A method for electrochemical bio-coupled production of saccharomyces cerevisiae proteins

Abstract

The application discloses a kind of electrochemical biological coupling production saccharomyces cerevisiae protein method, it is first carbon dioxide by electrochemical module reduction generation formic acid, again using generated formic acid as carbon source and substrate, by biological module production saccharomyces cerevisiae protein;Wherein, the electrochemical module includes gas chamber, extraction chamber filled with solid-state electrolyte, anode chamber and the cathode being arranged between gas chamber and extraction chamber, the anode being arranged between anode chamber and extraction chamber;The biological module is divided into two chamber structures by diaphragm, one is for making formic acid into acetic acid acetic acid bacteria chamber, another is using acetic acid production as yeast protein yeast chamber.The application is by electrocatalysis carbon dioxide reduction production formic acid, again using formic acid as substrate production acetic acid, and further using acetic acid synthesis cell cascade reaction, realize the production of saccharomyces cerevisiae protein, is expected to be applied to green biological manufacturing.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical fields of electrochemistry, carbon dioxide utilization, bioengineering and modern agricultural technology, and particularly relates to a method for producing Saccharomyces cerevisiae protein by electro-bio-coupling. BACKGROUND

[0002] Saccharomyces cerevisiae has been widely used in the food industry for a long time, ensuring its safety, nutritional value and public acceptance. In addition, Saccharomyces cerevisiae can also be a source of high-value products such as essential vitamin folic acid. The production of yeast protein mostly relies on traditional fermentation processes, usually using organic carbon sources such as sugars as a source of nutrition. However, with the global emphasis on sustainable development and the demand for efficient use of resources, it is particularly important to find new and sustainable sources of carbon. Carbon dioxide, as a widely existing greenhouse gas, if effectively utilized and converted into valuable chemicals or food ingredients, will have a profound impact on environmental protection and resource utilization. However, natural yeasts cannot directly fix carbon dioxide autotrophically.

[0003] Electro-bio-coupling technology is a technology that combines an electrochemical module and a biological module through electrocatalytic reduction of carbon dioxide to generate small-molecule organic compounds. Among them, carbon dioxide is first converted into small-molecule organic compounds through electrochemical carbon dioxide reduction reaction (CO2RR) driven by renewable energy, and then these small-molecule organic compounds can be used to cultivate food-producing organisms including fungi, yeasts, algae and even crops. Previous studies have proposed an intermediate carbon compound conversion pathway involving "electrochemical hydrogen production, bacterial acetic acid production, and yeast protein production"; but the generation of acetic acid in this method requires hydrogen as an electron donor, which brings challenges in safety and mass transfer. Another proposed pathway is "electrochemical acetic acid production, followed by yeast protein production". However, this method ignores the fact that only high selectivity and partial current density of C1 compounds from carbon dioxide can be achieved by CO2RR, and even with a series of electrochemical carbon dioxide reduction reactions (CORR), controlling the selectivity of acetic acid is still a challenge.

[0004] In addition, an important challenge for the practical application of electro-bio-coupling technology is the concentration of formic acid in the extract of the electrochemical module and the operation stability. For example, the extract containing formic acid is usually diluted when flowing into the biological module, so the concentration of formic acid in the extract needs to be high. In addition, in the prior art, the electrochemical module can only be stable for several to tens of hours, which cannot be well matched with the biological module using microbial catalysts. Therefore, how to effectively convert the intermediate product (formic acid) produced by CO2 reduction into Saccharomyces cerevisiae protein by electro-bio-coupling technology still has many technical obstacles. SUMMARY

[0005] The application provides an innovative electrochemical biological coupling method for producing Saccharomyces cerevisiae protein, which can realize efficient conversion from carbon dioxide to Saccharomyces cerevisiae protein.

[0006] To achieve the above-mentioned purpose, the application adopts the following technical solutions.

[0007] The application provides an electrochemical biological coupling method for producing Saccharomyces cerevisiae protein, which comprises the following steps: first, reducing carbon dioxide through an electrochemical module to generate formic acid; and then using the generated formic acid as a carbon source and a substrate to produce Saccharomyces cerevisiae protein through a biological module.

[0008] The electrochemical module comprises a gas chamber for introducing carbon dioxide, an extraction chamber filled with solid-state electrolyte, an anode chamber for generating an oxidation reaction, and a cathode arranged between the gas chamber and the extraction chamber for catalyzing the reduction of carbon dioxide, and an anode arranged between the anode chamber and the extraction chamber for catalyzing the oxygen evolution reaction.

