energy consumption; the electron transfer efficiency at the electrode-microorganism interface is limited; and the actual operating cost is high, restricting large-scale application. Existing technologies for improving the carbon fixation efficiency of non-photosynthetic microorganisms either rely on high-cost external inputs (electron donors / electrical energy) or are limited by the electron transfer and metabolic bottlenecks of the microorganisms themselves, and have not yet formed an efficient, sustainable, and low-cost solution.

[0005] In recent years, researchers have begun to explore the interaction between functional materials (such as conductive polymers, nanomaterials, and photosensitive molecules) and microorganisms to enhance their carbon fixation or product synthesis capabilities by regulating cell electron transport, providing additional reducing power, or activating specific metabolic pathways. One class of functional materials with photophysical activity (such as photogenerated electrons, exciton migration, and charge separation) is considered a potential "non-biological electron donor" or electron transport medium due to its ability to generate electron-hole pairs or excited-state species under light, showing promising potential in photocatalysis and photobiological coupling systems. However, in current technologies, these materials are mostly used for photocatalytic CO2 reduction (without microbial participation) or only in synergy with photosynthetic microorganisms (such as cyanobacteria-nanomaterial coupling systems). There is currently no technology that effectively combines photophysically active materials with "non-photosynthetic microorganisms" and promotes their carbon fixation capabilities by embedding the materials into the cell membrane and regulating their internal electron transport. Summary of the Invention

[0006] The purpose of this invention is to provide a type of membrane-embedded conjugated oligoelectrolyte material for promoting electron transfer in non-photosynthetic bacteria and enhancing their carbon fixation ability.

[0007] This invention achieves a triple function of "membrane embedding-electron transfer-metabolic synergy" through a unique molecular structure design, which significantly improves the efficiency of non-photosynthetic microorganisms in converting CO2 into organic carbon compounds.

[0008] The membrane-embedded conjugated oligomeric electrolyte material is an oligomeric molecule with the following characteristics: Main chain structure: An electronic system containing a conjugated "donor-acceptor-donor" (DAD) structure with a conjugation length of 3 to 15 units (preferably 5 to 10), which gives the material a stable structure that will not degrade due to light or heat, as well as excellent electron delocalization and conductivity; BTD with a strongly electron-deficient quinone structure and thiophene with electron-donating ability are often used as DAD conjugation elements, where thiophene is the donor and benzothiadiazole (BTD) is the acceptor; Side chain groups: C4-C12 straight-chain or branched alkyl groups attached to both sides of the main chain structure (conjugated skeleton); The ends of the side chains are modified with hydrophilic ionic groups, which are then orderly assembled with the hydrophobic backbone (such as straight-chain or branched alkyl groups of C4 to C12, or conjugated backbone) in the phospholipid bilayer of the microbial cell membrane.

[0009] The membrane-embedded conjugated oligoelectrolyte has the structural formula shown in Formula I:

[0010] In Equation I, n is an integer from 4 to 12; m is an integer from 0 to 3; x is an integer from 1 to 3, y is an integer from 1 to 3, and x and y may be the same or different; Y is a halogen (such as at least one of bromine and chlorine).

[0011] Given x=y=1, n=8, m=0, the membrane-embedded conjugated oligoelectrolyte shown in Equation I is named TBT-SC8; Given x=y=2, n=8, and m=0, the membrane-intercalated conjugated oligoelectrolyte shown in Equation I is named TBT-DC8. Given x=y=3, n=8, and m=0, the membrane-embedded conjugated oligoelectrolyte shown in Equation I is named TBT-TC8; Given x=y=2, n=4, and m=0, the membrane-embedded conjugated oligoelectrolyte shown in Equation I is named TBT-DC4. Given x=y=2, n=6, and m=0, the membrane-embedded conjugated oligoelectrolyte shown in Equation I is named TBT-DC6. Given x=y=2, n=8, and m=0, the membrane-intercalated conjugated oligoelectrolyte shown in Equation I is named TBT-DC8. Given x=y=2, n=10, and m=0, the membrane-intercalated conjugated oligoelectrolyte shown in Equation I is named TBT-DC10. Given x=y=2, n=12, and m=0, the membrane-embedded conjugated oligoelectrolyte shown in Equation I is named TBT-DC12. The non-photosynthetic microorganism may be *Sporomusa ovata*.

