Method for air purification of ozone by phyllosphere microorganism and plant cooperation

Abstract

The present application belongs to the technical field of ecological environment protection, and provides a method for purifying ozone in air by phyllosphere microorganism and plant in cooperation. The method comprises the following steps: preparing a culture medium by taking plant leaf extract and potato starch wastewater as main raw materials, culturing phyllosphere plant growth promoting bacteria, preparing a plant growth promoting bacteria inoculum, inoculating the plant growth promoting bacteria on plant leaves, and uniformly placing the potted plants inoculated with the plant growth promoting bacteria in an ozone-polluted room. The method can achieve the effect of purifying air by phyllosphere microorganism and plant in cooperation. The method utilizes the synergistic effect of phyllosphere microorganism and plant, has high ozone purification efficiency in air, is simple to operate, environment-friendly, low in cost, and has wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ecological environment protection, and particularly relates to a method for removing ozone in air by phyllosphere microorganisms and plants in cooperation. BACKGROUND

[0002] Ozone (O3) plays an important role in absorbing ultraviolet rays, sterilization and disinfection. However, a high concentration of O3 in the air near the ground is harmful to the health of organisms and ecosystems. The O3 near the ground is mainly generated by the photochemical reaction of oxygen in the air and nitrogen oxides (NOx) and volatile organic compounds (VOCs) emitted by motor vehicle exhaust, industrial waste, etc. under the irradiation of solar ultraviolet rays.

[0003] When the concentration of ozone reaches 50 ppb, people will begin to have symptoms of nasal and pharyngeal mucosa irritation, and as the concentration rises, a series of symptoms such as sore throat, cough, headache, chest tightness, etc. will occur. Under a higher concentration of ozone, lung function will be significantly affected, and even emphysema, consciousness disorder and death will occur. According to the influence of ozone on human health, the upper limit value of the concentration of ozone in the ambient air is stipulated in the Ambient Air Quality Standard (GB3095-2012) of China as follows: 100 μg / m 3 for the first level and 160 μg / m 3 for the second level. When the monitoring value exceeds 160 μg / m 3 , people can obviously feel uncomfortable, therefore, the O3 concentration 1-hour average value should not be greater than 160 μg / m 3 is stipulated in the Indoor Air Quality Standard (GB / T 18883-2002) of China.

[0004] At present, the main way to control O3 pollution is to control the emission of precursor substances, i.e. the reduction of NOx and VOCs. The methods for eliminating indoor air O3 mainly include ventilation, activated carbon adsorption, catalytic decomposition, etc., but are affected by the quality of external air or have a high cost. Previous studies have found that plants can significantly reduce the concentration of O3 in polluted air, but a high concentration of ozone can harm plants.

[0005] A large number of microorganisms exist on the surface of the aboveground part (including: leaves, stems, flowers, fruits) of plants, which are called phyllosphere microorganisms. Phyllosphere microorganisms play an important role in plant growth and development, pest control, organic pollutant degradation, etc. and exert an important ecological function. The inventors have found that a large number of phyllosphere microorganisms with diverse functions are mostly exposed to the air and can remove or transform ozone in the air, thereby reducing O3 pollution in the air. The leaf and stem surface area of plants is huge and has a strong adsorption effect on air pollutants, and can also partially reduce and metabolize pollutants. SUMMARY

[0006] The present application aims to provide a method for phyllosphere microorganism and plant to synergistically purify ozone in air; the phyllosphere plant growth promoting bacteria isolated and screened are prepared into a biofortified inoculant, which is inoculated on the leaves of landscape plants in an appropriate amount, the inoculated phyllosphere plant growth promoting bacteria have the ability to remove O3, and can also improve the ability of the plants to resist O3 stress and enhance the purification efficiency of the plants; the landscape plants inoculated with the phyllosphere plant growth promoting bacteria are uniformly placed in an indoor space polluted by O3, and an electric fan is used to drive air circulation, so as to improve the contact opportunity of air and the leaves of the plants and the purification efficiency of ozone.

