Soil microbial biomass culture and fumigation device

Abstract

The invention discloses a soil microbial biomass culturing and fumigating device, and relates to the technical field of soil microbial biomass detection.The soil microbial biomass culturing and fumigating device comprises a constant-temperature box body which is provided with a control panel, and the control panel can adjust the internal temperature of the constant-temperature box body to a set numerical value and keep the internal temperature constant; the sample culture system is arranged in the constant-temperature box body and is used for bearing a soil microorganism sample; the vacuum control system can control the vacuum degree in the sample culture system; chloroform is arranged in the fumigation system and can be conveyed into the sample culture system; the gas replacement system can convey air into the sample culture system; the tail gas recovery system is used for absorbing chloroform after the experiment; the control module is connected with the first electromagnetic valve, the second electromagnetic valve, the vacuum control system and the gas replacement system and can control starting and stopping of the first electromagnetic valve, the second electromagnetic valve, the vacuum control system and the gas replacement system. According to the invention, sample culture, fumigation and chloroform removal can be completed in a one-button manner without moving the device.

Description

Technical Field

[0001] The present invention relates to the technical field of soil microbial biomass detection, and particularly to an automated device for culturing and fumigating soil microbial biomass. Background Art

[0002] At present, the principles and steps of the method for measuring soil microbial biomass are as follows: Soil samples and chloroform are placed in a desiccator, and gaseous chloroform is diffused into the soil pores through vacuum pumping. The samples are cultured under dark conditions to allow chloroform to fully contact the soil, thereby destroying the cell membrane structure of soil microorganisms and promoting the release of active components of microbial cells. After fumigation, chloroform is removed, and the residual chloroform in the soil is removed by repeated vacuum pumping. The microbial cell contents released after soil fumigation cause a significant increase in extractable carbon, nitrogen, phosphorus, sulfur, etc. in the soil. By extracting with an appropriate extractant and measuring the total carbon, total nitrogen content, or inorganic phosphorus content in the extract, the contents of microbial biomass carbon, nitrogen, and phosphorus can be calculated.

[0003] The fumigation extraction method for soil microbial biomass mainly includes three steps, namely culturing, fumigating, and removing chloroform. Usually, a dedicated constant-temperature sealed darkroom needs to be established in the laboratory for culturing; after culturing, the samples need to be transferred to a vacuumable desiccator for fumigation with chloroform. Since chloroform is toxic, fumigation must be carried out in a fume hood. After fumigation, the desiccator is transferred back to the darkroom for culturing for 22 - 24 hours. Therefore, the overall operation needs to be completed at two locations. For larger desiccators, the moving process is time-consuming and laborious; during the fumigation process, it is impossible to monitor whether the desiccator is sealed. If the desiccator is not tightly sealed, chloroform will leak into the constant-temperature culture room, resulting in failed sample fumigation and harm to laboratory personnel; in the step of removing chloroform, it is difficult to break the negative pressure vacuum of the vessel, and the sealing insulating grease used to seal the connecting vessel and the vessel top cover has high viscosity after vacuum, making it difficult to open the vessel top cover, easily causing sample spillage and damage to the vacuum container top cover, etc.

[0004] Therefore, there is an urgent need to design a technical solution that can complete sample culturing and fumigation without moving, with online vacuum monitoring and automation. Summary of the Invention

[0005] The purpose of the present invention is to provide an automated device for culturing and fumigating soil microbial biomass to solve the problems existing in the above-mentioned prior art, which can eliminate the steps of sample transfer, movement of the sample culture system, and repeated opening and moving of the sample during the culturing and fumigating process of soil microbial biomass, and avoid problems such as the entire experiment failing due to loose sealing of the sample culture system during the operation process, and achieve culturing and fumigating samples without moving the vessels, with online vacuum monitoring and automation.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a device for culturing and fumigating soil microorganisms, comprising:

[0008] A constant temperature box body, which is provided with a control panel and can control the internal temperature of the constant temperature box body to a set value and keep it constant;

[0009] A sample culture system, which is arranged in the constant temperature box body, and the sample culture system is used to carry soil microorganism samples;

