A deep-sea sediment enclosure device for in-situ microbial cultivation

Abstract

This invention discloses a deep-sea sediment containment device for in-situ microbial culture. The device includes a containment body, a four-channel balanced timed injection mechanism, a trigger-activated gating mechanism, a PLC control system, an injection needle plate, and a nutrient source chamber, among other core components. During the lowering phase, the injection needle plate penetrates the seabed sediment under gravity. When the sediment surface contacts the trigger ring, the telescopic mechanism is activated, ensuring the injection hole is precisely positioned at a preset depth. During the in-situ experiment, the PLC control system controls the four-channel balanced timed injection mechanism to inject different nutrients into the surface and deep layers of the sediment. The trigger-activated gating mechanism automatically opens to collect samples when the sampling device approaches. After the predetermined culture time, the device releases a counterweight and floats to the surface using the buoyancy of the floating material for recovery.

Description

Technical Field

[0001] This invention relates to the field of deep-sea ecological experimental technology, specifically a deep-sea sediment containment device for in-situ culture of microorganisms. Background Technology

[0002] Deep-sea sediments are the core carriers of the Earth's deep-sea ecosystem, containing the vast majority of marine microbial species. These microorganisms exhibit different metabolic pathways and gene types in different environments, resulting in variations in sediment composition. Therefore, studying the iterative growth of sediment microbial communities can reveal microbial ecological functions and is the best way to explore the origin of species and the evolution of life. Research on deep-sea sediments can also provide a scientific basis for the sustainable development of resources.

[0003] Traditional methods for obtaining and culturing microorganisms in deep-sea sediments involve using equipment such as multi-tube samplers, box samplers, and gravity samplers to acquire samples and then transporting them to the laboratory for cultivation. However, the rapid pressure and temperature changes during sampler ascent can cause the death of some microorganisms in the sediment, and sample contamination from airborne or shipboard microorganisms during transport is difficult to avoid, severely hindering the accuracy of in-situ culture studies. Existing in-situ culture devices generally suffer from a fatal flaw: they typically inject nutrients directly into the overlying water. This method severely disrupts the inherent chemical gradient from the surface to the depths of the sediment, which is crucial for microbial community succession, leading to experimental results that deviate significantly from the natural state. More critically, this injection method causes the dominant microbial species on the sediment surface to proliferate rapidly, forming a "nutrient barrier" that prevents nutrients from penetrating to the deeper layers, ultimately producing distorted results of "eutrophic surface and nutrient-deficient deep layers," fundamentally affecting the scientific value of the experiment.

[0004] Existing devices that inject nutrients into sediments via injection needles typically rely on preset programs or external commands for operation, lacking the ability to adaptively adjust the injection process. Particularly in terms of injection depth control, the inability to achieve real-time monitoring and adjustment via wireless communication makes adjustments difficult once the device is deployed. This can lead to situations where, in complex geological conditions such as uneven sediment density or alternating layers of soft and hard sediments, the injection port may fail to reach the predetermined depth, or the needle may not effectively penetrate the sediment, severely impacting the accuracy and repeatability of the experiment.

[0005] To address the aforementioned issues, some existing technologies have been attempted. For example, patent CN114540178A discloses an intelligent injection device for microbial culture experiments in deep-sea sediments. This device injects culture medium into the sediment through an injection needle. However, the insertion depth of the injection needle is difficult to control, and the insertion process requires driving by other devices, making it impossible to achieve autonomous driving and adaptive adjustment.

[0006] For example, patent CN221326475U discloses a near-shore enclosure experimental system. Although the system can simulate seawater acidification, its application is limited to near-shore areas. It needs to be connected to land equipment through pipelines and cannot adapt to the deep-sea environment. Moreover, the pH adjustment process still requires manual intervention and cannot achieve fully automated control.

[0007] In summary, existing technologies contain a core contradiction that is difficult to reconcile:

[0008] 1. Poor environmental adaptability: Most devices cannot operate stably in the high-pressure environment of the deep sea below 2000 meters, limiting their application scenarios.

