Method for promoting decomposition of peracetic acid using metal compound and method for culturing microorganism using the same

Abstract

The present invention relates to a method for decomposing peracetic acid using a metal compound and a method for culturing microorganisms using the above method. When the method of the present invention is used, the decomposition of peracetic acid can be carried out extremely rapidly, and thereby microorganisms can be cultured in a sterilized medium.

Description

Technical Field

[0001] The present invention relates to a method for promoting the decomposition of peracetic acid using a metal compound and a method for culturing microorganisms using the above method.

Background Art

[0002] In the bioprocess industry, sterilization of the culture medium and reactor is very important for the mass production of microbial raw materials and useful metabolites derived from microorganisms.

[0003] Therefore, conventionally, an autoclave, which is a sterilization method using high temperature and high pressure, has been mainly used for sterilizing microbial culture media and reactors.

[0004] However, when sterilizing the culture medium and reactor using an autoclave, the sugar component of the culture medium reacts with proteins (peptone or yeast extract), which are other components of the culture medium, at high temperature, causing the generation of toxic substances such as hydroxymethyl furfural (HMF) that may interfere with the growth of microorganisms and inhibiting the growth of microorganisms. There is also a limitation that the microbial reactor must be made of materials that are resistant to heat and pressure such as metal and glass.

[0005] To overcome the above problems and limitations, a filtration method has been used. However, in the case of filtration, there is an inconvenience that the incubator itself must be sterilized separately, and there is a high risk of clogging and recontamination occurring during the filtration process. Also, since the size of the filter is limited and it is costly, there is a problem of low commercial viability.

[0006] In order to solve such problems, as disclosed in Korean Patent Publication No. 10-2015-0097295, a sterilization method using peracetic acid (PAA) has been developed. Korean Patent Publication No. 10-2015-0097295 discloses a method of sterilizing a photobioreactor using peracetic acid when purely culturing microalgae that require light. However, the prior art does not disclose at all a method of sterilizing a medium containing sugar and a nitrogen source (such as peptone, yeast extract, whey, etc.). Also, in the method of sterilizing a photobioreactor and a medium using peracetic acid, when the medium components contain sugar and a nitrogen source, a high concentration of peracetic acid must be used for complete sterilization. Especially when sterilizing a medium with a nitrogen source added together, there is a problem that nitrogen oxides (NO 3- ) are generated, and the generated nitrogen oxides combine with iron ions to inhibit the catalytic reaction for the decomposition of peracetic acid. With only such natural decomposition of peracetic acid and the catalytic reaction by iron and 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), it has taken more than one month for the peracetic acid reactant to decompose.

[0007] On the other hand, as disclosed in Korean Patent Publication No. 10-2020-0083909, when sterilizing using a method of adding iron ions, an alkali metal hydroxide, ethylenediaminetetraacetic acid (EDTA), and sugar to a peracetic acid mixture and reacting to decompose the peracetic acid mixture into acetic acid, water, and oxygen, the time required for the decomposition of peracetic acid becomes long, and there are technical limitations that acetic acid, which is a decomposition product, inhibits the growth or kills some microorganisms.

[0008] Therefore, the present inventors have developed a method for promoting the decomposition of peracetic acid using a metal compound and a method for culturing microorganisms using the same in order to solve the problems of the prior art, and have completed the present invention.

Summary of the Invention

Problems to be Solved by the Invention

[0009] An object of the present invention is to provide a method for decomposing peracetic acid, which includes a step of mixing peracetic acid with water, and a step of adding iron ions, a hydroxide of an alkali metal, ethylenediaminetetraacetic acid (EDTA), sugar, and a metal compound to the mixture obtained by mixing the peracetic acid with water.

[0010] Another object of the present invention is to provide a method for sterilizing a medium, which includes a step of adding peracetic acid to a medium containing sugar and a nitrogen source for sterilization, and a step of adding iron ions, a hydroxide of an alkali metal, ethylenediaminetetraacetic acid (EDTA), and a metal compound as a peracetic acid decomposition accelerator to the sterilized medium.