[0010] A vacuum control system, comprising a vacuum pump and a vacuum controller. The vacuum pump is connected to the sample culture system through a vacuum pipeline, and the vacuum controller can control the vacuum degree in the sample culture system;

[0011] A fumigation system, which is arranged in the constant temperature box body and is communicated with the sample culture system through a chloroform pipeline provided with a first electromagnetic valve. Chloroform is provided in the fumigation system and can transport chloroform vapor into the sample culture system;

[0012] A gas replacement system, which is communicated with the sample culture system through an air pipeline provided with a second electromagnetic valve and can transport air into the sample culture system;

[0013] An exhaust gas recovery system, which is communicated with the outlet of the vacuum pump through a pipeline and is used to absorb chloroform after the experiment;

[0014] A control module, which is respectively connected to the first electromagnetic valve, the second electromagnetic valve, the vacuum control system and the gas replacement system, and can respectively control the start and stop of the first electromagnetic valve, the second electromagnetic valve, the vacuum control system and the gas replacement system; The control module uses an existing programmable controller as an operation platform, constructs a multi-functional electromagnetic valve group for controlling the gas path, and performs program control for automatic culture-fumigation-dechloroform; A pressure control system is used for gas pressure control.

[0015] Preferably, an electric heating device and a refrigeration device are provided in the constant temperature box body. The electric heating device can adopt an electric heating tube; The refrigeration device adopts compression refrigeration; The electric heating device and the refrigeration device are respectively connected to the control panel, and the control panel can adjust the temperature in the constant temperature box body to a set value through the electric heating device and the refrigeration device; The constant temperature box body has a visual window, a box cover is provided at the visual window, and heat insulation layers are provided on the side wall and the surface of the box cover of the constant temperature box body, and a light-shielding layer is provided outside the heat insulation layer.

[0016] Preferably, the sample culture system includes a sealable sample chamber, on which a vacuum gauge is provided; a plurality of the sample chambers are fixedly provided in the constant temperature box, and the fumigation system includes a sealable chloroform chamber, wherein the plurality of the sample chambers are connected in series in sequence via a pipeline provided with a control valve, and the chloroform chamber is connected to one of the sample chambers via a chloroform pipeline provided with a first solenoid valve.

[0017] Preferably, the control module can control the closing state and closing time of the first solenoid valve and the second solenoid valve respectively through a program.

[0018] Preferably, the vacuum controller controls the start of the vacuum pump through the vacuum degree range set by the control module. When the vacuum degree in the sample culture system is lower than -0.65MPa, the vacuum pump is started; when the vacuum degree in the sample culture system reaches -0.85MPa, the vacuum pump is turned off.

[0019] Preferably, one end of the gas replacement pipeline passes through the constant temperature box and is connected to the sample culture system, and the other end of the gas replacement pipeline is connected to the air pipeline and the vacuum pipeline respectively through a three-way valve, and the air outlet of the vacuum pump is externally connected to the exhaust gas recovery system.

[0020] Preferably, the tail gas recovery system comprises an absorption chamber, in which activated carbon is arranged.

[0021] Preferably, a vent is provided on the side of the constant temperature box, and a fan is provided at the vent.

[0022] Preferably, the sample chamber comprises a cavity and a cavity cover, the material of the sample chamber is 2 cm thick acrylic, a 2 cm outer edge is provided at the contact position between the cavity cover and the cavity top, the outer edge is arranged on the outer side wall of the cavity cover, and is close to the contact position between the cavity cover and the cavity top, so as to facilitate opening the cavity cover by pushing upward through the outer edge, the cavity cover is fixedly buckled on the cavity top, and the contact interface between the cavity and the cavity cover is sealed with a raised silicone sealing strip; a four-way tube is connected to the center of the cavity cover, the bottom passage of the four-way tube is connected to the inside of the cavity cover, the top passage of the four-way tube is connected to the vacuum gauge, the passage on one side of the four-way tube is connected to the gas replacement pipeline, and the passage on the other side of the four-way tube is connected to the pressure relief valve, and a valve interface is provided on the side of the cavity 5 cm away from the bottom, the valve interface is used to connect the chloroform pipeline or connect the sample chamber in series, and when multiple sample chambers are provided, only one of the valve interfaces of the first sample chamber needs to be connected to the chloroform pipeline, and the remaining sample chambers are connected in series with the first sample chamber through their respective valve interfaces.