[0009] 2. Simulation distortion: The lack of in-situ, controllable stratified injection methods makes it impossible to reproduce the natural vertical distribution characteristics of nutrients in sediments, resulting in "eutrophic surface and undertrophic deep layers," and the experimental results cannot reflect the real ecological process;

[0010] 3. Insufficient precision in controlling sediment injection depth: The lack of closed-loop feedback between the needle length and the actual insertion depth makes it difficult to achieve the preset injection depth in different sediment layers or heterogeneous matrices;

[0011] 4. Insufficient automation and reliability: Critical operations such as opening and closing doors and injecting liquid rely on manual intervention or unreliable mechanical structures, which is not only inefficient but also introduces disturbances, compromising the closed nature of the experiment and the accuracy of the data.

[0012] Therefore, there is an urgent need in this field to develop a deep-sea sediment containment device that can operate in a high-pressure environment in the deep sea, features in-situ precise liquid injection and highly reliable automated control, and can autonomously complete the positioning of injection depth and precise stratified liquid injection, so as to achieve a realistic simulation and accurate revelation of deep-sea ecological processes. Summary of the Invention

[0013] The purpose of this invention is to overcome the shortcomings of the prior art and propose a deep-sea sediment containment device for in-situ microbial culture. This invention addresses the core contradictions in the environmental adaptability, simulation realism, and automation reliability of existing deep-sea containment experimental devices, thereby enabling in-situ, multi-factor, and automated ecological simulation of deep-sea sediments under high-pressure deep-sea conditions.

[0014] To achieve the above objectives, the technical solution specifically adopted by the present invention is as follows:

[0015] A deep-sea sediment containment device for in-situ microbial culture includes a containment body, a liquid injection system, a liquid injection needle plate with depth-adaptive triggering function, a trigger-type gating mechanism, a control system, and a nutrient source chamber.

[0016] The enclosure body is used to insert into deep-sea sediments to form a semi-enclosed experimental area. It includes an enclosure cavity and an installation frame, on which a nutrient source chamber is installed.

[0017] The injection system is used to deliver nutrient solution from the nutrient source chamber to different locations in the experimental area.

[0018] The injection needle plate is positioned at the bottom of the enclosing cavity and is used to deliver nutrient solution into the sediment. It includes a needle plate frame and a trigger-locking mechanism. The needle plate frame is equipped with several injection needles; the trigger-locking mechanism is connected between the injection needle plate and the enclosing body and is configured such that, during the device's penetration into the sediment, when the injection needle plate reaches a preset depth, it is triggered by the sediment surface, thereby releasing the relative fixation between the injection needle plate and the enclosing body, allowing the enclosing body to continue penetrating the sediment relative to the positioned injection needle plate.

[0019] Furthermore, the trigger-locking mechanism includes a trigger ring and a telescopic locking part. The trigger ring is disposed on the bottom side of the needle plate frame, and the telescopic locking part is disposed in the movable cavity of the needle plate frame, having a locked state and an unlocked state. In the locked state, the telescopic locking part fixes the injection needle plate to the surrounding body; when the trigger ring is triggered by the deposit surface and causes displacement, it drives the telescopic locking part to switch from the locked state to the unlocked state.

[0020] Furthermore, the telescopic locking part includes a connecting rod, a telescopic block, and an elastic element. The bottom of the connecting rod is fixedly connected to the trigger ring, and the elastic element keeps the telescopic block extended and inserted into the locking hole on the enclosure cavity to achieve locking. When the trigger ring is displaced, the connecting rod drives the telescopic block to overcome the elastic force of the elastic element and contract, thereby unlocking.

[0021] Furthermore, the outer wall of the needle plate frame is provided with a slider, and the inner wall of the partition cavity is provided with a corresponding groove. After unlocking, the partition body can continue to penetrate along the groove.

[0022] Furthermore, the injection system includes a multi-channel injection mechanism and a guide pipe. The multi-channel injection mechanism includes a peristaltic pump chamber, a multi-channel pump, and a drive motor. The multi-channel pump is integrated on the same drive shaft and is synchronously driven by the drive motor through a coupling. The guide pipe connects the nutrient source chamber to the inlet of the multi-channel pump and guides the multiple outlets connected to the outlet of the multi-channel pump to different injection positions within the experimental area.

