Apparatus for changing microbial composition of surrounding space and method for changing microbial composition of surrounding space

Abstract

To provide an apparatus for changing a microbial composition of a surrounding space that is unlikely to cause an excessive increase in humidity in the surrounding space, an unexpected change in the microbial composition, or a decrease in the number of viable bacteria.SOLUTION: An apparatus for supplying microorganisms to a surrounding space to change a microbial composition of the surrounding space comprises: a storage container with an opening for storing, in the inside, solid particles with microorganisms attached thereto; and a scattering unit for scattering the solid particles stored inside the storage container from the opening into the surrounding space.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an apparatus for altering the microbial composition of an ambient space and a method for altering the microbial composition of an ambient space. [Background technology]

[0002] Many types of microorganisms exist in the human body (e.g., intestines, skin, etc.), forming a so-called microflora (microbiome). Rapid urbanization in recent years has reduced contact between humans and nature, and it has been suggested that this may be causing various diseases by disrupting the symbiotic relationship between humans and microorganisms. The present inventors believe that taking in air containing a variety of microorganisms into the body plays an important role in regulating the symbiotic relationship between humans and microorganisms.

[0003] Patent Document 1 describes a method for evaluating a microbial testing environment, such as a chamber device used in bioaerosol testing. This evaluation method includes a step of spraying microorganisms onto a surface to be evaluated, in which a bacterial suspension is sprayed using a nebulizer installed in the space inside the spray chamber device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-172665 Summary of the Invention [Problem to be solved by the invention]

[0005] One possible method for supplying microorganisms to a surrounding space and changing the microbial composition of the surrounding space is to spray a bacterial suspension using a nebulizer, as described in Patent Document 1. However, with this method, the water in the sprayed bacterial suspension evaporates, causing an excessive increase in humidity in the surrounding space, potentially reducing the comfort of the surrounding space. Furthermore, depending on the storage conditions of the bacterial suspension, unexpected changes in the bacterial composition may occur. Furthermore, the evaporation of water from the sprayed bacterial suspension may result in the loss of bacterial carriers, potentially reducing the number of viable bacteria.

[0006] Therefore, the present disclosure provides an apparatus for changing the microbial composition of a surrounding space that is less likely to cause excessive humidity increases in the surrounding space, unexpected changes in the microbial composition, and a decrease in the number of viable bacteria, and a method for changing the microbial composition of a surrounding space using the same. [Means for solving the problem]

[0007] Aspects of the present disclosure include the following. [Aspect 1] 1. An apparatus for supplying microorganisms to an ambient space to change the microbial composition of the ambient space, comprising: a container having an opening for containing the solid particles having microorganisms attached thereto; a scattering unit that scatters the solid particles contained inside the container through the opening into the surrounding space; An apparatus comprising: [Aspect 2] the scattering unit is an agitator that agitates the solid particles contained inside the container, The scattering unit is Movable wings provided within the container; a drive unit that drives the movable blade; 2. The apparatus of embodiment 1, comprising: [Aspect 3] The movable blade is Axle and a protrusion including a spiral wire or plate that rotates integrally with the shaft; 3. The apparatus of embodiment 2, comprising: [Aspect 4] A method for changing the microbial composition of a surrounding space by supplying microorganisms to the surrounding space using the device according to any one of aspects 1 to 3, comprising: The method includes scattering solid particles having microorganisms attached thereto and contained inside a storage container into the surrounding space by a scattering unit. [Aspect 5] 5. The method of claim 4, wherein the container further contains a dispersion-promoting material that promotes dispersion of the solid particles. [Effects of the Invention]

[0008] The device for changing the microbial composition of a surrounding space disclosed herein and the method for changing the microbial composition of a surrounding space using the same are less likely to cause excessive humidity increases in the surrounding space, unexpected changes in the microbial composition, and a decrease in the number of viable bacteria when changing the microbial composition of the surrounding space. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view schematically illustrating an example of an apparatus used to change the microbial composition of a surrounding space using a composition according to an embodiment. [Figure 2] 2(A) to 2(E) are perspective views that schematically show examples of movable wings. [Figure 3] 1 is a graph showing the average particle numbers measured in Examples 1 to 4. [Figure 4] 1 is a graph showing the average particle number measured in Examples 5 and 6. [Figure 5] 1 is a graph showing the average particle numbers measured in Examples 7 to 10. [Figure 6] 1 is a graph showing the microbial composition measured in Example 11. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described with reference to the drawings as appropriate. In the drawings referred to in the following description, the same components or components having similar functions are designated by the same reference numerals, and repeated explanations may be omitted. For convenience of explanation, the dimensional ratios and shapes of each part in the drawings may be exaggerated and may differ from the actual dimensional ratios and shapes.

