Environmental nucleic acid recovery device and environmental nucleic acid recovery method

Abstract

This environmental nucleic acid recovery device for recovering an environmental nucleic acid from the environment is provided with: an air blowing flow path which is provided with an air blowing pipe and an air intake port for taking in air into the air blowing pipe, wherein the air blowing pipe has, formed therein, an air blowing port for discharging pressurized air; a suction flow path which is provided with a suction pipe and a discharge port, wherein the suction pipe has, formed therein, a suction port for taking in outside air and is provided with a collection unit to which a nucleic acid-containing deposit in the taken outside air is adhered and the discharge port is for discharging the outside air passing through the collection unit; a pressurizing mechanism which generates a blowing air pressure in the air blowing flow path and generates a suction pressure in the suction flow path; and a switching unit for switching between a blowing operation and a suction operation.

Description

Apparatus and method for recovering nucleic acids from the environment

[0001] The present disclosure relates to an apparatus for recovering nucleic acids derived from the environment and a method for recovering nucleic acids derived from the environment.

[0002] One method for investigating or monitoring biological species present in the environment involves recovering biologically derived nucleic acids from the environment, analyzing the recovered nucleic acids, and identifying the biological species from which the nucleic acids originate. Biologically derived nucleic acids are nucleic acids that contain the genetic information of an organism and have been released from an organism into the environment, and are included in nucleic acids present in the environment, i.e., environmentally derived nucleic acids.

[0003] As a method for recovering biological nucleic acids, microorganisms, etc. from the environment, Patent Document 1 discloses a method for collecting microbial aerosols (airborne microorganisms) in the air by collecting them in a simulated medium. Furthermore, Patent Document 2 and Non-Patent Document 1 disclose methods for collecting air and extracting airborne particles including bacteria, viruses, etc.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2009-55790

[0005] Lewis Cuthbertson et al., Characterization of Arctic Bacterial Communities in the Air above Svalbard, Biology(Basel), 2017 Jun;6(2):29. Published online 2017 May 6. doi: 10.3390 / biology602009

[0006] As disclosed in Patent Documents 1 and 2 and Non-Patent Document 1, when sampling from the air, it is difficult to recover biological nucleic acids that are not suspended in the air, and there is a possibility that the biological species present in the environment being investigated cannot be fully investigated. In contrast, when recovering environmental nucleic acids from, for example, the ground surface or the surface of an object, various sediments, including suspended matter that has fallen from the air, can be collected. In order to recover environmental nucleic acids, it is desirable to recover environmental nucleic acids from a relatively wide area while minimizing the bias of environmental nucleic acids contained in the recovered materials. However, there has been insufficient research into technologies that satisfy the above requirements for recovering environmental nucleic acids from surface sediments.

[0007] The present disclosure can be realized in the following forms. (1) One form of the present disclosure provides an apparatus for recovering environmental nucleic acids from an environment. The apparatus for recovering environmental nucleic acids includes an air flow path including an air blower duct having an air blower port that is an opening for releasing pressurized air and an air intake port for taking air into the air blower duct, an intake duct having an intake port that is an opening for taking in outside air and including a collection unit to which nucleic acid-containing deposits containing environmental nucleic acids present in the taken-in outside air adhere, and an intake duct having an exhaust port for discharging the outside air that has passed through the collection unit from the apparatus for recovering environmental nucleic acids, a pressurizing mechanism that generates air blowing pressure in the air blower duct for releasing air from the air blower port and generates intake pressure in the intake duct for taking in outside air through the intake port, and a switching unit that switches between an air blowing operation using the air blower duct and an intake operation using the intake duct. This type of environment-derived nucleic acid recovery device recovers nucleic acid-containing sediments by suction, making it easy to recover nucleic acid-containing sediments from a relatively wide area. Furthermore, pressurized air is released from the air outlet to stir up the nucleic acid-containing sediments, and then the stirred-up nucleic acid-containing sediments can be sucked in through the suction port and collected by the collection unit, thereby preventing the recovery of relatively large (heavy) sediments. As a result, it is possible to prevent the concentration of environmental nucleic acids in the recovered material from being biased due to the recovery of relatively large sediments. (2) In the above-described environment-derived nucleic acid recovery device, the air duct may be provided with a blocking unit located adjacent to the air duct, blocking the flow of air from the air duct into the air duct. This configuration prevents nucleic acid-containing sediments from entering the air duct through the air duct after the air duct operation is stopped, thereby reducing contamination caused by nucleic acid-containing sediments that have entered the air duct. (3) In the environmental nucleic acid recovery device of the above configuration, the blocking unit may include a blocking plate that can move between a position that blocks the air duct and a position that opens the air duct, and the blocking plate may block the flow of air from the air outlet into the air duct by moving from the open position to the closed position.With this configuration, the entry of nucleic acid-containing deposits into the air duct can be easily prevented by the simple configuration of moving the shielding plate. (4) In the device for recovering environmental nucleic acids of the above aspect, the collection unit may be a filter disposed to block the suction tube, allowing the outside air taken into the suction tube to pass through while collecting the nucleic acid-containing deposits. With this configuration, nucleic acid-containing deposits can be recovered by the simple configuration of adhering them to the filter. (5) In the device for recovering environmental nucleic acids of the above aspect, the air duct and the suction tube may be formed to extend in the same direction from a main body of the device for recovering environmental nucleic acids in which the pressurizing mechanism is disposed, the air duct may be formed longer than the suction tube, and the air outlet may open at a position farther from the main body than the suction port. With this configuration, the air outlet can be brought sufficiently close to the location where nucleic acid-containing deposits accumulate, allowing for efficient air blowing, and a sufficient distance can be secured between the surface on which the nucleic acid-containing deposits have accumulated and the inlet, preventing undesirably large deposits from being sucked in and recovered. (6) Another aspect of the present disclosure provides a method for recovering environmental nucleic acids from the environment. This method for recovering environmental nucleic acids involves setting a recovery target area, including at least one of the ground surface and the surface of an object, as a target for recovering environmental nucleic acids, positioning a blower that emits pressurized air at a distance from the surface of the recovery target area, and using the blower to blow air against the surface of the recovery target area, thereby stirring up nucleic acid-containing sediments present on the surface of the recovery target area, including the environmental nucleic acids, and, after the blowing of air by the blower is stopped, positioning a suction device, separate from the surface of the recovery target area, that draws in outside air, at a distance from the surface of the recovery target area, and using the suction device to suck in the nucleic acid-containing sediments stirred up by the blower, and depositing the sucked nucleic acid-containing sediments in a collection section provided in the suction device, and recovering the nucleic acid-containing sediments from the collection section. This form of the method for recovering environmental nucleic acids facilitates the recovery of nucleic acid-containing sediments from a relatively wide area, since the nucleic acid-containing sediments are recovered by suction.Then, after releasing pressurized air to stir up the nucleic acid-containing sediments, the stirred-up nucleic acid-containing sediments can be sucked in and collected in the collection unit, thereby preventing the recovery of relatively large (heavy) sediments. As a result, the bias in the environmental nucleic acids contained in the recovered material due to the recovery of relatively large sediments can be prevented. (7) In the above-described method for recovering environmental nucleic acids, the air blower may include an air duct with an air outlet opening at its tip for releasing air, and the flow of air into the air duct through the air outlet may be blocked after the nucleic acid-containing sediments are stirred up by air blowing using the air blower and before the start of suction using the suction device. This configuration prevents nucleic acid-containing sediments from entering the air blower after the air blowing operation is stopped, thereby preventing contamination caused by nucleic acid-containing sediments that have entered the air blower. (8) In the above-described method for recovering environmental nucleic acids, the angle at which the air is blown relative to the surface of the recovery target area may be between 80° and 100° relative to the surface. With this configuration, when air is blown, the nucleic acid-containing sediments can be blown upward with increased efficiency rather than being blown away and dispersed by the air blow. The present disclosure can be realized in various forms other than those described above, and can be realized in the form of, for example, an attachment for recovering environmental nucleic acids, a method for recovering surface sediments, a method for analyzing environmental nucleic acids, a method for monitoring environmental nucleic acids, and the like.

