Device and method for simulating diffusion of floating microorganisms in river

Abstract

The invention discloses a river planktonic microbiological diffusion simulation device and method, and belongs to the technical field of environmental science and ecology experiment devices.The river planktonic microbiological diffusion simulation device comprises a bottom plate, a plurality of plaque units are arranged on the bottom plate at equal intervals, every two adjacent plaque units communicate with each other, filter membrane assemblies are arranged in the plaque units, and a top plate is fixedly connected to the top face of the bottom plate; the top plate is provided with a driving mechanism, the driving mechanism is in transmission connection with a plurality of stirring mechanisms, the stirring mechanisms are located below the top plate, the stirring mechanisms are located above the plaque unit, and a monitoring mechanism is arranged outside the plaque unit. Through gradient diffusion frequency control, natural source heterogeneous plaque construction and precise environmental parameter maintenance, quantitative simulation of the diffusion process of the river microorganisms indoors is realized, and the action mechanism of different diffusion intensities on formation and maintenance of species diversity can be effectively analyzed; and a key technical support is provided for research on ecological hydrology and microbial community dynamics.

Description

Technical Field

[0001] This invention belongs to the technical field of experimental devices for environmental science and ecology, and particularly relates to a device and method for simulating the diffusion of river planktonic microorganisms. Background Technology

[0002] River ecosystems, as vital links connecting land and sea, directly impact global water cycles, material and energy flows, and biodiversity maintenance. Planktonic microorganisms, as a core component of river ecosystems, play an irreplaceable role in key ecological processes such as carbon cycling, pollutant degradation, and nutrient transformation. However, traditional research methods struggle to accurately elucidate the diffusion mechanisms and community building patterns of planktonic microorganisms in complex river environments. This has made the development of river planktonic microorganism diffusion simulation devices an important research direction in ecology and environmental science. River planktonic microorganism diffusion simulation devices typically consist of four core components: a patch unit array, a connecting pipeline system, a diffusion control module, and an environmental regulation unit.

[0003] Currently, there are two major technical bottlenecks in the device for simulating the diffusion of planktonic microorganisms:

[0004] 1. Insufficient precision in diffusion frequency control: Existing devices mostly use fixed-frequency diffusion or qualitative simulation, which cannot quantify the impact of gradient diffusion intensity on community dynamics;

[0005] 2. Lack of authenticity of heterogeneous patches: Artificially constructed communities cannot reproduce the differences in microbial species composition and function in natural water bodies, leading to experimental conclusions that deviate from actual ecological processes. Summary of the Invention

[0006] The purpose of this invention is to provide a device and method for simulating the diffusion of river planktonic microorganisms, in order to solve the problems existing in the prior art.

[0007] To achieve the above objectives, the present invention provides the following solution: The present invention provides a river planktonic microorganism diffusion simulation device, including a base plate, on which multiple groups of patch units are equally spaced, adjacent groups of patch units are interconnected, each patch unit contains a filter membrane assembly, a top plate is fixedly connected to the top surface of the base plate, a driving mechanism is provided on the top plate, the driving mechanism is drivenly connected to multiple stirring mechanisms, the stirring mechanisms are located below the top plate and above the patch units, and a monitoring mechanism is provided outside the patch units.

[0008] Optionally, the base plate is provided with a plurality of grooves at equal intervals, the patch unit includes experimental containers symmetrically arranged in the grooves, two experimental containers in the same patch unit are connected by a first connecting pipe, and experimental containers in adjacent patch units are connected by a second connecting pipe, and the filter membrane assembly is provided at both ends of the first connecting pipe and the second connecting pipe respectively.

[0009] Optionally, the filter membrane assembly includes a polyethersulfone filter membrane that is in communication with the first connecting tube and the second connecting tube respectively, and the polyethersulfone filter membrane is connected to the inner wall of the experimental container.

[0010] Optionally, the polyethersulfone filter membrane has a pore size of 0.45 μm.