[0012] The above-mentioned intercalated conjugated oligomeric electrolyte materials promote carbon fixation by non-photosynthetic microorganisms through the following pathways: Membrane embedding and localization: Utilizing the hydrophobic interaction between the amphiphilic side chains and the phospholipid bilayer of the cell membrane, the material is directionally embedded into the inner or outer side of the cell membrane (preferably the membrane region close to the cytoplasm side) to form a stable "electron transport channel"; Electron transport regulation: The conjugated π-electron system acts as an electron "highway," efficiently transferring reducing forces or exogenous electrons generated by intracellular metabolism to terminal active groups; the terminal groups further direct electrons to the active center of the target carbon-fixing enzyme, reducing the activation energy of CO2 reduction; Enhanced metabolic synergy: The material embedding can fine-tune cell membrane permeability and enrich carbon fixation-related enzymes through electrostatic interaction, thereby synergistically improving the overall efficiency of the carbon fixation pathway.

[0013] The organic carbon compounds include acetic acid, propionic acid, ethanol, lactic acid, and 3-hydroxypropionic acid.

[0014] The present invention also provides a method for promoting carbon fixation by non-photosynthetic microorganisms using the above-mentioned membrane-embedded conjugated oligoelectrolyte material.

[0015] The method for promoting carbon fixation by non-photosynthetic microorganisms using membrane-embedded conjugated oligoelectrolyte materials provided by this invention includes the following steps: In an anaerobic environment containing CO2 gas, and with the addition of basal culture medium, light culture medium, inorganic salts and electron donors, the membrane-embedded conjugated oligomeric electrolyte material is co-cultured with the target non-photosynthetic microorganisms under light conditions (during alternating day and night), so that the microorganisms convert CO2 into organic carbon compounds.

[0016] The preferred material for the membrane-embedded conjugated oligomeric electrolyte is at least one of TBT-TC8 and TBT-DC12. In the culture system, the concentration of the membrane-embedded conjugated oligomeric electrolyte material can be 0.25 μM-0.5 μM, specifically 0.25 μM.

[0017] In the anaerobic environment containing CO2 gas, the volume fraction of CO2 is ≥10%, and the remainder is in N2 / Ar equilibrium. The light-treated culture medium is specifically ATCC solid organic culture medium; The inorganic salt is specifically an 8% NaHCO3 solution; The electron donor may specifically be cysteine; The co-culture conditions are: temperature 25~37℃ (can be adjusted according to the type of microorganism), pH 6.5~7.5, stirring speed 50~200 rpm (to promote gas mass transfer), and culture time 12~96 hours.

[0018] Ultimately, microorganisms convert CO2 into organic carbon compounds (such as acetic acid, propionic acid, ethanol, lactic acid, 3-hydroxypropionic acid, etc.), and the molar yield of the target product is 20% to 500% higher than that of the control group without the addition of membrane-intercalated conjugated oligomeric electrolyte material (the specific amount depends on the type of microorganism and the degree of modification of the carbon fixation pathway).

[0019] This invention directly applies molecules (conjugated oligoelectrolytes) with "membrane embedding ability" and "photophysical activity" to the cell membranes of non-photosynthetic microorganisms, promoting the flow of endogenous electrons and CO2 fixation through photoinduced electron transfer. This approach has not been reported domestically or internationally and is an important innovative starting point of this invention.

[0020] Compared with the prior art, the key advantages of this invention include: Highly efficient electron transport: The conjugated oligomeric structure provides a low-resistance electron channel, reducing the energy barrier for electron transmembrane transport and increasing the efficiency of electron transport to carbon fixation enzyme by 3 to 10 times (verified by cyclic voltammetry and carbon fixation enzyme detection kit). Membrane stability and biocompatibility: The amphiphilic design and self-assembly embedding of microbial cell membranes avoid damage to the cell membrane (cell survival rate >90%) and produce no toxic byproducts; Environmentally friendly: The material is biodegradable (e.g., the side chain ionic groups hydrolyze under specific conditions), does not rely on precious metals (e.g., platinum, gold), and is inexpensive.

[0021] This invention proposes a novel technical approach: utilizing a type of photophysically active conjugated oligoelectrolyte that can embed itself in cell membranes, and combining it with non-photosynthetic microorganisms (such as Sporoma ovata), the photoinduced electron or excited-state energy transfer generated by this material under light promotes electron transfer within Sporoma ovata cells, thereby enhancing its reducing power supply, activating or strengthening its CO2 fixation metabolic pathway, and ultimately achieving efficient and green CO2 bioconversion into valuable chemicals. This strategy not only provides a new method for carbon fixation by non-photosynthetic microorganisms that is independent of exogenous electron donors and genetic modification, and possesses photomodulation potential, but also holds promise for advancing the development of microbial-material coupled carbon fixation technology, possessing significant scientific value and application prospects. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the process of the present invention.