[0009] Further, the solid-state electrolyte filled in the extraction chamber is ion exchange resin.

[0010] Further, the extraction chamber can be filled with an extraction liquid for extracting the formic acid generated by the reduction of carbon dioxide. The concentration of formic acid in the extraction liquid can be adjusted by controlling the current density, the voltage or the flow rate of the extraction liquid. The current density can be 10-300 mA / cm 2 , the voltage can be 3-15 V, and the flow rate of the extraction liquid can be 0.01-1 mL / min. The concentration of the formic acid-containing solution obtained is 0-100 g / L -1 .

[0011] Further, the extraction liquid can be pure water, a solution containing alkali metal cations or a biological culture medium.

[0012] Further, the anode chamber is filled with an anode liquid.

[0013] Further, the surface of the cathode, which faces the extraction chamber, is covered with a diaphragm such as an anion exchange membrane or filter paper to regulate the local microenvironment and improve the catalytic performance.

[0014] Further, the surface of the anode, which faces the extraction chamber, is covered with a cation exchange membrane to prevent anions in the anode chamber from entering the extraction chamber.

[0015] The biological module has a two-chamber structure, one of which is an acetogenic bacteria chamber for culturing acetogenic bacteria to convert formic acid into acetic acid, and the other is a yeast chamber for culturing Saccharomyces cerevisiae to convert acetic acid into yeast protein (i.e., acetic acid is the product of the acetogenic bacteria chamber and the substrate of the yeast chamber).

[0016] Further, the biological module is separated into two chambers by a filter paper or an anion membrane which can block microorganisms but not block the migration of acetic acid.

[0017] Further, the acetic acid bacteria chamber and the yeast chamber can be added with no organic carbon source, i.e., formic acid extracted from the electrochemical module as the only carbon source, or a certain concentration of organic carbon source can be added in the two chambers to strengthen the effect of producing Saccharomyces cerevisiae protein.

[0018] Further, the formic acid extracted from the electrochemical module can be continuously pumped into the acetic acid bacteria chamber of the biological module to realize the production and use of formic acid, or a certain concentration and volume of the extraction liquid containing formic acid can be collected and then fed into the acetic acid bacteria chamber of the biological module in batches.

[0019] The present application has the following advantages:

[0020] (1) In the present application, the electrochemical module is used to catalyze the reduction of carbon dioxide to produce formic acid, and the extraction liquid is introduced into the extraction chamber filled with solid-state electrolyte to extract formic acid. During the process, the concentration and running stability of formic acid in the extraction liquid can be improved by adjusting the flow rate of the extraction liquid, the current density and other parameters, thereby providing a stable carbon source for the subsequent biological conversion process.

[0021] (2) The biological module used in the present application adopts a two-chamber structure, and the two chambers are separated by a separation material which can block microorganisms but not block the migration of acetic acid, thereby ensuring the effective transfer of the substrate and the independent operation of the biological process, and preventing the mixing of acetic acid bacteria in Saccharomyces cerevisiae. In addition, the biological module is flexible, and whether to add an organic carbon source to strengthen the effect of producing Saccharomyces cerevisiae protein can be selected according to the needs.

[0022] (3) During the operation, the extraction liquid extracts formic acid from the electrochemical module, which can be continuously pumped into the acetic acid bacteria chamber of the biological module to realize the production and use of formic acid, or it can be collected and fed in batches to meet different production needs.

[0023] In summary, the present application produces Saccharomyces cerevisiae protein through innovative electrochemical biological coupling technology, which provides a new method for high-value utilization of carbon dioxide under the drive of sustainable energy, and also provides an important reference for generating edible protein through modern agricultural innovation technology under the background of large food. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1Figure 1 is a structural schematic diagram of an electrochemical-biological coupling device for producing Saccharomyces cerevisiae protein in one embodiment of the present application, wherein 1 is a gas chamber, 2 is a cathode, 3 is a diaphragm, 4 is an extraction chamber, 5 is a cation exchange membrane, 6 is an anode, 7 is an anode chamber, 8 is an acetogenic bacteria chamber, and 9 is a separation material.

[0025] Figure 2 Figure 2 is a graph showing the control of formic acid concentration in the extraction liquid by adjusting the flow rate of the extraction liquid in one embodiment of the present application.

[0026] Figure 3 Figure 3 is a graph showing the long-term stable operation effect of the electrochemical module for producing formic acid in one embodiment of the present application.

