Antimicrobial composition for plant culture medium

Abstract

The present invention relates to an antimicrobial composition for a plant culture medium, which has high physicochemical stability, so that active ingredients remain without being destroyed during a high-temperature and high-pressure sterilization process, thereby exhibiting an excellent antimicrobial effect, has no phytotoxicity, can be easily added to a plant medium, and has high convenience of long-term use without a problem of corroding a plant tissue culture container made of polycarbonate, thereby being able to be effectively used to prevent contamination of microorganisms with respect to a plant tissue culture medium or a nutrient solution for hydroponics.

Description

composition for antimicrobial use in plant media

[0001] The present invention relates to a composition for antimicrobial agents in a plant culture medium.

[0002] In the plant production process, it is very important to suppress the growth of microorganisms after the preparation of the culture medium. During the preparation of culture media for plant tissue culture, the medium is sterilized using filtration sterilization methods, such as filtering with a micropore filter, or high-temperature and high-pressure sterilization methods, such as high-temperature and high-pressure sterilization in an autoclave. However, after this process, microbial spores may unexpectedly enter through the air or microorganisms contained in the transplanted plant may enter, contaminating the inside of the culture bottle, which must be maintained in a sterile state.

[0003] To prevent this, the method of transplanting plants into a medium containing antifungal agents or antibiotics is conventionally used. Antifungal agents that have been conventionally added include benzimidazole, and antibiotics include penicillin G, streptomycin, and oxytetracycline.

[0004] However, high-temperature and high-pressure sterilization is problematic because it can destroy the molecular structure of antibiotics, thereby reducing their antibacterial efficacy, and there is also the issue of reduced culture efficiency due to the phytotoxicity of antibiotics and antifungals.

[0005] Meanwhile, in addition to plant tissue culture, hydroponics is another representative application of culture media in plant production. However, due to the nature of hydroponics, where plants are grown in a closed and isolated environment using nutrient solutions, contamination of the solution poses a significant problem. Consequently, the proliferation of microorganisms within the solution is generally suppressed by methods such as sterilizing the solution using ultraviolet (UV) light or ozone generators, or by continuously circulating the solution to inhibit microbial growth. However, such methods require investment in large-scale facilities, and in the case of some methods, such as UV sterilization, they currently fail to demonstrate sufficient sterilization effects.

[0006] In addition, in the Temporary Immersion System (TIS), which utilizes plant tissue culture technology but propagates explants by immersing them in a liquid medium rather than a solid medium, external air is continuously injected into the culture vessel. Although the system undergoes a single filtration process, contaminants from the outside air can still enter, making infection control necessary to maintain the TIS system.

[0007] Accordingly, the inventors conducted research to develop an antimicrobial composition that can be easily added to a plant culture medium and is highly effective in inhibiting microbial growth within the plant culture medium, thereby completing the present invention.

[0008] One objective of the present invention is to provide a composition for antimicrobial plant media comprising 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, potassium sorbate, and phenoxyethanol.

[0009] One aspect of the present invention provides a composition for antimicrobial plant media comprising 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, potassium sorbate, and phenoxyethanol.

[0010] According to one embodiment of the present invention, the weight ratio of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one may be 1:15 to 5:6.

[0011] According to one embodiment of the present invention, the composition further comprises water, and based on the total weight of the water, may comprise 0.0750 to 0.1875 weight% of 5-chloro-2-methyl-4-isothiazolin-3-one; 0.0125 to 0.0625 weight% of 2-methyl-4-isothiazolin-3-one; 0.40 to 0.60 weight% of potassium sorbate; and 0.45 to 0.30 weight% of phenoxyethanol.

[0012] According to one embodiment of the present invention, 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, potassium sorbate, and phenoxyethanol may be in an amount of 0.98 to 1.10% by weight based on the total weight of water.

[0013] According to one embodiment of the present invention, the plant medium may be a medium for plant tissue culture.

