Method for dynamically realizing change of microflora on surface of micro-plastic in environmental migration

Abstract

The invention discloses a method for dynamically realizing microplastic surface microflora change in environmental migration, which comprises the following steps of: setting a plurality of point locations and a plurality of placement times in an environment, and placing microplastic of which the surface is not initially adhered with microorganisms in the environment for pre-culture; migrating the microplastics with microorganisms colonized on the surface after pre-culture at the last point in a simulated manner, and meanwhile, reserving part of the microplastics at the last point and the next point as a control group; the continuous culture time is reset after simulated migration, the migrated microorganisms stay at the next point according to the continuous culture time, simulated migration micro-plastics are recycled at the next point after simulated migration, and control group micro-plastics are recycled at the previous point and the next point respectively; recycling the continuously cultured micro-plastics, analyzing surface microorganisms, and comparing and analyzing the simulated migration micro-plastics with a control group. The migration process of the microplastics in the environment is controllable by manually changing the culture position, and the device is suitable for simulation of all migration paths and all culture time.

Description

Technical Field

[0001] The present invention belongs to the field of environmental microorganisms and new pollutants, and in particular is a controllable control research method for the changes in surface microbial communities at different residence times when microplastics migrate in an environment. Background Art

[0002] Plastic products are widely used in human production and life. Due to unreasonable disposal, plastics enter the environment and are reduced in size to become microplastics under the action of light, weathering, particle friction, and microorganisms. Microplastics are currently widely present in the environment and have become a new pollutant. Microplastics are good carriers for microbial attachment due to their large specific surface area, strong hydrophobicity, and stable chemical properties. When microplastics migrate in the environment, the microorganisms attached to their surface will inevitably move with them, but it is still impossible to determine whether microplastics can carry the microorganisms on their surface to a new environment and continue to exist stably.

[0003] It is generally believed that the microbial community on the surface of microplastics is different from that in natural media such as water bodies and sediments. Since the original source of randomly collected microplastics in the environment is unknown and the residence time at the location is unknown, it is difficult to track their migration path. Therefore, by cultivating the biofilm on the surface of microplastics in situ in the natural environment and then artificially changing its position, the migration process of microplastics in the environment was simulated in a controllable manner. Different cultivation times were considered to simulate the different residence times of microplastics in the environment. Microplastics that were always cultivated in situ at the location were set as the control group in different environments before and after migration, and the changes in microorganisms attached to the surface of microplastics during environmental migration were analyzed.

[0004] Explanation of relevant terms:

[0005] Microplastics: A mixture of particles of different shapes, colors, sizes and polymer types with a diameter of no more than 5 mm, first proposed by Richard C. Thompson in a paper published in the journal Science in 2004.

[0006] In situ culture: Place the sample at a fixed point in the wild environment so that the microbial community in the environment is attached to its surface, and the geographical location environment is not changed during the culture process. Summary of the invention

[0007] The present invention aims to propose a method for dynamically realizing the changes of surface microbial communities during the migration of microplastics. The migration process of microplastics in the environment is controllable by artificially changing the culture position, and different culture times and recovery times are set to fully represent the actual situation of different residence time of microplastics in the environment. Microplastics with the same culture time are used as a control group to avoid the difference between free growth and attached growth of microorganisms, so as to fully analyze the changes of microbial communities on the surface of microplastics before and after migration.

[0008] In order to achieve the above-mentioned purpose of the invention, the present invention realizes a method for dynamically realizing the changes of microbial communities on the surface of microplastics during environmental migration, comprising:

[0009] A method for dynamically realizing changes in microbial communities on the surface of microplastics during environmental migration, comprising:

[0010] Place multiple groups of microplastics at various points for pre-cultivation at different time points, and set the pre-cultivation time of each group of microplastics at the original point before simulated migration. The formal definition includes: setting the maximum pre-cultivation time of microplastics before simulated migration to x n The pre-culture time of each group of microplastics is x a Days, pre-culture time index sequence a = 1, 2...(n-2), (n-1), n, n represents the index of each group of microplastics, the time for placing the first group of microplastics is set as day 0, and the time for simulating migration is set as day x. n Days, the time for placing each group of microplastics for pre-cultivation is (x n –x a ) days; select each group of microplastic pre-cultivation environments at each point before simulating migration, and place multiple groups of microplastics at each point for in situ pre-cultivation;