[0023] Preferably, the chloroform chamber includes a cavity and a chamber cover. The material of the chloroform chamber is raw glass with a thickness of 1 cm. The chamber cover is fixedly buckled on the top of the cavity, and the contact interface between the chamber cover and the cavity is sealed with a raised silicone sealing strip; the chamber cover is provided with an outer edge of 1 cm, and the outer edge can be arranged around the upper side wall of the chamber cover; a valve-equipped interface is provided at a position 5 cm from the bottom on the side of the cavity, and the valve-equipped interface is used to connect the chloroform pipeline.

[0024] The present invention has achieved the following technical effects compared with the prior art:

[0025] In the present invention, the sample culture system and the fumigation system are respectively fixed in a light-shielded constant temperature box body. The sample culture system and the fumigation system are connected by a pipeline with an electromagnetic valve, and the electromagnetic valve is connected to the control module. The control module controls the on-off of the electromagnetic valve, and thus can realize the connection or disconnection of the gas path, so as to complete the culture and fumigation in situ, and there is no need to move the equipment and samples during the culture and fumigation processes. The tail gas recovery system can absorb the waste gas containing chloroform extracted by the gas replacement system in situ, avoid direct emission into the atmosphere, and reduce environmental pollution. The present invention can automate the sample preparation process for measuring soil microbial biomass, standardize the operation steps, reduce the errors introduced by humans, reduce the labor cost, and make the subsequent measurement of soil microbial biomass more simple and controllable. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is the circuit connection diagram of the control module in the soil microbial biomass culture and fumigation device in one or some embodiments of the present invention;

[0028] Figure 2 It is the gas path schematic diagram of the soil microbial biomass culture and fumigation device in one or some embodiments of the present invention;

[0029] Figure 3 It is the structural layout schematic diagram of the soil microbial biomass culture and fumigation device in one or some embodiments of the invention.

[0030] In the figure: 1 - constant temperature box body, 2 - control module, 3 - sample chamber, 4 - chloroform chamber, 5 - first electromagnetic valve, 6 - second electromagnetic valve, 7 - vacuum pump, 8 - gas replacement pipeline, 9 - three-way valve, 10 - vacuum controller, 11 - air pipeline, 12 - vacuum pipeline, 13 - chloroform pipeline, 14 - power key, 15 - tail gas recovery system. Detailed implementation manners

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0032] The purpose of the present invention is to provide a device for culturing and fumigating soil microbial biomass, so as to solve the problems existing in the above-mentioned prior art, and the sample culture and fumigation can be completed without moving.

[0033] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0034] The existing fumigation extraction method for soil microbial biomass mainly includes three steps, namely culturing, fumigating, and dechloroforming. For freshly collected soil that cannot be processed within 24 hours, the microorganisms must be revived by culturing for 7-14 days. During the culturing process, the air needs to be artificially replaced 3-4 times. Usually, a dedicated constant-temperature closed darkroom needs to be established in the laboratory for culturing; after culturing, the sample needs to be transferred to a vacuumable desiccator and fumigated with chloroform. Since chloroform is toxic, the fumigation must be carried out in a fume hood. After the fumigation is completed, the desiccator is transferred to the darkroom for culturing for 22-24 hours. Therefore, this operation needs to be completed at two locations. Moving a large-capacity desiccator is very labor-consuming; after the fumigation is completed, the desiccator is under negative pressure, and a rubber hammer needs to be used to knock on the desiccator to open the lid, which is easy to damage the equipment; the chloroform cup is generally placed at the bottom of the sample cup and is not easy to take out.