[0027] Figure 4 Figure 4 is a graph showing the organic acid conversion and cell production in the acetogenic bacteria chamber when formic acid is used as the substrate of the biological module in one embodiment of the present application.

[0028] Figure 5 Figure 5 is a graph showing the organic acid conversion and cell production in the yeast chamber when formic acid is used as the substrate of the biological module in one embodiment of the present application. DETAILED DESCRIPTION

[0029] The technical solutions of the present application will be described in detail below with reference to the accompanying drawings.

[0030] The present application proposes an electrochemical-biological coupling technology for efficiently producing Saccharomyces cerevisiae protein. The technology first reduces carbon dioxide to formic acid through an electrochemical module, and then uses the generated formic acid as a carbon source and substrate to produce Saccharomyces cerevisiae protein through a biological module. The technology integrates the electrochemical and biological modules, and can realize the direct conversion from carbon dioxide to Saccharomyces cerevisiae protein. In the electrochemical module, carbon dioxide is catalytically reduced to formic acid, which is enriched in the extraction chamber filled with solid-state electrolyte and extracted by the extraction liquid. By adjusting parameters such as current density, voltage, and extraction liquid flow rate, the formic acid concentration in the extraction liquid can be accurately controlled to meet the carbon source requirements of the subsequent biological conversion. The biological module adopts a double-chamber structure design: one chamber is responsible for the conversion of formic acid to acetic acid, and the other chamber is responsible for the biosynthesis of acetic acid to Saccharomyces cerevisiae protein. The two chambers are separated by a separation material that is impermeable to microorganisms but permeable to acetic acid, which not only ensures the effective transfer of the substrate, but also maintains the independence of the biological process, effectively preventing the contamination of Saccharomyces cerevisiae protein by acetogenic bacteria.

[0031] In order to make the content of the present application more convenient to understand, the technical solutions described in the present application will be further described below with reference to the accompanying drawings, but the present application is not limited thereto.

[0032] Example 1

[0033] In this embodiment, the structure of the device for electrochemical biological coupling production of Saccharomyces cerevisiae protein in one specific embodiment of the present application is described, which comprises: Figure 1

[0034] 1. An electrochemical carbon dioxide reduction device:

[0035] The main components of the device include a gas chamber 1 for introducing CO2 gas, a cathode 2 for catalyzing the reduction of CO2 to form formic acid, a separator 3 covering the surface of the cathode for adjusting the microenvironment of the catalytic interface and preventing impurities in the extract solution from inhibiting the catalytic activity, an extraction chamber 4 filled with solid-state electrolyte, a cation exchange membrane 5 covering the surface of the anode for preventing the migration of inorganic acid anions in the anode chamber to the extraction chamber, an anode 6 for catalyzing the oxidation reaction, and an anode chamber 7 for introducing anode liquid.

[0036] Under the condition of electricity, the carbon dioxide introduced into the gas chamber 1 is catalytically reduced by the catalyst in the cathode 2 to form negatively charged formate ions, which are gathered in the extraction chamber 4 filled with solid-state electrolyte, and further combined with the positively charged hydrogen ions generated by the anode 6 to form formic acid molecules. At this time, the extraction liquid is introduced into the extraction chamber 4, so that the generated formic acid can be extracted by the extraction liquid. By adjusting parameters such as current density, voltage and flow rate of the extraction liquid, the concentration of formic acid in the extraction liquid can be accurately controlled to meet the carbon source demand of subsequent biological transformation.

[0037] In this embodiment, the preferred separator is filter paper (Whatman No. 1), the preferred solid-state electrolyte is strong acid cation exchange resin (particle size 30-1200 μM), the preferred cathode is a gas diffusion electrode with a sandwich structure composed of a nano-bismuth catalyst (particle size 50 nM) sprayed on a hydrophobic carbon paper as a catalytic layer, combined with a cation layer and a protective layer (its preparation method is described in patent CN 119243201A), and the preferred anode is a platinum-coated titanium felt (0.25 thick, 0.5 μm platinum-coated layer), and the preferred anode liquid is 0.5 M H2SO4 solution.

[0038] 2. A biological transformation device;

[0039] The main components of the device include an acetogenic bacteria chamber 8 for culturing acetogenic bacteria to convert formic acid to acetic acid, a separation material 9 for preventing microorganisms from passing through but allowing acetic acid to migrate, and a yeast chamber 10 for culturing Saccharomyces cerevisiae to convert acetic acid to yeast protein.

