Environment improving apparatus and environment improving method

Abstract

To improve the environment by improving the diversity of microorganisms in a specific space such as a room.SOLUTION: An environment improvement device for increasing microbial diversity in a space includes a soil cultivation unit configured to cultivate plants using soil, a water tank unit configured to grow aquatic organisms in water, a first water supply unit configured to supply water in the water tank unit to the soil cultivation unit, a second water supply unit configured to supply water discharged from the soil cultivation unit to the water tank unit, and an aeration unit configured to aerate water flowing in the environment improvement device.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an environment improvement device and an environment improvement method that increase microbial diversity in a space. [Background technology]

[0002] In recent years, various findings have been obtained regarding the impact of the state of environmental microbiota on human health. For example, it has been reported that there is a negative correlation between the diversity of microorganisms exposed to and the risk of asthma, and that the greater the number of species detected in the environment, the lower the incidence of asthma. It has also been reported that increasing environmental biodiversity increases the diversity of skin bacteria and strengthens their immunoregulatory function (see, for example, Non-Patent Documents 1, 2, and 3). It has also been suggested that a device that sprays microorganisms can be used to increase microbial diversity in the built environment (see, for example, Non-Patent Document 4). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Kohei Ito, "Understanding the characteristics of microbial flora in the built environment and their effects on the human body," Journal of Indoor Environment, 26(1), 29-42, 2023 [Non-patent document 2] Ege, MJ et al. "Exposure to environmental microorganisms and childhood asthma." N. Engl. J. Med. 364, 701-709 (2011). [Non-patent document 3] Roslund, MI et al. "Biodiversity intervention enhances immune regulation and health-associated commensal microbiota among daycare children." Sci Adv 6, (2020). [Non-patent document 4] BIOTA Co., Ltd. Website: https: / / biota.city / service2 / (verified June 12, 2024) Summary of the Invention [Problem to be solved by the invention]

[0004] However, there has been insufficient research into technologies for improving microbial diversity in specific spaces, such as indoor spaces, and there is a need for technologies that improve the environment by increasing microbial diversity. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms. (1) According to one aspect of the present disclosure, there is provided an environment improvement device for increasing microbial diversity in a space. The environment improvement device includes: a soil cultivation unit that cultivates plants using soil; The device comprises an aquarium section in which aquatic organisms grow, a first water supply section that supplies water from the aquarium section to the soil cultivation section, a second water supply section that supplies water discharged from the soil cultivation section to the aquarium section, and an aeration section that aerates the water circulating within the environmental improvement device. With this type of environmental improvement device, by aerating the water flowing through the device, the microorganisms contained in the water flowing through the device can be efficiently dispersed into the space, increasing the microbial diversity within the space in which the environmental improvement device is placed and making the state of the microbiome within the space more diverse and closer to a natural environment such as outdoors. (2) In the environmental improvement device of the above embodiment, the aeration unit may have a structure that allows at least one of the water in the water tank unit and the water discharged from the soil cultivation unit to fall by gravity. With this configuration, the water flowing through the environmental improvement device can be easily aerated by the simple structure of allowing the water to fall by gravity. (3) In the environmental improvement device of the above embodiment, the aeration unit may have a structure in which the water in the water tank unit overflows from the top of the water tank unit and falls by gravity. With this configuration, the water circulating in the environmental improvement device can be easily aerated by the simple structure of overflowing water from the water tank unit. In addition, the visual effect of aerating the water can be enhanced. (4) In the environmental improvement device of the above embodiment, the aeration unit may have at least one of holes and slits provided in the wall of the container constituting the water tank unit, through which the water in the water tank unit is discharged, as a structure for allowing the water in the water tank unit to fall by gravity. With this configuration, the water flowing through the environmental improvement device can be easily aerated by simply allowing the water to fall through holes or slits provided in the wall of the container constituting the water tank unit. Furthermore, the visual effect of aerating the water can be enhanced. (5) In the above-described environmental improvement device, the aeration unit may be configured to spray at least one of the water in the water tank unit and the water discharged from the soil cultivation unit. This configuration can efficiently aerate the water circulating in the environmental improvement device, thereby enhancing the effect of improving microbial diversity in the space. (6) In the above-described environmental improvement device, the first water supply unit may be configured to supply water from the water tank unit to the soil in the soil cultivation unit by gravity or by spraying, and the aeration unit may be configured by the first water supply unit. This configuration can increase the efficiency of dispersing microorganisms contained in the water in the water tank unit into space. (7) In the environmental improvement device of the above embodiment, the water tank section may include a plurality of divided water tank containers each containing water, and the aeration section may be configured to supply water from a first divided water tank container to a second divided water tank container by gravity or by spraying. This configuration increases the efficiency of dispersing microorganisms contained in the water in the water tank section into space by supplying water by gravity from the first divided water tank container to the second divided water tank container. It also enhances the visual effect of aerating the water. (8) In the above-described environmental improvement device, the second water supply unit may be configured to supply the water discharged from the soil cultivation unit to the water tank unit by gravity or by spraying, and the aeration unit may be configured by the second water supply unit. This configuration can increase the efficiency of dispersing microorganisms contained in the water discharged from the soil cultivation unit into space. (9) In the above-described environmental improvement device, the aeration unit may be configured as a bubbling device that blows air into at least one of the water in the water tank unit and the water discharged from the soil cultivation unit. This configuration can enhance the effect of dispersing microorganisms contained in the water flowing through the environmental improvement device into the air. (10) According to another aspect of the present disclosure, there is provided an environmental improvement method for increasing microbial diversity in a space, comprising: an apparatus including a soil cultivation section for cultivating plants using soil and an aquarium section for growing aquatic organisms in water; and a device for circulating water between the soil cultivation section and the aquarium section, wherein the device aerates water circulating within the apparatus. According to this form of environmental improvement method, by aerating the water flowing through the environmental improvement device, the efficiency of dispersing the microorganisms contained in the water flowing through the environmental improvement device into the space can be increased, increasing the microbial diversity within the space in which the environmental improvement device is placed and making the state of the microbiome within the space more diverse and closer to a natural environment such as outdoors. The present disclosure can be realized in various forms other than those described above, such as a method for manufacturing an environmental improvement device, a device for increasing microbial diversity in a space, and a method for increasing microbial diversity in a space. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is an explanatory diagram showing a schematic configuration of an environment improvement device according to a first embodiment. [Figure 2] FIG. 10 is an explanatory diagram showing a schematic configuration of an environment improvement device according to a second embodiment. [Figure 3] FIG. 10 is an explanatory diagram showing a schematic configuration of an environment improvement device according to a third embodiment. [Figure 4] FIG. 10 is an explanatory diagram showing a schematic configuration of an environment improvement device according to a fourth embodiment. [Figure 5] FIG. 2 is an explanatory diagram showing the appearance of the environment improvement device used. [Figure 6] FIG. 1 is an explanatory diagram showing an experiment schedule. [Figure 7] FIG. 1 is an explanatory diagram showing the details of sampling carried out in the room where the experiment was conducted. [Figure 8] An explanatory diagram showing the sequences of each primer used in PCR. [Figure 9] An explanatory diagram using a Venn diagram showing the change in the number of bacterial species. [Figure 10] FIG. 1 is an explanatory diagram showing the results of principal coordinate analysis based on the composition of each bacterial species. [Figure 11] Schematic representation of changes in alpha diversity of the bacterial microbiome. [Figure 12] Schematic representation of changes in alpha diversity of the fungal microbiome. [Figure 13] Schematic representation of changes in alpha diversity of the bacterial microbiome. [Figure 14] Schematic representation of changes in alpha diversity of the fungal microbiome. [Figure 15] FIG. 1 is an explanatory diagram showing the primer sequences used in PCR. [Figure 16] FIG. 1 is an explanatory diagram showing the change in concentration of various ions during the process of preparing liquid soil. [Figure 17]An explanatory diagram showing the bacterial flora composition of each sample by genus classification. [Figure 18] FIG. 10 is an explanatory diagram showing the results of measuring the number of particles in the air in a room. [Figure 19] FIG. 10 is an explanatory diagram showing the results of measuring the number of viable bacteria in the air in a room. [Figure 20] An explanatory diagram showing a Venn diagram created based on the analysis results of the bacterial flora composition. [Figure 21] FIG. 1 is an explanatory diagram showing the results of NMDS analysis. [Figure 22] An explanatory diagram showing the change in the diversity of airborne bacterial flora due to liquid soil. [Figure 23] An explanatory diagram showing the change in the diversity of airborne bacterial flora due to liquid soil. DETAILED DESCRIPTION OF THE INVENTION