[0011] The migration process of microplastics with microorganisms colonized on the surface after pre-culture at the origin is simulated, and some microplastics are kept at the origin as a control group; according to the pre-culture time of each group of microplastics, (2m+1) groups of microplastics are placed at the origin before migration at each time point, and (m+1) groups of microplastics are placed at the new point after migration, simulating m different continued culture times after migration; at the xth time point, n Days later, microplastics with different pre-culture times were recovered at the original point before migration and the new point after migration. Pre-culture x a There are 1 group of microplastics for each day, and a total of n groups at each point, representing the microorganisms on the surface of microplastics with different in situ pre-culture time at each point; simulate the migration process, recycle the m groups of microplastics from the previous point, and gently rinse the surface of the microplastics with filtered water from the current point, use ice bags to preserve them during transportation to protect the microorganisms, carry them to the next point on the migration path, and place them in the same environmental conditions as the microplastics pre-cultured at the next point; set up a control group of microplastics, and keep the m groups of microplastics incubated at each point.

[0012] After the simulated migration, the continued cultivation time is reset. After the migration, the microorganisms stay in the new environment according to the continued cultivation time. The simulated migration microplastics are recovered at the next point, and the control group microplastics are recovered at the previous point and the next point respectively.

[0013] The microplastics were recovered after being cultured in the environment, and the simulated migrated microplastics were compared with the control group for analysis: comparative analysis was conducted to compare the differences in the surface microorganisms of the simulated migrated microplastics recovered at the next point and the microplastics before simulated migration recovered at the previous point, so as to obtain the microbial situation of the simulated migrated microplastics continuing to colonize in the new environment after the environment was changed; and to compare the surface microorganisms of the simulated migrated microplastics and the control group microplastics recovered at the same time, so as to study the changing characteristics of the microorganisms on the surface of the migrated microplastics under different residence times in the original environment and the new environment before and after the simulated migration.

[0014] Compared with the prior art, the present invention has the following technical effects:

[0015] 1. The effect of the matrix on the growth of attached microorganisms was fully considered, and the surface microorganisms of the same microplastics cultured in the environment before and after migration were used as the control group;

[0016] 2. Taking into full consideration the differences of microbial communities at different colonization stages, the microbial communities on the surface of microplastics with the same culture time were selected as the control group;

[0017] 3. Applicable to simulations of all migration paths and all culture times. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is an overall flow chart of a method for dynamically realizing changes in microbial communities on the surface of microplastics during environmental migration according to the present invention;

[0019] Figure 2 is a schematic diagram of in situ cultivation of biofilm on microplastic surface;

[0020] Figure 3 This is a schematic diagram of the simulation of microplastic migration;

[0021] Figure 4 This is a schematic diagram of microplastic recycling;

[0022] Figure 5 It is a schematic diagram of the time flow of the overall method. DETAILED DESCRIPTION

[0023] The specific implementation modes of the present invention will be described in detail below with reference to the accompanying drawings.

[0024] like Figure 1 As shown, a method for dynamically realizing changes in microbial communities on the surface of microplastics during environmental migration of the present invention comprises the following specific steps:

[0025] Step 1: Place the microplastics with no microorganisms attached to the surface in a natural environment for pre-cultivation, such as Figure 1As shown, for example, multiple groups of microplastics are placed at point A and point B, respectively, that is, multiple culture points are set in the environment, and multiple placement times are set for each group of microplastics;

[0026] Step 1-1: Simulate the different residence times of microplastics in the original environment before migration, i.e., pre-cultivation time. Place multiple groups of microplastics at various locations for pre-cultivation at different time points. Set the pre-cultivation time of each group of microplastics at the original location before simulated migration. The formal definition includes: Set the maximum pre-cultivation (retention) time of microplastics before simulated migration as x n The pre-culture time of each group of microplastics is x a Days, pre-culture time index sequence a = 1, 2...(n-2), (n-1), n, n represents the index of each group of microplastics, the time for placing the first group of microplastics is set as day 0, and the time for simulating migration is set as day x. n Days, the time for placing each group of microplastics for pre-cultivation is (x n –x a )sky;

[0027] Step 1-2: Selecting a pre-cultivation environment for each group of microplastics at each point before simulating migration, including placing multiple groups of microplastics at each point for in situ pre-cultivation; for example, if the simulated migration path is from point A to point B, multiple groups of microplastics are placed at points A and B for in situ pre-cultivation;

[0028] Step 1-3: Obtain the microplastics that need to be placed at various points for pre-culture before simulated migration. The processing steps include rinsing the surface of the microplastics with 95% ethanol three times before placing the microplastics, and then rinsing the surface of the microplastics with ultrapure water three times to ensure that there is no microorganism attached to the surface of the microplastics before culture;