[0023] Furthermore, the different injection locations include a first injection port disposed on the inner wall of the enclosure body for injecting liquid into the surface layer of the sediment, and a second injection port disposed on the injection needle for injecting liquid into the deeper layer of the sediment.

[0024] Furthermore, the trigger-type door control mechanism is located at the top opening of the enclosure body and includes a door control cabin, a door body, a door control drive motor, a non-contact sensor, and a controller. The non-contact sensor detects the approach of an external sampling device and generates a trigger signal. The controller then controls the door control drive motor to automatically perform door opening and / or door closing operations based on the signal.

[0025] Furthermore, the door control drive motor drives the door body to move through a bevel gear set and a linkage transmission assembly, and a rotary mechanical seal is provided at the point where the motor shaft passes through the cabin body.

[0026] Furthermore, the nutrient source chamber is divided into multiple independent chambers by partitions for storing different types of experimental liquids, and is equipped with a pressure balance hole that connects to the outside seawater.

[0027] Furthermore, the upper part of the side wall of the enclosure cavity is provided with an exchange hole that allows water exchange but prevents experimental organisms from escaping.

[0028] Furthermore, the main enclosure and each pressure-resistant chamber are made of titanium alloy, and the end caps of each chamber are sealed by a combination of sealing grooves and metal sealing rings.

[0029] Furthermore, the multi-channel pump is a four-channel peristaltic pump, wherein three channel outlets are connected to the injection needle plate, one channel outlet is connected to the injection port on the inner wall of the diaphragm, and the diaphragm is provided with an annular groove for the installation of the guide tube.

[0030] Furthermore, the controller is a programmable logic controller, used to control the injection operation of the injection system according to a preset timing sequence, and to receive sensor signals to control the opening and closing of the door.

[0031] Furthermore, the overall structure and sealing design of the device make it suitable for high-pressure working environments at depths of 2000 meters and above.

[0032] This invention has the following characteristics and beneficial effects:

[0033] 1. Breakthrough in deep-sea environment adaptability bottleneck: Each structure has been pressure-resistant and sealed according to the high-pressure working environment of the deep sea, which can be used to conduct seabed sediment containment experiments at a water depth of less than 2,000 meters, overcoming the limitation that traditional devices cannot be used in the deep sea.

[0034] 2. Adaptive injection function achieved: Through the coordination of the injection needle disc and the telescopic locking part, a depth-triggered mechanism is realized, meaning the device forms a semi-enclosed enclosure only after the injection port reaches the predetermined depth in the sediment. This design cleverly solves the technical problem of uncontrollable insertion depth of the enclosure device into the sediment, making it difficult to ensure that the injection port on the injection needle can be inserted into the sediment to the predetermined depth in each deployment. After deployment, the enclosure device uniformly and regularly injects different types of nutrients into the surface and deep layers of the sediment, thereby maintaining the in-situ natural chemical gradient of the sediment and fundamentally solving the core problem of "rich surface and poor deep layer" caused by existing technologies.

[0035] 3. Highly reliable automated operation is achieved: The trigger-type gate control mechanism can perform stable and reliable door opening and closing operations based on sensor feedback. The entire process requires no manual intervention, avoiding disturbances and ensuring the accuracy of experimental data.

[0036] 4. An intelligent experimental platform has been constructed: the entire device is automatically controlled by a controller, with a high degree of overall automation, which can greatly improve the efficiency and stability of long-term experiments. Attached Figure Description

[0037] Figure 1 is a schematic diagram of a deep-sea sediment containment device for in-situ culture of microorganisms according to an embodiment of the present invention.

[0038] Figure 2 is Figure 1 A schematic diagram of the main structure of the central partition.

[0039] Figure 3 is Figure 1 A schematic diagram of the four-channel balanced timing injection mechanism.

[0040] Figure 4 is Figure 1 A schematic diagram of the structure of the trigger-type gate control mechanism.

[0041] Figure 5 is Figure 1 A schematic diagram of the structure of the trigger-type gating mechanism from another perspective (or in a specific state).

[0042] Figure 6 is a schematic diagram of the controller in an embodiment of the present invention.

[0043] Figure 7 is a schematic diagram of the injection needle disc in an embodiment of the present invention.

[0044] Figure 8 is a schematic diagram of the telescopic locking part in an embodiment of the present invention.