[0011] Still another object of the present invention is to provide a method for culturing microorganisms, which includes a step of adding the medium sterilized by the above method to a bioreactor, and a step of inoculating and purely culturing microorganisms in the added medium.

Means for Solving the Problems

[0012] To achieve the above object, the present invention provides a method for decomposing peracetic acid, which includes a step of mixing peracetic acid with water, and a step of adding iron ions, a hydroxide of an alkali metal, ethylenediaminetetraacetic acid (EDTA), sugar, and a metal compound to the mixture obtained by mixing the peracetic acid with water.

[0013] Further, the present invention provides a method for sterilizing a medium, which includes a step of adding peracetic acid to a medium containing sugar and a nitrogen source for sterilization, and a step of adding iron ions, a hydroxide of an alkali metal, ethylenediaminetetraacetic acid (EDTA), and a metal compound as a peracetic acid decomposition accelerator to the sterilized medium.

[0014] Furthermore, the present invention provides a method for culturing microorganisms, including the steps of adding a medium sterilized by the above method to a bioreactor, and inoculating and purely culturing microorganisms in the added medium.

Effects of the Invention

[0015] The present invention relates to a method for decomposing peracetic acid using a metal compound and a method for culturing microorganisms using the above method. When the method of the present invention is used, peracetic acid present in the medium can be decomposed at a remarkably high speed within several minutes, whereby microorganisms can be cultured in a sterilized medium.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Best Mode for Carrying Out the Invention

[0017] Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail with embodiments of the present invention. However, the following embodiments are presented as examples of the present invention, and when a detailed description of well-known techniques or configurations that are well-known to those skilled in the art is determined to unnecessarily obscure the gist of the present invention, the detailed description thereof may be omitted, and the present invention is not limited thereby. The present invention can be variously modified and applied within the scope of the claims described below and the equivalent scope interpreted therefrom.

[0018] Throughout the specification, when a part is "connected (connected, contacted, coupled)" to another part, this includes not only the case where it is "directly connected", but also the case where it is "indirectly connected" with other elements interposed therebetween. Also, throughout the specification, when a part "includes" a certain component, this means that, unless otherwise specified, it does not exclude other components, and may further include other components.

[0019] The terms used in this specification are merely used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "including" or "having" are used to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and are not to be construed as precluding the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0020] In addition, the terminology used in this specification is the terminology used to appropriately represent the preferred embodiments of the present invention, which may vary depending on the intention of the user, operator, or the convention in the field to which the present invention belongs. Therefore, the definitions of these terms should be made based on the content throughout this specification. Throughout the specification, when a certain part describes a component as "including", unless otherwise specified, this does not exclude other components, but means that other components may also be further included.

[0021] The term "sterilization" used in the present invention means killing the vegetative cells and spores of microorganisms.

[0022] The term "metal compound" used in the present invention may mean a compound containing metal ions that can bind to acetic acid, such as sodium, calcium, potassium, etc.

[0023] The term "alkali metal" used in the present invention may mean an element belonging to Group 1 of the periodic table, and specifically may include lithium (Li), sodium (Na), and potassium (K) excluding hydrogen.

[0024] The term "peracetic acid mixture" used in the present invention may mean a mixture formed by mixing peracetic acid with water. In the present invention, the peracetic acid mixture may contain peracetic acid, acetic acid, and hydrogen peroxide.

[0025] The term "peracetic acid reactant" used in the present invention may mean a substance obtained by adding iron ions, alkali metal hydroxides, ethylenediaminetetraacetic acid (EDTA), sugar, and metal compounds to the peracetic acid mixture. The peracetic acid reactant in the present invention may contain hydrogen peroxide, acetic acid, or sodium acetate (CH 3 COONa), etc. On the other hand, the peracetic acid reactant may contain sodium acetate (CH 3 COONa), calcium acetate ((CH 3 COO)2 (Ca), or may contain potassium acetate (CH 3 COOK), etc., but is not limited thereto.