[0029] Step 2: Simulate the migration process, that is, change the position of the microplastics with microorganisms colonized on the surface after pre-cultivation at the origin to simulate the migration process of microplastics in the environment, and keep some microplastics at the origin as a control group; according to the pre-cultivation time of each group of microplastics in step 1-1, place (2m+1) groups of microplastics at point A and (m+1) groups of microplastics at point B at each time point, and there are m different continued cultivation times after simulating migration;

[0030] like Figure 2 The figure shows a schematic diagram of in situ cultivation of biofilm on microplastic surface, with migration paths formed between various points;

[0031] Step 2-1: Recover the pre-cultured microplastics, that is, recover the microplastics with different pre-culture times at points A and B, and recover the pre-cultured x at each point. aThere is one group of microplastics for each day, a = 1, 2...(n-2), (n-1), n, and each point has a total of n groups, representing the microorganisms on the surface of microplastics with different in situ pre-culture (residence) times at each point;

[0032] Step 2-2: Simulate the migration process: After the m groups of microplastics at point A are recovered, the surface of the microplastics is gently rinsed with filtered water from point A, and ice packs are used to preserve them during transportation to protect the microorganisms. The microplastics are carried to point B and placed under the same environmental conditions as the microplastics pre-cultured at point B in step 1;

[0033] Step 2-3: Set up a control group of microplastics, that is, continue to culture the m groups of microplastics at point A and point B respectively at point A and point B;

[0034] Step 3: Recover microplastics, that is, reset the continued cultivation time after simulated migration. After migration, the microplastics stay in the new environment according to the continued cultivation time. The simulated migration microplastics are recovered at point B, and the control group microplastics are recovered at points A and B respectively. Figure 3 Shown is a schematic diagram of microplastic migration simulation;

[0035] Step 3-1: Set the microplastic recycling time, that is, set the maximum time for microplastics to continue to be cultured (stay) after simulated migration to y m The cultivation time of each group is y b Days, continue to cultivate the time index sequence b = 1, 2... (m-2), (m-1), m, the recovery time of each group of microplastics is (x n +y b ) days, the corresponding culture time of each group of microplastics is (x a +y b ) days, the last recycling time is (x n +y m ) day, such as Figure 4 Shown is a schematic diagram of plastic recycling;

[0036] Step 3-2: Recycle the microplastics after simulated migration, that is, according to the recycling time of each group of microplastics in step 3-1 (x n +y b ) days, the cells were collected at point B and cultured at point A for x a After 15 days, the migrating microplastics were simulated to point B, a=1, 2...(n-2), (n-1), n, and n groups were collected at each time point. After collection, the surface of the microplastics was gently rinsed with filtered water from point B and stored with ice packs during transportation;

[0037] Step 3-3: Recycle microplastics in the control group, i.e., collect the microplastics in each group according to the recycling time (x) in step 3-1. n +yb ) days, the cells were collected at point A and point B and cultured at the same point for x a Days later, continue to cultivate y at this point b The control group of microplastics on the day, a = 1, 2...(n-2), (n-1), n, each time point A and B point were respectively collected n groups, after which the surface of the microplastics was gently rinsed with filtered water from the current point, and ice packs were used to store them during transportation;

[0038] Step 4: Conduct microbial data analysis, i.e. recover the microplastics after culture in the environment and analyze the surface microorganisms, and compare the simulated migration microplastics with the control group;

[0039] Step 4-1: Isolate and extract microorganisms on the surface of microplastics, that is, after transporting the microplastics to the laboratory at each recycling time point, separate and extract the microorganisms on the surface of the microplastics as soon as possible;

[0040] Step 4-2: Set up a control group, that is, the microplastics that migrated from point A to point B are the migration group, and the microplastics that were always cultured at point A or point B with the same pre-culture time and the same continued culture time are the control groups of the original environment before migration and the new environment after migration. a Day 2, continue to cultivate y at point B b The surface microorganisms of the simulated migration group on the day of the migration were cultured at point A (x a +y b ) days, the control group in the new environment after migration was cultured at point B (x a +y b ) days of microplastic surface microorganisms;

[0041] Step 4-3: Comparative analysis, i.e., comparing the differences in microorganisms on the surface of the simulated migrating microplastics recovered at point B in step 3-2 and the microplastics recovered at point A in step 2-1, so as to obtain the microbial conditions that continue to colonize the simulated migrating microplastics in the new environment after the environment is changed;

[0042] In step 4-2, the microorganisms on the surface of the simulated migrating microplastics and the control group microplastics recovered at the same time are compared to study the changing characteristics of the microorganisms on the surface of the migrating microplastics under different residence times in the original environment and the current environment before and after the simulated migration.