[0023] Figure 2 The structural formulas of five MICOE molecules with the same main chain structure but different side chain lengths: TBT-DC4, TBT-DC6, TBT-DC8, TBT-DC10, and TBT-DC12.

[0024] Figure 3 The structural formulas of MICOE molecules with the same main chain structure and side chain length but different numbers of side chains are TBT-SC8, TBT-DC8, and TBT-TC8.

[0025] In Figure 4, a) is the UV-Vis absorption spectrum of MICOE; b) is the fluorescence spectrum.

[0026] Figure 5 shows the biotoxicity of MICOE with different numbers of side chains.

[0027] Figure 6 shows the biotoxicity of MICOE with different side chain lengths.

[0028] Figure 7 shows SEM images of S. ovata and S. ovata-MICOE.

[0029] Figure 8 shows CLSM images of S. ovata and S. ovata-MICOE with different sidechain lengths.

[0030] Figure 9 is S. ovata and different numbers of side chains S. ovata -CLSM image of MICOE.

[0031] Figure 10 shows the carbon fixation performance of the MICOE-S. ovata hybrid system with different side chain lengths.

[0032] Figure 11 The carbon fixation performance of MICOE-S. ovata hybrid systems with different numbers of side chains is shown. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0034] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0035] Example 1 use Figure 2 As shown in (a), there are five MICOE molecules with the same main chain structure but different side chain lengths: TBT-DC4, TBT-DC6, TBT-DC8, TBT-DC10, and TBT-DC12. Figure 3 As shown in (b), TBT-SC8, TBT-DC8, and TBT-TC8 are MICOE molecules with the same main chain length and the same side chain length but different numbers of side chains. The specific operation is as follows: Weigh ATCC solid (ATCC 1425, Shandong Top Bioengineering Co., Ltd.), formula: NaCl (2250 mg / L), K2HPO4 (348 mg / L), NH4Cl (500 mg / L), MgSO47H2O (500 mg / L), KH2PO4 (227 mg / L), CaCl2H2O (25 mg / L), FeSO4 7.86 g of organic culture medium containing 7H2O (2 mg / L), NaHSeO3 (0.015 mg / L), Yeast extract (2000 mg / L), Cistone (2000 mg / L), and Resazurin (1 mg / L) was dissolved in 1 L of deionized water. Three vials (3 mL) of S2232 (trace element solution SL-6) were added, and the mixture was heated to boiling for 5 min. The mixture was then rapidly cooled to room temperature in ice water under 80% N2 and 20% CO2 conditions. The culture was dispensed, and one vial (1 mL) of SD010 (8% NaHCO3 solution) was added to every 100 mL of culture medium. The mixture was then autoclaved at 121℃ for 15 min and cooled to room temperature. One vial (5 mL) of SD011 (10% betaine solution) was added to every 100 mL of culture medium under aseptic conditions for later use. Before inoculation, one vial (1 mL) of SD012 (3% L-cysteine ​​hydrochloride solution) was added to every 100 mL of culture medium under aseptic conditions. Adjust the pH to 7.0-7.2 with hydrochloric acid or sodium hydroxide. After equilibration for 6 h, the culture medium changed from pink to pale yellow. After equilibration for 6 h, inoculate with glycerol-preserved *S. ovata* at a concentration of 10% (v / v), then transfer to an anaerobic container with an anaerobic zone and culture at 37°C and 180 rpm in a constant temperature shaking incubator. After 72 h, *S. ovata* reached the logarithmic growth phase, with an OD value of approximately 0.1, and proceed to the next step.

[0036] Prepare a light-enhanced culture medium. Using phosphate-buffered saline (PBS) as the base solvent, accurately weigh out NaCl (0.4 g / L), KCl (0.25 g / L), NH4Cl (0.4 g / L), and MgSO4·7H2O (0.33 g / L), and add ultrapure water to obtain a PBS stock solution with a pH of 7.4. Then, add trace element solution (SL-6, Shandong Top Biotechnology Co., Ltd., 10 mL / L) and Trace Mineral Solution (Shandong Top Biotechnology Co., Ltd., 10 mL / L). Finally, autoclave at 121°C for 15 min for the following purposes. S. ovata - Construction of MICOE hybrid systems.