[0011] In this application, unless otherwise specified, numerical ranges expressed using the symbol "~" include the numerical values ​​written before and after the symbol "~" as the lower and upper limits, respectively. The upper and lower limits described in this application can be used alone or in any combination.

[0012] In this application, unless otherwise specified, "comprising" means that additional components or elements may be included, and includes "consisting essentially of" and "consisting of." "Consisting essentially of" means that additional components or elements may be included that do not have a substantial adverse effect. "Consisting of" means that the material or element is included only, but does not exclude the further inclusion of unavoidable impurities.

[0013] In this application, "perpendicular" includes not only exactly perpendicular but also substantially perpendicular, and "parallel" includes not only exactly parallel but also substantially parallel.

[0014] I. Device for changing the microbial composition of the surrounding space An example of an apparatus for supplying microorganisms to a surrounding space to change the microbial composition of the surrounding space according to an embodiment will be described with reference to the drawings. In this application, the surrounding space is an indoor space or an outdoor space. In the following description, when the apparatus is installed so as to be able to change the microbial composition of the surrounding space, the upstream side in the direction of gravity is defined as "up" and the downstream side in the direction of gravity is defined as "down."

[0015] The device 1 shown in Figure 1 comprises a storage container 10 for storing solid particles with microorganisms attached (hereinafter referred to as "microorganism-attached particles") therein, and a scattering unit 20 for scattering the microorganism-attached particles contained in the storage container 10 into the surrounding space.

[0016] The storage vessel 10 has an opening 12. The opening 12 may be formed in the top of the storage vessel 10. Microorganism-adhered particles are released from the inside of the storage vessel 10 to the outside (i.e., the surrounding space) through the opening 12.

[0017] The entrainment unit 20 is an agitator that agitates the microorganism-adhered particles contained inside the storage container 10. The entrainment unit 20 includes a movable blade 22 provided inside the storage container 10 and a drive unit 24 that drives the movable blade 22.

[0018] The movable wing 22 is supported by the container 10 and includes a shaft 223 and a protrusion 225 that rotates integrally with the shaft 223. The movable wing 22 is a rotor that rotates around the shaft 223. The shaft 223 is parallel to the direction of gravity. The protrusion 225 may have various shapes, as illustrated in FIGS. 2(A) to 2(E). The protrusion 225A shown in FIG. 2(A) includes a spiral wire material. The protrusion 225B shown in FIG. 2(B) includes a spiral plate material. The spiral formed from the wire material or plate material may be a single spiral or a double or more spiral. The protrusion 225C shown in FIG. 2(C) includes a pair of long plate materials that are parallel to the shaft 223 and face each other across the shaft 223. The protrusion 225D shown in FIG. 2(D) includes a rod-shaped member extending from the shaft 223 in a direction perpendicular to the shaft 223. The protrusion 225E shown in Fig. 2(E) comprises a broom-shaped flexible plate with a notch extending in the vertical direction at the bottom. The scattering unit 20 having the movable blades 22A to 22D shown in Figs. 2(A) to 2(D) can agitate the entire layer of microorganism-adhered particles inside the storage container 10. The scattering unit 20 having the movable blade 22E shown in Fig. 2(E) can agitate the surface and its vicinity of the layer of microorganism-adhered particles inside the storage container 10.

[0019] The driving unit 24 includes a power source, such as an electric motor, for rotating the shaft 223. The rotation speed and the like of the driving unit 24 may be controlled by a control unit (not shown). The rotation speed of the movable blades 22 may be set appropriately, and may be, for example, 75 to 85 rpm.