[0011] Optionally, a first connecting post is fixedly connected to each of the four corners of the top surface of the base plate, and the top plate is fixedly connected to the top surface of the first connecting post. The driving mechanism includes a first electric telescopic rod fixedly connected to the top surface of the top plate. The output shaft of the first electric telescopic rod is fixedly connected to a first connecting plate. A second connecting post is fixedly connected to each of the four corners of the bottom surface of the first connecting plate. The top plate is provided with a plurality of first through holes. The second connecting post passes through the first through holes and is fixedly connected to the second connecting plate. The second connecting plate is located below the base plate, and the stirring mechanism is fixedly connected to the bottom surface of the second connecting plate.

[0012] Optionally, the stirring mechanism includes a first motor fixed to the bottom surface of the second connecting plate. The first motor is located above the experimental container. The output shaft of the first motor is fixed to a first connecting shaft. The bottom surface of the first connecting shaft is fixed to a first connecting seat. The bottom surface of the first connecting seat is fixed to a stirring component.

[0013] Optionally, the stirring component includes a plurality of stirring blocks that are fixed at equal intervals to the bottom surface of the first connecting seat.

[0014] Optionally, the monitoring mechanism includes a second electrically operated telescopic rod fixed to the outside of the experimental container, the second electrically operated telescopic rod being fixed to the top surface of the base plate, and a monitoring camera being installed on the top surface of the second electrically operated telescopic rod.

[0015] A method for using a river planktonic microbial diffusion simulation device includes the following steps:

[0016] S1. Constructing heterogeneous patches: Screening native microbial communities in natural paddy field water bodies, grouping them according to richness gradients, and filling them into patch units;

[0017] S2. Set diffusion frequency: Drive the stirring mechanism through the timer controller to perform diffusion operations in gradients of 0, 1, 3, 6, 15, and 30 times / day, with each stirring lasting 15 seconds and followed by 60 seconds of stillness.

[0018] S3. Dynamic monitoring: Starting from the second day of cultivation, the conditions inside the experimental container are observed through a monitoring camera. 2 mL of samples are taken daily for microscopic examination to identify species composition and calculate richness, diversity index and cross-patch migration rate.

[0019] Optionally, the patch units described in step S1 are configured according to the source-collection community model, divided into 5 paddy field ecosystems, with 2 parallel patches in each system. The community species richness is divided into 3 gradients: low, medium, and high. Patches with the same richness share ≤50% of the species.

[0020] This invention discloses the following technical effects: a base plate supports a patch unit array, and a top plate integrates a drive mechanism to control the stirring mechanism, achieving cross-patch diffusion regulation. This constructs a scalable river habitat simulation platform that supports flexible configuration of the number and connection methods of patches. Through gradient diffusion frequency control, construction of naturally sourced heterogeneous patches, and precise maintenance of environmental parameters, this invention achieves quantitative simulation of river microbial diffusion processes indoors. It can effectively analyze the mechanisms by which different diffusion intensities affect the formation and maintenance of species diversity, providing key technical support for ecohydrological and microbial community dynamics research. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0022] Figure 1 This is a schematic diagram of the structure of the river planktonic microbial diffusion simulation device of the present invention;

[0023] Figure 2 This is a front view of the river planktonic microbial diffusion simulation device of the present invention.

[0024] In the diagram: 1. Base plate; 2. Top plate; 3. Groove; 4. Experimental container; 5. First connecting pipe; 6. Second connecting pipe; 7. First connecting column; 8. First electric telescopic rod; 9. First connecting plate; 10. Second connecting column; 11. First through hole; 12. Second connecting plate; 13. First motor; 14. First connecting shaft; 15. First connecting seat; 16. Stirring block; 17. Second electric telescopic rod; 18. Monitoring camera. Detailed Implementation

[0025] River ecosystems, as vital links connecting land and ocean, directly impact global water cycles, material and energy flows, and biodiversity maintenance. Planktonic microorganisms, as a core component of river ecosystems, play an irreplaceable role in key ecological processes such as carbon cycling, pollutant degradation, and nutrient transformation. However, traditional research methods struggle to accurately elucidate the dispersal mechanisms and community building patterns of planktonic microorganisms in complex river environments. This has made the development of river planktonic microorganism dispersal simulation devices an important research direction in ecology and environmental science.