[0037] The cultured *S. ovata* was centrifuged (8000 rpm, 5 min) and washed three times with PBS or sterile water. *S. ovata* was resuspended in light-treated medium, and its optical density (OD600) was adjusted to 0.1. 5 mL of this resuspended medium was placed in 18 × 200 mm Blach anaerobic culture tubes. A 1 wt% cysteine ​​hydrochloride solution was added as a sacrificial agent, along with a specific concentration of MICOE. N2 and CO2 (N2:CO2 = 80:20) were then introduced into the tubes. The tubes were then placed on a magnetic stirrer and stirred at 600 rpm, with the temperature maintained at 30°C using a water bath. The *S. ovata*-MICOE hybrid system was irradiated with a 520 nm LED light source. A 12-hour light-dark cycle was used to simulate the intermittent nature of solar light.

[0038] The carbon fixation efficiency under light conditions was investigated, and the following preliminary experimental results were obtained: 1) Characterization of the photophysical properties of MICOE molecules. The optical properties of the embedded molecules were characterized and analyzed by measuring their UV-Vis absorption and fluorescence emission spectra. For example... Figure 4 As shown in Figure a, in the UV-Vis absorption spectrum of intercalated molecules, the UV absorption spectrum of MICOE is mainly concentrated in the 450-550 nm range, with a maximum absorption peak around 500 nm, indicating that the intercalated molecules have a broad absorption peak and can absorb more light. The fluorescence spectrum of MICOE was detected using a fluorescence spectrophotometer. Figure 4 As shown in Figure b, in the fluorescence emission spectrum of the intercalated molecules, the strongest fluorescence emission peaks of these MICOE molecules are distributed between 600-700 nm.

[0039] 2) Biotoxicity analysis of MICOE molecules. Six different concentrations (0 μM, 0.5 μM, 1 μM, 3 μM, 5 μM, 10 μM) of MICOE solution were co-incubated with S. ovata solution (incubated in light-treated medium at 600 rpm with stirring, at 30°C). After 3 days of culture, the OD values ​​were measured. 600 Numerical values ​​were used to assess the toxicity of MICOE to S. ovata.

[0040] like Figure 5 , Figure 6 As shown, when the concentration of MICOE is below 10 μM, it does not have a significant effect on bacterial growth, indicating that MICOE has good biocompatibility.

[0041] When the concentration of the membrane-intercalated conjugated oligoelectrolyte MICOE is below 10 μM, the OD of S. ovata...600 The value was higher than that of the control group without MICOE. This phenomenon is mainly attributed to the slight interaction between the membrane-embedded conjugated oligoelectrolyte and the bacteria under low concentration conditions. This interaction stimulated the metabolic activity of the bacteria, leading to an increase in biomass.

[0042] 3) Construction and characterization of the *S. ovata*-MICOE hybrid system. To more comprehensively and intuitively investigate the morphological changes of *S. ovata* after treatment with the membrane-embedded conjugated oligoelectrolyte MICOE, it was characterized by SEM. SEM images clearly show the surface morphology of this biohybrid system. For example... Figure 7 As shown, *S. ovata* exhibits a typical rod-shaped morphology with a smooth surface. However, the surface of *S. ovata* strains co-incubated with the membrane-embedded conjugated oligoelectrolytes MICOE (TBT-DC12 and TBT-TC8) became significantly rougher, indicating that the membrane-embedded conjugated oligoelectrolytes MICOE can be embedded in the *S. ovata* bacterial membrane. Meanwhile, the overall morphology of *S. ovata* loaded with MICOE did not change significantly, demonstrating the good interfacial compatibility of the MICOE molecules.

[0043] To more intuitively illustrate the binding of the membrane-intercalated conjugated oligoelectrolyte MICOE to *S. ovata* via membrane intercalation, fluorescence imaging of the *S. ovata*-MICOE hybrid system was performed using laser confocal microscopy. Figure 8 As shown, the left image is the fluorescence image of the intercalated molecule MICOE, and the right image is the superimposed image of MICOE and S. ovata. It can be seen from the images that MICOE can be well localized on the surface of S. ovata, and its spatial distribution highly overlaps with the cell outline in the bright-field image, with the fluorescence marker in red. Calculations of the loading rate of MICOE on S. ovata revealed that among hybrid systems with different side chain lengths, the TBT-DC12 group, with the longest side chain, had the highest loading rate, approximately 80%, which also verifies that TBT-DC12 has the best binding affinity to S. ovata. Among hybrid systems with different numbers of side chains, the TBT-SC8 hybrid system with only two side chains showed the weakest intercalation effect. Figure 9 The loading rate is only about 2%, which may be due to the fact that it has only one side chain on each side of the conjugated backbone, with a small number of charges, resulting in low hydrophilicity and poor solubility, making it difficult for the molecule to be loaded onto bacteria, which belong to aquatic biological systems.