[0020] In the device 1 of FIG. 1, the axis 223 of the movable blade 22 is parallel to the direction of gravity, but the direction of the axis 223 is not limited to this. For example, the axis 223 may be perpendicular to the direction of gravity. Furthermore, the shape of the protrusion 225 may be selected appropriately depending on the direction of the axis 223. Furthermore, the entrainment unit 20 is not limited to an agitator. For example, the entrainment unit 20 may be a blower that generates an airflow toward the microorganism-adhered particles contained inside the storage container 10, or a vibration generator that agitates the microorganism-adhered particles contained inside the storage container 10.

[0021] II. Methods for Altering Microbial Composition A method for changing the microbial composition of the surrounding space using the device 1 according to the above embodiment will now be described. The method for changing the microbial composition of the surrounding space includes scattering microorganism-adhered particles contained inside the storage container 10 into the surrounding space using the scattering unit 20.

[0022] Natural or artificial soil particles can be used as the microorganism-attached particles. The microorganism-attached particles may include one or more selected from coarse sand, fine sand, silt, and clay. The microorganism-attached particles may be sandy soil, loamy sand soil, sandy loam, loam, silty loam, sandy clay loam, clay loam, silty clay loam, sandy clay soil, light clay soil, silty clay soil, or heavy clay soil. The microorganism-attached particles may be, for example, andosol (e.g., volcanic ash soil), diluvial soil (e.g., red-yellow soil, brown forest soil, red forest soil, red soil, yellow soil, dark red soil, gray plateau soil, gley plateau soil), alluvial soil (e.g., brown lowland soil, gray lowland soil, immature sand dune soil), or soil for various uses such as agriculture (e.g., rice paddies, fields, forests, grasslands), civil engineering, and green spaces (e.g., turfgrass, flower beds). Artificially produced inorganic or organic particles to which microorganisms are attached can also be used as microorganism-attached particles.

[0023] The microorganism-adhering particles may have an average particle size of 2 mm or less, or 0.1 μm to 2 mm, but is not limited thereto. In this application, the average particle size means the particle size at which the integrated value (cumulative distribution) is 50% in the volume-based particle size distribution measured by the dry sieving test method specified in JIS Z 8815:1994.

[0024] The composition of the microorganisms attached to the solid particles is not particularly limited. For example, the microorganisms attached to the solid particles may have a composition similar to that of any soil microbiome.

[0025] In addition to the microorganism-adhered particles, a scattering promoter that promotes scattering of the microorganism-adhered particles may be further contained inside the storage container 10.

[0026] The dispersion-promoting material is a small piece of material that promotes the dispersion of microorganism-adhered particles when the microorganism-adhered particles are dispersed into the surrounding space by stirring, etc. The shape, size, material, specific gravity, specific surface area, elastic modulus, etc. of the dispersion-promoting material may be appropriately selected depending on the properties of the microorganism-adhered particles, the dispersion conditions, etc.

[0027] The scattering-promoting material may be a linear piece having a length greater than the average particle diameter of the microorganism-adhered particles, or a planar or three-dimensional piece having a major axis greater than the average particle diameter of the microorganism-adhered particles. The scattering-promoting material may be, for example, a linear piece having a length of 1 to 100 mm and a diameter of 0.1 to 1 mm, a planar piece having a major axis diameter of 1 to 100 mm, a minor axis diameter of 1 to 100 mm, and a thickness of 0.01 to 1 mm, or a three-dimensional piece having a major axis diameter of 1 to 100 mm, a minor axis diameter of 1 to 100 mm, and a thickness of 1 to 100 mm. Examples of linear scattering-promoting materials include threads such as embroidery thread. Examples of planar scattering-promoting materials include paper (e.g., copy paper, paper towels), cloth (e.g., nonwoven fabrics such as felt, woven fabrics), metal foils (e.g., aluminum foil), and plastic sheets. Examples of three-dimensional scattering-promoting materials include cotton. The linear scattering-promoting material may be straight, curved, and / or bent. The planar scattering-promoting material may be flat, or may be curved and / or bent. The scattering-promoting material is preferably made of a material containing fiber such as paper, cloth, thread, or cotton, and at least a portion of its surface may be fluffy.