[0026] The term "medium" used in the present invention is also called a culture vessel or a culture solution, and is a substance designed to maintain a nutritional state similar to the natural environment in which microorganisms generally survive and reproduce for the purpose of growing or culturing microorganisms, and means liquid and solid substances made by adding all the nutrients necessary for growth. The culture of microorganisms in a culture medium depends on various important factors such as the selection of essential nutrients, oxygen or gases necessary for culture, moisture, pH and temperature, and important nutrients may include carbon, nitrogen, inorganic phosphate and sulfur, trace metals, water and vitamins, etc.

[0027] As one aspect for achieving the above technical problem, the present invention mixing peracetic acid with water, adding iron ions, an alkali metal hydroxide, ethylenediaminetetraacetic acid (EDTA: Ethylenediaminetetraacetic acid), sugar and a metal compound to the mixture, the metal compound is sodium bicarbonate (NaHCO 3 ), sodium hydrogen phosphate (Na 2 HPO 4 ), calcium carbonate (CaCO 3 ), calcium lactate (Ca(CH 3 CHOHCOO) 2 ·5H 2 O), and dipotassium phosphate (K 2 HPO 4 ), and provides a method for decomposing peracetic acid, characterized by containing any one or more selected from the group consisting of.

[0028] In the method for decomposing peracetic acid of the present invention, the iron ions may be Fe 2+ ions or Fe 3+ ions, and the iron ions are FeCI 3 、FeCI2 and / or salts derived from Fe ions such as FeSO 4 may also be included.

[0029] The hydroxide of the alkali metal may be LiOH, NaOH or KOH, but is not limited thereto.

[0030] The sugar may be dextrose, glucose, sucrose, and / or molasses, but is not limited thereto.

[0031] The metal compound is sodium bicarbonate (NaHCO 3 ), sodium hydrogen phosphate (Na 2 HPO 4 ), calcium carbonate (CaCO 3 ), calcium lactate (Ca(CH 3 CHOHCOO) 2 ·5H 2 O), and dipotassium phosphate (K 2 HPO 4 ), and may be characterized by containing any one or more selected from the group consisting of them.

[0032] The concentration of the contained compound may be characterized by being 0.005% (w / v) or more, preferably 0.025% (w / v) or more, more preferably 0.05% (w / v) or more, and most preferably 0.08% (w / v) or more.

[0033] The method for decomposing peracetic acid of the present invention may be characterized by removing acetic acid that inhibits the growth of microorganisms contained in the peracetic acid reactant and significantly promoting the overall peracetic acid decomposition reaction. In one embodiment of the present invention, in order to remove acetic acid contained in the peracetic acid reactant, sodium bicarbonate (NaHCO 3 ), sodium hydrogen phosphate (Na 2 HPO 4 ), calcium carbonate (CaCO 3 ), calcium lactate (Ca(CH 3 CHOHCOO) 2 ·5H 2(O), and dipotassium phosphate (K 2 HPO 4 ) or any one or more selected from the group consisting thereof were used, but the metal compound may include a compound composed of ions capable of binding to acetic acid such as sodium, potassium, and / or calcium, and the scope of the right is not limited thereto.

[0034] In the step of mixing peracetic acid in the method for decomposing peracetic acid of the present invention with water, peracetic acid and water can be mixed at room temperature, whereby a peracetic acid mixture can be produced, and the peracetic acid mixture may contain hydrogen peroxide and acetic acid. 1) CH 3 CO 3 H (peracetic acid) + H 2 O → H 2 O 2 (hydrogen peroxide) + CH 3 CO 2 H (acetic acid)

[0035] On the other hand, hydrogen peroxide produced by the reaction of peracetic acid and water can be decomposed into acetic acid, water and oxygen by the Fenton reaction with iron ions as shown in the following reaction formula. 2) 2CH 3 CO 3 H → 2CH 3 CO 2 H + O 2 3) 2H 2 O 2 → 2H 2 O + O 2

[0036] At this time, hydrogen peroxide may be used as an oxidizing agent, a bleaching agent and a disinfectant, and may also be used for sterilizing the medium in relation to the present invention.