[0008] An explanatory diagram schematically showing the appearance of the device for recovering environmental nucleic acids. An explanatory diagram schematically showing the outline of the configuration of the device for recovering environmental nucleic acids. A perspective view showing the suction tube and the air blower tube as viewed from the tip side. A flowchart showing a method for recovering environmental nucleic acids. An explanatory diagram showing the main steps of the method for recovering environmental nucleic acids. An explanatory diagram schematically showing the outline of the configuration of the device for recovering environmental nucleic acids. An explanatory diagram showing the analysis results of an environmental DNA sample.

[0009] A. First Embodiment: (A-1) Configuration of the Device for Isolating Environmentally Derived Nucleic Acids: Fig. 1 is an explanatory diagram that schematically shows the appearance of a device 10 for recovering environmentally derived nucleic acids according to a first embodiment, and Fig. 2 is an explanatory diagram that schematically shows the overall configuration of the device 10 for recovering environmentally derived nucleic acids, including its internal configuration. The device 10 for recovering environmentally derived nucleic acids is a device for recovering nucleic acid-containing sediments that contain environmentally derived nucleic acids from the surfaces of objects both indoors and outdoors, the ground outdoors, and the like. The device 10 for recovering environmentally derived nucleic acids according to this embodiment is a device that includes both a blower that releases pressurized air and a suction device that draws in outside air.

[0010] The device 10 for recovering environmental nucleic acids comprises a main body 12, an inlet tube 20, and an air blower tube 40. The tip of the inlet tube 20 is formed with an inlet port 22, which is an opening for taking in outside air, and the tip of the air blower tube 40 is formed with an air blower port 42, which is an opening for releasing pressurized air. In the device 10 for recovering environmental nucleic acids of this embodiment, the inlet tube 20 and the air blower tube 40 are formed to extend in the same direction from the main body 12. The air blower tube 40 is formed to be longer than the inlet tube 20, and the air blower port 42 opens at a position farther away from the main body 12 than the inlet port 22. In the following description, the end of the device 10 for recovering environmental nucleic acids on the side where the inlet port 22 and the air blower port 42 are provided in the extension direction of the inlet tube 20 and the air blower tube 40 is referred to as the "tip side," and the end on the side opposite the tip side in the extension direction of the inlet tube 20 and the air blower tube 40 is also referred to as the "rear end."

[0011] 2 , the device 10 for recovering environmental nucleic acids is provided with an air flow path 46 as a structure including an air supply tube 40. One end of the air flow path 46 opens as the air supply port 42 described above, and the other end opens on the surface of the rear end of the main body 12 as an air intake port 44 for taking air into the air supply tube 40. The device 10 for recovering environmental nucleic acids is also provided with an intake flow path 26 as a structure including an intake tube 20. One end of the intake flow path 26 opens as the air intake port 22 described above, and the other end opens on the surface of the rear end of the main body 12 as an exhaust port 24 for discharging outside air that has passed through the intake tube 20 from the device 10 for recovering environmental nucleic acids.

[0012] The main body 12 is provided with a gripping portion 14 that allows an operator recovering nucleic acid-containing deposits to grip the environmental nucleic acid recovery device 10, and an operating portion 16 that is provided with a drive switch and the like (see FIG. 1 ). The main body 12 also includes a pressurizing mechanism 60 that generates, in the air supply flow path 46, a blowing pressure for releasing pressurized air from the air supply port 42, and generates, in the intake flow path 26, a suction pressure for taking in outside air from the intake port 22. The main body 12 also includes a switching portion 68 that switches between a blowing operation using the air supply flow path 46 and a suction operation using the intake flow path 26. The main body 12 also includes a battery (not shown) that serves as an energy source for driving the pressurizing mechanism.

[0013] The pressurizing mechanism 60 includes a first blower unit 64 that is disposed at the rear end of the suction pipe 20 in the suction flow path 26 and that includes a fan that generates suction pressure, and a second blower unit 66 that is disposed at the rear end of the air blower duct 40 in the air blowing flow path 46 and that includes a fan that generates blowing pressure. The pressurizing mechanism 60 also includes a motor 62 that drives the first blower unit 64 and the second blower unit 66. The motor 62 is a double-shaft motor that has rotating shafts on both the left and right sides.