[0014] According to one embodiment of the present invention, the composition may be included in an amount of 0.5 to 10.0 ml based on 1 L of the plant tissue culture medium.

[0015] According to one embodiment of the present invention, the plant medium may be a nutrient solution for hydroponic cultivation.

[0016] According to one embodiment of the present invention, the composition may be included in an amount of 0.1 to 1.5 weight percent based on the total weight of the nutrient solution for hydroponic cultivation.

[0017] According to one embodiment of the present invention, the composition may have antibacterial activity against Staphylococcus aureus and Botrytis cinerea.

[0018] According to the composition for antimicrobial use in plant culture media, it exhibits excellent antimicrobial effects as the active ingredients remain intact without being destroyed during high-temperature and high-pressure sterilization due to high physicochemical stability. Furthermore, it is non-toxic to plants, can be easily added to plant culture media, and offers high convenience for long-term use as it does not cause corrosion of polycarbonate plant tissue culture containers. Therefore, it can be effectively utilized to prevent microbial contamination of plant tissue culture media or hydroponic nutrient solutions.

[0019] Figure 1 is a photograph showing a comparison of whether discoloration of the culture bottle occurs in (A) a culture bottle with an antimicrobial composition for a plant medium according to one embodiment of the present invention added, and (B) a culture bottle with a conventional infection inhibitor added.

[0020] One aspect of the present invention provides a composition for antimicrobial plant media comprising 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, potassium sorbate, and phenoxyethanol.

[0021] The term "plant medium" as used in the present invention refers to a medium used in plant production and includes a tissue culture medium applied to the proliferation, growth, and differentiation induction of plant tissue or callus, a liquid or solid medium that provides an environment such as water and nutrients necessary for the proliferation, growth, and reproductive activities of plant individuals through the plant roots, and a medium that provides mechanical strength so that the plant roots can be physically supported. The plant medium of the present invention may be, for example, a medium for plant tissue culture and a nutrient solution for plant hydroponics.

[0022] In the present invention, "antimicrobial" or "antimicrobial activity" refers to a property of resisting microorganisms such as bacteria or fungi, and more specifically, refers to a characteristic of antibiotics, etc., that inhibits the growth or proliferation of microorganisms.

[0023] In the present invention, "antimicrobial composition" means a composition having activity that inhibits the growth of microorganisms such as bacteria or fungi. In the present invention, the antimicrobial composition means a composition having activity that inhibits the growth of microorganisms such as bacteria or fungi, using 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one as main ingredients.

[0024] Healthy plants generally do not contain internal microorganisms, but infection can occur in diseased plants or through structural wounds on the roots or above-ground parts. If even a single bacterium is present in the inoculated tissue, there is a possibility of contamination during culture. Internal plant infections are commonly caused by rod-shaped bacteria, particularly Bacillus licheniformis and Bacillus subtilis; their spores can withstand adverse environmental conditions such as heat, dryness, and low temperatures, as well as ultraviolet radiation.

[0025] The antimicrobial composition of the present invention has excellent antibacterial effects against plant internal infectious bacteria such as Bacillus licheniformis and Bacillus subtilis, so it can effectively prevent contamination of the sterile medium by plant internal infectious bacteria. In addition, the antimicrobial composition of the present invention has excellent antibacterial activity against microorganisms problematic in plant media, such as Staphylococcus aureus and Botrytis cinerea, a fungus that causes gray mold disease, so it can effectively prevent contamination of the sterile medium by various external microorganisms.

[0026] In addition, the antimicrobial composition of the present invention may be used by further including existing antimicrobial agents and / or antifungal agents, for example, may further include antimicrobial / antifungal agents of the penicillin class, quinolone class, tetracycline class, sulfonamide class, and macrolide class, but is not limited thereto.