[0037] The step of adding iron ions, alkali metal hydroxides, ethylenediaminetetraacetic acid (EDTA), sugar, and metal compounds to the peracetic acid mixture in the method for decomposing peracetic acid of the present invention may be carried out at room temperature, whereby peracetic acid reactants can be generated. The peracetic acid reactants may contain hydrogen peroxide, acetic acid, or sodium acetate (CH 3 COONa), etc. On the other hand, depending on the added metal compound, the peracetic acid reactants may contain sodium acetate (CH 3 COONa), calcium acetate ((CH 3 COO) 2 Ca), or potassium acetate (CH 3 COOK), etc., but are not limited thereto.

[0038] The following example is one in which sodium bicarbonate (NaHCO 3 ) is added to acetic acid (CH 3 ) to produce sodium acetate (CH 3 COONa). 4-1)CH 3 COOH + NaHCO 3 →CH 3 COONa + CO 2 + H 2 O 4-2)2CH 3 COOH + Na2HPO 4 →2CH 3 COONa + H 3 PO 4

[0039] The following example is one in which calcium carbonate (CaCO 3 ) is added to acetic acid (CH 3 ) to produce calcium acetate ((CH 3 COO) 2 Ca). 4-3)2CH 3 COOH + CaCO 3 →(CH 3 COO) 2 Ca + CO 2 + H 2 O 4 - 4) 2CH 3 COOH + Ca(CH 3 CHOHCOO) 2 ·5H 2 O + 6O 2 → (CH 3 COO) 2 Ca + 6CO 2 + 6H 2 O

[0040] The following example is the one where sodium bicarbonate is added to acetic acid (CH 3 COOH) to produce sodium acetate. 4 - 5) CH 3 COOH + KH 2 PO 4 → CH 3 COOK + H 2 PO 4 - 4 - 6) 2CH 3 COOH + K 2 HPO 4 → 2CH 3 COOK + H 3 PO 4

[0041] In the method for decomposing peracetic acid of the present invention, a basic buffer solution may be used instead of the alkali metal hydroxide, and a basic buffer solution may be further added. The basic buffer solution may be 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), but is not limited thereto.

[0042] As another aspect, the present invention includes the steps of adding peracetic acid to a medium containing a sugar and a nitrogen source for sterilization, and adding iron ions, an alkali metal hydroxide, ethylenediaminetetraacetic acid (EDTA), and a metal compound as a peracetic acid decomposition accelerator to the sterilized medium. The metal compound is sodium bicarbonate (NaHCO3 ) Sodium hydrogen phosphate (Na 2 HPO 4 ), calcium carbonate (CaCO 3 ), calcium lactate (Ca(CH 3 CHOHCOO) 2 ·5H 2 O), and dipotassium phosphate (K 2 HPO 4 ), and provides a method for sterilizing a medium, characterized by containing any one or more selected from the group consisting of.

[0043] In the method for sterilizing a medium of the present invention, the details of the method for decomposing peracetic acid can be appropriately applied without departing from the gist of the present invention.

[0044] By the method for sterilizing a medium of the present invention, peracetic acid, a peracetic acid mixture, and a peracetic acid reaction product present in the sterilized medium can be decomposed, and the medium produced thereby can be used for culturing microorganisms.

[0045] In the method for sterilizing a medium of the present invention, the iron ion may be an Fe 2+ ion or an Fe 3+ ion, and the iron ion may be derived from a salt containing an Fe ion such as FeCI 3 , FeCI 2 , and / or FeSO 4 .

[0046] In the method for sterilizing a medium of the present invention, the hydroxide of an alkali metal may be LiOH, NaOH, or KOH, but is not limited thereto.

[0047] In the method for sterilizing a medium of the present invention, the sugar may be dextrose, glucose, sucrose, and / or waste sugar, but is not limited thereto.

[0048] In the method for sterilizing the medium of the present invention, the concentration of the metal compound is 0.005% (w / v) or more, preferably 0.025% (w / v) or more, more preferably 0.05% (w / v) or more, and most preferably 0.08% (w / v) or more.