[0014] The switching unit 68 is a mechanism for switching the power generated by the motor 62 so that it is transmitted to only one of the first blower unit 64 and the second blower unit 66. A gear or a clutch can be disposed between each drive shaft of the motor 62 and the first blower unit 64 or the second blower unit 66, as a power transmission mechanism, so that desired blowing pressure and suction pressure can be achieved in the first blower unit 64 and the second blower unit 66. The switching unit 68 switches between a blowing operation using the air flow path 46 and a suction operation using the suction flow path 26 by maintaining the power transmission path between the drive shaft of the motor 62 and one of the fans of the first blower unit 64 or the second blower unit 66 while cutting the power transmission path between the other fan. When an instruction to perform a blowing operation is input via the operation unit 16, the motor 62 is driven and the power transmission path between the motor 62 and the first blower unit 64 is disconnected, and when an instruction to perform a suction operation is input via the operation unit 16, the motor 62 is driven and the power transmission path between the motor 62 and the second blower unit 66 is disconnected. In Figure 2, the switching of the power transmission path as described above is indicated by a hollow double-headed arrow.

[0015] The above-described switching of the power transmission path can be achieved in various ways. For example, the first blower unit 64, the motor 62, and the second blower unit 66 may be arranged in this order so that the axes of the motor 62, the first blower unit 64, and the second blower unit 66 are aligned in a straight line, and the motor 62 may be moved parallel to the axis. This allows the drive shaft of the motor 62 to be separated from one of the first blower unit 64 and the second blower unit 66, thereby cutting the power transmission path between the one blower unit and the motor 62. Furthermore, when the drive shaft of the motor 62 is separated from the other blower unit, a shielding plate can be used to block the connection between the motor 62 and the one blower unit, thereby preventing contamination caused by nucleic acid-containing deposits that have infiltrated near the connection.

[0016] As described above, by using a double-shaft motor as the motor 62, it is possible to drive both the first blower unit 64 and the second blower unit 66 with a single motor 62, thereby simplifying the configuration and reducing the size of the environmental nucleic acid recovery apparatus 10. However, separate drive motors may be provided for the first blower unit 64 and the second blower unit 66.

[0017] In the apparatus 10 for recovering environmental nucleic acids of this embodiment, the structure formed by the first blower unit 64 and the suction flow path 26 is also referred to as the "suction device." Similarly, the structure formed by the second blower unit 66 and the air supply flow path 46 is also referred to as the "air blower." In this specification, the phrase "the air blower and the suction device are separate devices" refers to the fact that the suction flow path 26, which performs the suction operation, and the air supply flow path 46, which performs the air supply operation, are separate systems that are independent of each other. In other words, the phrase "the air blower and the suction device are separate devices" includes not only cases in which the air blower and the suction device are completely separate devices, but also cases in which a single device includes both a air blower and a suction device, as in the apparatus 10 for recovering environmental nucleic acids of this embodiment.

[0018] Fig. 3 is a perspective view showing the suction pipe 20 and the blower pipe 40 as viewed from the tip side. The suction pipe 20 and the blower pipe 40 shown in Fig. 3 have a cylindrical structure with a circular cross section, but the suction pipe 20 and the blower pipe 40 may have any shape other than a cylinder, such as a tubular shape with a rectangular cross section, as long as they have a flow path formed therein.

[0019] As shown in FIGS. 1 to 3 , the inlet tube 20 includes a dust collection filter 30 near the inlet 22 that collects nucleic acid-containing deposits, including environmental nucleic acids, present in the ambient air taken in through the inlet 22. The dust collection filter 30 is also referred to as a "collection unit." The dust collection filter 30 is a porous filter disposed to close the inlet tube 20, allowing the ambient air flowing through the inlet tube 20 to pass through while collecting nucleic acid-containing deposits contained in the ambient air. Because the dust collection filter 30 is disposed within the inlet tube 20, the dust collection filter 30 is indicated by a dashed line in FIG. 1 . The dust collection filter 30 can be formed, for example, from a resin fiber such as a polyolefin (e.g., polypropylene or polyethylene), polyester, polyamide, polyimide, or polytetrafluoroethylene, or a glass fiber. The collection unit is not limited to the above-described configuration, as long as it is capable of collecting nucleic acid-containing deposits contained in the ambient air flowing through the inlet tube 20.

[0020] The smaller the pore size of the dust collection filter 30, the smaller the particles of nucleic acid-containing deposits that can be collected; however, the dust collection filter 30 becomes more susceptible to clogging, which may limit the amount of nucleic acid-containing deposits that can be collected in a single collection operation. Furthermore, the larger the pore size of the dust collection filter 30, the less likely it is that small particles of nucleic acid-containing deposits can be collected. However, because dust, which constitutes nucleic acid-containing deposits, generally exists as a tangle of particles of various sizes, it is actually possible to collect nucleic acid-containing deposits that are smaller than the pore size of the dust collection filter 30. Therefore, the pore size of the dust collection filter 30 may be appropriately set, for example, in the range of 0.1 to 100 μm, taking into consideration the type of dust that accumulates in the location where nucleic acid-containing deposits are to be collected, the efficiency of collection of nucleic acid-containing deposits, and the like.

[0021] In this embodiment, the dust collection filter 30 is formed in a circular shape, and its outer periphery is supported by an annular frame. The dust collection filter 30 is positioned by fitting the frame into a protruding engagement portion (not shown) provided on the inner wall surface of the suction pipe 20. The dust collection filter 30 can be collected by removing the frame from the engagement portion of the suction pipe 20. Note that the dust collection filter 30 only needs to be positioned to block the suction pipe 20, and the structure for holding the dust collection filter 30 within the suction pipe 20 is not particularly limited. The tip of the suction pipe 20, including the attachment point for the dust collection filter 30, may be configured as an attachment that can be detached from the rear end, and the dust collection filter 30 can be collected by attaching and detaching the attachment.

[0022] As shown in FIGS. 1 to 3 , the air duct 40 is provided with a blocking section 50 that is disposed adjacent to the air outlet 42 and blocks the inflow of air from the air outlet 42 into the air duct 40. In this embodiment, the blocking section 50 includes a slit 51, a shielding plate 52, and an elastic section 53, as shown in FIG. 3 . The shielding plate 52 of the blocking section 50 blocks the inflow of air from the air outlet 42 into the air duct 40 by moving from a position that places the air duct 40 in an "unblocked state" to a position that places the air duct 40 in a "blocked state." FIGS. 1 and 2 show the "blocked state," while FIG. 3 shows the "unblocked state." As will be described later, the blocking section 50 is designed to prevent nucleic acid-containing deposits from entering the air duct 40 when the air blowing operation is stopped, and therefore, it is desirable that the distance between the air outlet 42 and the blocking section 50 be short. Furthermore, since it is sufficient for blocking section 50 to suppress the intrusion of nucleic acid-containing deposits into air duct 40 while the air blowing operation is stopped, shielding plate 52 does not need to airtightly close air duct 40. Furthermore, although shielding plate 52 does not need to completely close air duct 40 without any gaps, it is desirable for shielding plate 52 to cover the entire cross section of air duct 40 from the viewpoint of increasing the reliability of suppressing the intrusion of nucleic acid-containing deposits into air duct 40.

