Optimization of affinity microbial ionic liquid and application of affinity microbial ionic liquid in microbial battery system

Abstract

The invention relates to the optimization of an affinity microbial ionic liquid and the use thereof in a microbial electrolysis cell system, characterized in that the electron transfer rate is increased by using the ionic liquid to cultivate bacteria, observing the influence on the growth activity of the bacteria, defining the affinity microbial ionic liquid, and subsequently using the affinity microbial ionic liquid as an electrolyte in an MEC system.

Description

Technical Field

[0001] This invention relates to the application of ionic liquids, specifically a preferred microbial-friendly ionic liquid and its application in a microbial battery system. Background Technology

[0002] Ionic liquids (ILs) are a class of materials composed entirely of anions and cations, existing as liquids at room temperature. Due to their high CO2 absorption capacity, thermodynamic stability, and low volatility, they have attracted increasing attention in the field of CO2 capture. To improve the applicability of ILs for CO2 capture, researchers have modified the structure of traditional ILs and developed a series of functionalized ILs specifically for CO2 capture, including amino-functionalized ILs, non-amino-functionalized ILs, and supported ILs. These improvements have resulted in ILs exhibiting higher adsorption capacity and selectivity, faster adsorption rates, and better adsorption-desorption cycle stability when capturing CO2. ILs, with their high solubility and low loss characteristics, have become an important family of materials for CO2 capture. Recently, considering the high conductivity of ILs, researchers have begun to consider their application in the electrochemical reduction of CO2 to achieve the integration of CO2 capture and conversion. The first idea is to directly use ILs instead of aqueous solutions as the electrolyte. In this case, it can not only utilize the high solubility and conductivity of CO2 but also suppress the competitive hydrogen evolution reaction during CO2 conversion. Furthermore, researchers have discovered that using certain electrolytes (ILs) as electrolyte additives or modifying electrodes can also produce unique effects, thereby improving CO2 conversion efficiency. Therefore, ILs have been extensively studied as electrolytes, electrolyte additives, and electrode modifiers.

[0003] The emerging MEC (Metal-Oriented Cell) is also an important approach to CO2 capture, but due to the lack of a good electrolyte, the electron transfer efficiency within the MEC system is relatively low, resulting in low CO2 conversion efficiency. Ionic liquids are excellent electrolytes, but currently they are mainly used in fuel cells, and some ionic liquids are toxic to microorganisms. Therefore, selecting an ionic liquid that is harmless to microorganisms is crucial. Summary of the Invention

[0004] The purpose of this invention is to select an ionic liquid that is compatible with microorganisms, and to identify an ionic liquid that has a smaller impact on bacterial growth by culturing bacteria and observing its effect on bacterial growth activity, so as to use it as an electrolyte in MEC systems to improve electron transfer rate.

[0005] This invention is achieved through the following steps: Using Shewanella as the research object, we cultured it with ionic liquids [N2222]Im (IL1) and [N2222]Gly (IL2) to investigate their effects on the growth activity, electrochemical activity and metabolites of Shewanella.

[0006] Three enrichment culture experiments were designed, in which different concentrations of ionic liquid were added at different time points and the mixture was shaken during culture.

[0007] In experimental group a, Shewanella bacteria and different concentrations of ionic liquids were added to 100 mL of LB medium (NaCl, 10 g / L; tryptone, 10 g / L; yeast extract, 5 g / L) and cultured with shaking for 24 h. Experimental group b: Shewanella was cultured in 100 mL LB medium with shaking for 8 h, and then different concentrations of ionic liquids were added, and the culture was continued with shaking for 16 h. Experimental group c: After Shewanella was cultured in 100 mL LB medium with shaking for 12 h, the OD value reached 2. Different concentrations of ionic liquid were added, and the culture was continued with shaking for another 12 h.