[0049] In the method for sterilizing the medium of the present invention, a basic buffer solution may be used instead of the alkali metal hydroxide, or a basic buffer solution may be further added. The basic buffer solution may be 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES).

[0050] When the medium is sterilized as in the method of the present invention, there is an advantage that it can be stored for a long time without autoclaving before neutralization and without being contaminated even in an open container.

[0051] As yet another aspect, the present invention provides a step of adding the medium sterilized by the above method to a bioreactor, and a step of inoculating the added medium with microorganisms and performing pure culture.

[0052] In the method for culturing microorganisms of the present invention, the details of the method for sterilizing the medium can be appropriately applied without departing from the gist of the present invention.

[0053] In the method for culturing the microorganism of the present invention, the microorganism may be, but is not limited to, Aurantiochytrium sp., Schizochytrium sp., Chlorella sp., Synechocystis sp., Debaryomyces sp., yeast flora, lactic acid bacteria flora, actinomycetes flora, Euglena, Mortierella, filamentous flora and / or photosynthetic bacteria.

[0054] The inoculation of the microorganism may mean an act of planting the microorganism in an environment where the microorganism can grow in order to culture the microorganism, and may include, but is not limited to, the streak plating method, the spread plate method, and the pour plate method.

[0055] The pure culture means culturing a microorganism or the like in a state where only a single species exists in a medium. At this time, it is possible to confirm whether or not it has been purely cultured by confirming whether or not a single colony has been formed using the streak plating method.

[0056] According to one embodiment of the present invention, it was confirmed that when sodium hydrogen carbonate is added to the peracetic acid mixture, the decomposition rate of peracetic acid increases significantly, and as the concentration of sodium hydrogen carbonate added increases, the decomposition rate of peracetic acid gradually increases (Examples 1 to 6 and Comparative Example 1).

[0057] Hereinafter, the present invention will be described in detail with reference to examples.

[0058] However, the following examples illustrate the present invention, and the content of the present invention is not limited by the examples.

[0059] Example 1. Confirmation of acceleration of peracetic acid decomposition by sodium hydrogen carbonate 5 g / L of yeast extract and 20 g / L of dextrose were added to 1 L of distilled water to prepare a microbial medium, and then peracetic acid (same name ONC, 160126) was added so that the concentration of the peracetic acid solution was 0.05% (v / v).

[0060] 96 uM FeCl 3 (Sigma, 7705 - 08 - 0), 5.5 mM NaOH (Sigma, 1310 - 73 - 2) and 96 uM EDTA (Sigma, 60 - 00 - 4) were added, and then sodium bicarbonate (NaHCO 3 , Samchun Pure Chemical Industry, S0343) was added so that the concentration was 0.05% (w / v).

[0061] The decomposition degree of peracetic acid was measured using a peroxide test (Peroxide Test) (MQuant 1100810001) that can measure peroxide, which is a decomposition product of the peracetic acid solution.

[0062] Comparative Example 1. Without addition of sodium bicarbonate The experiment was conducted in the same manner as in Example 1, but sodium bicarbonate was not added.

[0063] Examples 2 - 6. Concentration difference of sodium bicarbonate The experiment was conducted in the same manner as in Example 1, but sodium bicarbonate was added at concentrations of 0.1% (w / v) (Example 2), 0.15% (w / v) (Example 3), 0.2% (w / v) (Example 4), 0.25% (w / v) (Example 5), and 0.3% (w / v) (Example 6), respectively.

[0064] Example 7. Confirmation of promotion of peracetic acid decomposition by sodium dihydrogen phosphate The experiment was conducted in the same manner as in Example 1, but sodium hydrogen phosphate (Na 2 HPO 4 , Samchun Pure Chemical Industry, S0893) was added at a concentration of 0.05% (w / v).

[0065] Example 8. Confirmation of Promotion of Peracetic Acid Decomposition by Calcium Carbonate The experiment was conducted in the same manner as in Example 1, but calcium carbonate (CaCO 3、 Samchun Pure Chemical Industries, S0076) was added at a concentration of 0.05% (w / v).