[0035] To solve the above problems, the present invention provides a device for culturing and fumigating soil microbial biomass. Refer to attached drawing Figure 1 , attached drawing Figure 2 and attached drawing Figure 3As shown in the figure; it includes a constant-temperature box body 1, which is provided with a mature and well-known control panel that can control the internal temperature of the constant-temperature box body 1 to a set value and keep it constant; a sample culture system is arranged inside the constant-temperature box body 1, and the sample culture system is used to carry soil microorganism samples; the vacuum control system includes a vacuum pump 7 and a vacuum controller 10. The vacuum pump 7 is connected to the sample culture system through a vacuum pipeline 12. The vacuum controller 10 can control the on-off of the vacuum pump 7 to control the vacuum degree inside the sample culture system; the fumigation system is arranged inside the constant-temperature box body 1 and is connected to the sample culture system through a chloroform pipeline 13 provided with a first solenoid valve 5. There is chloroform in the fumigation system, which can transport chloroform vapor into the sample culture system; the gas replacement system is connected to the sample culture system through an air pipeline 11 provided with a second solenoid valve 6 and can transport air into the sample culture system; the tail gas recovery system 15 is connected to the outlet of the vacuum pump 7 through a pipeline and is used to absorb chloroform after the experiment; the control module 2 is respectively connected to the first solenoid valve 5, the second solenoid valve 6, the vacuum control system and the gas replacement system, and can respectively control the start and stop of the first solenoid valve 5, the second solenoid valve 6, the vacuum control system and the gas replacement system; the control module 2 uses an existing programmable controller as an operation platform to construct a solenoid valve group formed by the first solenoid valve 5 and the second solenoid valve 6 to control their respective gas passages. A mature and existing program for automatic culture-fumigation-dechloroform is set in the control module 2, which can realize the connection or disconnection of the gas path, thus realizing in-situ culture and fumigation, and there is no need to move the equipment and samples during the culture and fumigation processes.

[0036] In order to achieve the control of constant temperature and the adjustment of temperature values, an electric heating device and a refrigeration device are arranged inside the constant-temperature box body 1 of this embodiment. The electric heating device can use an electric heating tube; the refrigeration device uses compression refrigeration; the electric heating device and the refrigeration device are controlled by the control panel, and the control panel can adjust the temperature inside the constant-temperature box body 1 to a set value through the electric heating device and the refrigeration device; the constant-temperature box body 1 has a visual window, a box cover is provided at the visual window, and heat insulation layers are provided on the side wall and the surface of the box cover of the constant-temperature box body 1. A light-shielding layer is provided outside the heat insulation layer. When fumigating, the cover plate is opened to observe the boiling of chloroform; a ventilation port is provided on the side of the constant-temperature box body 1, and a fan is provided at the ventilation port to maintain suitable ventilation conditions.

[0037] The sample culture system includes a sealable sample chamber 3, and a vacuum gauge is provided on the sample chamber 3; multiple sample chambers 3 are fixedly arranged inside the constant-temperature box body 1. The fumigation system includes a sealed chloroform chamber 4. Multiple sample chambers 3 are sequentially connected in series through a pipeline provided with a control valve, and the chloroform chamber 4 is connected to one of the sample chambers 3 through a chloroform pipeline 13 provided with a first solenoid valve 5.

[0038] The control module 2 can separately control the opening or closing states of the first solenoid valve 5 and the second solenoid valve 6 through a program, as well as the duration for maintaining the opening or closing states. The vacuum control system of this embodiment further includes a vacuum controller 10; the control module 2 is connected to the vacuum controller 10, and the vacuum controller 10 controls the startup of the vacuum pump 7 according to the vacuum degree range set by the control module 2. When the vacuum degree in the sample culture system is lower than -0.65 MPa, the vacuum pump 7 starts, and when the vacuum degree in the sample culture system reaches -0.85 MPa, the vacuum pump 7 is turned off.

[0039] In order to smoothly carry out the vacuum and air replacement respectively, a gas replacement pipeline 8 is provided in this embodiment. One end of the gas replacement pipeline 8 penetrates through the constant temperature box 1 and is connected to the sample culture system. The other end of the gas replacement pipeline 8 is respectively connected to an air pipeline 11 and a vacuum pipeline 12 through a three-way valve 9. The three-way valve 9 is also connected to the control module 2, and the control module 2 can control the switching of the conduction circuits of the three-way valve 9; the air outlet of the vacuum pump 7 is externally connected to a tail gas recovery system. The tail gas recovery system 15 includes an absorption chamber, and activated carbon is provided in the absorption chamber to absorb chloroform after the experiment, avoiding the problem of air pollution caused by the direct emission of chloroform vapor during the air replacement process. In order to improve the absorption efficiency, a condensation device can be provided in front of the absorption chamber to condense the chloroform vapor in the tail gas and then enter the absorption chamber to be adsorbed by the activated carbon.