[0023] The slit 51 is formed in an arc shape along the outer periphery of the air duct 40 on a plane perpendicular to the axial direction of the air duct 40, and has a notch structure provided so as to penetrate the side wall of the cylindrical air duct 40. Specifically, the slit 51 is formed over an area of ​​more than half of the circular outer periphery on a plane (cross section) perpendicular to the axial direction of the air duct 40. The width of the slit 51 (the length of the air duct 40 in the axial direction at the slit 51) is greater than the thickness of the shielding plate 52 and slightly smaller than the sum of the thickness of the shielding plate 52 and the thickness of an elastic portion 53 (described later) when no external force is applied.

[0024] As described above, the shielding plate 52 is a circular plate-like member for blocking the air duct 40. The outer peripheral shape of the shielding plate 52 is substantially the same as the outer peripheral shape of the cross section of the air duct 40. The shielding plate 52 may be attached to the air duct 40 so as to be able to block the air duct 40. Specifically, for example, a rotation axis parallel to the axial direction may be provided near the end of the slit 51 in the side wall of the air duct 40, and the shielding plate 52 may be attached to the rotation axis so as to be rotatable around this rotation axis. Alternatively, the shielding plate 52 may be prepared separately from the air duct 40, and an operator may insert the shielding plate 52 into the slit 51 from outside the air duct 40 when changing the state from the "non-blocked state" to the "blocked state." The shielding plate 52 may be made of, for example, resin or metal, and may be rigid enough to withstand the action of inserting the shielding plate 52 into the slit 51.

[0025] The elastic portion 53 is bonded to one of a pair of opposing end surfaces at the end surface of the air duct 40 where the slit 51 is formed, spaced apart by a distance corresponding to the width of the slit 51. The shielding plate 52 is inserted between the other of the pair of end surfaces and the elastic portion 53 in the slit 51, placing the air duct 40 in a "closed state." The elastic portion 53 allows the shielding plate 52 to be inserted into the slit 51 and holds the shielding plate 52 in a "closed state" in the slit 51. However, the blocking portion 50 may have a different configuration. For example, an elastic portion may be bonded to each of the pair of end surfaces of the slit 51, and the shielding plate 52 may be pushed into the opposing position of the pair of elastic portions to place the shielding plate 52 in a "closed state." The elastic portion 53 may be made of, for example, natural rubber, synthetic rubber, or an elastomer such as polyurethane, silicone, nylon, or polystyrene.

[0026] (A-2) Method for recovering environmental nucleic acids: FIG. 4 is a flowchart showing a method for recovering environmental nucleic acids using the apparatus 10 for recovering environmental nucleic acids. FIG. 5 is an explanatory diagram showing the main steps of a method for recovering environmental nucleic acids using the apparatus 10 for recovering environmental nucleic acids. In this embodiment, to recover environmental nucleic acids, the apparatus 10 for recovering environmental nucleic acids is used to recover nucleic acid-containing sediments containing environmental nucleic acids from at least one of the ground surface and the surface of an object. Nucleic acid-containing sediments include cells and tissue fragments detached from various organisms, excrement-derived substances, and substances (fragments, etc.) derived from the remains of organisms. Nucleic acid-containing sediments present on the ground surface contain environmental nucleic acids derived from various biological species present above the ground surface (e.g., on the ground, in the air, etc.).

[0027] When recovering environmental nucleic acids, the operator first sets a target recovery area from which environmental nucleic acids will be recovered (step T100). The target recovery area is, for example, an area targeted for investigation and monitoring of biological species inhabiting the area. By recovering and analyzing environmental nucleic acids from the designated target recovery area, it becomes possible to investigate and monitor the biological species inhabiting the area. Next, the operator prepares the device 10 for recovering environmental nucleic acids (step T110). The operator then positions the device 10 for recovering environmental nucleic acids away from the surface 70 of the target recovery area, and, while pointing the air outlet 42 of the device 10 toward the surface 70 of the target recovery area, operates the operating unit 16 to begin blowing pressurized air from the air outlet 42 toward the surface 70 of the target recovery area. This stirs up nucleic acid-containing sediments 72 (such as fine dust on the ground) containing environmental nucleic acids present on the surface 70 of the target recovery area (step T120; see FIG. 5 ). In step T120, the air pressure when blowing air from the air outlet 42, the distance between the surface 70 of the recovery area and the air outlet 42, or the time for blowing air may be set appropriately depending on the condition of the surface 70 of the recovery area, etc., so that the nucleic acid-containing deposits are sufficiently stirred up.

[0028] Here, when air is blown onto surface 70 in the recovery target area in step T120, the angle at which the air is blown relative to surface 70 is preferably close to perpendicular to surface 70. This increases the efficiency of lifting nucleic acid-containing deposits present on surface 70 upward rather than blowing them horizontally away from the environmental nucleic acid recovery device 10. The angle at which the air is blown relative to surface 70 is preferably, for example, 70° or more, and more preferably 80° or more. Furthermore, the angle at which the air is blown relative to surface 70 is preferably, for example, 110° or less, and more preferably 100° or less.

[0029] Thereafter, the operator operates the operation unit 16 to stop the air blowing from the air outlet 42 and closes the air duct 40 using the shielding plate 52 of the blocking unit 50 (step T130). Then, while maintaining the environment-derived nucleic acid recovery device 10 positioned away from the surface 70 of the recovery target area, the operator operates the operation unit 16 to start the operation of drawing in outside air through the inlet 22. As a result, the nucleic acid-containing deposits 72 stirred up in step T120 are drawn in through the inlet 22 and attached to the dust collection filter 30 (step T140, see FIG. 5 ).