[0066] Example 9. Confirmation of Promotion of Peracetic Acid Decomposition by Calcium Lactate The experiment was conducted in the same manner as in Example 1, but calcium lactate (Ca(Ca(CH 3 CHOHCOO) 2 ·5H 2 O, Oi Chemical Industry, 2513 - 4405) was added at a concentration of 0.05% (w / v).

[0067] Example 10. Confirmation of Promotion of Peracetic Acid Decomposition by Dipotassium Phosphate The experiment was conducted in the same manner as in Example 1, but dipotassium phosphate (K 2 HPO 4、 Samchun Pure Chemical Industries, P1098) was added at a concentration of 0.05% (w / v).

[0068] Example 11. Confirmation of the Presence or Absence of Growth Inhibition of Microorganisms by Sodium Acetate The following experiment was conducted to confirm whether sodium peracetate, a decomposition product of peracetic acid, inhibits the growth of microorganisms.

[0069] A nutrient medium for culturing Euglena gracilis (containing triple - distilled water, KH 2 PO 4 , citrate, MgSO 4 ·3H 2 O, vitamin B1, vitamin B6, vitamin B12, vitamin H, yeast extract, peptone, and dextrose) was prepared by autoclaving at 121°C for 15 minutes. Sodium acetate (CH 30.05% (w / v) of sodium acetate was added, and then the Euglena gracilis strain (KCTC AG40099) was inoculated. While stirring at 130 rpm, the culture was carried out at 28 °C under the condition of 100 μE photons / m 2 / s, and its growth degree was measured by the absorbance at a wavelength of 680 nm.

[0070] Examples 12 - 15. Concentration difference of sodium acetate Experiments were conducted in the same manner as in Example 11, but sodium acetate was added at concentrations of 0.1% (w / v) (Example 12), 0.15% (w / v) (Example 13), 0.2% (w / v) (Example 14), and 0.25% (w / v) (Example 15), respectively.

[0071] Comparative Example 2. Confirmation of the presence or absence of growth inhibition of microorganisms by acetic acid Experiments were conducted in the same manner as in Example 11, but acetic acid was added instead of sodium acetate.

[0072] Comparative Examples 3 - 6. Concentration difference of acetic acid Experiments were conducted in the same manner as in Comparative Example 2, but acetic acid was added to the prepared nutrient medium at concentrations of 0.1% (w / v) (Comparative Example 3), 0.15% (w / v) (Comparative Example 4), 0.2% (w / v) (Comparative Example 5), and 0.25% (w / v) (Comparative Example 6), respectively, instead of sodium acetate.

[0073] Example 16. Confirmation of the effect of sodium bicarbonate on the growth of microorganisms for promoting peracetic acid decomposition In order to confirm the effect of sodium bicarbonate added to the peracetic acid mixture on the growth of microorganisms, the following experiment was conducted.

[0074] Specifically, a nutrient medium for culturing Euglena gracilis (triple - distilled water, KH 2 PO 4 , citrate, MgSO 4 ·3H 2O, vitamin B1, vitamin B6, vitamin B12, vitamin H, yeast extract, peptone and dextrose) was prepared by autoclaving at 121 °C for 15 minutes, and peracetic acid was added to the nutrient medium so that the concentration of the peracetic acid solution became 0.05% (w / v). Then, 96 uM FeCl 3 (Sigma, 7705-08-0), 5.5 mM NaOH (Sigma, 1310-73-2) and 96 uM EDTA (Sigma, 60-00-4) were added, and then sodium bicarbonate (NaHCO 3 ) was added so that the concentration became 0.05% (w / v). After confirming that the added peracetic acid was decomposed using a Peroxide Test (MQuant 1100810001), Euglena gracilis was inoculated and cultured, and the growth degree of Euglena gracilis was measured by the absorbance at a wavelength of 680 nm.

[0075] Comparative Example 7. Without addition of sodium bicarbonate An experiment was conducted in the same manner as in Example 16, but sodium bicarbonate was not added.