[0007] A. First embodiment: FIG. 1 is an explanatory diagram showing a schematic configuration of an environment improvement device 10 according to a first embodiment of the present disclosure. The environment improvement device 10 is a device for increasing microbial diversity within a space. The environment improvement device 10 includes a soil cultivation section 20 for cultivating plants, an aquarium section 30 for cultivating aquatic organisms, a first water supply section 40, a second water supply section 50, and an aeration section for aerating water flowing through the environment improvement device 10.

[0008] The soil cultivation unit 20 includes soil 22, a plant 24, and a cultivation container 26. In the soil cultivation unit 20, the soil 22 is contained in the cultivation container 26, and the plant 24 is cultivated using the soil 22. There are no particular limitations on the soil 22, as long as it can be used to cultivate the plant 24. For example, soil generally available commercially for plant cultivation can be used. Furthermore, a porous carrier such as Hydroball may be added to the soil 22 to improve its permeability. Water is supplied to the soil 22 from the water tank 30 by a first water supply unit 40. The configuration of the first water supply unit 40 will be described in detail later. By supplying water from the water tank 30 to the soil cultivation unit 20, ammonia nitrogen, which is harmful to aquatic organisms and contained in the excrement of aquatic organisms in the water tank 30, is converted into harmless nitrate nitrogen by microorganisms in the soil 22. In the soil cultivation unit 20, the plant 24 utilizes such nitrate nitrogen as a nutrient, thereby purifying the water. By virtue of the above-described function, simply feeding the aquatic organisms in the aquarium section 30 eliminates or reduces the need for additional fertilization of the soil 22 in the soil cultivation section 20 or the installation of a water purification device in the aquarium section 30.

[0009] The cultivation container 26 further includes a water / soil separation section 60 and a water storage section 62. The water / soil separation section 60 is a structure for separating water supplied to and retained in the soil 22 from the soil 22. Various structures capable of separating water and soil, such as a filter, a net, a mesh, or a gravity-based sedimentation structure, can be used. Figure 1 shows an example in which a net structure is used as the water / soil separation section 60. Here, the water / soil separation section 60 divides the cultivation container 26 into a section containing soil 22 and a water storage section 62 without soil 22. The water separated from the soil 22 by the water / soil separation section 60 is stored in the water storage section 62. The water supplied to the soil cultivation section 20 permeates from above to below the soil 22, diffusing into the soil 22, and some of it reaches the water / soil separation section 60. In FIG. 1, arrows indicate the movement of water from within the soil 22 through the water / soil separator 60 to the water reservoir 62 .

[0010] The aquarium unit 30 includes water 32, aquatic organisms 34, and an aquarium container 36. In the aquarium unit 30, the water 32 and aquatic organisms 34 are contained in the aquarium container 36, and the aquatic organisms 34 are grown in the water 32. The aquatic organisms 34 may include aquatic animals such as fish, as well as aquatic plants and aquatic microorganisms, but preferably include at least fish. In the environment improvement device 10 of FIG. 1, the aquarium container 36 is disposed within the cultivation container 26 and protrudes above the soil 22. The aquarium container 36 is formed from a transparent resin or the like, allowing the aquatic organisms in the aquarium container 36 to be visible from outside the aquarium container 36. Water is supplied to the aquarium unit 30 from a second water supply unit 50. The configuration of the second water supply unit 50 will be described in detail later.

[0011] The first water supply unit 40 is a structure for supplying water from the water tank unit 30 to the soil cultivation unit 20. The first water supply unit 40 provided in the environment improvement device 10 of Fig. 1 is configured with an overflow unit 41 formed lower than other parts at the upper end of the water tank wall that forms the upper opening of the water tank container 36, and allowing the water from the water tank container 36 to overflow. The water from the water tank container 36 that overflows from the overflow unit 41 falls due to gravity and is supplied to the soil 22 located below the overflow unit 41.

[0012] The second water supply unit 50 is configured to supply water discharged from the soil cultivation unit 20 to the water tank unit 30, and includes a water supply pipe 54, a water circulation pump 52 attached to the water supply pipe 54, and a water outlet 56 at the end of the water supply pipe 54. Water in the water storage unit 62 is pumped up by the water circulation pump 52 and guided to the water tank unit 30 by the water supply pipe 54. The water in the water supply pipe 54 is discharged from the water outlet 56 and falls by gravity to be supplied to the water tank unit 30. A spray nozzle may be attached to the water outlet 56, and the water discharged from the soil cultivation unit 20 may be sprayed toward the water tank unit 30 using the pressure generated by the water circulation pump 52.

[0013] As described above, the environmental improvement device 10 includes an aeration unit that aerates the water flowing through the device. In the environmental improvement device 10 shown in FIG. 1, the aeration unit is comprised of the overflow unit 41 of the first water supply unit 40 or the water outlet 56 of the second water supply unit 50. The overflow unit 41 aerates the water in the water tank unit 30. The water outlet 56 aerates the water discharged from the soil cultivation unit 20. The overflow unit 41 and the water outlet 56 allow the water in the water tank unit 30 or the water discharged from the soil cultivation unit 20 to fall by gravity or by spraying, thereby aerating the water as it falls. When water is dropped onto the water surface, as with the water outlet 56, air bubbles are generated in the water 32 where it falls, thereby enhancing the efficiency of aeration.

[0014] The environment improvement device 10 of this embodiment, configured as described above, includes the soil cultivation section 20 and the water tank section 30, as well as an aeration section that aerates the water circulating within the environment improvement device 10. This promotes the dispersion of a wide variety of microorganisms, including those in the water tank section 30 where aquatic organisms 34 are grown and those in the soil 22 where plants 24 are cultivated, outside the environment improvement device 10, thereby achieving an excellent effect of increasing microbial diversity within the space in which the environment improvement device 10 is installed. In other words, by including the soil cultivation section 20 in addition to the water tank section 30, the microbial flora contained in the water circulating within the environment improvement device 10 becomes more diverse, closer to the natural outdoor environment. This increases microbial diversity (including an increase in the number of microbial species and an improvement in the balance of microbial species composition by increasing trace microbial species) in spaces such as indoor environments in which the environment improvement device 10 is installed, thereby enhancing the environmental improvement effect.

[0015] Furthermore, with the environment improvement device 10 of this embodiment, it is possible to appreciate plants 24 cultivated in a natural environment using the soil 22, and aquatic organisms 34 such as fish swimming in the aquarium container 36. For example, by arranging the soil 22 around the aquarium container 36 in the cultivation container 26, the habitat of the aquatic organisms 34 such as fish can be surrounded by the plants 24. This improves the restorative properties (escape, fascination, expansion, etc. as psychological effects on people) of the space in which the environment improvement device 10 is installed, and enhances the effect of increasing feelings of relaxation and vitality among people staying in the space.