[0026] Modern river planktonic microbiota diffusion simulation devices typically consist of four core components: patch unit arrays, connecting pipeline systems, diffusion control modules, and environmental regulation units. As the basic unit for simulating habitats, the patch unit's design must balance habitat heterogeneity and experimental reproducibility. Traditional patch units often use homogeneous glass containers, while modern devices incorporate adjustable substrate modules and dynamic culture medium supply systems, enabling continuous regulation from homogeneous to heterogeneous habitats.

[0027] Connecting pipeline systems serve as channels for material exchange between plaque units, and their design must balance material exchange efficiency with biosecurity requirements. Traditional systems often employ fixed-pore-size filter membranes for bioretention, while modern devices introduce electroporous filter membranes and intelligent valve systems, enabling dynamic adjustment of membrane pore size and reconfigurable connection topology. This design allows researchers to simulate different connectivity patterns, from linear rivers to complex river networks, and analyze the impact of network topology on microbial dispersal.

[0028] As the core operating unit of the simulation device, the diffusion control module's performance directly affects the simulation accuracy of the diffusion process. Traditional devices often use mechanical stirring to achieve diffusion control, while modern devices introduce a precise stirring system driven by a stepper motor and microfluidic chip technology. By precisely controlling the stirring speed, direction, and frequency, researchers can simulate different flow field environments from laminar to turbulent flow and analyze the impact of flow field characteristics on microbial diffusion.

[0029] As a key component for maintaining experimental stability, the environmental control unit must be designed to precisely control multiple environmental parameters, including temperature, dissolved oxygen, and pH. Traditional systems often employ passive temperature control devices, while modern systems incorporate PID controllers and IoT communication modules, enabling remote real-time control and automatic feedback optimization of environmental parameters. This design allows researchers to simulate diverse environmental conditions, from temperate to tropical rivers, and analyze the impact of environmental heterogeneity on microbial dispersal.

[0030] With continuous technological breakthroughs and theoretical advancements, river planktonic microbial diffusion simulation devices will play an increasingly important role in river ecological protection, water environment management, and biodiversity maintenance. By accurately simulating microbial diffusion processes, researchers can gain a deeper understanding of the structural-functional relationships of ecosystems, predict the ecological effects of environmental changes, and provide solid support for formulating scientifically sound ecological management strategies. The development and application of such devices not only promote the advancement of ecology and environmental science but also provide crucial technological safeguards for global water ecological security and sustainable development.

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Reference Figures 1 to 2 As shown, this embodiment provides a river planktonic microbial diffusion simulation device, including a base plate 1, on which multiple groups of patch units are equally spaced, and adjacent groups of patch units are interconnected. A filter membrane assembly is provided inside the patch unit. A top plate 2 is fixed to the top surface of the base plate 1, and a driving mechanism is provided on the top plate 2. The driving mechanism is connected to multiple stirring mechanisms, which are located below the top plate 2 and above the patch units. A monitoring mechanism is provided outside the patch units.

[0034] A base plate 1 supports an array of patch units, while a top plate 2 integrates a drive mechanism to control a stirring mechanism, enabling cross-patch diffusion regulation and constructing a scalable river habitat simulation platform that supports flexible configuration of the number and connection methods of patches. This invention achieves quantitative simulation of river microbial diffusion processes indoors through gradient diffusion frequency control, construction of naturally sourced heterogeneous patches, and precise maintenance of environmental parameters. It can effectively analyze the mechanisms by which different diffusion intensities affect the formation and maintenance of species diversity, providing key technical support for ecohydrological and microbial community dynamics research.