[0076] Examples 17 to 21. Concentration difference of sodium bicarbonate An experiment was conducted in the same manner as in Example 16, but sodium bicarbonate was added at concentrations of 0.1% (w / v) (Example 17), 0.15% (w / v) (Example 18), 0.20% (w / v) (Example 19), 0.25% (w / v) (Example 20), and 0.3% (w / v) (Example 21), respectively.

[0077] Experimental Example 1. Confirmation of the promoting effect of sodium bicarbonate on the decomposition of peracetic acid according to the concentration In order to confirm the effect of sodium bicarbonate and its concentration on the decomposition of peracetic acid, an experiment was conducted in the same manner as in Examples 1 to 6 and Comparative Example 1.

[0078] As a result, i) when sodium bicarbonate, which is a metal compound, was added (Examples 1 to 6), it was confirmed that the decomposition rate of peracetic acid increased significantly compared to the case where sodium bicarbonate was not added (Comparative Example 1) (Table 1), and ii) it was confirmed that the decomposition rate of peracetic acid increased by increasing the sodium bicarbonate concentration from 0.05 to 0.25.

[0079] Specifically, when 0.2% (w / v) or more of sodium bicarbonate was added (Examples 4 to 6), the decomposition of peracetic acid was completed within several minutes. However, when sodium bicarbonate was not added (Comparative Example 1), it was confirmed that it took 48 hours for peracetic acid to be completely decomposed (Table 1). Even when 0.05% (w / v) of sodium bicarbonate was added (Example 1), peracetic acid was completely decomposed within 3 hours. Therefore, compared to Comparative Example 1 where the decomposition time exceeded 24 hours, the decomposition time was 1 / 8 or less, and it was confirmed that the decomposition rate increased significantly.

[0080] [Table 1] -NHC:NaHCO 3 - The numerical values in Tables 1 to 5 represent the concentration of the existing peroxide. For example, ">100" means that a peroxide of 100 mg / L or more remains. - The numerical values in parentheses in Tables 1 to 5 represent the concentration % (w / v) of NaHCO 3 .

[0081] Experimental Example 2: Confirmation of the effect of promoting the decomposition of peracetic acid by different types of metal compounds In order to confirm the effect of the metal compound on the decomposition of peracetic acid, experiments were conducted in the same manner as in Example 1, Examples 7 to 9, and Comparative Example 1.

[0082] As a result, when sodium bicarbonate (NaHCO 3 ), which is a metal compound, was added (Example 1), peracetic acid was decomposed quite rapidly within 1 hour. However, when disodium phosphate (Na 2 HPO 4When was added (Example 7), the decomposition rate of peracetic acid increased significantly, and peracetic acid was completely decomposed within 12 hours. Also, in the case of calcium carbonate, it was completely decomposed within 1 hour as in the case of sodium hydrogen carbonate (Example 8). When calcium lactate or dipotassium phosphate was added, it was also completely decomposed within 24 hours. It was confirmed that the decomposition rate increased compared to the case where no metal compound was added (Examples 9 and 10) (Table 2).

[0083]

Table 2

[0084] Experimental Example 3: Presence or absence of growth inhibition of microorganisms by acetic acid or sodium acetate Acetic acid (CH 3 COOH), which is a decomposition product of peracetic acid, and sodium acetate (CH 3 COONa), which is the final product, were used to confirm the effects on the growth of microorganisms. Experiments were conducted in the same manner as in Examples 11 to 15 and Comparative Examples 2 to 6.

[0085] As a result, in Comparative Example 2 where the concentration of acetic acid was 0.05% (w / v), it was confirmed that it did not act as an inhibitory factor for the growth of Euglena gracilis. However, in the groups where a concentration of 0.1% (w / v) or more was added (Comparative Examples 3 to 6), it was confirmed that the growth of Euglena gracilis was inhibited (Figure 1).