[0040] In order to be able to conveniently open the sample chamber 3 or the chloroform chamber 4 on the premise that the sample chamber 3 and the chloroform chamber 4 are airtight, in one embodiment, the sample chamber 3 and the chloroform chamber 4 have the same structure, both including a cavity and a chamber cover; at the position where the top of the cavity of the sample chamber 3 contacts the chamber cover, there is a 2-cm outer edge. The chamber cover is fixedly buckled on the top of the cavity, and the contact interface between the chamber cover and the outer edge is sealed with a raised silicone rubber sealing strip, with good sealing effect, ensuring the internal airtightness; a four-way pipe is connected to the center of the chamber cover. The bottom passage of the four-way pipe is connected to the inside of the chamber cover. The top passage of the four-way pipe is connected to a vacuum gauge. One side passage of the four-way pipe is connected to the gas replacement pipeline 8, and the other side passage of the four-way pipe is connected to a pressure relief valve. At a position 5 cm from the bottom on the side of the cavity, there is a valve interface made of 2-cm-thick acrylic, and the valve interface is used to connect the chloroform pipeline 13. The chamber cover of the chloroform chamber 4 is fixedly buckled on the top of the cavity, and the contact interface between the chamber cover and the outer edge is sealed with a raised silicone rubber sealing strip, thereby realizing the internal airtightness of the sample chamber 3 and the chloroform chamber 4; a horizontal outer edge is provided at the edge of the chamber cover, and by pushing up this outer edge, the chamber cover can be quickly opened; at a position 5 cm from the bottom on the side of the cavity, there is a valve interface made of 1-cm-thick raw glass, and the valve interface is used to connect the chloroform pipeline 13.

[0041] To achieve precise control, the present invention is also provided with a program control module 2, which is connected to a vacuum controller 10, a power supply, a first solenoid valve 5 and a second solenoid valve 6, and is used to automatically control the vacuum pumping and gas replacement processes in the sample chamber 3.

[0042] The present invention adopts a mature and known program control software of the control module 2 to control the ventilation time and frequency during the cultivation process, and can also control the on-off of the chloroform pipeline 13 during the fumigation process, so as to realize in-situ cultivation, fumigation and de-chloroform of the sample in the constant temperature box 1; the fumigation system is independent of the sample cultivation system, and the contact and isolation of chloroform vapor with the sample are realized by controlling the closing of the first solenoid valve 5, reducing the turnover of the sample. Specifically, as Figure 1 shown, the right side of the control module 2 has four interfaces. The first interface is externally connected to a power button 14, the second interface is externally connected to the first solenoid valve 5 connected to the chloroform chamber 4 to control the connection and disconnection of chloroform vapor, the third interface is externally connected to the second solenoid valve 6 connected to an air pump, and the air pipeline 11 where the second solenoid valve 6 is located is externally connected to an air pump for controlling gas replacement. The fourth interface is externally connected to a vacuum controller 10, and the vacuum pump 7 is controlled through the vacuum controller 10. Through the suction effect after the vacuum pump 7 is started, the vacuum degree in the sample chamber 3 of the present invention is controlled; the control module 2 completes automated cultivation-fumigation by controlling the on-off and on-off duration of the second interface, the third interface and the fourth interface through the control keys to edit the existing mature program.