[0045] Figure 9 is a schematic diagram of the injection needle in an embodiment of the present invention.

[0046] Figure 10 is a schematic diagram of the nutrient source chamber in an embodiment of the present invention.

[0047] Figure label:

[0048] 1-Enclosure body, 11-Mounting frame, 12-Enclosure cavity, 121-Annular groove, 122-Exchange hole, 13-Slide groove, 14-Locking hole;

[0049] 2-Multi-channel injection mechanism, 21-Peristaltic pump chamber, 22-Multi-channel pump, 221-Drive shaft, 224-Multi-channel pump inlet, 225-Multi-channel pump outlet, 222-Drive motor, 223-Coupling, 23-Guide pipe;

[0050] 3-Trigger-type gate control mechanism, 31-Gate control cabin, 32-Linkage transmission assembly, 332-Drive connecting rod, 33-Gate control drive motor, 331-Bevel gear set, 34-Non-contact sensor, 35-Rotary mechanical seal;

[0051] 4-Controller, 41-Control Cabin, 42-Programmable Logic Controller, 43-Power Module;

[0052] 5-Injection needle disc, 51-Needle disc frame, 52-Injection needle, 53-Trigger ring, 54-Telescopic locking part, 541-Connecting rod, 542-Telescopic block, 543-Elastic element, 55-Slider;

[0053] 6-Nutrition source compartment, 61-Partition. Detailed Implementation

[0054] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0055] This invention provides a deep-sea sediment containment device for in-situ microbial culture, such as... Figure 1 As shown, the overall structure is a vertical cylindrical shape, mainly consisting of a containment body 1, a multi-channel liquid injection mechanism 2, a trigger-type gating mechanism 3, a controller 4, a liquid injection needle plate 5, and a nutrient source chamber 6. The various functional modules are integrated together through the frame 11 of the containment body 1, forming an integrated experimental platform that can operate autonomously in the high-pressure environment of the deep sea.

[0056] Specifically, such as Figure 2 As shown, the enclosure body 1 is the core support and enclosure structure of the device. Its main body is a cylindrical enclosure cavity 12 made of titanium alloy, which has extremely high strength and corrosion resistance and can withstand the hydrostatic pressure of deep sea water at depths of 2000 meters and above. The lower half of the enclosure cavity 12 is designed to penetrate into the seabed sediment, thereby forming a semi-enclosed physical isolation area in the sediment, i.e., the experimental area.

[0057] Multiple water exchange holes 122 are evenly distributed on the upper part of the side wall of the enclosure 12, and microporous escape-proof nets (not shown separately in the figure) are installed inside the holes. Its function is to allow the water in the enclosure area to slowly exchange with the external marine environment in order to maintain the relative stability of environmental parameters such as temperature and salinity, while effectively preventing the escape of experimental target microorganisms or small organisms and ensuring the closed nature of the experiment.

[0058] An annular groove 121 is machined on the upper part of the inner wall of the septum 12. Its function is to fix and organize the guide tube 23 from the liquid injection mechanism (see Figure 3 On the inner wall of the septum 12, at least two axially arranged sliding grooves 13 are also provided, which interact with the slider 55 on the injection needle plate 5 (see...). Figure 6 In conjunction with the septum 13, its function is to guide the injection needle disc 5 to slide precisely in a straight line relative to the septum 12. In addition, a locking hole 14 is provided on the upper part or at the corresponding position of the septum 13 to lock the injection needle disc 5 during the initial lowering of the device.

[0059] Further settings in this embodiment, such as Figure 7 , Figure 8 and Figure 9 As shown, the injection needle plate 5 is a key component for achieving precise deep injection and depth self-adaptation.

[0060] The injection needle tray 5 includes a disc-shaped needle tray frame 51. Slider blocks 55, matching the septum cavity slide groove 13, are mounted on the circumferential side of the needle tray frame 51, allowing the needle tray frame 51 to slide up and down along the slide groove 13. Multiple hollow injection needles 52 are fixed on the needle tray frame 51. The tip of each injection needle 52 is closed, while an injection hole is formed on the side wall near the tip (see...). Figure 8 The function of this "bottom-sealed, side-opening" design is to effectively prevent sediment from flowing directly into the needle tip opening and blocking the internal flow channel during the process of the needle plate penetrating the sediment, thus ensuring the smooth flow of the injection channel.