[0030] Here, the nucleic acid-containing sediments that were blown up from the surface 70 in step T120 gradually fall back to the surface 70. Therefore, in order to suck up the floating nucleic acid-containing sediments in step T140, it is desirable to quickly switch from blowing to suction. In the device 10 for recovering environmental nucleic acids of this embodiment, the suction tube 20 and the air supply tube 40 are formed so that they extend in the same direction from the main body 12. Therefore, when the air blowing operation is stopped, the suction port 22 of the suction tube 20 opens toward the floating nucleic acid-containing sediments. Furthermore, commands to stop the air blowing operation and start the suction operation can be given via the operation unit 16. Therefore, the device 10 for recovering environmental nucleic acids of this embodiment can easily quickly switch from blowing to suction.

[0031] However, it is desirable to start the suction operation after the air blowing operation has completely stopped. This allows suction to begin after relatively large (heavy) deposits, such as leaf fragments or insect carcasses, have fallen, thereby reducing the possibility of suctioning such relatively large deposits. When relatively large deposits are collected as described above, the proportion of environmental nucleic acids originating from the relatively large deposits in the collected sample increases, making it difficult to accurately grasp the conditions in the collection target area. Thus, collecting relatively large deposits may lead to bias in the results of analyzing the collected nucleic acid-containing deposits (introducing sampling bias), and therefore, these relatively large deposits are considered undesirable as sampling targets.

[0032] Furthermore, in the environmental nucleic acid recovery device 10 of this embodiment, the suction pipe 20 and the air blower pipe 40 are formed to extend in the same direction from the main body 12, and the suction port 22 and the air blower pipe 42 are provided relatively close to each other. Therefore, when the suction operation is started after the air blowing from the air blower pipe 42 has stopped, the force of the suction at the suction port 22 may cause nucleic acid-containing deposits to enter the air blower pipe 42. In this embodiment, a blocking section 50 is provided in the air blower pipe 40, and the air blower pipe 40 is closed near the air blower pipe 42 in step T130. Therefore, even when the suction operation from the suction port 22 is started in step T140, it is possible to prevent nucleic acid-containing deposits from entering the air blower pipe 40 from the air blower pipe 42, for which air blowing has stopped. If nucleic acid-containing deposits enter the air blower pipe 40 during the suction operation of step T140 without providing the blocking section 50 in the air blower pipe 40, the suctioned nucleic acid-containing deposits may adhere to the inner wall surface of the air blower pipe 40. In such a case, if the environmental nucleic acid recovery device 10 is used repeatedly in different recovery target areas while replacing the dust collection filter 30, in step T120 of the next use, nucleic acid-containing deposits from the different recovery target areas that have adhered to the inside of the air duct 40 will be expelled from the air outlet 42. As a result, in step T140 of the next use, nucleic acid-containing deposits from the different recovery target areas will be collected on the dust collection filter 30, which may cause contamination of the sampled nucleic acid-containing deposits. By providing a blocking section 50 in the air duct 40, such contamination can be suppressed.

[0033] Furthermore, the timing for shielding air duct 40 using blocking unit 50 may be before the air flow is stopped, rather than after the air flow is stopped through air duct 40. With this configuration, even if a backflow of air occurs within air duct 40 when the air flow operation is stopped by stopping second blower unit 66, it is possible to prevent nucleic acid-containing deposits from flowing into air duct 40 through air outlet 42, thereby suppressing the above-mentioned contamination.

[0034] After the operation unit 16 is operated to stop the suction from the suction port 22, the dust collection filter 30 is removed from the suction tube 20, and the collection of the nucleic acid-containing deposits is completed (step T150).

[0035] (A-3) Analysis of Environmentally Derived Nucleic Acids: Extracting and analyzing nucleic acids from nucleic acid-containing sediments recovered as described above enables analysis such as biological monitoring using environmentally derived nucleic acids. An example of a method for extracting nucleic acids from nucleic acid-containing sediments is described below. When extracting nucleic acids, first, the nucleic acid-containing sediments retrieved from the dust collection filter 30 are suspended in a liquid. The liquid used here may be a lysis buffer for lysing cells and tissues. The suspension in the liquid may be performed by adding, for example, ceramic beads to the liquid and stirring. This suspends the nucleic acid-containing sediments contained in the dust collection filter 30 in the liquid, and the biologically derived nucleic acids in the nucleic acid-containing sediments are eluted into the suspension. The biologically derived nucleic acids are then extracted from the suspension containing the eluted biologically derived nucleic acids. The biologically derived nucleic acids can be extracted, for example, by centrifuging the suspension, recovering the supernatant containing the dissolved biologically derived nucleic acids, selecting an appropriate column to remove impurities, and then purifying the biologically derived nucleic acids using a column that adsorbs nucleic acids. Examples of the impurities include substances that inhibit the PCR reaction described below. Such a nucleic acid extraction step is a known method, and for example, a commercially available soil DNA extraction kit may be used.

[0036] The extracted biological nucleic acids can be analyzed by various known methods. For example, species-specific analyses, such as quantitative PCR (qPCR), can be performed to determine the presence or absence of specific biological species or quantify their abundance. By selecting appropriate primers and performing PCR with a focus on a specific group of biological species, such as arthropods, microorganisms, birds, or mammals, analysis can be narrowed down to that specific group. Furthermore, PCR using appropriate universal primers can identify a wider range of biological species at once. Furthermore, comprehensive analyses can be performed, such as by comparing the base sequence obtained using a next-generation sequencer with a database containing base sequences of various organisms with known base sequences to identify the biological species. Furthermore, since the sampling method of this embodiment enables sampling of nucleic acids from a large number of individuals of the same species present at a specific location, haplotype analysis of the specific species can also be performed. In this way, information about the organisms inhabiting or residing on the target surface can be obtained.

[0037] The environmental nucleic acid recovery device 10 of this embodiment, configured as described above, allows nucleic acid-containing sediments to be recovered by suction from the surface of a recovery target area. Because nucleic acid-containing sediments can be recovered by a simple method using a device with suction functionality, it is possible to easily recover environmental nucleic acids contained in various sediments, including suspended matter that has fallen from the air, from a relatively large recovery target area. In this embodiment, nucleic acid-containing sediments are stirred up by air blowing, and then recovered by suction. However, if nucleic acid-containing sediments are recovered by suction alone without air blowing, relatively large (heavy) sediments that are difficult to recover when stirred up by air blowing (e.g., withered plants, relatively small animal carcasses such as insects, and debris from animals and plants) will also be recovered. Such relatively large sediments may cause bias in the results of analyzing the recovered nucleic acid-containing sediments (inducing sampling bias). In contrast, when nucleic acid-containing sediments stirred up by air blowing are recovered by suction as in this embodiment, the recovery of such relatively large sediments is suppressed, thereby reducing the sampling bias resulting from the recovery of relatively large sediments.