[0027] When conventional antimicrobial agents and / or antifungal agents are added to the antimicrobial composition of the present invention, antimicrobial activity against a wider variety of microorganisms can be exhibited due to antimicrobial / antifungal actions with different mechanisms, and further antimicrobial activity can be enhanced. Additionally, since sufficient antimicrobial activity can be exhibited with a smaller amount compared to when conventional antimicrobial / antifungal agents are used alone, plant toxicity issues associated with the sole use of conventional antimicrobial / antifungal agents can be mitigated or resolved.

[0028] The antimicrobial composition according to the present invention may be prepared, for example, in the form of a directly sprayable solution, powder, and suspension, or as a highly concentrated aqueous, oily, or other suspension, dispersion, emulsion, oily dispersion, paste, dust, scattering material, or granule, but is not limited thereto.

[0029] According to one embodiment of the present invention, the weight ratio of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one may be 1:15 to 5:6.

[0030] If 5-chloro-2-methyl-4-isothiazolin-3-one is included in an amount of less than 1 weight per 15 weight of 2-methyl-4-isothiazolin-3-one, or if 5-chloro-2-methyl-4-isothiazolin-3-one is included in an amount of more than 5 weight per 6 weight of 2-methyl-4-isothiazolin-3-one, the antibacterial and antifungal activity of the composition may not be sufficient, and the synergistic effect with potassium sorbate and / or phenoxyethanol may not be sufficient. Therefore, the weight ratio of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one is preferably 1:15 to 5:6, more preferably 2:1 to 4:1, and most preferably 3:1.

[0031] According to one embodiment of the present invention, the composition further comprises water, and based on the total weight of the water, may comprise 0.0750 to 0.1875 weight% of 5-chloro-2-methyl-4-isothiazolin-3-one; 0.0125 to 0.0625 weight% of 2-methyl-4-isothiazolin-3-one; 0.40 to 0.60 weight% of potassium sorbate; and 0.45 to 0.30 weight% of phenoxyethanol.

[0032] According to one embodiment of the present invention, 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, potassium sorbate, and phenoxyethanol may be in an amount of 0.98 to 1.10% by weight based on the total weight of water.

[0033] When, based on the total weight of water, 5-chloro-2-methyl-4-isothiazolin-3-one is 0.0750 to 0.1125 wt%, 2-methyl-4-isothiazolin-3-one is 0.0500 to 0.0625 wt%, potassium sorbate is 0.40 to 0.45 wt%, and phenoxyethanol is 0.40 to 0.45 wt%, an effect on antibacterial and antifungal activity is exhibited. In addition, when 5-chloro-2-methyl-4-isothiazolin-3-one is 0.1500 wt%, 2-methyl-4-isothiazolin-3-one is 0.0375 to 0.0500 wt%, potassium sorbate is 0.45 to 0.50 wt%, and phenoxyethanol is 0.35 wt% based on the total weight of water, an effect on antibacterial and antifungal activity is observed. In addition, when 5-chloro-2-methyl-4-isothiazolin-3-one is 0.1875 wt%, 2-methyl-4-isothiazolin-3-one is 0.0125 to 0.0250 wt%, potassium sorbate is 0.55 to 0.60 wt%, and phenoxyethanol is 0.30 wt% based on the total weight of water, an effect on antibacterial and antifungal activity is observed.

[0034] Meanwhile, when 5-chloro-2-methyl-4-isothiazolin-3-one is 0.0375 to 0.1500 wt%, 2-methyl-4-isothiazolin-3-one is 0.0125 wt%, potassium sorbate is 0.60 wt%, and phenoxyethanol is 0.35 to 0.50 wt% based on the total weight of water, the mixture of 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, potassium sorbate, and phenoxyethanol is included in an amount of 0.11 to 1.15 wt% based on the total weight of water, and no effect on antibacterial and antifungal activity is observed in this range. On the other hand, the mixing ratio of the mixture of 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, potassium sorbate, and phenoxyethanol exhibiting antibacterial and antifungal effects is 0.98 to 1.10% by weight based on the total weight of water, and since it exhibits antibacterial and antifungal effects at less than 0.11% by weight based on the total weight of water, a synergistic effect on the antibacterial and antifungal effects of 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, potassium sorbate, and phenoxyethanol is recognized in that range.