[0007] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0008] The present application provides a method for phyllosphere microorganism and plant to synergistically purify ozone in air, which comprises the following steps:

[0009] (1) a plant growth promoting bacteria culture medium is prepared by using plant leaf extract and potato starch wastewater as main raw materials;

[0010] (2) a high-efficiency strain of phyllosphere plant growth promoting bacteria, which is isolated and screened from the surface of plant leaves and has the ability to improve the stress resistance of plants, is inoculated into the culture medium prepared in step (1), and aerobic culture is carried out, so as to obtain a plant growth promoting bacteria culture solution;

[0011] (3) glycerol and rhamnolipid are added into the plant growth promoting bacteria culture solution in step (2), so as to obtain a plant growth promoting bacteria inoculant;

[0012] (4) the plant growth promoting bacteria inoculant in step (3) is diluted with water, so as to obtain a plant growth promoting bacteria inoculation solution, the inoculation solution is sprayed on both sides of the leaves of plants, and plants inoculated with the plant growth promoting bacteria are obtained;

[0013] (5) the plants inoculated with the plant growth promoting bacteria in step (4) are placed in an indoor space polluted by ozone according to a ratio of plant canopy volume to indoor air volume of 1:50-150.

[0014] Preferably, the preparation process of the plant growth promoting bacteria culture medium in step (1) is as follows: 1.5-3 kg of fresh leaves are collected and placed in a 50 L reaction kettle, 30 L of tap water is added, and boiling is carried out at 100 ℃ for 5-10 minutes; the leaves are removed, and a leaf extract is obtained; fresh potato starch wastewater is collected from a potato starch production workshop, and is diluted with tap water to a COD concentration of 10-15 g / L; the leaf extract is added according to a volume ratio of 1:1, and a sodium hydroxide solution is used to adjust the pH value to 7.0-8.0; and high-pressure sterilization is carried out at 115 ℃ for 10-15 minutes, so as to obtain the plant growth promoting bacteria culture medium.

[0015] Preferably, the plant growth promoting bacteria in step (2) comprise one or both of Bacillus subtilis with the accession number of CGMCC No.8188 and Paenibacillus polymyxa with the accession number of CGMCC No.2377.

[0016] Preferably, the aerobic culture process of the plant growth promoting bacteria in step (2) comprises: the culture medium prepared in step (1) is divided into 500 mL flasks at a liquid volume of 100-200 mL / flask, high-pressure sterilized at 115°C for 5-10 minutes, and naturally cooled to near room temperature; in a clean bench, the plant growth promoting bacteria preserved in a slant are inoculated into the liquid culture medium, and placed in a constant temperature shaker, and cultured at 25-35°C and 100-200 rpm for 18-36 hours to obtain an activated bacteria solution of the plant growth promoting bacteria; the activated bacteria solution of the plant growth promoting bacteria is inoculated into the bioreactor containing the plant growth promoting bacteria culture medium at an inoculation amount of 2%-6% by volume, sterile air is passed, and the culture is carried out at 25-35°C for 15-30 hours; when the effective viable cell count reaches 2×10 9 CFU / mL or above, the culture is stopped, and a plant growth promoting bacteria culture solution is obtained.

[0017] Preferably, the preparation process of the plant growth promoting bacteria inoculant in step (3) comprises: 0.5%-1% glycerol and 0.2%-0.5% rhamnolipid are added to the plant growth promoting bacteria culture solution in step (2) by volume, and the plant growth promoting bacteria inoculant is obtained and stored in a refrigerator at 2-10°C for standby use.

[0018] Preferably, the preparation process of the plant inoculated with the plant growth promoting bacteria in step (4) comprises: the plant growth promoting bacteria inoculant in step (3) is diluted with water to obtain a plant growth promoting bacteria inoculant solution with an effective viable cell count of 5×10 6 -5×10 7 CFU / mL; the inoculant solution is sprayed on both sides of the plant leaves, and the spraying amount is such that the wetted area of the leaf surface is ≥70%.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] The plant growth promoting bacteria in the application have the functions of improving the O3 stress tolerance of plants and improving the air purification efficiency of plants. The culture medium for culturing the plant growth promoting bacteria is prepared by using a plant leaf extract and potato starch wastewater, which can improve the survival of the plant growth promoting bacteria in the phyllosphere environment, and realizes the resource utilization of high-concentration wastewater. The method for purifying ozone in air by using phyllosphere microorganisms and plants has the advantages of improving the ozone purification effect in air, removing ozone in air by the cooperation of phyllosphere microorganisms and plants, beautifying the environment, improving the air purification efficiency, simple operation, environmental friendliness, remarkable effect and low cost. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0022] Figure 1 The change curve of the ozone concentration in air in Example 3 of the present application;

[0023] Figure 2 The change curve of the ozone concentration in air in Example 4 of the present application;

[0024] Figure 3 The change curve of the ozone concentration in air in Example 5 of the present application.