[0038] In addition to suction, other methods for recovering nucleic acid-containing deposits from the surface of the recovery target area include, for example, pressing a transfer member for adhering the nucleic acid-containing deposits against the surface of the recovery target area, thereby adhering the nucleic acid-containing deposits on the surface to the transfer member. Alternatively, a method is considered in which the surface is wiped with a wiping member such as a swab, and the nucleic acid-containing deposits on the surface are adhered to the wiping member for recovery. However, when recovering nucleic acid-containing deposits by directly contacting a recovery member such as a transfer member or wiping member with the surface, relatively large deposits such as those described above may adhere to the recovery member, potentially causing sampling bias. Furthermore, when recovering nucleic acid-containing deposits by directly contacting the surface of the recovery target area with the recovery member described above, the amount of nucleic acid-containing deposits adhering to the recovery member may relatively easily reach the upper limit of adhesion, making it difficult to recover nucleic acid-containing deposits from a wider range of the recovery target area with reduced bias. According to this embodiment, nucleic acid-containing deposits stirred up by air are recovered by suction, enabling the recovery of nucleic acid-containing deposits from a relatively wider range of the recovery target area with reduced bias. The method for recovering environmental nucleic acids of this embodiment can be suitably used when recovering nucleic acid-containing deposits from surfaces where sampling by direct contact with the recovery member is likely to result in uneven adhesion of specific substances and cause sampling bias, such as surfaces with a high proportion of relatively large deposits as described above, surfaces with accumulated wood chips, or relatively soft surfaces such as those covered with moss.

[0039] Furthermore, in the environmental nucleic acid recovery device 10 of this embodiment, the intake flow path 26 including the intake tube 20 and the air supply flow path 46 including the air supply tube 40 are provided as separate, independent flow paths. A device configuration that allows the air supply and intake operations to be switched between rather than simultaneously can be achieved, for example, by using a single common flow path for the air supply and intake operations and reversing the drive of a pressure device such as a blower. However, in such a case, the intake nucleic acid-containing deposits that have been sucked in may adhere and remain in the flow path and be expelled the next time air is blown, potentially causing contamination between different target areas. In the environmental nucleic acid recovery device 10 of this embodiment, the air supply device and the aspirator are separate devices. Specifically, the intake flow path 26 used for the intake operation and the air supply flow path 46 used for the air supply operation are separate, independent systems, thereby preventing the above-mentioned contamination.

[0040] Furthermore, in the environmental nucleic acid recovery device 10 of this embodiment, prior to the inhalation operation using the inhalation flow path 26, the blocking unit 50 blocks the inflow of air from the air outlet 42 into the air duct 40. This prevents nucleic acid-containing deposits from flowing into the air duct 40 during the inhalation operation, thereby suppressing contamination caused by nucleic acid-containing deposits that have flowed into the air duct 40. Furthermore, the provision of the blocking unit 50 prevents fine dust, which is the stirred-up nucleic acid-containing deposits, from adhering due to static electricity to the vicinity of the air outlet 42 or inside the air duct 40, thereby suppressing contamination caused by the nucleic acid-containing deposits that have adhered in this manner.

[0041] Furthermore, in the environmental nucleic acid recovery device 10 of this embodiment, the suction tube 20 and the air supply tube 40 are formed to extend in the same direction from the main body 12, the air supply tube 40 is formed to be longer than the suction tube 20, and the air supply port 42 opens at a position farther from the main body 12 than the suction port 22. Therefore, the air supply port 42 can be brought sufficiently close to the surface to be recovered to efficiently blow air, and a sufficient distance can be ensured between the surface to be recovered and the suction port 22, making it easy to prevent the suction of the above-mentioned relatively large deposits, etc. However, the air supply tube 40 and the suction tube 20 may have different shapes, such as by making the lengths of the air supply tube 40 and the suction tube 20 the same.

[0042] B. Second Embodiment: Fig. 6 is an explanatory diagram showing the outline of the configuration of an apparatus 110 for recovering environmental nucleic acids according to a second embodiment, similar to Fig. 2. In the second embodiment, parts common to the apparatus 10 for recovering environmental nucleic acids according to the first embodiment are given the same reference numerals.

[0043] In the first embodiment of the apparatus 10 for recovering environmental nucleic acids, the suction tube 20 and the air blower tube 40 are formed to extend in the same direction from the main body 12, but may have a different configuration. In a second embodiment of the apparatus 110 for recovering environmental nucleic acids shown in FIG. 6 , the suction tube 20 and the air blower tube 40 are formed to extend in different directions (opposite directions in FIG. 6 ) from the main body 12. When recovering environmental nucleic acids using the apparatus 110 for recovering environmental nucleic acids, the operator simply performs an air blowing operation in step T120 of FIG. 4 , in which the air blowing port 42 of the air blower tube 40 is directed toward the surface 70 of the recovery target area to release pressurized air. Then, after stopping the air blowing in step T130, in step T140, the operator inverts the apparatus 110 for recovering environmental nucleic acids, directs the suction port 22 of the suction tube 20 toward the surface 70 of the recovery target area, and draws in outside air through the suction port 22.

[0044] With this configuration, the nucleic acid-containing sediments are stirred up by blowing air and then collected by suction, so that environmental nucleic acids can be collected from a relatively wide area while minimizing bias in the environmental nucleic acids contained in the collected material, similar to the environmental nucleic acid collection device 10 of the first embodiment.

[0045] Furthermore, in the device 110 for recovering environmental nucleic acids of the second embodiment, the air outlet 42 and the suction port 22 are positioned at greater distances during the suction operation, and the air outlet 42 is positioned at greater distances from nucleic acid-containing deposits blown up from the surface of the object to be recovered, making it difficult for nucleic acid-containing deposits to enter the air outlet 42, thereby making it possible to eliminate the need for the blocking unit 50. However, from the perspective of preventing nucleic acid-containing deposits from entering the air outlet 42 due to the influence of static electricity, the blocking unit 50 may also be provided in the air duct 40 near the air outlet 42 in the device 110 for recovering environmental nucleic acids.