[0035] Further optimization of the design involves multiple equally spaced grooves 3 on the base plate 1. Each plaque unit includes experimental containers 4 symmetrically arranged within the grooves 3. Two experimental containers 4 within the same plaque unit are connected by a first connecting pipe 5, and experimental containers 4 in adjacent plaque units are connected by a second connecting pipe 6. Filter membrane assemblies are respectively installed at both ends of the first connecting pipe 5 and the second connecting pipe 6. The second connecting pipe 6 is a sterile silicone tube of equal length (5mm inner diameter, 20cm length) that connects to the bottom of adjacent plaque units.

[0036] The groove 3 positions the experimental container 4, and the first connecting pipe 5 and the second connecting pipe 6 enable intra-patch / cross-patch liquid communication. This achieves the synergistic simulation of the homogeneous environment within a patch and the heterogeneous environment between patches, allowing for precise control of microbial migration pathways. The experimental container 4 is a 5L glass beaker with a smooth inner wall and is sterilized. BG11 culture medium (pH 7.5±0.2, light intensity 50μmol·m⁻²·s⁻¹, temperature 25±1℃) is filled into the experimental container 4. Culture medium: BG11 (NaNO3 1.5g / L, K₂HPO₄ 40mg / L), aeration rate 0.5L·min⁻¹, light intensity 12h / d.

[0037] The scheme is further optimized so that the filter membrane assembly includes a polyethersulfone filter membrane that is connected to the first connecting pipe 5 and the second connecting pipe 6 respectively, and the polyethersulfone filter membrane is connected to the inner wall of the experimental container 4.

[0038] Further optimization of the design resulted in a polyethersulfone filter membrane with a pore size of 0.45 μm.

[0039] Polyethersulfone (PES) filter membranes physically trap microorganisms while allowing the diffusion of nutrients / signal molecules. With a pore size ≤ microbial cell size, they prevent nitrogen-fixing cyanobacteria from migrating across patches, allow solute exchange in the culture medium, maintain species isolation, and enable gradient diffusion of metabolites.

[0040] In a further optimized design, a first connecting column 7 is fixedly connected to the four corners of the top surface of the base plate 1, and a top plate 2 is fixedly connected to the top surface of the first connecting column 7. The driving mechanism includes a first electric telescopic rod 8 fixedly connected to the top surface of the top plate 2. The output shaft of the first electric telescopic rod 8 is fixedly connected to a first connecting plate 9. A second connecting column 10 is fixedly connected to the four corners of the bottom surface of the first connecting plate 9. The top plate 2 is provided with a plurality of first through holes 11. The second connecting column 10 passes through the first through holes 11 and is fixedly connected to a second connecting plate 12. The second connecting plate 12 is located below the base plate 1, and a stirring mechanism is fixedly connected to the bottom surface of the second connecting plate 12.

[0041] The first electric telescopic rod 8 drives the first connecting plate 9 and the second connecting plate 12 to move vertically, thereby raising and lowering the stirring mechanism and achieving precise alignment between the stirring mechanism and the experimental container 4. This supports synchronous / asynchronous stirring control for multiple patches. Six diffusion frequencies (0, 1, 3, 6, 15, 30 times / day) are achieved through a timer controller, with each operation lasting 1 minute (including stirring and settling).

[0042] The scheme is further optimized. The stirring mechanism includes a first motor 13 fixed to the bottom surface of the second connecting plate 12. The first motor 13 is located above the experimental container 4. The output shaft of the first motor 13 is fixed to a first connecting shaft 14. The bottom surface of the first connecting shaft 14 is fixed to a first connecting seat 15. The bottom surface of the first connecting seat 15 is fixed to a stirring component.

[0043] The design is further optimized so that the mixing component includes multiple mixing blocks 16 that are fixed at equal intervals to the bottom surface of the first connecting seat 15.

[0044] The first motor 13 drives the first connecting shaft 14 to rotate, and the stirring component generates directional water flow to simulate the disturbance effect of river turbulence on the diffusion of microorganisms. The equally spaced stirring blocks 16 form a turbulent field to promote mixing, enhance diffusion efficiency, and avoid simulation distortion caused by local dead zones.