[0061] The depth-adaptive triggering mechanism is integrated into the injection needle plate 5 and mainly consists of a trigger ring 53 and a telescopic locking part 54. The trigger ring 53 is connected to the telescopic locking part 54, which is located in the movable cavity inside the needle plate frame 51, via a connecting rod (connecting rod 541 in the figure). The telescopic locking part 54 includes a telescopic block 542 that can move horizontally within the cavity and a spring 543 that provides preload. In its natural state, the spring 543 causes the telescopic block 542 to extend outward, and the locking pin at its end is precisely inserted into the locking hole 14 on the diaphragm cavity 12, thereby rigidly locking the injection needle plate 5 to the diaphragm cavity 12.

[0062] The working principle of the triggering mechanism is as follows: When the device is lowered under the action of counterweight, the injection needle disk 5 first penetrates the sediment. As the penetration deepens, the surface of the sediment eventually contacts and supports the trigger ring 53 located in the lower part of the injection needle 52. As the containment body 1 continues to descend under the action of gravity, the trigger ring 53 is displaced upward relative to the descending containment cavity 12. This displacement is transmitted to the telescopic block 542 through the connecting rod 541. The telescopic block 542 has an oblique groove on its side, and the protrusion at the top of the connecting rod 541 slides in this groove. When the connecting rod 541 is pushed upward, the oblique action forces the telescopic block 542 to retract towards the center against the elastic force of the spring 543, causing its locking pin to disengage from the locking hole 14. At this point, the locking state is released, the injection needle disk 5 stops at its current position due to being blocked by the sediment (i.e., the injection hole reaches the preset depth), and the containment cavity 12 can continue to slide down the slide groove 13 relative to the fixed needle disk until it is inserted into the sediment to form a stable containment area. This mechanism ensures that the injection depth is independent of the final penetration depth of the entire device, achieving adaptive and precise positioning.

[0063] In this embodiment, it should be further explained that the injection needles on the injection needle plate 5 are of different lengths, so that nutrients can be delivered into the sediment at different depths at will.

[0064] Furthermore, such as Figure 3 As shown, this mechanism is responsible for transporting nutrients from the storage chamber to the target location. Its core is a multi-channel pump 22 installed within the peristaltic pump chamber 21. The rotors of the four pump channels are integrated onto the same drive shaft 221. The drive motor 222 directly drives this drive shaft 221 via a coupling 223. This "one shaft, multiple pumps, single motor drive" design ensures that the pumping actions of the four channels are strictly synchronized. Mechanically, this guarantees a highly balanced and consistent instantaneous flow rate and cumulative flow of nutrient solution delivered to different injection points, completely solving the problem of unavoidable flow rate differences inherent in multi-channel independent pumping.

[0065] One end of the guide pipe 23 is connected to the outlet of each independent chamber of the nutrient source chamber 6, and the other end is connected to the feed port 224 of the multi-channel pump. The discharge port 225 of the multi-channel pump branches into four guide pipes. One guide pipe is laid along the annular groove 121 on the inner wall of the enclosure chamber 12, and its end opens at the upper part of the inner wall of the enclosure chamber, serving as the first injection port, which is used to inject nutrients into the surface water or surface sediment. The other three guide pipes are connected downward to the injection needle plate 5 and are respectively connected to the pipelines of the three injection needles 52, serving as the second injection port, which is used to directly inject nutrients into the target depth of the middle and deep layers of the sediment.

[0066] Furthermore, such as Figure 4 and Figure 5As shown, the mechanism is installed on the top of the enclosure body 1 and is used to automatically open the channel when sampling is required.

[0067] The mechanism includes a pressure-resistant door-controlled compartment 31. A door-controlled drive motor 33 is installed inside the compartment. The output shaft of the motor 33 changes the transmission direction via a pair of bevel gears 331, driving a transverse drive linkage 332 to rotate. The drive linkage 332 then converts the rotational motion into the lifting or rotating motion of the top door through a linkage transmission assembly 32, thereby realizing the opening and closing of the top of the enclosed area.