[0035] According to one embodiment of the present invention, the plant medium may be a medium for plant tissue culture.

[0036] According to one embodiment of the present invention, the composition may be included in an amount of 0.5 to 10.0 ml based on 1 L of the plant tissue culture medium.

[0037] When the antimicrobial composition for plant tissue culture of the present invention is used in an amount of less than 0.5 ml per 1 L of plant tissue culture medium, the antimicrobial activity against microorganisms in the medium may not be sufficient, and when it is included in an amount of more than 10.0 ml, the antimicrobial activity does not increase significantly compared to when it is included in an amount of 10.0 ml. Therefore, it is preferable that the antimicrobial composition of the present invention be included in an amount of 0.5 to 10.0 ml per 1 L of plant tissue culture medium, and more preferable that it be included in an amount of 1 to 4 ml.

[0038] According to one embodiment of the present invention, the plant medium may be a nutrient solution for hydroponic cultivation.

[0039] According to one embodiment of the present invention, the composition may be included in an amount of 0.1 to 1.5 weight percent based on the total weight of the nutrient solution for hydroponic cultivation.

[0040] When the antimicrobial composition of the plant medium of the present invention is used in an amount of less than 0.1% by weight based on the total weight of the nutrient solution for hydroponic cultivation, the antimicrobial activity against microorganisms in the nutrient solution may not be sufficient, and when it is included in an amount of more than 1.5% by weight, the antimicrobial activity does not increase significantly compared to when it is included in an amount of 1.5% by weight. Therefore, it is preferable that the antimicrobial composition of the plant medium of the present invention be included in an amount of 0.1 to 1.5% by weight based on the total weight of the nutrient solution for hydroponic cultivation, and it is more preferable that it be included in an amount of 0.15 to 0.50% by weight.

[0041] According to one embodiment of the present invention, the composition may have antibacterial activity against Staphylococcus aureus and Botrytis cinerea.

[0042] The present invention will be explained in more detail below through one or more embodiments. However, these embodiments are intended to illustrate the invention and the scope of the invention is not limited to these embodiments.

[0043]

[0044] Example 1. Determination of the mixing ratio of potassium sorbate and phenoxyethanol exhibiting a synergistic effect with 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one.

[0045] 1-1. Verify the mixing ratio of each component exhibiting a synergistic effect

[0046] The mixing ratio of potassium sorbate and phenoxyethanol, which exhibit a synergistic effect with 5-chloro-2-methyl-4-isothiazolin-3-one (MCI) and 2-methyl-4-isothiazolin-3-one (MI), was analyzed.

[0047] Specifically, the plant tissue culture medium was prepared by adding 20 g / L of sucrose to the basic salt of the Murashing & Skoog medium and adjusting the pH to 5.7, then placing it in a culture vessel. Subsequently, a composition for antimicrobial use in the plant medium was prepared by mixing water with a mixture of MCI, MI, potassium sorbate, and phenoxyethanol in a combination selected from the ratios in Table 1, such that the mixture constituted 0.95 to 1.15% by weight based on the total weight of the water. Then, the prepared composition for antimicrobial use in the plant medium was added to the plant tissue culture medium at a concentration of 1 ml / L and sterilized at high temperature and high pressure. Afterward, the stopper of the culture vessel was removed to allow the entry of microorganisms through air, and the degree of contamination of the medium was visually measured on day 14 to evaluate the antimicrobial effect. - indicates a state where contamination is not visually observed, and + indicates a state where contamination is visually observed.