[0025] DEPOSIT INFORMATION

[0026] Bacillus subtilis, Latin name Bacillus subtilis, depositing unit name China General Microbiological Culture Collection Center, address No. 3, Beichen West Road, Chaoyang District, Beijing, depositing date September 16, 2013, depositing number CGMCC No. 8188;

[0027] Paenibacillus polymyxa, Latin name Paenibacillus polymyxa, depositing unit name China General Microbiological Culture Collection Center, address No. 3, Beichen West Road, Chaoyang District, Beijing, depositing date February 26, 2008, depositing number CGMCC No. 2377. DETAILED DESCRIPTION

[0028] In order to better understand the present application, the content of the present application will be further illustrated by combining with the examples below, but they cannot be understood as limiting the scope of protection of the present application.

[0029] Example 1

[0030] Preparation of Bacillus polymyxa bioaugmentation inoculant:

[0031] Preparation of culture medium of Bacillus polymyxa in bioaugmentation inoculant: Fresh Rhaphiolepis umbellate leaves 2 kg were collected and placed in a 50 L reactor, 30 L tap water was added, and boiled at 100 ℃ for 10 min; the leaves were removed, and leaf extract was obtained; fresh potato starch wastewater was collected from a potato starch production workshop, diluted with tap water to a COD concentration of 10 g / L, and then the leaf extract was added at a volume ratio of 1:1, and the pH value was adjusted to 7.0-7.3 with a sodium hydroxide solution, and autoclaved at 115 ℃ for 10 min to obtain the Bacillus polymyxa culture medium.

[0032] Culture of Bacillus polymyxa: The above-mentioned plant growth-promoting bacteria culture medium was divided into 500 mL triangular bottles at a liquid volume of 200 mL / bottle, autoclaved at 115 ℃ for 10 min, and naturally cooled to room temperature; Bacillus polymyxa preserved on a slant was inoculated into the liquid culture medium in a clean bench, and placed in a constant temperature shaker, and cultured at 30 ℃ and 150 rpm for 24 h to obtain Bacillus polymyxa activation liquid; the Bacillus polymyxa activation liquid was inoculated into the bioreactor containing the Bacillus polymyxa culture medium at a volume ratio of 5% inoculation, and sterilized air was supplied to culture at 30 ℃ for 20 h; when the effective viable cell count reached more than 2×10 9 CFU / mL, the culture was stopped, and Bacillus polymyxa culture liquid was obtained.

[0033] Preparation of Bacillus polymyxa bioaugmentation inoculant: 0.5% glycerol and 0.3% rhamnolipid were added to the Bacillus polymyxa culture liquid at a volume ratio to obtain the Bacillus polymyxa bioaugmentation inoculant, which was stored in a refrigerator at 2-6 ℃ for later use.

[0034] Example 2

[0035] Preparation of Bacillus polymyxa bioaugmentation inoculant:

[0036] Preparation of culture medium of Bacillus polymyxa in bioaugmentation inoculant: Fresh Rhaphiolepis umbellate leaves 2 kg were collected and placed in a 50 L reactor, 30 L tap water was added, and boiled at 100 ℃ for 10 min; the leaves were removed, and leaf extract was obtained; fresh potato starch wastewater was collected from a potato starch production workshop, diluted with tap water to a COD concentration of 10 g / L, and then the leaf extract was added at a volume ratio of 1:1, and the pH value was adjusted to 7.0-7.3 with a sodium hydroxide solution, and autoclaved at 115 ℃ for 10 min to obtain the Bacillus polymyxa culture medium.