[0016] Furthermore, the environment improvement device 10 of this embodiment is equipped with an overflow section 41 as an aeration section, through which the water in the water tank container 36 overflows. By making this overflow section 41 a waterfall structure in which water flows down in one go, a soothing sound can be expected from the falling water, and the effect of promoting the dispersal of microorganisms contained in the water flowing through the environment improvement device 10 into the air can be enhanced.

[0017] B. Second embodiment: 2 is an explanatory diagram showing a schematic configuration of an environment improvement device 110 according to the second embodiment. In the environment improvement device 110, parts common to the environment improvement device 10 according to the first embodiment are given the same reference numerals.

[0018] The environmental improvement device 110, like the environmental improvement device 10, includes a soil cultivation section 20 and a water tank section 30, but has a two-tiered structure in which the soil cultivation section 20 is located above the water tank section 30. In the second embodiment, the first water supply section 40, which supplies water from the water tank section 30 to the soil cultivation section 20, includes a water supply pipe 44, a water circulation pump 42 attached to the water supply pipe 44, and a water outlet 46, which is the end structure of the water supply pipe 44. Water from the water tank section 30 is pumped up by the water circulation pump 42 and guided to the soil cultivation section 20 via the water supply pipe 44. Water from the water supply pipe 44 is discharged through the water outlet 46 and falls by gravity to be supplied to the soil 22. This allows the water outlet 46 to function as an aeration section. A spray nozzle may be attached to the water outlet 46, and water from the water tank section 30 may be sprayed toward the soil 22 using pressure generated by the water circulation pump 42.

[0019] The second water supply unit 50, which supplies water discharged from the soil cultivation unit 20 to the water tank unit 30, includes a water supply pipe 54 and a water outlet 56, which is the end structure of the water supply pipe 54. Water in a water storage unit 62 provided in the cultivation container 26 is supplied to the water tank unit 30 from the water outlet 56 via the water supply pipe 54. The water outlet 56 functions as an aeration unit. Water can be supplied from the water supply pipe 54 to the water tank unit 30 in various ways, such as gravity (natural fall), a siphon structure, or a pump.

[0020] C. Third embodiment: 3 is an explanatory diagram showing a schematic configuration of an environment improvement device 210 according to a third embodiment. In the environment improvement device 210, parts common to the environment improvement device 10 according to the first embodiment are given the same reference numerals.

[0021] Similar to the environment improvement device 110 of the second embodiment, the environment improvement device 210 has a two-tiered structure with the soil cultivation section 20 located above the water tank section 30, and the first water supply section 40 and the second water supply section 50 have the same configuration as those of the environment improvement device 110. However, in the environment improvement device 210, the soil cultivation section 20 is tilted so that the water storage section 62 is located downward. This increases the efficiency with which water in the soil 22 flows into the water storage section 62 in the soil cultivation section 20.

[0022] D. Fourth embodiment: 4 is an explanatory diagram showing a schematic configuration of an environment improvement device 310 according to the fourth embodiment. In the environment improvement device 310, parts common to the environment improvement device 10 according to the first embodiment are given the same reference numerals.

[0023] The environmental improvement device 310 has a single-tank structure in which the soil cultivation section 20 and the water tank section 30 are integrated. The environmental improvement device 310 has a common container 64 in which the soil cultivation section 20 and the water tank section 30 are formed, and the soil cultivation section 20 and the water tank section 30 are separated by a water-soil separation section 60. The water-soil separation section 60 can function as a first water supply section 40 that supplies water from the water tank section 30 to the soil cultivation section 20 and a second water supply section 50 that supplies water discharged from the soil cultivation section 20 to the water tank section 30. However, the environmental improvement device 310 has a first water supply section 40 separate from the water-soil separation section 60, which actively circulates water between the water tank section 30 and the soil cultivation section 20, promoting water purification by the soil cultivation section 20. Similar to the first water supply unit 40 of the environment improvement device 110 and the environment improvement device 210, the first water supply unit 40 of the environment improvement device 310 includes a water supply pipe 44, a water circulation pump 42 attached to the water supply pipe 44, and a water outlet 46 which is the end structure of the water supply pipe 44. Water in the water tank unit 30 is pumped up by the water circulation pump 42 and led to the soil cultivation unit 20 by the water supply pipe 44. At this time, the water outlet 46 of the water supply pipe 44 functions as an aeration unit.

[0024] E. Other Embodiments: (E-1) Aeration section: As shown in the above-described embodiments, the aeration unit can be configured to allow at least one of the water in the water tank unit 30 and the water discharged from the soil cultivation unit 20 to fall by gravity. As an example of such an aeration unit configured by a structure included in the first water supply unit 40, the first embodiment provides an overflow unit 41 that allows the water in the water tank unit 30 to overflow from the top of the water tank unit 30, but other configurations may also be used. For example, the aeration unit may be configured by at least one of holes and slits provided in the wall of the water tank container 36 that constitutes the water tank unit 30 and through which the water in the water tank container 36 is discharged.

[0025] The aeration unit may also be configured with a structure that is not included in either the first water supply unit 40 or the second water supply unit 50. For example, the aeration unit may be configured with a bubbling device that blows air into at least one of the water in the water tank unit 30 and the water discharged from the soil cultivation unit 20. Specifically, such a bubbling device may be disposed, for example, in the water tank container 36 or in the water storage unit 62 provided in the cultivation unit container 26.

[0026] (E-2) About the water tank: In the above-described embodiments, the water tank section 30 includes a single water tank container 36. However, other configurations are also possible. For example, the water tank section 30 may be configured by combining multiple divided water tank containers. In such a case, the aeration section may be configured by providing a structure for supplying water from any first divided water tank container among the multiple divided water tank containers to a different second divided water tank container by spraying water using a pressurizing pump and a spray nozzle. Alternatively, the multiple divided water tank containers may be configured to have different heights, and the aeration section may be configured by allowing water to fall by gravity from the taller first divided water tank container to the shorter second divided water tank container. Specifically, the wall of the water tank container 36 may be provided with multiple holes, or multiple slits, or an overflow section 41 similar to that in the first embodiment may be provided. In this way, by providing multiple divided aquarium containers and allowing water to flow between the divided aquarium containers, an environmental improvement device with high design and visual impact can be created, and the effect of increasing microbial diversity within the space through aeration can be enhanced.

[0027] The environment improvement device is only required to have at least the soil cultivation section 20 that cultivates the plants 24 using soil as a cultivation section for cultivating the plants 24, and may further include other cultivation sections. For example, the environment improvement device may further include a hydroponic cultivation section that cultivates the plants by hydroponic cultivation, and that is supplied with water from the water tank section 30 and that also supplies discharged water to the water tank section 30. [Example]

[0028] <Investigation of changes in indoor microbial diversity due to the installation of environmental improvement devices> [Sampling methods for microbiota surveys] FIG. 5 is an explanatory diagram showing the exterior of an environmental improvement device 410 actually used to examine changes in indoor microbial diversity due to the installation of an environmental improvement device. The environmental improvement device 410 includes three divided aquarium containers 36A-36C. Water is supplied to divided aquarium container 36B through multiple slits in the wall of divided aquarium container 36A. Water is then supplied to divided aquarium container 36C in a waterfall-like fashion from a lowered portion of the wall of divided aquarium container 36B, causing water to flow from the taller divided aquarium container to the shorter divided aquarium container. Water is also supplied to the soil cultivation section 20 through multiple holes in the wall of divided aquarium container 36C. Water discharged from the soil cultivation section 20 passes through a water storage section and a water supply pipe 54 (not shown) and is then discharged from a water outlet 56 into divided aquarium container 36A.