[0048]

[0049] Classification Added Concentration (Weight%) MCI 0.0375, 0.0750, 0.1125, 0.1500, 0.1875 MI 0.0125, 0.0250, 0.0375, 0.0500, 0.0625 Potassium Sorbate 0.40, 0.45, 0.50, 0.55, 0.60 Phenoxyethanol 0.30, 0.35, 0.40, 0.45, 0.50

[0050]

[0051] As a result, as shown in Table 2, the synergistic effect of each component according to the mixing ratio was confirmed.

[0052]

[0053] MCI Added Concentration (Weight%) 0.0375 0.07500 0.1125 0.1500 0.1875 MI Added Concentration (Weight%) 0.0125++++-0.60 Potassium Sorbate Added Concentration (Weight%) 0.0250++++-0.55 0.0375+++-+0.50 0.0500+---+0.45 0.0625+--++0.40 0.50 0.45 0.400.35 0.30 Phenoxyethanol Added Concentration (Weight%)

[0054]

[0055] Specifically, while it was confirmed that contamination of the culture medium by microorganisms occurred in a composition for antimicrobial plant media in which a mixture of MCI, MI, potassium sorbate, and phenoxyethanol was mixed with water at a ratio of 1.11% by weight or more based on the total weight of water, based on the total weight of water, i) mixing MI 0.0500 to 0.0625% by weight, potassium sorbate 0.40 to 0.45% by weight, and phenoxyethanol 0.40 to 0.45% by weight within the range of MCI 0.0750 to 0.1125% by weight, ii) mixing MI 0.0375 to 0.0500% by weight, potassium sorbate 0.45 to 0.50% by weight, and phenoxyethanol 0.35% by weight within MCI 0.1500% by weight, or iii) mixing MI within MCI 0.1875% by weight It was confirmed that no contamination of the culture medium by microorganisms occurred in a composition for antimicrobial plant culture medium mixed with 0.125 to 0.0250 wt%, 0.55 to 0.60 wt% potassium sorbate, and 0.30 wt% phenoxyethanol, even though the composition was mixed at 1.10 wt% or less based on the total weight of water.

[0056] Through these results, the mixing ratio with water for MCI, MI, potassium sorbate, and phenoxyethanol to exhibit a synergistic effect in preventing contamination of the culture medium by microorganisms during plant tissue culture was determined.

[0057]

[0058] 1-2. Confirmation of Antimicrobial Activity of Antimicrobial Compositions for Plant Media at Different Treatment Concentrations

[0059] The antimicrobial activity of the plant culture medium antimicrobial composition of the present invention was analyzed according to the treatment concentration on a plant tissue culture medium.

[0060] Specifically, the antimicrobial activity was analyzed in the same manner as in Example 1-1, except that the composition for plant culture antimicrobials, mixed with 0.1500 wt% MCI, 0.0500 wt% MI, 0.45 wt% potassium sorbate, and 0.35 wt% phenoxyethanol based on the total weight of water as the mixing ratio in which a synergistic effect was confirmed in Example 1-1, was treated in a plant tissue culture medium at concentrations of 0, 1, 2, or 4 ml / L, respectively.

[0061] As a result, while microbial contamination was observed in the untreated group starting from day 7, no microbial contamination was observed in the group treated with the antimicrobial composition of the plant medium of the present invention until day 14 at all concentrations.

[0062]

[0063] Example 2. Confirmation of excellent antimicrobial activity and low phytotoxicity of a composition for antimicrobial use in plant media during tissue culture of apple dwarf rootstock

[0064] In order to confirm the excellent antimicrobial activity and low phytotoxicity of the antimicrobial composition for plant media that was confirmed to show a synergistic effect in Example 1, it was applied to the tissue culture of the apple rootstock variety M.26.