[0068] An ultrasonic sensor 34 is installed on the gated enclosure 31. Its function is to monitor obstacles within a predetermined range on top of the device in a non-contact manner. When an underwater robot (ROV) carrying a sampler or other sampling device approaches to a preset distance, the sensor 34 generates a trigger signal.

[0069] A rotary mechanical seal 35 (which may be a combination of a silicon carbide rotating ring and a graphite stationary ring) is installed at the location where the motor shaft passes through the bulkhead. Its function is to ensure that the interior of the bulkhead maintains a reliable static seal while the motor shaft is rotating, preventing the intrusion of high-pressure seawater.

[0070] The function of this facility is to achieve fully automated sampling channel management without human interference. It will only be activated briefly when a legitimate sampling device is detected, thus maintaining the stability of the enclosure environment during the experiment to the greatest extent possible.

[0071] Furthermore, such as Figure 6 As shown, controller 4 is the "brain" of the entire device. Its control compartment 41 houses a programmable logic controller 42 (PLC) and a power module 43 (such as a high-voltage battery pack). The PLC 42 is connected to all electrical components, such as drive motor 222, gate drive motor 33, and ultrasonic sensor 34, via high-voltage cables.

[0072] Its control logic functions mainly include:

[0073] Injection program control: According to the preset experimental plan (such as injection start delay time, single injection duration, injection interval period), start and stop commands are sent to drive motor 222 at regular intervals to control the injection process.

[0074] Door control response: Receives signals from the ultrasonic sensor 34 in real time. When the signal indicates that the sampling device is approaching, immediately sends a "forward" command to the door drive motor 33 to open the door; after the sensor signal disappears (indicating that the sampling device has left) and a preset safety time is delayed, sends a "reverse" command to the motor to close the door.

[0075] Status monitoring and recovery control: It can monitor the system status and execute the recovery sequence at the end of the experiment, such as controlling the electromagnetic lock that releases the counterweight.

[0076] Furthermore, such as Figure 10 As shown, the nutrient source chamber 6 is divided into multiple (e.g., four) independent chambers by vertical partitions 61. Their function is to store different types of nutrients or experimental liquids, such as different carbon sources, nitrogen sources, electron acceptors, or specific inhibitors, to meet the needs of multi-factor coupling experiments.

[0077] Understandably, each independent chamber is divided into two chambers by an elastic membrane. One chamber stores the nutrient solution, and the other chamber is connected to the outside seawater through the pressure balance hole 62.

[0078] This embodiment is combined with the appendix Figure 1-10 The complete experimental procedure of this device is as follows:

[0079] Preparation and Decentralization Phase

[0080] Before the experiment, nutrient solution was filled into each chamber of the nutrient source chamber 6 according to the design, and the seals of all chambers (peristaltic pump chamber 21, gate control chamber 31, control chamber 41, and nutrient source chamber 6) were checked for integrity. The configuration of buoyancy materials and counterweights was adjusted using the mounting frame 11 to ensure the device as a whole exhibited appropriate negative buoyancy. The device was lowered using a ship-borne winch and release device. Under gravity, the injection needle disk 5 first contacted and penetrated the seabed sediment. During penetration, the trigger ring 53 was triggered by the sediment surface, and the telescopic locking part 54 actuated, releasing the lock between the needle disk and the enclosure chamber 12. The enclosure chamber 12 then continued to slide down the chute 13 under its own weight, inserting into the sediment until it reached a stable position, forming a semi-enclosed experimental area surrounded by sediment at the bottom and sides, open at the top, and with the upper side able to exchange water with the outside. At this point, the injection hole on the injection needle 52 was precisely located at the preset sediment depth.

[0081] In situ culture and experimental stage

[0082] After the device is in place, controller 4 begins operation. It first enters a preset "environmental recovery period" to allow the sediment disturbance caused by the device's penetration to subside naturally. After the recovery period, PLC 42 initiates the injection cycle according to the program: powering the drive motor 222 to drive the multi-channel pump 22 to operate synchronously, pumping different nutrient solutions from each chamber in the nutrient source chamber 6 evenly through the guide pipe 23 to the injection port on the surface of the enclosure cavity and the deep injection port of the injection needle 52, achieving stratified, timed in-situ nutrient addition. After injection is complete, the system enters a sleep state until the next injection cycle.