[0029] 6 is an explanatory diagram showing the sampling schedule for an experiment conducted to investigate changes in indoor microbial diversity due to the installation of an environmental improvement device. The environmental improvement device 410 was installed indoors (approximately 4 m wide and 8 m deep) for 21 consecutive weeks from May 9, 2023 to September 26, 2023, and then removed, and changes in the indoor microbial flora were investigated.

[0030] First, for six weeks from May 9 to June 13, the stable state of the room before the installation of the environment improvement device 410 was confirmed (step T100). Then, on June 19 (week 7), the environment improvement device 410 was installed in the room (step T110). Then, for eight weeks from June 20 to August 8, changes in the microbiome in the room while the environment improvement device 410 was installed were tracked (step T120). Then, on August 9 (week 14), the environment improvement device 410 was removed from the room (step T130). Then, for three weeks from August 29 to September 26, changes in the microbiome after the removal of the environment improvement device 410 were confirmed (step T140). Here, from May 9 (week 1) to August 8 (week 14), sampling was conducted every Tuesday in processes T100 and T120, and approximately every other Tuesday in process T140 (sampling was conducted in weeks 17, 19, and 21). According to the schedule described above, sampling was conducted to confirm the state and stability of the indoor microbial flora (microbiome) under three conditions: before installation, during installation, and after removal of the environment improvement device 410. In the following explanation, the period before installation of the environment improvement device 410 (process T100) will be referred to simply as "before installation," the period during installation of the environment improvement device 410 (process T120) will be referred to simply as "during installation," and the period after removal of the environment improvement device 410 (process T140) will be referred to simply as "after removal."

[0031] FIG. 7 is an explanatory diagram showing the details of each sampling session conducted in the experimental room. Sampling for microbiome analysis was performed using the swab method and water sampling. A total of eight samples were collected using the swab method: five locations on the floor (50 cm × 50 cm areas, designated "Floor 1" to "Floor 5" in FIG. 7), two locations on the wall (100 cm × 100 cm areas, designated "Wall 1" and "Wall 2" in FIG. 7), and one location on the desk (50 cm × 50 cm areas, designated "Desk" in FIG. 7). Furthermore, two samples (two 100 mL bottles) of water were collected from the divided aquarium container 36C in which fish were kept in the environmental improvement device 410.

[0032] For the swab method, a DNA collection swab (DNA / RNA Shield Collection Tube w / Swab, manufactured by Zymo Research) was used to scrape the surface of the area to be sampled, and then the sample was placed in a storage tube for the DNA collection swab (DNA / RNA Shield Collection Tube, manufactured by Zymo Research). An environmental sensor (Environmental Sensor 2JCIE-BL, manufactured by Omron) was used to measure room temperature, humidity, and air pressure. Three types of plants cultivated in the soil cultivation section 20 of the environmental improvement device 410, as well as soil, gravel, and rocks, were also sampled at one time using the swab method.

[0033] [DNA extraction and sequencing] Samples collected by swabbing from floors, walls, desks, etc. were thoroughly mixed using a vortex in the tube containing the sample (DNA / RNA Shield Collection Tube, manufactured by Zymo Research). The entire solution in the tube was then transferred to a bead tube included with a DNA extraction kit (ZymoBIOMICS DNA / RNA Miniprep Kit, manufactured by Zymo Research). Water collected from the environmental improvement device 410 for DNA extraction was filtered through a filter system with a membrane pore size of approximately 0.2 μm (Analytical Test Filter Funnel-145-0020, manufactured by Thermo Scientific Nalgene). The filtered membrane was divided into four sections, and two of the sections were placed in each of two bead tubes.

[0034] The prepared bead tubes were stored at 4°C or -80°C (depending on the time between sampling and DNA extraction) until DNA extraction. DNA extraction was then performed according to the protocol provided with the DNA extraction kit. To investigate the bacterial microbiome, PCR amplification was performed using the extracted DNA as a template, with primers 515-F-1stPCR and 806-R-1stPCR targeting the V4 region of 16S rRNA. To investigate the fungal microbiome, PCR amplification was performed using primers ITS1-30F-1stPCR and ITS1-217R-1stPCR targeting the ITS region.

[0035] Figure 8 shows the sequences of the primers used in PCR. The V4 and ITS regions of 16S rRNA are relatively conserved among bacteria and fungi, respectively, and are known as genomic regions that can be used to identify bacterial and fungal species. The amplified products were purified using magnetic beads (AMPure XP, Beckman Coulter) and further amplified by PCR using a DNA library preparation kit (Nextera XT Index Kit v2 Set D, Illumina). The resulting amplified products were purified again using magnetic beads. Equal amounts of the amplified products from each sample were then mixed and diluted to 50 pM, and 20% PhiX, a sequencing control DNA library, was added to prepare a DNA library for sequencing. The prepared DNA library was subjected to 300-bp single-end sequencing using a next-generation sequencer (iSeq 100, Illumina).

[0036] [Microbiome analysis] The FASTQ files (a formatted file containing DNA base sequences and quality scores) obtained as a result of sequencing were analyzed using QIIME2 (Bolyen E, Rideout JR, Dillon MR, et. al. 2019. Reproducible, interactive, scalable, and extensible microbiome data science using QIIME 2. Nat Biotechnol. 37: 852-857), an analysis pipeline for amplicon sequence analysis, with Cutadapt (Marcel M. 2011. Cutadapt removes adapter sequences from high-throughput sequencing reads. EMBnet.journal. 17(1):10-12) and DADA2 (Callahan B, McMurdie P, Rosen M, et al. 2016. DADA2: High-resolution sample inference from Illumina amplicon data. Nat Methods). Using the JSML (13:581-583) plugin, adapter sequences were removed and filtered at an error rate of 0.3 to obtain representative sequences. The representative sequences were then compared with a reference sequence database to perform phylogenetic classification at the genus or species level, after which the occupancy rate of each bacterial species was calculated. Reads classified as mitochondria or chloroplasts at this point were filtered out from further analysis.

[0037] [Statistical analysis] To examine differences due to the presence or absence of plants and sampling locations, we performed principal coordinate analysis based on weighted UniFrac distances. Weighted UniFrac distances are the molecular phylogenetic distances based on representative sequences constituting each sample's microbiome, and the distance between bacterial communities, taking into account the number of reads for each representative sequence (Lozupone C, Lladser M, Knights D, et al. 2011. UniFrac: an effective distance metric for microbial community comparison. ISME. J5:169-172). Principal coordinate analysis was performed using the diversity plugin in QIIME2 after filtering to include only samples with a total read count of 9,000 or more. Additionally, we used ANCOMBC (Lin H, Peddada SD. 2020. Analysis of compositions of microbiomes with bias correction. Nat Commun. 11(1):1-11) to identify bacterial species with significant differences in abundance when comparing the indoor microbiomes before and during plant removal, and during and after plant removal. ANCOMBC is a method that corrects for sampling bias and estimates whether there are statistically significant differences in the abundance of each bacterial species between samples using a chi-square test. To examine the diversity of each sample, we also calculated alpha diversity indices (Xia Y, Sun J, Chen D. 2018. Statistical Analysis of Microbiome Data with R. Springer Singapore. eBook ISBN:978-981-13-1534-3). The indices calculated were: Observed features (the number of observed species), Chao1 (an index based on the number of observed species, weighting particularly rare species), Shannon (an index that weights mainly rare species, and is high when the number of observed species is high and each bacterial species is evenly distributed), and Faith-PD (an index calculated based on the microbial phylogenetic tree).