[0046] C. Other Embodiments: In the suction tube 20 of the environmental nucleic acid recovery device of each of the above-described embodiments, a blocking section similar to the blocking section 50 provided in the air supply tube 40 may be provided at a position closer to the main body 12 than the dust collection filter 30. In this case, when nucleic acid-containing deposits are collected on the dust collection filter 30 by suction, the blocking section closes the suction tube 20 before suction is stopped. With this configuration, even if a backflow of air occurs within the suction tube 20 when suction operation is stopped by stopping the first blower unit 64, impurities present on the main body 12 side of the dust collection filter 30 (e.g., dust that flowed into and remained in the suction tube 20 during a previous sampling operation) can be prevented from flowing back toward the dust collection filter 30, thereby preventing contamination.

[0047] Although the air duct 40 of the environmental nucleic acid recovery device in each of the above-described embodiments is provided with a blocking unit 50, the blocking unit 50 is not essential, and the air duct 40 may not be provided with a blocking unit 50. For example, if the air duct 40 is detachable from the main body 12 and replaced each time an environmental nucleic acid recovery operation is performed, nucleic acid-containing deposits that have entered the air duct 40 will not cause contamination during subsequent environmental nucleic acid recovery operations, making the blocking unit 50 unnecessary. Alternatively, instead of attaching the blocking unit 50 to the air duct 40 in advance, a blocking unit may be provided separately from the environmental nucleic acid recovery device including the air duct 40. Specifically, for example, a cover that covers the air outlet 42 may be provided as a blocking unit, and the air duct 40 may be closed by attaching the cover to the air outlet 42 at the end of the air blowing operation.

[0048] In the above-described embodiments, the intake port 22 is provided at the most distal end of the intake pipe 20, and the air outlet 42 is provided at the most distal end of the blower pipe 40, so that the flow direction of the intake air at the intake port 22 is parallel to the axial direction of the intake pipe 20, and the flow direction of the pressurized air at the air outlet 42 is parallel to the axial direction of the blower pipe 40. However, a different configuration may be used. For example, the intake port 22 may be provided on the side surface of the distal end of the intake pipe 20, or the air outlet 42 may be provided on the side surface of the distal end of the blower pipe 40. With such a configuration, for example, the axial direction of the blower pipe 40 and the flow direction of the pressurized air at the air outlet 42 can be made different from each other.

[0049] In each of the above-described embodiments, the method for extracting environmental nucleic acids shown in Fig. 4 was carried out using an apparatus for extracting environmental nucleic acids that was equipped with both a "blower" and an "aspirator," but a different configuration may also be used. That is, environmental nucleic acids may be extracted in the same manner as in Fig. 4 using a blower and an aspirator that are separate devices.

[0050] According to the method for recovering nucleic acids from the environment disclosed herein, nucleic acid-containing sediments were recovered by blowing air and then suctioning, and information about animals in the environment obtained from the environmental nucleic acids was examined. ２Two areas with different surface areas (Points 1 and 2 shown in Figure 7, described below) were designated as the collection target area. Dust collection was then performed in this collection target area during a daytime period without rain on December 5, 2022. Two commercially available dust collectors (Blower Dust Collector MUB1200, manufactured by Makita Corporation) with a switching function between blowing and suction were prepared. One was used as a blower, and the other was used as a suction device with a disposable nonwoven fabric filter attached to its opening. First, one of the devices was used to blow air from approximately vertically above, stirring up dust accumulated on the ground as nucleic acid-containing deposits. After the 30-second blowing operation was stopped, the other device was immediately used at the same location to perform 30-second suction, and the dust was collected. Furthermore, at each of the two locations where dust collection by air blowing and suction was performed as described above, a comparative example was performed in which dust was collected by suction only using a similar dust collector without air blowing. In the comparative example, dust collection and analysis of the collected dust were performed under the same conditions except that air blowing was not performed prior to suction.

[0051] After collecting dust by suction, the filters for each sample were removed and stored at -80°C. DNA was then extracted. A commercially available soil DNA extraction kit (NucleoSpin Soil, Takara Bio Inc.) (NucleoSpin is a registered trademark) was used to extract DNA from the filters. The nucleic acid extract obtained using this kit was used as an environmental DNA sample from the target collection area, and the 12S rRNA sequence was amplified by PCR using designated primers (existing avian and mammalian universal primers). Amplification was performed using the Kapa Hifi PCR Kit (KAPABIOSYSTEMS), with PCR repeated four times. Further PCR was performed to add indexes for sequence analysis, and the PCR products were bead-purified. Sequences were then obtained using a next-generation sequencer. The sequencer used was the Illumina iSeq100 (Illumina Inc.) (iSeq is a registered trademark). The obtained sequences were processed using Qiime2 (version 2019.1). The quality scores of the Fastq data were visualized, and the reads were denoised and primer sequences were removed using the dada2 denoise-paired dada2 plugin. The forward and reverse sequences were merged to remove chimeric sequences, and a feature table and representative sequences were created. The representative sequences were then subjected to a BLASTN search against the NCBI nt database. Only sequences classified as avian or mammalian with a homology of 97% or higher were listed as identification results.

[0052] FIG. 7 is an explanatory diagram showing the analysis results of the above-mentioned environmental DNA samples. Here, the results are shown in which the number of animal species detected was counted by comparing the sequences obtained as described above with a database. In FIG. 7, samples in which dust was collected by blowing air and then suctioning according to the environmental nucleic acid collection method of the present disclosure are shown as "with fan," while comparative samples in which dust was collected without blowing air are shown as "without fan." As shown in FIG. 7, at both points 1 and 2, more animal species were detected in the "with fan" samples than in the "without fan" samples, demonstrating that biological nucleic acids in the collection area can be collected with reduced bias.

[0053] 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.