[0065] Specifically, a growth point was collected from an axillary bud of M.26, a dwarf apple rootstock variety, and the collected growth point was placed on an LS (Linsmaier and Skoog, 1965) medium containing 1 mg / L of BAP (6-benzylamino purine), 0.5 mg / L of IAA (Indole acetic acid), and 30 g / L of sucrose to grow new shoots for 90 days. After 90 days, in vitro growth characteristics such as the number of new shoots, shoot length, contamination rate, and mortality rate were investigated. At this time, the plant culture medium antimicrobial composition was prepared by mixing 0.1500 wt% MCI, 0.0500 wt% MI, 0.45 wt% potassium sorbate, and 0.35 wt% phenoxyethanol based on the total weight of water, and the prepared plant culture medium antimicrobial composition was applied to the LS medium at concentrations of 0, 0.5, 1, 2, or 4 ml / L, respectively. In addition, as a control group, penicillin G, carbenicillin, or kanamycin were applied to the medium at the concentrations shown in Table 3 below, respectively. The treatment concentration for each antibiotic was determined by referring to the Antibiotics in Plant Tissue Culture Protocol (Merck).

[0066]

[0067] Classification Concentration (ppm) Penicillin G 0, 0.5, 1, 2, 4 Carbenicillin 0, 500, 1000, 2000, 4000 Kanamycin 0, 40, 80, 160, 320

[0068]

[0069] As a result, compared to the groups treated with penicillin G, carbenicillin, or kanamycin, the group treated with the antimicrobial composition for plant media of the present invention showed a significant increase in the number and length of new shoots and a lower mortality rate. In addition, the contamination rate by microorganisms was also found to be significantly lower, and no contamination was observed in the 4 ml / L treatment group. In particular, according to a two-way analysis of variance, the interaction effect between the antimicrobial composition for plant media of the present invention and its treatment concentration was found to have a significant influence on shoot length, contamination rate, and mortality rate (Table 4).

[0070]

[0071] Classification Treatment Concentration Number of Shoots (Pieces / Sections) Shoot Length (mm) Contamination Rate (%) Death Rate (%) Penicillin G 0 ppm 3.8 a 33.2 a 19.5 a 14.2 d 0.5ppm3.5 ab 29.5 b 15.3 b 18.7 cd 1ppm3.2 bc 28.2 b 13.6 bc 21.5 c 2ppm3.1 c 27.1 b 11.8 c 25.1 ab 4ppm2.9 c 26.3 b 10.1 c 28.4 a Carbenicillin 0 ppm 3.4 a 32.8 a 20.1 a 13.8 d 500ppm3.1 ab 30.7 ab 16.7 b 18.4 c 1000ppm2.9 bc 28.9 bc 14.2 bc 21.2 b 2000ppm2.7 c 27.8c 11.4 c 24.6 a 4000ppm2.5 c 26.9 c 9.6 c 29.1 a Kanamycin 0 ppm 3.6 a 33.5 a 19.8 a 14.5 d 40ppm3.4 ab 31.4 ab 17.2 b 17.9 c 80ppm3.1 bc 29.3 bc 14.9 bc 20.5 b 160ppm2.9 c 27.4 c 12.7 c 24.3 a 320ppm2.6 c 25.8 c 10.8 c 28.6 a Composition for antimicrobial plant media 0 ml / L 3.7 a 33.1 a 20.4 a 13.9 d 0.5㎖ / L 3.6 a 32.0 a 8.9 b 14.6 c 1㎖ / L 3.4 a 31.6 a 4.1 bc 15.7 b 2㎖ / L3.3 a 31.0 a 1.2 cd 16.1 a 4㎖ / L3.1 a 30.5 a 0.0 d 16.3 a F-value Two-way ANOVA Antibiotic type (A) 13.24 ** 8.42 ** 14.37 ** 7.85 ** Antibiotic concentration (B) 22.15 ** 18.75 ** 20.49** 16.28 ** A×B2.34 NS 2.98 * 3.21 ** 3.72 ** a~d Mean separation within columns by Duncan's multiple range test at P=0.05. NS,*,** Nonsignificant or significant at P≤0.05 or 0.01, respectively.