[0037] Culture of Bacillus subtilis: The above-mentioned Bacillus subtilis culture medium was divided into 500 mL flasks according to a liquid volume of 150 mL / flask, autoclaved at 115°C for 5 minutes, and naturally cooled to near room temperature. In a clean bench, the slant-preserved Bacillus subtilis was inoculated into the liquid culture medium, and placed in a constant temperature shaker, and cultured at 30°C and 150 rpm for 24 hours to obtain an activated Bacillus subtilis liquid. Then, the activated Bacillus subtilis liquid was inoculated into the bioreactor containing the plant growth-promoting bacteria culture medium according to a volume ratio of 3%, and sterilized air was supplied to culture at 30°C for 18 hours. When the effective viable cell count reached more than 3×109CFU / mL, the culture was stopped, and a Bacillus subtilis culture liquid was obtained.

[0038] Preparation of Bacillus subtilis bioaugmentation inoculant: 0.6% glycerol and 0.2% rhamnolipid were added to the plant growth-promoting bacteria culture medium according to a volume ratio, and a Bacillus subtilis bioaugmentation inoculant was obtained, which was stored in a refrigerator at 2-6°C for later use.

[0039] Example 3

[0040] The Bacillus polymyxa and the plant cooperated to purify ozone in the air, and the steps were as follows:

[0041] Inoculation of Bacillus polymyxa on plant leaves: The Bacillus polymyxa inoculant was diluted with tap water to obtain an effective viable cell count of 2×107CFU / mL in the inoculant liquid. The diluted bacterial liquid was uniformly sprayed onto the front and back of the Schefflera arboricola leaves using a sprayer, so that the wetted area of the leaves reached more than 80%.

[0042] Phyllosphere microorganism Bacillus subtilis cooperates with plants to purify air: The potted Schefflera actinophylla inoculated with Bacillus subtilis (i.e. plant inoculation group) is evenly placed in a smoke box simulating O3 polluted air according to the plant canopy volume: indoor air volume = 1:100, with the potted Schefflera actinophylla sprayed with water but not inoculated with bioaugmentation bacteria as the control group, and with the empty flowerpot as the blank group; the ozone generator is turned on, and ozone is introduced into the box for 25 min. When the introduction of ozone is stopped, the ozone concentration in the smoke box is 121 ppb, and after 25 min of reduction, the ozone concentration in the smoke box is 43.5 ppb. The ozone reduction rate of the Schefflera actinophylla inoculated with Bacillus subtilis liquid (plant inoculation group) is 64%. The control group is the Schefflera actinophylla sprayed with sterile water on the leaves, which is also placed in another identical smoke box. Ozone is introduced into the box for 25 min. When the introduction of ozone is stopped, the ozone concentration in the smoke box is 142 ppb, and after 25 min of reduction, the ozone concentration in the smoke box is 79.6 ppb. The ozone reduction rate of the control group Schefflera actinophylla (i.e. plant purification group) is 43.8%. The blank group is the empty flowerpot placed in the same smoke box. Ozone is introduced into the box for 25 min. When the introduction of ozone is stopped, the ozone concentration in the smoke box is 178 ppb, and after 25 min of reduction, the ozone concentration in the smoke box is 130 ppb. The ozone reduction rate of the blank group without plants in the natural state is 27%, which is significantly lower than that of the control group sprayed with sterile water and the plant inoculated with plant growth-promoting bacteria. Among them, the ozone purification efficiency of the plant inoculated with Bacillus subtilis is increased by 20% compared with the control group.

[0043] Example 4

[0044] Bacillus subtilis cooperates with plants to purify ozone in air, and the steps are as follows:

[0045] Inoculation of Bacillus subtilis on plant leaves: Bacillus subtilis inoculant is diluted with tap water to make the effective viable bacterial count in the inoculum liquid 3×107 CFU / mL. The diluted bacterial liquid is uniformly sprayed onto the front and back of the leaves of the V. macrophylla using a sprayer, so that the wetted area of the leaves is more than 90%.