[0008] Preferably, three sets of fuel cells were designed to investigate the effect of ionic liquids on the electrochemical activity of Shewanella. The cathode of the fuel cell was 150 mL of phosphate buffer, and the anode was a mixture of 150 mL of bacterial solution and culture medium without the addition of IL. Preferably, 150 mL of bacterial suspension with 10 mmol / L IL1 is mixed with the culture medium; Preferably, a mixture of 150 mL of bacterial culture with added 10 mmol / L IL2 and culture medium; Preferably, the bacteria in the preservation bottle are inoculated into a conical flask using an inoculation loop for culture. The conical flask is then placed in a shaking incubator and cultured for 24 hours. After 24 hours, the effect of the ionic liquid on Shewanella is evaluated by OD value detection, liveness and death observation, and electron microscopy.

[0009] IL2 has a weak ability to inhibit microorganisms, making it suitable for use in microbial electrolysis cells.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) By optimizing the selection of ionic liquids, the present invention improves the electron transfer efficiency inside the MEC system, which is crucial for improving the energy conversion efficiency of the entire system. (2) By using microbial-friendly ionic liquids as electrolytes for the MEC system, the CO2 conversion efficiency can be improved, thereby helping to reduce greenhouse gas emissions and combat global climate change. (3) Improving the efficiency and performance of the MEC system can reduce energy consumption and costs, and has potential economic benefits for promoting the development of sustainable energy technologies. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure and chemical formula of an ionic liquid.

[0012] Figure 2 This is a schematic diagram of the experimental procedure. In the diagram, 1-preservation bottle, 2-inoculation loop, 3-shaking incubator, 4-ultraviolet spectrophotometer, 5-fluorescence microscope, 6-scanning electron microscope.

[0013] Figure 3 The effect of different concentrations of ionic liquids on bacterial viability and death.

[0014] Figure 4 SEM images of bacteria in different ionic liquid culture media. Detailed Implementation

[0015] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0016] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0017] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0018] Example A method for determining the affinity of ionic liquids for microorganisms, the process flow is as follows: Figure 2 As shown, proceed as follows: Draw 1 mL of culture medium from the conical flask. Then dilute it by half and measure the OD600 using a UV spectrophotometer. The results are shown in Table 1. Then take 1 mL of culture medium and observe it under a fluorescence microscope. The specific steps are as follows: (1) Mix 3 μL of SYTO® 9 staining agent and 3 μL of propidium iodide staining agent with 1 ml of deionized water and refrigerate for later use; (2) Evenly drop 200 μL of staining solution onto the surface of the sample to be tested; (3) Stain at room temperature, away from light, for 20-30 minutes; (4) Rinse the sample slowly with deionized water 4 times; (5) Store samples at room temperature. Test results are as follows: Figure 3As shown in the image. Then, 1 mL of culture medium was taken out for cryo-scanning electron microscopy observation, and the results are as follows. Figure 4 As shown.

[0019] The experimental results show that IL2 has a weak inhibitory effect on microorganisms and can be used in microbial electrolysis cells.

[0020] Table 1. Effects of different concentrations of IL-1 on Shewanella OD600 Concentration mmol / L group 0 5 10 15 20 a 4.5 3.5 3 2.5 2.2 b 4.5 3.5 2 1 0.2 c 4.5 4 1 0.45 0.1 Table 2. Effects of different concentrations of IL2 on Shewanella OD600 IL2 concentration (mmol / L) group 0 5 10 15 20 50 100 150 200 a 4.5 4.5 4 3.8 3.5 b 4.5 4.5 3.5 3.5 3 1.5 1 0.5 0.4 c 4.5 4 3.5 3.2 2.5 The above are merely embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structures made using the content of the present invention specification, whether directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of the present invention.

Claims

1. A preferred microbial-affinity ionic liquid and its application in a microbial battery system, characterized in that, By using ionic liquids to culture bacteria, we observed their effects on bacterial growth activity in order to identify ionic liquids with minimal impact on bacterial growth.

2. The method as described in claim 1, characterized in that, Used as an electrolyte in MEC systems to improve electron transfer rates.

3. The method as described in claim 1, characterized in that, The selected ionic liquid is [N2222]Gly.

4. The method as described in claim 1, characterized in that, The cathode of the fuel cell is 150 mL of phosphate buffer.

5. The method as described in claim 1, characterized in that, The concentration of the ionic liquid culture medium was 10 mmol / L.

6. The method as described in claim 1, characterized in that, The preference for ionic liquids is based on their effects on the growth activity, electrochemical activity, and metabolites of Shewanella.

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