[0072]

[0073] Example 3. Confirmation of antimicrobial activity of a composition for antimicrobial use in plant media in hydroponic nutrient solution

[0074] 3-1. Confirmation of the antimicrobial activity of a plant culture medium antimicrobial composition against Staphylococcus aureus in hydroponic nutrient solutions

[0075] The antimicrobial activity of the plant culture medium antimicrobial composition of the present invention against Staphylococcus aureus in a hydroponic nutrient solution was analyzed according to the added concentration.

[0076] Specifically, an antimicrobial composition for plant culture media was prepared by mixing 0.1500 wt% MCI, 0.0500 wt% MI, 0.45 wt% potassium sorbate, and 0.35 wt% phenoxyethanol based on the total weight of water. For the nutrient solution for hydroponic cultivation, 3.2 × 10⁶ Staphylococcus aureus were added to 1 L of Yamazaki standard solution. 5 It was prepared by inoculating at a concentration of CFU / mL. Immediately after inoculation, the above composition for antimicrobial plant culture medium was added to the hydroponic nutrient solution in increments of 0.05% by weight from 0.05% by weight up to 0.50% by weight, based on the total weight of the hydroponic nutrient solution, and after being left at 25°C for 30 minutes, the antimicrobial activity was evaluated by measuring the reduction rate of the microbial community according to the bacteriostatic reduction rate calculation method.

[0077]

[0078] Added Concentration (Weight%) Antibacterial Activity (%) 0.00 (Control) - 0.05 59.1 20.1 07 7.6 40.1 58 8.40 0.2 09 0.1 10.2 59 3.6 30.3 09 6.2 30.3 59 7.5 50.4 09 8.1 70.4 59 9.9 90.5 09 9.99

[0079]

[0080] As a result, it was confirmed that when the composition for plant culture medium antimicrobials of the present invention is added at a rate of 0.20% by weight or more to a nutrient solution for hydroponic cultivation, it exhibits an antibacterial activity of 90% or more, and when added at a rate of 0.45% by weight or more, it exhibits an antibacterial activity of 99.99% (Table 6).

[0081] Through these results, it was confirmed that when the composition for antimicrobial growth in a plant medium according to the present invention is added at a concentration of 0.45% by weight or more based on the total weight of the nutrient solution for hydroponic cultivation, contamination of the nutrient solution by Staphylococcus aureus during hydroponic cultivation can be prevented.

[0082]

[0083] 3-2. Confirmation of Antifungal Activity of Plant Medium Antimicrobial Composition Against Botrytis cinerea in Hydroponic Nutrient Solutions

[0084] The antifungal activity of the composition for plant culture medium antimicrobials of the present invention was analyzed at different concentrations against Botrytis cinerea, a fungus that causes gray mold disease in hydroponic nutrient solutions.

[0085] Specifically, for the nutrient solution for hydroponic cultivation, 3.2 × 10⁶ Botrytis cinerea are added to 1 L of Yamazaki standard solution. 5 It was prepared by inoculating at a concentration of CFU / mL. Immediately after inoculation, the composition for plant medium antimicrobials of Example 3-1 was added to the hydroponic nutrient solution in increments of 0.05% weight from 0.05% weight up to 0.50% weight, based on the total weight of the hydroponic nutrient solution, and after being left at 25°C for 30 minutes, the antifungal activity was evaluated by measuring the reduction rate of the microbial community according to the bacteriostatic reduction rate calculation method.

[0086]

[0087] Added Concentration (Weight%) Antifungal Activity (%) 0.00 (Control) - 0.05 98.20 0.10 98.91 0.15 99.74 0.20 99.99 0.25 99.99 0.30 99.99 0.35 99.99 0.40 99.99 0.45 99.99 0.50 99.99

[0088]

[0089] As a result, it was confirmed that when the composition for plant culture medium antimicrobials of the present invention is added at 0.05% by weight or more to a nutrient solution for hydroponic cultivation, it exhibits an antifungal activity of 98.20% or more, and when added at 0.20% by weight or more, it exhibits an antifungal activity of 99.99% (Table 7).