[0083] When sampling is required, the ROV carrying the sampler approaches the top of the enclosure. The ultrasonic sensor 34 detects the ROV entering its sensing range and immediately sends a signal to the PLC 42. The PLC 42 then drives the gate drive motor 33, which opens the top door via bevel gear 331 and connecting rod 32. The ROV performs in-situ sampling and then withdraws. Once the sensor 34 signal disappears, after a short delay, the PLC 42 controls the motor 33 to reverse, closing the door and restoring the enclosure to its closed state.

[0084] recycling phase

[0085] Upon completion of the scheduled experiment or receipt of a recovery command, controller 4 executes the recovery procedure. First, all liquid injection and gating operations are stopped. Then, the control release mechanism (such as an electromagnetic lock) releases the counterweight. After losing the counterweight, the device slowly and steadily rises to the sea surface automatically under the positive buoyancy provided by the buoyancy material, where it is recovered by personnel. After recovery, sediment samples can be obtained by opening the chamber, experimental log data stored in the PLC can be downloaded, and the device can be maintained for future use.

[0086] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A deep-sea sediment enclosure device for in-situ cultivation of microorganisms, an enclosure body (1) for insertion into deep-sea sediments to form a semi-closed experimental area; the enclosure body (1) comprising an enclosure cavity (12) and a mounting rack (11) on which a nutrient source tank (6) is mounted, characterized in that, Also includes: The nutrient solution injection system is used to deliver the nutrient solution in the nutrient source chamber (6) to the experimental area; A liquid injection needle plate (5) with depth adaptive triggering function is used to deliver nutrient solution to the experimental area inside the deep-sea sediment and is disposed at the bottom of the enclosed cavity (12); The injection system includes a multi-channel injection mechanism (2) and several guide tubes (23). The multi-channel injection mechanism (2) includes a peristaltic pump chamber (21) mounted on a mounting frame (11) and a multi-channel pump (22) and a drive motor (222) disposed in the peristaltic pump chamber (21). The multi-channel pump (22) is provided with a drive shaft (221). The output end of the drive motor (222) is connected to the drive shaft (221) through a coupling (223). The multi-channel pump (22) is connected to the multi-channel pump inlet (224) and the nutrient source chamber (6) through the guide pipe (23). The multi-channel pump (22) is connected to the guide pipe (23) through the multi-channel pump outlet (225), and the outlets of the multiple guide pipes (23) are respectively guided to different injection positions in the experimental area; The different injection locations include a first injection port for injecting liquid into the surface layer of sediments, which is set on the inner wall of the enclosure body (1), and a second injection port for injecting liquid into the deep layer of sediments, which is set on the injection needle (52) of the injection needle plate (5). The injection needle plate (5) includes: The needle plate frame (51) and the trigger-locking mechanism are provided with a plurality of injection needles (52) for injecting liquid into the sediment. The outer wall of the needle plate frame (51) is provided with several sliders (55), and the inner wall of the enclosure cavity (12) is provided with a groove (13) corresponding to the sliders (55). When the locking pin disengages from the locking hole to unlock, the enclosure body (1) is allowed to continue to penetrate the deposit relative to the positioned injection needle plate (5). The trigger-locking mechanism is connected between the injection needle plate (5) and the enclosure body (1); The trigger-locking mechanism includes a trigger ring (53) and a telescopic locking part (54); the trigger ring (53) is disposed on the bottom side of the needle plate frame (51); the needle plate frame (51) has a movable cavity, and the telescopic locking part (54) is disposed in the movable cavity. The telescopic locking part (54) is connected to the trigger ring (53) and has a locked state and an unlocked state; in the locked state, the telescopic locking part (54) fixes the injection needle plate (5) to the enclosure body (1); when the trigger ring (53) is triggered by the surface of the deposit and causes displacement, the telescopic locking part (54) is driven to switch from the locked state to the unlocked state. The telescopic locking part (54) includes a connecting rod (541), a telescopic block (542), and an elastic element (543). The bottom of the connecting rod (541) is fixedly connected to the trigger ring (53). One end of the elastic element (543) is fixedly connected to the inner wall of the movable cavity, and the other end of the elastic element (543) is fixedly connected to one side of the telescopic block (542). A locking post extending to the outside of the needle plate frame (51) is provided on the other side of the telescopic block (542), and the inner wall of the enclosure cavity (12) is correspondingly locked. The column is provided with a locking hole (14). The telescopic block (542) is normally extended under the action of the elastic element (543) to be inserted into the corresponding locking hole (14) to achieve locking. The side wall of the telescopic block (542) is provided with an inclined groove. The top of the connecting rod (541) is provided with a displacement block that slides into the inclined groove. The displacement of the trigger ring (53) drives the telescopic block (542) to overcome the elastic force of the elastic element (543) and contract through the connecting rod (541), so that the locking column disengages from the locking hole to achieve unlocking. The trigger-locking mechanism is configured such that, during the process of the device being lowered into the sediment, when the injection needle plate (5) reaches a preset depth, it is triggered by the sediment surface, thereby releasing the relative fixation between the injection needle plate (5) and the enclosure body (1), allowing the enclosure body (1) to continue penetrating the sediment relative to the positioned injection needle plate (5), so as to deliver nutrient solution to the experimental area inside the deep-sea sediment.