[0045] The scheme is further optimized. The monitoring mechanism includes a second electric telescopic rod 17 fixed to the outside of the experimental container 4. The second electric telescopic rod 17 is fixed to the top surface of the base plate 1. A monitoring camera 18 is installed on the top surface of the second electric telescopic rod 17.

[0046] The monitoring camera 18 collects real-time images of the community's dynamics, enabling non-invasive in-situ observation and behavioral analysis of the diffusion process.

[0047] A method for using a river planktonic microbial diffusion simulation device includes the following steps:

[0048] S1. Constructing heterogeneous patches: Screening native microbial communities from natural paddy field water bodies, grouping them according to richness gradients, and filling them into patch units; numbering multiple groups of patch units a1-a2, b1-b2, c1-c2, d1-d2, e1-e2 (representing 5 paddy field ecosystems, 2 parallels per system), low richness (3 groups): communities a1, a2, b1, b2, 5-10 species (screened from natural paddy field water bodies, with Anabaena as the dominant species); medium richness (3 groups): communities c1, c2, d1, d2, 10-20 species (with additional Nostoc and Oscillatoria); high richness (4 groups): communities e1, e2 (4 patches in total, satisfying 5 systems × 2 parallels), >20 species (including rare groups such as Microcystis); the common species in patches of the same richness are ≤50% (verified by DGGE fingerprinting), ensuring significant differences in species composition.

[0049] S2. Set diffusion frequency: Drive the stirring mechanism through the timer controller to perform diffusion operations in gradients of 0, 1, 3, 6, 15, and 30 times / day, with each stirring lasting 15 seconds and followed by 60 seconds of stillness.

[0050] Definition of diffusion frequency: The duration of a single diffusion event per unit time (day), which is 1 minute (inclusive).

[0051] ① Remove the polyethersulfone filter membrane (using sterile forceps);

[0052] ② Stir the agitator clockwise at a constant speed for 15 seconds (50 rpm, to avoid eddy current disturbance).

[0053] ③ Let stand for 60 seconds (to allow the particles to settle);

[0054] ④ Reattach the polyethersulfone filter membrane (seal the edges to prevent leakage of the culture medium).

[0055] S3. Dynamic monitoring: Starting from the second day of cultivation, the contents of the experimental container 4 were observed through the monitoring camera 18. 2 mL samples were taken daily for microscopic examination to identify species composition and to calculate richness, diversity index and cross-patch migration rate.

[0056] Sampling was conducted daily at 12:00 (to avoid photoperiod interference). Samples were taken from two different sites using a 1 mL sterile pipette to avoid spatial heterogeneity errors. The samples were then counted under a microscope (10× objective lens, 25-grid counting chamber) and the diversity index was calculated.

[0057] Detection parameters:

[0058] Species richness (microscopic count, number of species / 500μL);

[0059] Community structure (Shannon-Wiener diversity index, Pielou evenness);

[0060] Diffusion efficiency (cross-patch species migration rate = number of species shared by adjacent patches / total number of species in donor patches).

[0061] Further optimize the scheme. In step S1, the patch units are configured according to the source-collection community model, divided into 5 paddy field ecosystems. Each system has 2 parallel patches. The community species richness is divided into 3 gradients: low, medium and high. Patches with the same richness share ≤50% of the species.

[0062] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0063] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A device for simulating the diffusion of river planktonic microorganisms, characterized in that it comprises: Includes a base plate (1), on which multiple groups of patch units are equally spaced, and adjacent groups of patch units are interconnected. Each patch unit contains a filter membrane assembly. A top plate (2) is fixed to the top surface of the base plate (1). A driving mechanism is provided on the top plate (2). The driving mechanism is connected to multiple stirring mechanisms. The stirring mechanisms are located below the top plate (2) and above the patch units. A monitoring mechanism is provided outside the patch units.