[0038] [Results and Discussion] (Bacterial species composition) The bacterial species whose abundances were significantly different by ANCOMBC when comparing indoor samples taken before and during installation, and during and after installation and removal, are described below. In the bacterial microbiome, when the bacterial species detected in significantly higher amounts during installation compared to before installation were sorted in descending order of p-value, many of the top-ranked species were also detected in the water within the environmental improvement device 410. For example, on "Floor 5," the second most prevalent bacterial species in the water within the environmental improvement device 410, "d_Bacteria; p_Patescibacteria; c_Saccharimonadia; o_Saccharimonadales; f_Saccharimonadaceae (bacterial species thought to originate from soil)," showed the most significant increase (in order of p-value) during installation compared to before installation. Because "Floor 5" is located immediately adjacent to the installation location of the environmental improvement device 410, it is possible that the microbiome was directly affected by droplets or other factors. Furthermore, many of the bacterial species whose detected amounts changed significantly between when the device was installed and after it was removed were contained in the water within the environment improvement device 410.

[0039] On the other hand, with regard to the fungal microbiome, most of the sequences contained in the water inside the environmental improvement device 410 did not lead to species identification (they were only displayed as k__fungi or as Unassigned), and in fact only 86 species were found to have more than one count in the water inside the environmental improvement device.Even among the species output by ANCOMBC as species with significant differences in detected amount before and during installation, and during and after installation, many of the species details were unknown.

[0040] (Comparison of the number of common bacterial species with the water from the environmental improvement equipment) Figure 9 is an explanatory diagram using a Venn diagram to show the changes in the number of bacterial species detected at each indoor sampling point, the number of bacterial species detected in the water within the environmental improvement device 410, and the number of bacterial species common to both, for bacterial species detected at least once at at least one sampling point. The numbers in the diagram indicate the number of bacterial species that meet the conditions of each region in the Venn diagram. Note that throughout the entire experiment in this example, the number of bacterial species detected at least once at at least one sampling point was 5,651. Figure 9 shows the results of an investigation into the relationship between the number of common bacterial species and the water within the environmental improvement device 410, with the sampling points "Floor 5" and "Wall 2" showing significant changes in the number of common bacterial species when divided into three groups: before installation, during installation, and after removal. The results also show the relationship between the sampling points and the water within the environmental improvement device 410 and non-water components such as plants and rocks. Although a tendency for the number of common bacterial species to increase during installation was also observed at sampling points other than "Floor 5" and "Wall 2," the number of common bacterial species with the water inside the environmental improvement device 410 increased particularly at "Floor 5" and "Wall 2" during installation. This is thought to be because "Floor 5" and "Wall 2" are sampling points adjacent to the installation location of the environmental improvement device 410, and therefore may have been more susceptible to direct influences such as splashes of water inside the environmental improvement device 410 due to the physical distance.

[0041] Furthermore, for samples other than water ("other" samples) of plants, rocks, and other organisms in the environmental improvement device 410, the proportion of bacterial species common to the water in the environmental improvement device 410 was significantly higher than for other indoor samples. Because water circulates throughout the entire device, including the aquarium section 30 and the soil cultivation section 20, the rocks in contact with the water are thought to share a microbiome with the water. For example, many bacterial species thought to originate from soil (dBacteria; pPatescibacteria; cSaccharimonadia; oSaccharimonadales; fSaccharimonadaceae) were found in the water in the aquarium section 30. This suggests that the soil near the roots of plants cultivated in the soil cultivation section 20 is likely to be an important source of microbiome for the water in the aquarium section 30. From this, when considering the microbiome of the environment improvement device 410, it is thought that by examining the water in the water tank section 30, microbiome data that is roughly representative of the entire environment improvement device 410 can be obtained.

[0042] On the other hand, the number of fungal species detected with a count of 1 or more at at least one sampling point was 578. Regarding the number of detected species in the fungal microbiome and the number of species common to the water within the environmental improvement device 410, there was little change observed among the three groups before installation, during installation, and after removal at any of the sampling points. Furthermore, the fungal species identified in components other than water within the environmental improvement device 410 (such as plants and rocks) and in the water within the environmental improvement device 410 were similar, as were the bacterial microbiome (data not shown).

[0043] (Results of principal coordinate analysis) FIG. 10 is an explanatory diagram showing the results of principal coordinate analysis based on the bacterial species composition of all samples taken during the experiment. The plots in the figure indicate the sampling locations for each sampling date, and the same marks represent the same attributes (for example, the plots indicated by black circles in FIG. 10 are plots for the water inside the environment improvement device 410 while it was installed). The results of the principal coordinate analysis of the bacterial microbiome shown in FIG. 10 show that the plots for the water inside the environment improvement device 410 and the other samples are significantly different. Furthermore, the results show that there was little change in the water inside the environment improvement device 410 before installation, during installation, and after removal. This suggests that the bacterial species composition of the water inside the environment improvement device 410 was significantly different from that of the indoor microbiome, and that the bacterial species composition remained relatively stable throughout the experiment.

[0044] Furthermore, Figure 10 shows that some of the wall samples are plotted closer to the water inside the environmental improvement device 410. For example, the samples from "Wall 1" and "Wall 2" collected on June 20 and "Wall 2" collected on July 11 were taken while the device was installed, and therefore may have been affected by the water inside the environmental improvement device 410. The bacterial species found in abundance in the water inside the environmental improvement device 410 are known as ammonia-oxidizing archaea (Herbold, CW, Lebedeva, E., Palatinszky, M., and Wagner, M. 2016. Candidatus Nitrosotenuis. In Bergey's Manual of Systematics of Archaea and Bacteria (eds ME Trujillo, S. Dedysh, P. DeVos, B. Hedlund, P. Kampfer, FA Rainey, and WB Whitman)), which are widely distributed in freshwater and soil.

[0045] (Changes in alpha diversity) Figures 11 and 12 are explanatory diagrams showing changes in microbiome alpha diversity. Figure 11 shows changes related to the bacterial microbiome, and Figure 12 shows changes related to the fungal microbiome. Of the alpha diversity indices, Figures 11(A) and 12(A) show the results for Chao1, and Figures 11(B) and 12(B) show the results for Shannon. Figures 11 and 12 show the results of calculating each alpha diversity index for each sampling point, divided into three groups: before installation (labeled "B"), during installation (labeled "D"), and after removal (labeled "A").

[0046] Figures 13 and 14 are diagrams illustrating changes in microbiome alpha diversity, showing Chao1 results for each sampling date. Figure 13 shows changes in the bacterial microbiome, and Figure 14 shows changes in the fungal microbiome. In Figures 13 and 14, the horizontal axis shows the sampling date, and the vertical axis shows the Chao1 index value.