[0044] 4) Carbon fixation studies of the S. ovata-MICOE hybrid system. The membrane-intercalated conjugated oligoelectrolyte MICOE, as one of the main components of the S. ovata-MICOE biohybrid system, is a key component of the intracellular wood of S. ovata. The Ljungdahl pathway provides electrons for normal metabolism. To investigate the effects of different side chain lengths and numbers of MICOE on the carbon fixation efficiency of the system, the yield of acetic acid converted from MICOE in the system at 0 μM, 0.25 μM, and 0.5 μM was tested. Different side chain length groups are shown below. Figure 10 As shown, the concentrations of TBT-DC4 and TBT-DC6 at 0.25 μM and 0.5 μM showed almost no improvement compared to the control. However, the acetic acid conversion was increased by 185% in the 0.25 μM system for TBT-DC12. Different side chain group numbers are shown below. Figure 11 As shown, TBT-SC8 and TBT-DC8 had almost no effect at concentrations of 0.25 μM and 0.5 μM, while the acetic acid conversion was increased by 330% when TBT-TC8 was at 0.25 μM.

[0045] The present invention has been described in detail above. Those skilled in the art will recognize that the invention can be practiced in a wide range of ways with equivalent parameters, concentrations, and conditions without departing from its spirit and scope, and without requiring unnecessary experiments. While specific embodiments have been provided, it should be understood that further modifications can be made to the invention. In summary, according to the principles of the invention, this application is intended to include any changes, uses, or improvements to the invention, including changes made using conventional techniques known in the art that depart from the scope disclosed herein.

Claims

1. Application of membrane-embedded conjugated oligomeric electrolyte materials in promoting electron transfer and enhancing carbon fixation capacity in non-photosynthetic bacteria. The membrane-embedded conjugated oligomeric electrolyte material is an oligomeric molecule with the following characteristics: Main chain structure: An electronic system containing a conjugated "donor-acceptor-donor" structure, with a conjugation length of 3 to 15 units; Side chain groups: C4-C12 straight-chain or branched alkyl chains attached to both sides of the main chain structure; The ends of the side chains are modified with hydrophilic ionic groups, which are orderly assembled with the hydrophobic backbone in the middle of the microbial cell membrane phospholipid bilayer.

2. The application according to claim 1, characterized in that, The membrane-embedded conjugated oligoelectrolyte has the structural formula shown in Formula I: In Equation I, n is an integer from 4 to 12; m is an integer from 0 to 3; x is an integer from 1 to 3, y is an integer from 1 to 3, and x and y may be the same or different; Y represents halogen.

3. The application according to claim 1, characterized in that, The non-photosynthetic microorganism is *Sporomusa ovata*.

4. The application according to claim 1, characterized in that, The organic carbon compounds include acetic acid, propionic acid, ethanol, lactic acid, and 3-hydroxypropionic acid.

5. The application according to claim 1, characterized in that, The membrane-intercalated conjugated oligoelectrolyte is any one of the following compounds: 。 6. A method for promoting carbon fixation by non-photosynthetic microorganisms using the intercalated conjugated oligoelectrolyte material of claim 1, comprising the following steps: In an anaerobic environment containing CO2 gas, and with the addition of basal culture medium, light-enhanced culture medium, inorganic salts, and electron donors, the membrane-embedded conjugated oligomeric electrolyte material is co-cultured with the target non-photosynthetic microorganisms under light conditions, so that the microorganisms convert CO2 into organic carbon compounds.

7. The method according to claim 6, characterized in that, In the culture system, the concentration of the membrane-embedded conjugated oligomeric electrolyte material is 0.25 μM-0.5 μM.

8. The method according to claim 6, characterized in that, In the anaerobic environment containing CO2 gas, the volume fraction of CO2 is ≥10%, and the remainder is in N2 / Ar equilibrium. The light-treated medium is ATCC solid organic medium; The inorganic salt is an 8% NaHCO3 solution; The electron donor is cysteine; The co-culture conditions are: temperature 25~37℃, pH 6.5~7.5, stirring speed 50~200 rpm, and culture time 12~96 hours.

Images