[0046] Phyllosphere microorganism Bacillus subtilis cooperates with plants to purify air: The potted Schefflera actinophylla inoculated with Bacillus subtilis (i.e. plant inoculation group) is evenly placed in a smoke box simulating O3 polluted air according to the plant canopy volume: indoor air volume = 1:80, with the potted Schefflera actinophylla sprayed with water but not inoculated with bioaugmentation bacteria as the control group, and with the empty flowerpot as the blank group; the ozone generator is turned on, and ozone is introduced into the box for 25 min.

[0047] The ozone concentration-time curve is shown in FIG. 1. Figure 2The ozone concentration in the smoke box was 135 ppb when the ozone supply was stopped, and the ozone concentration in the smoke box was 44 ppb after 25 min of reduction. The ozone reduction rate of the Schefflera arboricola inoculated with Bacillus subtilis (the plant inoculation group) was 67%. The control group was the Schefflera arboricola to which only sterile water was sprayed, and was placed in another identical smoke box. The ozone concentration in the smoke box was 139 ppb when the ozone supply was stopped, and the ozone concentration in the smoke box was 92 ppb after 25 min of reduction. The ozone reduction rate of the control group (i.e., the plant purification group) was 34%. The blank group was an empty pot placed in the same smoke box. The ozone concentration in the smoke box was 185 ppb when the ozone supply was stopped, and the ozone concentration in the smoke box was 146 ppb after 25 min of reduction. The ozone reduction rate in the natural state (i.e., the plant group) was 21%, which was lower than the ozone reduction rate of the plant sprayed with sterile water and the plant sprayed with the bacterial liquid. The ozone purification efficiency of the Schefflera arboricola inoculated with Bacillus subtilis was increased by 33%.

[0048] Example 5

[0049] The phyllosphere microbial complex and the plant cooperatively purify ozone in the air, and the steps are as follows:

[0050] Inoculation of Bacillus polymyxa and Bacillus subtilis on the plant leaves: the Bacillus polymyxa inoculant in Example 1 was diluted with tap water to make the effective viable bacterial number in the inoculant liquid 2 x 107 CFU / mL; the Bacillus subtilis inoculant in Example 2 was diluted with tap water to make the effective viable bacterial number in the inoculant liquid 3 x 107 CFU / mL; the two inoculants were mixed uniformly at a volume ratio of 1:1, and the diluted mixed bacterial liquid was uniformly sprayed onto the front and back of the Schefflera arboricola leaves by using a sprayer, so that the wetted area of the leaves reached more than 80%.

[0051] The phyllosphere microbial complex and the plant cooperatively purify ozone in the air: the Schefflera arboricola inoculated with Bacillus polymyxa and Bacillus subtilis was placed in a smoke box for simulating O3 polluted air (i.e., the plant inoculation group) according to the plant canopy volume: indoor air volume = 1:100. The Schefflera arboricola to which only water was sprayed and which was not inoculated with the bioaugmentation bacteria was used as the control group, and the empty pot was used as the blank group. The ozone generator was turned on, and ozone was supplied into the box for 30 min.

[0052] The ozone concentration-time curve is shown in Figure 3 The ozone concentration-time curve is shown in Figure 3It can be known that when the ozone is stopped, the ozone concentration in the smoke box is 131ppb, after 30min of reduction, the ozone concentration in the smoke box is 31ppb, the mixed bacteria liquid inoculated Schefflera Arboricola (plant inoculation group) has an ozone reduction rate of 77%; the control group Schefflera Arboricola which is only sprayed with sterile water is placed in another smoke box, the ozone is passed into the box for 30min, when the ozone is stopped, the ozone concentration in the smoke box is 158ppb, after 30min of reduction, the ozone concentration in the smoke box is 95ppb, the control group Schefflera Arboricola (i.e. plant purification group) has an ozone reduction rate of 40%; the blank group is placed in the same smoke box without plants, the ozone is passed into the box for 30min, when the ozone is stopped, the ozone concentration in the smoke box is 192ppb, after 30min of reduction, the ozone concentration in the smoke box is 141ppb, the ozone reduction rate in the natural state (i.e. without plants) is 27%, which is lower than that of the plants sprayed with sterile water and the plants sprayed with bacteria liquid, wherein the Schefflera Arboricola inoculated with the mixed bacteria liquid has an ozone purification efficiency increased by 36%.