[0028] The dispersion unit 20 is operated to agitate the microorganism-adhered particles and optional dispersion-promoting material contained inside the storage container 10 with the rotating movable blades 22. As a result, the microorganism-adhered particles are stirred up and dispersed from inside the storage container 10 to the outside of the storage container 10 (i.e., the surrounding space) through the opening 12. As a result, microorganisms are supplied to the surrounding space, and the microbial composition of the surrounding space changes. For example, the microbial concentration and / or the number of microbial species in the surrounding space increases.

[0029] In the method according to this embodiment, solid particles serve as carriers for microorganisms, which offers the following advantages over a method using water as a carrier for microorganisms: First, excessive humidity rise in the surrounding space is unlikely to occur; Second, the composition of microorganisms is more stable and easier to control, so unexpected changes in the microbial composition are unlikely to occur; and, because the solid particles serving as carriers absorb moisture, an appropriate amount of moisture is maintained for a long period of time, reducing the decrease in viable cell count.

[0030] Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above embodiments, and various design modifications can be made without departing from the technical scope described in the claims. [Example]

[0031] The present disclosure will be specifically described below using examples, but the present disclosure is not limited to these examples.

[0032] Example 1 Ventilation volume: 0.5m 3 The device shown in Figure 1 was installed in the center of a room measuring 1.7 m long, 2.6 m wide, and 2.4 m high, with a rotation speed of 1 / min and an air-conditioning temperature set at 25°C. The device's movable blades had spiral wire protrusions, as shown in Figure 2(A). A particle counter was installed approximately 1 m away from the device toward the corner of the room. Commercially available potting soil (HB-101 potting soil, Flora Co., Ltd.) was ground using an electric mill (LAB MILL II, Osaka Chemical Co., Ltd.) to obtain soil particles, which were then placed in the device's container. The soil particles were stirred with a mixer for 3 hours to disperse them, while the particle count in 14.15 L of air was measured every 10 minutes using the particle counter. The average particle count in the room was calculated by averaging the measurements taken 1 to 3 hours after the start of dispersion. The results are shown in Table 1.

[0033] Example 2 The average number of particles in the space was determined in the same manner as in Example 1, except that movable blades having spiral plate members as protrusions as shown in Figure 2(B) were used. The results are shown in Table 1.

[0034] Example 3 The average number of particles in the space was determined in the same manner as in Example 1, except that movable blades having a pair of long plates parallel to the axis and facing each other across the axis as protrusions were used, as shown in Figure 2(C). The results are shown in Table 1.

[0035] Example 4 The average number of particles in the space was determined in the same manner as in Example 1, except that a movable blade having a rod-shaped protrusion extending from the axis in a direction perpendicular to the axis, as shown in Figure 2(D), was used. The results are shown in Table 1.

[0036] Example 5 The average particle number in the air was determined in the same manner as in Example 1, except that a broom-shaped movable blade made of cardboard as shown in Figure 2(E) was used. The movable blade was fabricated by wrapping and fixing cardboard around the movable blade used in Example 3. The results are shown in Table 1.

[0037] Example 6 Using movable blades made of cardboard having the same shape as the movable blades used in Example 5 except that the protrusions did not have notches, the average number of particles in the space was determined in the same manner as in Example 5. The results are shown in Table 1.

[0038] Examples 7 to 10 The average number of particles in the space was determined in the same manner as in Examples 1 to 4, except that the mixture prepared as follows was used instead of the soil particles. The results are shown in Table 1.

[0039] Copy paper was cut into small pieces (0.55 g per piece) measuring 2 mm x 3 mm using a cross-cut shredder scissors (Kanematsu Industries Co., Ltd.). The small pieces cut using the shredder scissors were curved and had fuzzy cut surfaces. These small pieces were mixed with soil particles as a dispersal accelerator to prepare a mixture. The amount of dispersal accelerator added was 4 wt% based on the total weight of the mixture. The results are shown in Table 1.

[0040] [Table 1]

[0041] The measurement results of the average particle number for Examples 1 to 4 are shown in Figure 3, the measurement results of the average particle number for Examples 5 and 6 are shown in Figure 4, and the measurement results of the average particle number for Examples 7 to 10 are shown in Figure 5. The error bars in the figures represent standard deviations.

[0042] In all examples, it was confirmed that soil particles were dispersed into the air.