[0090] Through these results, it was confirmed that when the composition for plant culture medium antimicrobials of the present invention is added at a concentration of 0.20% by weight or more based on the total weight of the nutrient solution for hydroponic cultivation, contamination of the nutrient solution by Botrytis cinerea during hydroponic cultivation can be prevented.

[0091]

[0092] Example 4. Confirmation of improvement in the problem of culture bottle discoloration by the antimicrobial composition for plant media

[0093] It has been confirmed that conventional infection inhibitors containing parabens (parahydroxybenzoic acid esters) cause problems such as micro-corrosion or turbidity in polycarbonate plant tissue culture containers. Accordingly, it was confirmed whether the antimicrobial composition for plant culture media of the present invention causes discoloration of the culture bottles.

[0094] Specifically, the conventional infection inhibitor was prepared by mixing an MCI / MI 3:1 mixed formulation, potassium sorbate, methylparaben, and propylparaben at 0.15 wt%, 0.50 wt%, 0.25 wt%, and 0.25 wt%, respectively, based on the total weight of water, and the composition for antimicrobial growth in plants according to the present invention was prepared by mixing MCI 0.1500 wt%, MI 0.0500 wt%, potassium sorbate 0.45 wt%, and phenoxyethanol 0.35 wt% based on the total weight of water. Subsequently, the antimicrobial activity was analyzed in the same manner as in Example 1-1, except that the conventional infection inhibitor and the composition for antimicrobial growth in plants according to the present invention were each treated in a plant tissue culture medium at a concentration of 4 ml / L.

[0095] As a result, it was confirmed that in a culture bottle to which a conventional infection inhibitor was added, the culture bottle was discolored in the shape of the medium contained therein (Fig. 1B), whereas it was confirmed that no such discoloration problem occurred in a culture bottle to which the antimicrobial composition for plant culture media of the present invention was added (Fig. 1A).

[0096]

[0097] The present invention has been described above with reference to its embodiments. Those skilled in the art will understand that the present invention may be embodied in modified forms without departing from the essential characteristics of the invention. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the invention is defined by the claims, not by the foregoing description, and all variations within the scope of equivalents should be interpreted as being included in the invention.

Claims

A composition for antimicrobial plant media comprising 1,5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, potassium sorbate, and phenoxyethanol.

2. A composition for antimicrobial plant media according to claim 1, wherein the weight ratio of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one is 1:15 to 5:

6.

3. In claim 4, the composition further comprises water, and Based on the total weight of the water mentioned above, 5-chloro-2-methyl-4-isothiazolin-3-one 0.0750 to 0.1875 wt%; 2-methyl-4-isothiazolin-3-one 0.0125 to 0.0625 wt%; Potassium sorbate 0.40 to 0.60 weight%; and 0.45 to 0.30 wt% phenoxyethanol A composition for antimicrobial plant media comprising 4. A composition for antimicrobial plant culture media according to claim 3, wherein 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, potassium sorbate, and phenoxyethanol are in an amount of 0.98 to 1.10% by weight based on the total weight of water.

5. A plant medium antimicrobial composition according to claim 1, wherein the plant medium is a plant tissue culture medium.

6. A composition for antimicrobial use in a plant culture medium according to claim 5, wherein the composition is included in an amount of 0.5 to 10.0 ml based on 1 L of the plant tissue culture medium.

7. A composition for antimicrobial use in a plant medium, wherein the plant medium is a nutrient solution for hydroponic cultivation, in accordance with claim 1.

8. A composition for antimicrobial growth in a plant culture medium according to claim 7, wherein the composition is included in an amount of 0.1 to 1.5 weight percent based on the total weight of the nutrient solution for hydroponic cultivation.

9. A composition for plant culture medium antimicrobials according to claim 1, wherein the composition has antimicrobial activity against Staphylococcus aureus and Botrytis cinerea.

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