[0043] (1) When culturing soil microbial samples in this embodiment, the temperature of the constant temperature box 1 is set to 25 °C, and the control module 2 sets the program: ① Close the first solenoid valve 5 and close the second solenoid valve 6. At this time, both the first solenoid valve 5 and the second solenoid valve 6 are in the cut-off state for 48 h, disconnecting the connection between the sample chamber 3 and the chloroform chamber 4 and the air, and performing constant temperature and sealed cultivation for 24 h; ② The control module 2 sends a signal to the vacuum controller 10 to close the power supply of the vacuum pump 7 for 5 min. The vacuum pump 7 starts, and the control three-way valve 9 connects the gas replacement pipeline 8 to the vacuum pump 7 to pump out the air in the sample chamber 3. Then, the power supply of the vacuum pump 7 is turned off, the control three-way valve 9 connects the gas replacement pipeline 8 to the air pipeline 11, and the second solenoid valve 6 is closed. At this time, the second solenoid valve 6 is in the conducting state and the maintenance time is 5 min. Since the air pressure in the sample chamber 3 is relatively low at this time, fresh air is transported into the sample chamber 3 through the air pipeline 11 due to the air pressure difference inside and outside the sample chamber 3, realizing automatic gas replacement; ③ Close the second solenoid valve 6, and the sample chamber 3 is hermetically cultivated; ④ Repeat ① to ③ for 4 times to automatically complete multiple gas replacements within the cultivation cycle and ensure the revival activity of the soil sample.

[0044] (2) When fumigating the soil microbial sample in this embodiment, chloroform without ethanol is placed in the chloroform chamber 4. The control module 2 sets the program as follows: ① Turn on the power of the vacuum pump 7, control the three-way valve 9 to connect the gas replacement pipeline 8 with the vacuum pipeline 12 where the vacuum pump 7 is located, and the vacuum pump 7 starts to evacuate the system, and automatically stops when it reaches the range of the vacuum controller 10; ② Close the first solenoid valve 5, connect the chloroform pipeline 13 between the sample chamber 3 and the chloroform chamber 4, and maintain for 24 hours to allow chloroform vapor to enter the sample chamber 3 to achieve sample fumigation. (3) Removing chloroform from the sample. The control module 2 sets the program as follows: ① Close the first solenoid valve 5 to disconnect the chloroform pipeline 13 between the sample chamber 3 and the chloroform chamber 4 to isolate the chloroform vapor from entering the sample chamber 3; ② Turn off the power of the vacuum pump 7, control the three-way valve 9 to switch to connect the gas replacement pipeline 8 with the air pipeline 11, close the second solenoid valve 6, and maintain for 5 minutes to deliver fresh air to the sample chamber 3 through the air pressure difference inside and outside the sample chamber; ③ Turn on the power of the vacuum pump 7, close the second solenoid valve 6, and maintain for 5 minutes. Control the three-way valve 9 to switch to connect the gas replacement pipeline 8 with the vacuum pump 7, and evacuate the sample chamber 3; ④ Turn off the power of the vacuum pump 7 through the vacuum controller 10, close the second solenoid valve 6, and maintain for 5 minutes. Control the three-way valve 9 to switch to connect the gas replacement pipeline 8 with the air pipeline 11 to deliver fresh air to the sample chamber 3; ⑤ Repeat steps ③ to ④ for 7 times to automatically complete the process of removing chloroform. The vacuum pump 7 extracts the chloroform in the sample chamber 3 and the chloroform chamber 4 to the tail gas recovery system 15 to absorb harmful gases such as chloroform and reduce the emission of chloroform into the environment. The three steps of culturing - fumigating - removing chloroform can be edited separately according to the usage requirements by using the program of the control module 2, or combined into one program to achieve "one-key" automatic completion of culturing - fumigating - removing chloroform of the sample.

[0045] In the present invention, specific examples are used to elaborate the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, based on the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A soil microbial biomass cultivation and fumigation device, characterized in that: include: A constant temperature box is provided with a control panel capable of controlling the internal temperature of the constant temperature box to a set value and keeping it constant; A sample culture system is disposed in the constant temperature box, and the sample culture system is used to carry soil microorganism samples; A vacuum control system, comprising a vacuum pump and a vacuum controller, wherein the vacuum pump is connected to the sample culture system via a vacuum pipeline, and the vacuum controller is capable of controlling the vacuum degree in the sample culture system; A fumigation system is disposed in the constant temperature box and is connected to the sample culture system through a chloroform pipeline provided with a first electromagnetic valve. Chloroform is provided in the fumigation system and chloroform vapor can be transported to the sample culture system. a gas replacement system, which is connected to the sample culture system via an air pipeline provided with a second solenoid valve and is capable of delivering air into the sample culture system; A tail gas recovery system, connected to the gas outlet of the vacuum pump through a pipeline, for absorbing chloroform after the experiment; The control module is connected to the first solenoid valve, the second solenoid valve, the vacuum control system and the gas replacement system respectively, and can control the start and stop of the first solenoid valve, the second solenoid valve, the vacuum control system and the gas replacement system respectively.