[0047] When the alpha diversity of the bacterial microbiome was divided into three groups: before installation, during installation, and after removal, the three indices Chao1, Shannon, and Observed Features showed the highest values ​​during installation. Figure 11 shows the results for the two indices Chao1 and Shannon as representative examples. These results indicate that the installation of the environmental improvement device 410 increased the diversity of the indoor microbiome. Furthermore, when viewed over time, as shown in Figure 13, the value of the Chao1 index in particular increased sharply immediately after the installation of the environmental improvement device 410, confirming that the increase in alpha diversity due to the installation of the environmental improvement device 410 occurred within a short period of time. For example, in a prior study, a plant called spider plant was placed in an enclosed space and the microbiome in the space was examined. Six months later, the microbiome in the space was reported to have become similar to the microbiome on the plant's leaves (Mahnert A, Moissl-Eichinger C, Berg G. 2015. Microbiome interplay: plants alter microbial abundance and diversity within the built environment. Front Microbiol. 6:887). Based on the results of the changes in alpha diversity in the examples of the present application, it can be said that installing the environment improvement device 410 changes the microbiome more quickly after installation than in the prior study, and is therefore considered to be effective in efficiently changing the indoor microbiome.

[0048] The alpha diversity of the fungal microbiome increased during installation and after removal compared to before installation (Figure 12). The alpha diversity of the bacterial microbiome increased during installation and then decreased again after removal, but the fungal microbiome maintained a high alpha diversity even after removal. Furthermore, although the timing of the increase in the alpha diversity index value was not as pronounced as that of the bacterial microbiome, an increase was observed immediately after installation, particularly in Chao1, as shown in Figure 14.

[0049] (Conclusion) As described above, by placing the environmental improvement device 410 indoors, many of the alpha diversity index values, particularly for the bacterial microbiome, were highest while the device 410 was installed. Therefore, it is believed that installing the environmental improvement device has the effect of increasing the diversity of the indoor microbiome. Furthermore, since the number of bacterial species thought to be derived from soil increased on the floor and other indoor surfaces during installation compared to before installation, it is believed that installing the soil cultivation unit 20 can further enhance the effect of increasing the diversity of the indoor microbiome. Furthermore, topic analysis using VITCIMIC and LEA revealed that the water within the environmental improvement device 410 accounted for a high proportion of the total of three topics related to nature, such as rivers. It was confirmed that the above three topics increased in some wall samples and desk samples during installation (data not shown). These results suggest that installing the environmental improvement device brings the state of the indoor microbiome closer to the natural state outdoors.

[0050] <Investigation of changes in indoor microbiome using a soil aeration device> [Preparation of liquid soil] Liquid soil containing soil microorganisms was prepared as a model for the water discharged from the soil cultivation section of an environmental improvement device. The effects of aerating this liquid soil were investigated by aerating the water discharged from the soil cultivation section. The liquid soil was prepared according to a report by Shinohara et al. (2011) Soil Sci. Plant Nutr., 57, 190-203.) The procedure for preparing the liquid soil was as follows: First, two 8-liter Tombo buckets (Shinki Gosei Co., Ltd.; product number 739) were prepared. Each bucket was filled with 5 liters of RO water, 25 g of fully matured compost containing charcoal (Kyowa Kaihatsu), and 5 g of NatureAid (Sakata Seed), a plant-based amino acid liquid fertilizer. Next, an air stone (Ibuki Air Stone 30φ series 30φ x 78) connected to a Silent β-120 air pump (Nisso) was placed in the bucket and aeration was performed. Five grams of NatureAid was added on the first and second days after aeration began. Because the volume of the liquid soil during preparation decreased due to evaporation, RO water was added each time to compensate for the decrease. Liquid soil preparation was carried out in an NK system constant temperature and humidity chamber (Nihon Medical and Chemical Instruments Manufacturing Co., Ltd.; LP-1PH-2P2) at 25°C under 16 hours of light and 8 hours of darkness.

[0051] [Water quality measurement] After the start of liquid soil preparation (start of aeration), samples were taken from the liquid soil (including during preparation) on the 5th, 8th, 122nd, 15th, 19th, 22nd, and 26th days, and NH4 + , NO2 - , NO3 - , PO4 3- , and pH measurements were performed. + Reflectoquant Ammonium Test (Kanto Chemical Co., Ltd., 16892-1M; 16977-1M; 16899-1M), NO2 - Reflectoquant Nitrite Test (Kanto Chemical Co., Ltd., 16973-1M; 16732-1M), NO3 - Reflectoquant Nitric Acid Test (Kanto Chemical Co., Ltd., 16971-1M; 16995-1M), PO4 3-was measured using a Reflectoquant Phosphate Test (Kanto Chemical Co., Ltd., 16978-1M) and a simple reflectance photometer (Kanto Chemical Co., Ltd., RQ Flex 20).

[0052] [Measurement of airborne bacteria] The number of viable bacteria and other particles in the air in the temperature- and humidity-controlled chamber used to prepare the liquid soil was measured. A BioTrak bioparticle counter (TSI, 9510-BD-P) was used for the measurements. The day before measurements, the room was treated with an Airdog X3s air purifier (Airdog, KJ200F-X3) for one hour to remove particles. The following day, the BioTrak measured the air for two hours. This involved two consecutive measurements of 1680 L of air per hour (0-60 min and 61-120 min). Measurements were taken on days 1, 6, 9, 13, 16, 20, 23, and 27 after the start of the liquid soil preparation (aeration).

[0053] [Liquid soil, air, etc. sampling, and genomic DNA extraction] To extract microbiome genomic DNA from the liquid soil, 50 mL of liquid soil (including soil samples taken during the preparation process) was collected on days 5, 8, 12, 15, 19, 22, and 26 after the start of the preparation (aeration), as described above in the [Water Quality Measurement] section. The microbiome was then recovered by filtering the liquid soil through a 0.2 μm nitrocellulose filter using an Analytical Test Filter Funnel (ThermoFisher, 145-0020). The filter was then placed in a Power Bead Pro Tube included with the DNeasy PowerSoil Pro Kit (QIAGEN, 47014), and genomic DNA was extracted according to the QIAGEN instructions.

[0054] Similarly, microbiome genomic DNA was extracted from the NatureAid liquid fertilizer used to prepare the liquid soil. Specifically, NatureAid was diluted with RO water to a final concentration of 1 g / L, and 100 mL and 500 mL of the solution were filtered through an Analytical Test Filter Funnel to recover the NatureAid microbiome. Genomic DNA was then extracted from the filter containing the NatureAid microbiome using the DNeasy PowerSoil Pro Kit.

[0055] Microbiome genomic DNA was also extracted from the fully matured compost containing charcoal used to prepare the liquid soil. Specifically, the fully matured compost containing charcoal was directly poured into a PowerBead Pro Tube included with the DNeasy PowerSoil Pro Kit.

[0056] Microbiome genomic DNA was also extracted from the inner wall of the Tombo bucket after liquid soil preparation. Specifically, the inner wall of the Tombo bucket on day 33 after the start of liquid soil preparation was swabbed with Puritan HydraFlock Sterile Flocked Collection Devices (Puritan, 25-3306-H) to collect the microbiome. The tip of the Puritan HydraFlock tube containing the collected microbiome was cut off with scissors and placed in a PowerBead Pro Tube included with the DNeasy PowerSoil Pro Kit for genomic DNA extraction.

[0057] Microbiome genomic DNA was also extracted from the air in rooms with and without liquid soil. To obtain the microbiome from rooms with liquid soil, the microbiome (air with liquid soil) was sampled on a gelatin filter (Sartorius, Disposable Gelatin Filter 17528-80) using an MD8 Airscan Air Sampler (Sartorius, 16746) at a suction power of 50 L / min on days 26 and 30 after the start of liquid soil preparation (3,000 L of air was collected). To obtain the microbiome from rooms without liquid soil, the liquid soil was removed and the room was first treated with an Airdog X3s air purifier for 2 hours in a temperature- and humidity-controlled chamber 16 days after the liquid soil was removed to remove particulate matter. After three days, the microbiome (air without liquid soil on day 3) was sampled onto a gelatin filter (Sartorius, Disposable Gelatin Filter 17528-80) using an MD8 Airscan Air Sampler (Sartorius, 16746) at a suction power of 50 L / min (3,000 L of collected air). The air was then again treated with an AirdogX3s air purifier for two hours to remove indoor particulates. The next day, the microbiome (air without liquid soil on day 1) was sampled onto a gelatin filter (Sartorius, Disposable Gelatin Filter 17528-80) under the same conditions as above.