[0086] On the other hand, in the sodium acetate-added groups (Examples 11 to 15), it was confirmed that Euglena gracilis grew well under all conditions (Figure 2). Thus, it was confirmed that sodium acetate did not inhibit the growth of Euglena gracilis.

[0087] The numerical values in Tables 3 and 4 represent the absorbance (AU, 680 nm) of Euglena gracilis culture solution, and the result values in Tables 3 and 4 are shown graphically in Figure 3.

[0088]

Table 3

[0089]

Table 4

[0090] Experimental Example 4. Presence or absence of growth inhibition of microorganisms by sodium hydrogen carbonate In order to confirm the effect of sodium hydrogen carbonate used to decompose peracetic acid and the decomposition products of peracetic acid into the final products on the growth of Euglena gracilis, experiments were conducted in the same manner as in Comparative Example 7 and Examples 16 to 21.

[0091] As a result, it was confirmed that the growth of Euglena was high in all experimental groups of Comparative Example 7 with only peracetic acid added and Examples 16 to 21 with peracetic acid and sodium hydrogen carbonate added. Thus, it was confirmed that peracetic acid and sodium hydrogen carbonate used for the decomposition of peracetic acid did not particularly affect the growth of Euglena gracilis (Table 5 and Figure 4).

[0092]

Table 5

Claims

1. A step of mixing peracetic acid with water, A step of adding iron ions, hydroxides of alkali metals, ethylenediaminetetraacetic acid (EDTA), sugar, and a metal compound to the mixture, comprising, The metal compound is sodium bicarbonate (NaHCO ３ ), sodium hydrogen phosphate (Na ２ HPO ４ ), calcium carbonate (CaCO ３ ), calcium lactate (Ca(CH ３ CHOHCOO) ２ ·5H ２ O), and dipotassium phosphate (K ２ HPO ４ ), and the method for decomposing peracetic acid is characterized by containing one or more selected from the group consisting of these substances.

2. The iron ion is Fe ２＋ ion or Fe ３＋ ion, and the method for decomposing peracetic acid according to claim 1.

3. The method for decomposing peracetic acid according to claim 1, wherein the sugar is dextrose, glucose, sucrose, or waste sugar.

4. The method for decomposing peracetic acid according to claim 1, characterized in that the concentration of the metal compound is 0.005% (w / v) or more.

5. The method for decomposing peracetic acid according to claim 1, further adding a basic buffer solution.

6. A step of adding peracetic acid to a medium containing sugar and a nitrogen source and sterilizing, A step of adding iron ions, hydroxides of alkali metals, ethylenediaminetetraacetic acid (EDTA), and a metal compound as a peracetic acid decomposition accelerator to the sterilized medium, comprising, The metal compound is sodium bicarbonate (NaHCO ３ ), sodium hydrogen phosphate (Na ２ HPO ４ ), calcium carbonate (CaCO ３ ), calcium lactate (Ca(CH ３ CHOHCOO) ２ ·5H ２ O), and dipotassium phosphate (K ２ HPO ４ ), and the method for sterilizing a medium is characterized by containing any one or more selected from the group consisting of these substances.

7. The iron ion is Fe ２＋ ion or Fe ３＋ ion, and the method for sterilizing the medium according to claim 6.

8. The method for sterilizing a medium according to claim 6, wherein the sugar is dextrose, glucose, sucrose, or waste sugar.

9. The method for sterilizing a medium according to claim 6, characterized in that the concentration of the metal compound is 0.005 (w / v)% or more.

10. The method for sterilizing a medium according to claim 6, further adding a basic buffer solution.

11. A step of adding the medium sterilized by the method according to claim 6 to a bioreactor, A step of inoculating microorganisms into the added medium and performing pure culture, comprising, a method for culturing microorganisms.

12. The method for culturing microorganisms according to claim 11, wherein the microorganisms are one or more selected from the group consisting of Aurantiochytrium sp., Schizochytrium sp., Chlorella sp., Synechocystis sp., Debaryomyces sp., yeast flora, lactic acid bacteria, actinomycetes, Euglena, Mortierella, filamentous flora, and photosynthetic bacteria.

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