2. The soil microbial biomass cultivation and fumigation device according to claim 1, characterized in that: An electric heating device and a refrigeration device are provided in the constant temperature box, and the electric heating device and the refrigeration device are respectively connected to the control panel. The control panel can adjust the temperature in the constant temperature box to a set value through the electric heating device and the refrigeration device; a visual window is provided on the constant temperature box, a box cover is provided at the visual window, and the side walls and the box cover surfaces of the constant temperature box are provided with an insulation layer, and a shading layer is provided on the outside of the insulation layer.

3. The soil microbial biomass cultivation and fumigation device according to claim 1, characterized in that: The sample culture system comprises a sealable sample chamber, on which a vacuum gauge is provided; a plurality of the sample chambers are fixedly provided in the constant temperature box, and the fumigation system comprises a sealable chloroform chamber, wherein the plurality of the sample chambers are serially connected in sequence through a pipeline provided with a control valve, and the chloroform chamber is connected to one of the sample chambers through a chloroform pipeline provided with a first solenoid valve.

4. The soil microbial biomass cultivation and fumigation device according to claim 1, characterized in that: The control module can control the closing state and closing time of the first solenoid valve and the second solenoid valve respectively through a program.

5. The soil microbial biomass cultivation and fumigation device according to claim 1, characterized in that: The vacuum controller controls the start of the vacuum pump through the vacuum degree range set by the control module. When the vacuum degree in the sample culture system is lower than -0.65MPa, the vacuum pump is started. When the vacuum degree in the sample culture system reaches -0.85MPa, the vacuum pump is turned off.

6. The soil microbial biomass cultivation and fumigation device according to claim 3, characterized in that: It also includes a gas replacement pipeline, one end of which passes through the constant temperature box and is connected to the sample culture system, and the other end of the gas replacement pipeline is connected to the air pipeline and the vacuum pipeline respectively through a three-way valve, and the air outlet of the vacuum pump is externally connected to the exhaust gas recovery system.

7. The soil microbial biomass cultivation and fumigation device according to claim 1, characterized in that: The tail gas recovery system comprises an absorption chamber, in which activated carbon is arranged.

8. The soil microbial biomass cultivation and fumigation device according to claim 1, characterized in that: A vent is provided on the side of the constant temperature box, and a fan is provided at the vent.

9. The soil microbial biomass cultivation and fumigation device according to claim 6, characterized in that: The sample chamber comprises a cavity and a cavity cover, wherein an outer edge is provided at the contact position between the cavity cover and the cavity top, the cavity cover is fixedly buckled on the cavity top, and the contact interface between the cavity cover and the outer edge is sealed with a raised silicone sealing strip; a four-way pipe is connected to the center of the cavity cover, the bottom passage of the four-way pipe is connected to the inside of the cavity cover, the top passage of the four-way pipe is connected to the vacuum gauge, the passage on one side of the four-way pipe is connected to the gas replacement pipeline, the passage on the other side of the four-way pipe is connected to a pressure relief valve, and a valve interface is provided on the side of the cavity, and the valve interface is used to connect the chloroform pipeline or connect the sample chamber in series.

10. The soil microbial biomass cultivation and fumigation device according to claim 3, characterized in that: The chloroform chambers each include a cavity and a cavity cover, wherein the cavity cover is fixedly buckled on the top of the cavity, and the contact interface between the cavity cover and the outer edge is sealed with a raised silicone sealing strip; the cavity cover is provided with an outer edge; a valved interface is provided on the side of the cavity, and the valved interface is used to connect the chloroform pipeline.

Images