[0040] The formic acid transported from the electrochemical module is biologically transformed into acetic acid in the acetogenic bacteria chamber 8, and then transported to the yeast chamber 10 for further fermentation to produce Saccharomyces cerevisiae protein.

[0041] In this embodiment, the preferred acetogenic bacteria is Acetobacterium woodii ​(DSM1030), the preferred separator is an anion exchange membrane, and the preferred brewer's yeast is... Saccharomyces cerevisiae (BNCC341572).

[0042] Example 2

[0043] In this embodiment, combined with Figure 2 The following describes a specific embodiment of the invention, which describes how the flow rate of the extract is adjusted to control the change in the concentration of formic acid in the extract.

[0044] In this embodiment, filter paper (Whatman No. 1) was used as the separating material, and the extraction chamber was filled with 0.67 g of hydrogen-form strong acid cation exchange resin (IRC120H). The anode was a platinum-plated titanium felt. The anolyte was 100 mL of 0.5 M H₂SO₄ solution. The anolyte was circulated at a flow rate of 2 mL / min. -1 The cathode is a sandwich-structured gas diffusion electrode, consisting of a 50 nm nano-bismuth catalyst layer sprayed onto hydrophobic carbon paper, combined with a cation layer and a protective layer. The electrochemical module operates under a constant current of 400 mA via a battery testing system, considering the cathode area is 4 cm². 2 Therefore, the current density is constant at 100 mA·cm. -2 50 mL / min of pure CO2 gas was introduced into the gas chamber. -1 The experiment was conducted at room temperature. Deionized water was used as the extraction buffer, and the flow rate was adjusted sequentially to 0.05, 0.1, 0.18, 0.26, 0.5, 0.75, and 1 mL / min. -1 The electrochemical module was run for 1 hour at each flow rate to ensure stable operation. The extract was collected and the formic acid concentration in the extract was determined by liquid chromatography.

[0045] Depend on Figure 2 It can be seen that the formic acid concentration decreases with increasing extract flow rate, and the formic acid concentration is highest at a flow rate of 0.05 mL / min. -1 It reached its highest value of 53.5 g / L. -1 At a flow rate of 1 mL·min -1 It reached its lowest value of 3.4 g·L⁻¹. -1It can be observed that the formic acid concentration in the extract can be easily adjusted by controlling the flow rate of the extract. In this way, formic acid extracted from the electrochemical module can be continuously pumped into the acetic acid-producing bacteria chamber of the biomodule, achieving simultaneous production and use of formic acid; alternatively, a certain concentration and volume of formic acid-containing extract can be collected and added in batches to the acetic acid-producing bacteria chamber of the biomodule. In other words, depending on the parameters such as the concentration, activity, and volume of microorganisms in the biomodule, the collected extract can be mixed with a certain volume of biological culture medium, or compounds can be directly added to the extract to prepare a culture medium.

[0046] Example 3

[0047] In this embodiment, combined with Figure 3 The following describes the long-term stable operation of the electrochemical module producing formic acid in a specific embodiment of the present invention.

[0048] In this embodiment, filter paper (Whatman No. 1) was used as the separating material. The extraction chamber was filled with 0.67 g of hydrogen-form strong acid cation exchange resin (IRC120H). The anode was a platinum-plated titanium felt, and the cathode was a sandwich-structured gas diffusion electrode formed by spraying nano-bismuth catalyst (50 nM particle size) onto hydrophobic carbon paper as a catalyst layer, combined with a cation layer and a protective layer. The unidirectional flow rate of the extract (deionized water) was 0.05 mL / min. -1 The anolyte was 100 mL of 0.5 MH2SO4 solution at a flow rate of 2 mL / min. -1 CO2 is introduced into the gas chamber at a flow rate of 50 mL / min. -1 The extract was collected and formic acid was determined by constant current operation at 480 mA.

[0049] Depend on Figure 3 The results show that the formic acid produced by the electrochemical module has long-term stability, and the formic acid concentration in the extract remains at 40 g / L for 60 hours. -1 Above that, approximately 1 M in height.

[0050] Example 4

[0051] In this embodiment, combined with Figure 4 and Figure 5 In a specific embodiment of the present invention, when formic acid is used as the substrate of the biological module, the organic acid conversion and cell production in the acetic acid-producing bacteria chamber and the yeast chamber are described.