[0054] The present disclosure can also be realized in the following forms: [Application Example 1] An apparatus for recovering environmental nucleic acids from an environment, comprising: an air supply flow path including an air supply duct having an air supply port that is an opening for releasing pressurized air, and an air intake port for taking air into the air supply duct; an intake flow path including an intake duct having an intake port that is an opening for taking in outside air, and having a collection part to which nucleic acid-containing deposits containing environmental nucleic acids present in the taken-in outside air adhere, and an exhaust port for discharging the outside air that has passed through the collection part from the apparatus for recovering environmental nucleic acids; a pressurizing mechanism that generates air supply pressure in the air supply flow path for releasing air from the air supply port, and generates in the intake flow path an intake pressure for taking in outside air from the inlet; and a switching part that switches between an air supply operation using the air supply flow path and an intake operation using the intake flow path. [Application Example 2] The device for recovering environmental nucleic acids according to Application Example 1, wherein the air duct comprises a blocking unit provided adjacent to the air outlet, blocking air from flowing into the air duct from the air outlet. [Application Example 3] The device for recovering environmental nucleic acids according to Application Example 2, wherein the blocking unit comprises a blocking plate that is movable between a position that blocks the air duct and a position that opens the air duct, and the blocking plate blocks air from flowing into the air duct from the air outlet by moving from the position that opens the air duct to the position that opens the air. [Application Example 4] The device for recovering environmental nucleic acids according to any one of Application Examples 1 to 3, wherein the collection unit is a filter that is arranged to block the suction tube, and that allows outside air taken into the suction tube to pass through and collects the nucleic acid-containing sediments. [Application Example 5] The device for recovering environmental nucleic acids according to any one of Application Examples 1 to 4, wherein the air blowing tube and the suction tube are formed to extend in the same direction from a main body of the device for recovering environmental nucleic acids in which the pressurizing mechanism is disposed, the air blowing tube is formed to be longer than the suction tube, and the air blowing port opens at a position farther away from the main body than the suction port.Application Example 6 A method for recovering environmental nucleic acids from an environment, comprising: setting a recovery target area including at least one of the ground surface and the surface of an object as a target for recovering environmental nucleic acids; arranging a blower that emits pressurized air at a distance from the surface of the recovery target area, and using the blower to blow air toward the surface of the recovery target area, thereby stirring up nucleic acid-containing sediments that contain the environmental nucleic acids and are present on the surface of the recovery target area; after the blowing of air by the blower is stopped, placing a suction device that is a device different from the blower and that draws in outside air at a distance from the surface of the recovery target area, and using the suction device to suck in the nucleic acid-containing sediments that have been stirred up by the air blower, and attaching the sucked nucleic acid-containing sediments to a collection unit provided in the suction unit; and recovering the nucleic acid-containing sediments from the collection unit. [Application Example 7] The method for recovering environmental nucleic acids according to Application Example 6, wherein the air blower comprises an air duct having an air outlet at its tip that discharges air, and wherein the flow of air into the air duct via the air outlet is blocked after the nucleic acid-containing sediment is stirred up by air blown by the air blower and before inhalation using the suction device is started. [Application Example 8] The method for recovering environmental nucleic acids according to Application Example 6 or 7, wherein the angle at which the air is blown relative to the surface of the recovery target area is 80° or more and 100° or less relative to the surface.

[0055] DESCRIPTION OF SYMBOLS 10, 110... Environmentally derived nucleic acid recovery device 12... Main body 14... Grip part 16... Operation part 20... Intake pipe 22... Intake port 24... Exhaust port 26... Intake flow path 30... Dust collection filter 40... Air supply pipe 42... Air supply port 44... Air intake port 46... Air supply flow path 50... Blocking part 51... Slit 52... Shielding plate 53... Elastic part 60... Pressurizing mechanism 62... Motor 64... First blower part 66... ​​Second blower part 68... Switching part 70... Surface 72... Nucleic acid-containing deposits

Claims

1. An environmental nucleic acid recovery device for recovering environmental nucleic acids from the environment, comprising: an air flow path including an air blower duct formed with an air blower port, which is an opening for releasing pressurized air, and an air intake port for taking air into the air blower duct; an intake flow path including an intake duct formed with an intake port, which is an opening for taking in outside air, and having a collection section to which nucleic acid-containing deposits containing environmental nucleic acids present in the taken-in outside air adhere; and an exhaust port for discharging the outside air that has passed through the collection section from the environmental nucleic acid recovery device; a pressure mechanism that generates air blowing pressure in the air blower duct for releasing air from the air blower port, and generates in the intake flow path an intake pressure in the intake flow path for taking in outside air from the intake port; and a switching section that switches between air blowing operation using the air blower duct and intake operation using the intake flow path.

2. An apparatus for recovering nucleic acids derived from the environment according to claim 1, wherein the air duct is provided with a blocking section disposed adjacent to the air outlet, which blocks the inflow of air from the air outlet into the air duct.

3. An apparatus for recovering nucleic acids of environmental origin as described in claim 2, wherein the blocking unit is provided with a blocking plate that is movable between a position that blocks the air duct and a position that opens the air duct, and the blocking plate blocks the flow of air from the air outlet into the air duct by moving from the position that opens the air duct to the position that opens the air duct.

4. An apparatus for recovering nucleic acids derived from the environment according to claim 1, wherein the collection unit is a filter that is arranged to block the intake tube, allows the outside air taken into the intake tube to pass through, and collects the nucleic acid-containing deposits.

5. An environmental nucleic acid recovery device as described in claim 1, wherein the air supply pipe and the suction pipe are formed to extend in the same direction from a main body of the environmental nucleic acid recovery device in which the pressurizing mechanism is arranged, the air supply pipe is formed to be longer than the suction pipe, and the air supply port opens at a position farther away from the main body than the suction port.

6. A method for recovering environmental nucleic acids from the environment, comprising: setting a recovery target area including at least one of the ground surface and the surface of an object as a target for recovering environmental nucleic acids; arranging a blower that emits pressurized air at a distance from the surface of the recovery target area, and using the blower to blow air toward the surface of the recovery target area, thereby stirring up nucleic acid-containing sediments that are present on the surface of the recovery target area and contain the environmental nucleic acids; after the blowing of air by the blower is stopped, placing a suction device that is a device different from the blower and sucks in outside air at a distance from the surface of the recovery target area, and using the suction device to suck in the nucleic acid-containing sediments that have been stirred up by the blower, and attaching the sucked nucleic acid-containing sediments to a collection section provided in the suction device; and recovering the nucleic acid-containing sediments from the collection section.

7. A method for recovering nucleic acids derived from the environment as described in claim 6, wherein the air blower comprises an air duct having an air outlet at its tip for discharging air, and after the nucleic acid-containing sediment has been stirred up by blowing air using the air blower and before suction using the suction device is started, the flow of air into the air duct via the air outlet is blocked.

8. A method for recovering nucleic acids derived from the environment according to claim 6, wherein the angle at which air is blown relative to the surface of the recovery target area is between 80° and 100° relative to the surface.

Images