[0053] In summary, the high-efficiency phyllosphere plant growth-promoting bacteria separated and screened by the application are prepared into a bio-enhanced bacteria inoculant, which is inoculated on the leaves of landscape plants in an appropriate amount, and can synergistically promote the ozone purification effect in the air. The synergistic effect of microorganisms and plants can effectively remove ozone in the air, improve the air purification efficiency while beautifying the environment, and has the advantages of simple operation, environmental friendliness, remarkable effect and low cost.

[0054] The above only describes the preferred embodiments of the application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the application, and these improvements and refinements should also be considered as the protection scope of the application.

Claims

1. A method for synergistic purification of ozone in the air by phyllosphere microorganisms and plants, characterized in that, Includes the following steps: (1) A culture medium for plant growth-promoting bacteria was prepared using plant leaf extracts and potato starch wastewater as the main raw materials; (2) The plant growth-promoting bacteria strains that are suitable for foliar survival and can improve plant stress resistance obtained by isolating and screening on plant leaves are inoculated into the culture medium prepared in step (1) and cultured aerobically to obtain plant growth-promoting bacteria culture solution. The plant growth-promoting bacteria include one or both of Bacillus subtilis and Bacillus polymyxa, wherein the Bacillus subtilis preservation number is CGMCC No. 8188 and the Bacillus polymyxa preservation number is CGMCC No. 2377. The effective viable bacteria count in the plant growth-promoting bacteria culture medium reached 2×10⁻⁶. 9 CFU / mL or higher; (3) Add 0.5% to 1% glycerol and 0.2% to 0.5% rhamnolipid to the plant growth-promoting bacteria culture medium in step (2) by volume ratio to obtain the plant growth-promoting bacteria inoculum, and store it in a refrigerator at 2 to 10°C for later use. (4) Dilute the plant growth-promoting bacteria inoculum mentioned in step (3) with water to obtain an effective viable count of 5 × 10⁻⁶ bacteria. 6 ~5×10 7 Prepare a plant growth-promoting bacteria inoculation solution at CFU / mL; then spray the inoculation solution onto both sides of the plant leaves, ensuring that the leaf surface is wetted to a depth of ≥70%. (5) Place the plants inoculated with plant growth-promoting bacteria as described in step (4) in an indoor space polluted by ozone, with the ratio of plant canopy volume to indoor air volume being 1:50 to 150.

2. The method for synergistic purification of air ozone by phyllosphere microorganisms and plants according to claim 1, characterized in that, The preparation process of the plant growth-promoting bacteria culture medium described in step (1) is as follows: 1.5-3 kg of fresh leaves are collected, placed in a 50 L reactor, and 30 L of tap water is added. The mixture is boiled at 100℃ for 5-10 minutes. The leaves are removed to obtain the leaf extract. Fresh potato starch wastewater is collected from the potato starch production workshop, diluted with tap water to a COD concentration of 10-15 g / L, and added to the leaf extract at a volume ratio of 1:

1. The pH value is adjusted to 7.0-8.0 with sodium hydroxide solution, and the mixture is autoclaved at 115℃ for 10-15 minutes to obtain the plant growth-promoting bacteria culture medium.

3. The method for synergistic purification of ozone in the air by phyllosphere microorganisms and plants according to claim 2, characterized in that, The aerobic culture process of plant growth-promoting bacteria described in step (2) includes: dispensing the culture medium prepared in step (1) into 500 mL Erlenmeyer flasks at a volume of 100-200 mL / bottle, autoclaving at 115℃ for 5-10 minutes, allowing it to cool naturally to near room temperature, inoculating the plant growth-promoting bacteria preserved on slant culture medium into the liquid culture medium in a clean bench, placing it in a constant temperature shaker, and culturing at 25-35℃ and 100-200 rpm for 18-36 h to obtain activated plant growth-promoting bacteria solution; then, inoculating the activated plant growth-promoting bacteria solution into a bioreactor containing plant growth-promoting bacteria culture medium at an inoculation volume of 2%-6%, purging with sterile air, and culturing at 25-35℃ for 15-30 h; the effective viable count reaches 2×10⁻⁶. 9 Stop culturing when CFU / mL is above a certain level to obtain plant growth-promoting bacteria culture medium.

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