[0052] In this embodiment, the acetic acid-producing bacteria compartment and the yeast compartment are separated by an anion exchange membrane, and the liquid volume of both compartments is 100 mL. The bacterial strain used in the acetic acid-producing bacteria compartment is... A. woodiiThe medium formula is: 1.00 g NH4CI; 0.33 g KH4PO4; 0.45 g K2HPO4; 0.10 g MgSO4x7H2O; 20.00 mL modified Wolin's mineral solution; 2.00 g yeast extract; 0.50 mL Soudium resazurin (0.1% w / v); 10.00 g NaHCO3; 1.00 mL Wolin's vitamin solution (10x); 0.50 g L-Cysteine HCl x H2O; 0.50 g Na2S x 9H2O; 1000.00 mL deionized water. The strain used in the yeast chamber is S. cerevisiae The medium formula is: 1.000 g (NH4)2SO4; 1.000 g KH2PO4; 1.000 g MgSO4x7H2O; 0.100 g NaCI; 0.033 g CaCI2x2H2O; 5.000 mg Fe(II)SO4x7H2O; 1.600 mg ZnSO4x7H2O; 1.120 mg Mn(II)SO4xH2O; 0.280 mg Na2MoO4; 0.180 mg Co(II)CI2; 0.180 mg Cu(II)CI2x2H2O; 20.000 mg myo-inositol; 4.400 mg thiamine; 1.200 mg pyridoxine; 1.000 mg D-pantothenic acid hemicalcium salt; 0.030 mg biotin; 1000 mL deionized water. The culture temperature is 30°C.

[0053] The strain used in the yeast chamber is Figure 4 , 5 It can be seen that, in the 96 h culture time, the formic acid concentration in the acetogenesis chamber decreased from the initial 18.5 g L -1 to 3.9 g L -1 ; at the same time, the acetate concentration started to accumulate from 0 and reached 3.0 g L -1 ; in addition, the OD value of the acetogenic bacteria increased from 0.06 at the time of inoculation to 0.12. The formic acid concentration in the yeast chamber fluctuated between 1.8 and 2.2 g L -1 , indicating that formic acid can enter the yeast chamber from the acetogenesis chamber by diffusion; the acetate concentration started to accumulate from 0 and reached 0.3 g L -1 ; in addition, the OD value of the yeast increased from 0.08 at the time of inoculation to 0.3. After the reaction was completed, the yeast cells in the yeast chamber were collected by centrifugation, and the yeast protein raw material was obtained.

[0054] In summary, the acetic acid-producing bacteria in the acetic acid-producing bacteria chamber can convert formic acid into acetic acid; the Saccharomyces cerevisiae in the yeast chamber can convert acetic acid into yeast protein. That is, formic acid is the initial carbon source of the entire biological module; acetic acid is the product of the acetic acid-producing bacteria chamber and is also the substrate of the yeast chamber.

[0055] Although the present application has been described in detail, modifications within the spirit and scope of the application will be apparent to those skilled in the art, with the above description being offered by way of example only, and not intended to limit the present application.

Claims

1. A method for electrochemical biosynthetic production of Saccharomyces cerevisiae proteins, characterized by, Carbon dioxide is first reduced by an electrochemical module to form formic acid, and then the formic acid is used as a carbon source and substrate to produce Saccharomyces cerevisiae protein by a biological module; The electrochemical module comprises a gas chamber for introducing carbon dioxide, an extraction chamber filled with solid electrolyte, an anode chamber for generating oxidation reaction, and a cathode arranged between the gas chamber and the extraction chamber, and an anode arranged between the anode chamber and the extraction chamber; the solid electrolyte filled in the extraction chamber is ion exchange resin; an extraction liquid is introduced into the extraction chamber for extracting formic acid generated by reduction of carbon dioxide; The biological module is a two-chamber structure, one of which is an acetogenic bacteria chamber for culturing acetogenic bacteria to convert formic acid into acetic acid, and the other is a yeast chamber for culturing Saccharomyces cerevisiae to convert acetic acid into yeast protein; the biological module is separated into two chambers by a separation material capable of blocking microorganisms but not acetic acid migration; the acetogenic bacteria used are Acetobacterium woodii , and the Saccharomyces cerevisiae used is Saccharomyces cerevisiae .

2. The electrobiocoupled production of Saccharomyces cerevisiae proteins method according to claim 1, characterized by, The cathode surface, the side facing the extraction chamber, is covered with a diaphragm.

3. The electrobiocoupled production of Saccharomyces cerevisiae proteins method according to claim 1, characterized in that, The anode surface, the side facing the extraction chamber, is covered with a cation exchange membrane.

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