2. The deep-sea sediment containment device for in-situ microbial culture according to claim 1, characterized in that, It also includes a trigger-type gate control mechanism (3), which is disposed at the top opening of the enclosure body (1). The trigger-type gate control mechanism (3) includes a gate control cabin (31) mounted on a mounting frame (11) and a door body disposed at the top of the enclosure cavity (12). The trigger-type gate control mechanism (3) also includes a door body disposed within the gate control cabin (31). A door control drive motor (33) is used to drive the door to open or close; A non-contact sensor (34) is used to detect the proximity of an external sampling device and generate a trigger signal; The controller (4), which is signal-connected to the non-contact sensor (34) and the door drive motor (33), is configured to control the door drive motor (33) to automatically perform door opening and / or door closing operations according to the trigger signal.

3. A deep-sea sediment containment device for in-situ microbial culture according to claim 2, characterized in that, The door control cabin (31) is provided with a horizontally arranged drive linkage rod (332). The two ends of the drive linkage rod (332) are transmitted to the door body through the linkage transmission assembly (32). A bevel gear set (331) is provided between the output shaft of the door control drive motor (33) and the drive linkage rod (332). A rotary mechanical seal (35) is provided at the penetration point between the drive linkage rod (332) of the door control drive motor (33) and the cabin body.

4. A deep-sea sediment containment device for in-situ microbial culture according to claim 1, characterized in that, It also includes a nutrient source chamber (6), which is divided into multiple independent chambers by partitions (61) for storing different types of experimental liquids.

5. A deep-sea sediment containment device for in-situ microbial culture according to claim 1, characterized in that, The upper side wall of the enclosure (12) is provided with an exchange hole (122) that allows water exchange but prevents experimental organisms from escaping.

6. A deep-sea sediment containment device for in-situ microbial culture according to claim 1, characterized in that, The enclosure body (1) and each pressure chamber of the device are made of titanium alloy, and the end caps of each chamber are sealed by a combination of sealing groove and metal sealing ring.

7. A deep-sea sediment containment device for in-situ microbial culture according to claim 1, characterized in that, The multi-channel pump (22) is a four-channel peristaltic pump. The guide tube (23) connects the outlets of three channels to the injection needle plate (5) and the outlet of one channel to the injection port on the inner wall of the diaphragm cavity (12). The diaphragm cavity (12) is provided with an annular groove (121) for the guide tube (23) to be installed.

8. A deep-sea sediment containment device for in-situ microbial culture according to claim 2, characterized in that, The controller (4) is a PLC programmable logic controller, configured to control the injection operation of the injection system according to a preset timing sequence, and to receive sensor signals from the trigger-type gate control mechanism (3) to control the opening and closing of the gate.

9. A deep-sea sediment containment device for in-situ microbial culture according to any one of claims 1-8, characterized in that, The overall structure and sealing design of the device make it suitable for deep-sea high-pressure working environments at depths of 2000 meters and above.

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