[0058] The gelatin filter containing the collected air microbiome was transferred to a 50 mL test tube, and 50 mL of dH2O (distilled H2O) (Ambion, AM9906) was added. The tube was heated on a heat block at 50°C for 20 minutes (mixing by inversion every 5 minutes) to completely dissolve the gelatin filter. The air microbiome was collected by filtering the solution through an Analytical Test Filter Funnel. The filter was then placed in a PowerBead Pro Tube included with the DNeasy PowerSoil Pro Kit, and genomic DNA was extracted.

[0059] As a negative control (NC), a gelatin filter that had not been subjected to air sampling was prepared, and the same procedures were carried out as for the gelatin filter with the air microbiome attached as described above, and microbiome genomic DNA was extracted from the gelatin filter.

[0060] [Next-generation sequencing] Next-generation sequencing (NGS) libraries were prepared according to the Illumina protocol. The 16S rRNA V3-V4 region was amplified by PCR from each microbiome genomic DNA sample. The PCR enzyme used was Ex Taq Hot Start Version (Takara Bio, Inc., RR006A).

[0061] Figure 15 is an explanatory diagram showing the primer sequences used in the PCR amplification. The primers are mixed primers in which random sequences of varying lengths of 0-5 bases are inserted into the region indicated as "NNNNN" in order to improve the quality of sequence analysis. The PCR reaction conditions were a 2-minute thermal denaturation reaction at 95°C, 30 cycles of a 3-step PCR reaction (94°C for 30 seconds, 55°C for 30 seconds, and 72°C for 30 seconds), and a 5-minute extension reaction at 72°C.

[0062] Index PCR was then performed using index primers. The index primers used were the primers with Index2 (SEQ ID NOS: 7 to 14) and the primers with Index1 (SEQ ID NOS: 15 to 22). The index PCR reaction conditions were a 2-minute heat denaturation reaction at 94°C, 10 cycles of a 3-step PCR reaction (94°C for 30 seconds, 60°C for 30 seconds, and 72°C for 30 seconds), and a 5-minute extension reaction at 72°C. PCR cleanup was performed using the Agencourt AMPure XP kit (Beckman Coulter) according to the Beckman Coulter protocol. The library was loaded onto the MiSeq Sequencing System (Illumina) using the Miseq Reagent Kit v3 (Illumina) and sequencing was performed at 2 × 300 bp according to the protocol provided by Illumina, Inc.

[0063] [Bacteria flora analysis] Using the fastx_barcode_splitter tool in FASTX-Toolkit (ver. 0.0.14), we extracted only read sequences whose initial read sequence completely matched the primer sequence used. Primer sequences were then removed from the extracted reads using fastx_trimer in FASTX-Toolkit. Sickle (ver. 1.33) was then used to remove sequences with a quality score of less than 20, and sequences with a length of 130 bases or less and their paired sequences were discarded. The reads were then merged using the paired-end read merging script FLASH (ver. 1.2.11). After removing chimeric and noise sequences using the dada2 plugin in Qiime2 (ver. 2021.11), we used the feature-classifier plugin to compare the representative sequences obtained with the 97% OTUs of Silva (ver. 132) to perform phylogenetic inference.

[0064] The bacterial community analysis of each microbiome sample was performed by removing OTUs (Operational Taxonomic Units) classified as chloroplasts or mitochondria derived from plant cells, i.e., OTUs whose annotations include Chloroplast or Mitochondria, and OTUs classified as bacteria but not classified at the phylum level. The microbiome composition results were visualized using the "phyloseq" package in R.

[0065] Non-metric multidimensional scaling (nMDS) analysis was performed using Primer-e v7 software (PRIMER-E Ltd., UK). Differences (dissimilarity) in the microbiota composition between samples were calculated based on the Bray-Curtis dissimilarity. Other parameters were the number of repeats: 500, minimum stress: 0.01, and Kruskal fit scheme: 1. The data were plotted in two dimensions.

[0066] [Results and Discussion] (Analysis of liquid soil) Figure 16 shows the NH4 + , NO2 - , NO3 - , PO4 3- The ion concentrations in the liquid soil in the two buckets (No. 1 and No. 2) showed similar behavior, and NH4 + The concentration peaked and then decreased. - The concentration began to increase around the 10th day, peaked on the 19th day, and then decreased.

[0067] Figure 17 is an explanatory diagram showing the bacterial flora composition of each sample by genus (Genus) classification, and visualizes the bacterial flora composition using a stacked bar graph. The results for the liquid soil in the two buckets (No. 1 and No. 2) are shown in chronological order by the sampling date. As shown in Figure 17, the bacterial flora composition of the liquid soil in each bucket behaved similarly. After aeration began, the proportion of the Azospirillum genus, to which nitrogen-fixing bacteria belong, increased, but decreased within about a week, followed by NO3 - Around the 19th day, when the concentration peaked, the proportion of Niveispirillum, a genus of nitrogen-fixing bacteria, increased. In Figure 17, the change in the proportion of Azospirillum is shown surrounded by a solid line, and the change in the proportion of Niveispirillum is shown surrounded by a dotted line. These results confirmed that the liquid soil became suitable for plant growth around the 19th day after aeration began.

[0068] (Measurement of airborne bacteria) Figure 18 is an explanatory diagram showing the results of measuring the number of particles in the air in a temperature and humidity chamber during the liquid soil preparation process. Figure 19 is an explanatory diagram showing the results of measuring the number of viable bacteria in the air in a temperature and humidity chamber during the liquid soil preparation process. Figures 18(A) and 19(A) show the measurement results 60 minutes after the start of measurement, and Figures 18(B) and 19(B) show the measurement results from 61 to 120 minutes after the start of measurement. In Figures 18 and 19, the horizontal axis shows the number of days elapsed since the start of measurement. In Figure 18, the vertical axis shows the number of particles, and in Figure 19, the vertical axis shows the number of viable bacteria. The BioTrak used in the measurements can count particles and viable bacteria in the air by particle size. Figures 18 and 19 show the fluctuations in particle count by particle size.

[0069] BioTrak measurements showed a significant increase in the number of 0.5-0.7 μm particles in the indoor air after aeration began (Figure 18). Furthermore, increases in the number of particles in the 0.7-1.0 μm and 1.0-3.0 μm sizes were also observed (Figure 18). Furthermore, a significant increase in the number of viable bacteria was observed after aeration for particles in the 1.0-3.0 μm size range, which corresponds to the size of common bacteria (Figure 19). These results suggest that aeration of the liquid soil dissipates bacteria-containing particles into the air. BioTrak measurements were conducted for two hours, but as mentioned above, the results were evaluated separately for the first hour and the second hour. This was done to take into account the effect of opening and closing the temperature and humidity chamber door to start the BioTrak measurement on the number of airborne particles. However, the measurement results for both the first hour and the second hour showed similar trends, suggesting that the effect of opening and closing the door was not significant.