2. The riverine planktonic microbe dispersion simulation apparatus of claim 1, wherein: The base plate (1) is provided with a plurality of grooves (3) at equal intervals. The patch unit includes experimental containers (4) symmetrically arranged in the grooves (3). Two experimental containers (4) in the same patch unit are connected by a first connecting pipe (5). The experimental containers (4) in adjacent patch units are connected by a second connecting pipe (6). The filter membrane assembly is provided at both ends of the first connecting pipe (5) and the second connecting pipe (6).

3. The riverine planktonic microbe dispersion simulation apparatus of claim 2, wherein: The filter membrane assembly includes a polyethersulfone filter membrane that is connected to the first connecting tube (5) and the second connecting tube (6) respectively, and the polyethersulfone filter membrane is connected to the inner wall of the experimental container (4).

4. The riverine planktonic microbe dispersal simulation apparatus of claim 3, wherein: The polyethersulfone filter membrane has a pore size of 0.45 μm.

5. The riverine planktonic microbe dispersal simulation apparatus of claim 2, wherein: The top surface of the base plate (1) is fixedly connected to the four corners of the top surface of the base plate (1), and the top plate (2) is fixedly connected to the top surface of the first connecting column (7). The driving mechanism includes a first electric telescopic rod (8) fixedly connected to the top surface of the top plate (2). The output shaft of the first electric telescopic rod (8) is fixedly connected to a first connecting plate (9). The bottom surface of the first connecting plate (9) is fixedly connected to the four corners of the bottom surface of the first connecting plate (9). The top plate (2) is provided with a plurality of first through holes (11). The second connecting column (10) passes through the first through hole (11) and is fixedly connected to a second connecting plate (12). The second connecting plate (12) is located below the base plate (1). The stirring mechanism is fixedly connected to the bottom surface of the second connecting plate (12).

6. The riverine planktonic microbe dispersal simulation apparatus of claim 5, wherein: The stirring mechanism includes a first motor (13) fixed to the bottom surface of the second connecting plate (12). The first motor (13) is located above the experimental container (4). The output shaft of the first motor (13) is fixed to a first connecting shaft (14). The bottom surface of the first connecting shaft (14) is fixed to a first connecting seat (15). The bottom surface of the first connecting seat (15) is fixed to a stirring component.

7. The riverine planktonic microbe dispersion simulation apparatus of claim 6, wherein: The stirring component includes a plurality of stirring blocks (16) that are fixed at equal intervals to the bottom surface of the first connecting seat (15).

8. The riverine planktonic microbe dispersal simulation apparatus of claim 2, wherein: The monitoring mechanism includes a second electric telescopic rod (17) fixed to the outside of the experimental container (4), the second electric telescopic rod (17) being fixed to the top surface of the base plate (1), and a monitoring camera (18) being installed on the top surface of the second electric telescopic rod (17).

9. A method of using a river planktonic microorganism diffusion simulation device based on the river planktonic microorganism diffusion simulation device according to any one of claims 1 to 8, characterized by, Includes the following steps: S1. Constructing heterogeneous patches: Screening native microbial communities in natural paddy field water bodies, grouping them according to richness gradients, and filling them into patch units; S2, set diffusion frequency: through the timing controller drive stirring mechanism, according to 0, 1, 3, 6, 15, 30 times / day gradient implementation diffusion operation, each stirring 15 seconds after 60 seconds; S3, dynamic monitoring: from the second day of culture, through the monitoring camera (18) to observe the situation in the experimental container (4), 2mL daily sampling, microscopic identification of species composition, calculate the richness, diversity index and cross patch migration rate.

10. The method of using a river planktonic microorganism dispersion simulation device of claim 9, wherein: The patch unit in step S1 is configured according to a source-sink collection community model, and is divided into 5 rice field ecosystems, each system is provided with 2 parallel patches, the community species richness is divided into low, medium and high three gradients, and the common species in the patches with the same richness is ≤50%.

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