[0043] Among Examples 1 to 4, Example 3, which used movable blades including opposed long plate members as shown in Figure 2(C), had the highest number of particles, followed by Example 2, which used movable blades including spiral plate members as shown in Figure 2(B). The number of particles in Example 1, which used movable blades including spiral wire members as shown in Figure 2(A), was about one-fourth that of Example 2. The number of particles in Example 4, which used movable blades including rod-shaped members as shown in Figure 2(D), was extremely small compared to the number of particles in Examples 1 to 3.

[0044] The number of particles in Example 5 was significantly higher than the number of particles in Example 6. It was shown that forming notches in the movable blades to give them a broom-like shape significantly increased the amount of particles scattered.

[0045] The particle counts in Examples 7 to 10, which used a dispersal-accelerating material, were significantly higher than those in Examples 1 to 4, which did not, demonstrating that the use of a dispersal-accelerating material significantly increased the amount of particles dispersed. Furthermore, among Examples 7 to 10, Example 7, which used a movable blade containing a spiral wire as shown in Figure 2(A), had the highest particle count, followed by Example 10, which used a movable blade containing a rod-shaped body as shown in Figure 2(D). This indicates that the dispersal-accelerating effect of the dispersal-accelerating material was most effective when combined with a movable blade containing a spiral wire as shown in Figure 2(A).

[0046] Example 11 Ventilation volume: 0.5m 3 3000 L of air was sampled from a space measuring 1.7 m in length, 2.6 m in width, and 2.4 m in height, with an air conditioning setting of 25°C and a flow rate of 1 / min. Sampling was performed by aspirating 3000 L of air from the space using an MD8 Air Scan Sampler (manufactured by Sartorius). Next, as in Example 7, soil particles were dispersed in the space, and 3000 L of air was sampled from the space using the MD8 Air Scan Sampler.

[0047] DNA was extracted from air samples taken before and during dispersal, and the DNA concentration in terms of 16S rRNA was measured using real-time PCR.

[0048] Air sampling was conducted twice before and during dispersion in the same manner as above.

[0049] The gelatin filters used for sampling before and during dispersal were dissolved and filtered through a 0.2 μm pore size filter, and DNA was extracted using the DNeasy PowerWater Kit (QIAGEN). Libraries were prepared using primers targeting the V1-V2 region of 16S rRNA. Paired-end sequencing of 150 bp x 2 was performed using the iSeq 100 System (Illumina). Only the forward reads obtained were analyzed using Qiime2 to obtain data on microbial composition and species abundance.

[0050] The DNA concentration and number of microbial species are shown in Table 2, and the microbial composition is shown in Figure 6. The number of microbial species shown in Table 2 is the average value of two samplings.

[0051] [Table 2]

[0052] It was confirmed that scattering soil particles increased the DNA concentration in the air. An increase in DNA concentration means an increase in the concentration of microorganisms. It was also confirmed that scattering soil particles changed the microbial composition in the air, increasing the number of microbial species. [Explanation of symbols]

[0053] 1: device, 10: container, 12: opening, 20: scattering unit, 22: movable blade, 24: drive unit, 223: shaft, 225: protrusion

Claims

1. 1. An apparatus for supplying microorganisms to an ambient space to change the microbial composition of the ambient space, comprising: a container having an opening for containing the solid particles having microorganisms attached thereto; a scattering unit that scatters the solid particles contained inside the container through the opening into the surrounding space; An apparatus comprising:

2. the scattering unit is an agitator that agitates the solid particles contained inside the container, The scattering unit is Movable wings provided within the container; a drive unit that drives the movable blade; The apparatus of claim 1 , comprising:

3. The movable blade is Axle and a protrusion including a spiral wire or plate that rotates integrally with the shaft; 3. The apparatus of claim 2, comprising:

4. A method for changing the microbial composition of an ambient space by supplying microorganisms to the ambient space using the device according to any one of claims 1 to 3, comprising the steps of: The method includes scattering solid particles having microorganisms attached thereto and contained inside a storage container into the surrounding space by a scattering unit.

5. The method according to claim 4 , further comprising storing a scattering accelerator material in the container to accelerate scattering of the solid particles.

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