[0070] (Bacterial flora analysis) Figure 20 is an explanatory diagram depicting a Venn diagram created based on the analysis results of the bacterial flora composition shown in Figure 17. This figure shows the results of a comparison between air without liquid soil, air with liquid soil, liquid soil, and the negative control NC (gelatin filter only). The numbers in Figure 20 indicate the number of bacterial species at the genus level belonging to each range in the Venn diagram, and represent the combined numbers for all detection results shown in Figure 17 (e.g., for liquid soil, days 5, 8, 12, 15, 19, 22, and 26). As shown in Figure 20, it was confirmed that aeration of the liquid soil increased the bacterial species in the liquid soil in the air.

[0071] Figure 21 is an explanatory diagram showing the results of a non-metric multidimensional scaling (NMDS) analysis. Here, a large number of points expressed in multiple dimensions are rearranged on a two-dimensional plane so that similar points are close to each other and dissimilar points are far from each other. As shown in Figure 21, it was confirmed that the composition of the air bacterial flora in a temperature and humidity chamber with liquid soil installed was more similar to that of the liquid soil compared to when liquid soil was not installed.

[0072] Figures 22 and 23 are explanatory diagrams showing the changes in the diversity of airborne bacterial flora due to liquid soil. Figure 22 shows the results for observed OTUs (operational taxonomic units), and Figure 23 shows the results for Shannon diversity. As shown in Figure 22, it was confirmed that all diversity evaluation indices in the indoor air increased with the installation of liquid soil. Furthermore, bacteria of the genus Brevibacillus, which accounted for the largest proportion in the air in rooms where liquid soil was installed, not only possess nitrogen fixation ability like bacteria of the genus Niveispirillum, but also, like bacteria of the genus Azospirillum, produce auxin, a plant growth-promoting hormone, and are known as plant growth-promoting bacteria.

[0073] (Conclusion) As described above, by placing and aerating liquid soil prepared as a model of the water discharged from the soil cultivation section, it was confirmed that the bacterial flora of the air in the space could be made closer to the natural environment in terms of bacterial species and number of species.

[0074] The present disclosure is not limited to the above-described embodiments, and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted.

[0075] The present disclosure can also be realized in the following forms. [Application example 1] An environmental improvement device for increasing microbial diversity in a space, a soil cultivation unit that cultivates plants using soil; an aquarium section where aquatic organisms grow in water; A first water supply unit that supplies water in the water tank unit to the soil cultivation unit; A second water supply unit that supplies water discharged from the soil cultivation unit to the water tank unit; an aeration unit that aerates water flowing through the environment improvement device; Equipped with Environmental improvement device. [Application example 2] The environmental improvement device according to Application Example 1, The aeration unit has a structure that allows at least one of the water in the water tank unit and the water discharged from the soil cultivation unit to fall by gravity. Environmental improvement device. [Application example 3] The environmental improvement device according to Application Example 2, The aeration unit has a structure in which the water in the water tank unit overflows from the top of the water tank unit and falls by gravity. Environmental improvement device. [Application example 4] The environmental improvement device according to Application Example 2, The aeration unit has a structure for allowing the water in the water tank unit to fall by gravity, and includes at least one of holes and slits provided on a wall surface of a container constituting the water tank unit and through which the water in the water tank unit is discharged. Environmental improvement device. [Application example 5] The environmental improvement device according to Application Example 1, The aeration unit has a structure for spraying at least one of the water in the water tank unit and the water discharged from the soil cultivation unit. Environmental improvement device. [Application Example 6] The environmental improvement device according to any one of Application Examples 1 to 5, The first water supply unit has a structure that supplies water from the water tank unit to the soil provided in the soil cultivation unit by gravity or by spraying, The aeration section is constituted by the first water supply section. Environmental improvement device. [Application Example 7] The environmental improvement device according to any one of Application Examples 1 to 5, The water tank section includes a plurality of divided water tank containers each containing water therein, The aeration unit has a structure that supplies water from a first divided water tank container to a second divided water tank container by gravity or by spraying. Environmental improvement device. [Application Example 8] The environmental improvement device according to any one of Application Examples 1 to 5, The second water supply unit has a structure that supplies water discharged from the soil cultivation unit to the water tank unit by gravity or by spraying, The aeration section is constituted by the second water supply section. Environmental improvement device. [Application Example 9] The environmental improvement device according to Application Example 1, The aeration unit is composed of a bubbling device that blows air into at least one of the water in the water tank unit and the water discharged from the soil cultivation unit. Environmental improvement device. [Application Example 10] An environmental improvement method for increasing microbial diversity in a space, comprising: In an apparatus having a soil cultivation section for cultivating plants using soil and an aquatic tank section for growing aquatic organisms in water, and circulating water between the soil cultivation section and the aquatic tank section, the apparatus aerates the water circulating within the apparatus. How to improve the environment. [Explanation of symbols]

[0076] 10, 110, 210, 310, 410...Environmental improvement equipment 20...Soil Cultivation Department 22...Soil 24...Plant 26…Cultivation department container 30...Aquarium section 32…Water 34…aquatic life 36...Aquarium container 36A~36C…Divided aquarium container 40...First water supply section 41...Overflow section 42...Water circulation pump 44…Water supply pipe 46...Water outlet 50...Second water supply section 50cm…50cm× 52...Water circulation pump 54…Water supply pipe 56...Water outlet 60...Water / soil separation section 62...Water storage section 64...Common container

Claims

1. An environmental improvement device for increasing microbial diversity in a space, a soil cultivation unit that cultivates plants using soil; an aquarium section where aquatic organisms grow in water; A first water supply unit that supplies water in the water tank unit to the soil cultivation unit; A second water supply unit that supplies water discharged from the soil cultivation unit to the water tank unit; an aeration unit that aerates water flowing through the environment improvement device; Equipped with Environmental improvement device.

2. The environmental improvement device according to claim 1, The aeration unit has a structure that allows at least one of the water in the water tank unit and the water discharged from the soil cultivation unit to fall by gravity. Environmental improvement device.

3. The environmental improvement device according to claim 2, The aeration unit has a structure in which the water in the water tank unit overflows from the top of the water tank unit and falls by gravity. Environmental improvement device.

4. The environmental improvement device according to claim 2, The aeration unit has a structure for allowing the water in the water tank unit to fall by gravity, and includes at least one of holes and slits provided on a wall surface of a container constituting the water tank unit and through which the water in the water tank unit is discharged. Environmental improvement device.

5. The environmental improvement device according to claim 1, The aeration unit has a structure for spraying at least one of the water in the water tank unit and the water discharged from the soil cultivation unit. Environmental improvement device.

6. The environmental improvement device according to claim 1, The first water supply unit has a structure that supplies water from the water tank unit to the soil provided in the soil cultivation unit by gravity or by spraying, The aeration section is constituted by the first water supply section. Environmental improvement device.

7. The environmental improvement device according to claim 1, The water tank section includes a plurality of divided water tank containers each containing water therein, The aeration unit has a structure that supplies water from a first divided water tank container to a second divided water tank container by gravity or by spraying. Environmental improvement device.

8. The environmental improvement device according to claim 1, The second water supply unit has a structure that supplies water discharged from the soil cultivation unit to the water tank unit by gravity or by spraying, The aeration section is constituted by the second water supply section. Environmental improvement device.

9. The environmental improvement device according to claim 1, The aeration unit is composed of a bubbling device that blows air into at least one of the water in the water tank unit and the water discharged from the soil cultivation unit. Environmental improvement device.

10. An environmental improvement method for increasing microbial diversity in a space, comprising: In an apparatus having a soil cultivation section for cultivating plants using soil and an aquatic tank section for growing aquatic organisms in water, and circulating water between the soil cultivation section and the aquatic tank section, the apparatus aerates the water circulating within the apparatus. How to improve the environment.

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