[0043] Furthermore, in a method for dynamically realizing changes in microbial communities on the surface of microplastics during environmental migration of the present invention, the different pre-culture time x in step 1-1 a It can be an arithmetic sequence or a non-arithmetic sequence.

[0044] Furthermore, in a method for dynamically realizing changes in microbial communities on the surface of microplastics during environmental migration according to the present invention, multiple paths and multiple points can be set for in situ culture in steps 1-2.

[0045] Furthermore, in a method for dynamically realizing changes in microbial communities on the surface of microplastics during environmental migration of the present invention, the microplastics are placed in steps 1-3, and the culture environment can be selected according to research needs, including but not limited to water bodies, sediments, and the interface between water bodies and sediments.

[0046] Furthermore, the present invention provides a method for dynamically realizing changes in microbial communities on the surface of microplastics during environmental migration, wherein the recovery time of different microplastics in step 3-1, y b Can be an arithmetic or non-arithmetic progression, and can be related to x a The values ​​are the same or different.

[0047] Furthermore, the method of the present invention for dynamically realizing changes in microbial communities on the surface of microplastics during environmental migration can combine step 1-1, step 1-3 and step 2-1 to obtain changes in microorganisms on the surface of microplastics cultured in situ.

[0048] The specific embodiment of the present invention is described as follows, comprising the following steps:

[0049] S1. In situ culture: polypropylene microplastics with no microorganisms attached to the surface are placed in the river-sea environment for in situ pre-culture, with 2 culture point environments and 4 pre-culture times set;

[0050] S1-1. Set different pre-cultivation times for microplastics at the origin before migration: Set 4 different residence times for microplastics in the original environment before migration. Since the microbial community on the surface of microplastics usually changes rapidly in the early stage and tends to be stable in the later stage, set the pre-cultivation at the origin for 1, 3, 7, and 14 days respectively. Set the start of the experiment as day 0. At this time, place the sample at the origin for 14 days, place the sample at the origin for 7 days on the 7th day, place the sample at the origin for 3 days on the 11th day, and place the sample at the origin for 1 day on the 13th day;

[0051] S1-2. Select different environments for pre-cultivation at each point before simulating migration: Since the flow of microplastics from rivers to the sea is an important process for the entry of microplastics into the ocean, select the upstream of the river entering the sea as point A, and the downstream of the river entering the sea as point B to simulate the migration process of microplastics from rivers to the sea;

[0052] S1-3. Place pre-cultured microplastics at the origin: In order to simulate the floating flow of microplastics in the river, widely used polypropylene was selected as a representative polymer type, and the samples were cut into circles with a diameter of 4 mm. Before placement, the surface of the microplastics was rinsed 3 times with 95% ethanol, and then the surface of the microplastics was rinsed 3 times with ultrapure water to ensure that there were no microorganisms attached to the surface of the microplastics before cultivation. Multiple pieces of microplastics were placed in a 40-mesh nylon mesh bag with a size of 5cm×5cm. One nylon bag was regarded as a group of samples. The samples were connected and fixed to the shore with nylon ropes and placed on the water surface to float freely. Five different pre-culture durations of microplastics were set before migration. On the 0th, 7th, 11th, and 13th days of the experiment, (2×5+1)=11 groups of samples were placed at point A, and (5+1)=6 groups of samples were placed at point B;

[0053] S2, simulated migration: the microplastics with microorganisms colonized on the surface after pre-cultivation at point A in the upper reaches of the river were artificially moved to point B in the lower reaches of the river, while some microplastics were retained at points A and B as control groups;

[0054] S2-1. Recover the pre-cultured microplastics at the original point: Collect water from points A and B in advance and filter through a 0.22μm filter membrane to remove microorganisms. Recover 1 group of samples pre-cultured for 1, 3, 7, and 14 days at points A and B, respectively, for a total of 4 groups of samples at each point. After recovery, use the filtered water from the corresponding point to gently rinse the sample surface;

[0055] S2-2, simulated migration process: after the 5 groups of samples from point A are recovered, the sample surface is gently rinsed with filtered water from point A, ice packs are used to preserve the samples during transportation to protect the microorganisms, and the samples are carried to point B and placed in the same environmental conditions as the microplastics pre-cultured at point B in step S1;

[0056] S2-3. Set up a control group of microplastics: continue to culture the 5 groups of samples at point A at point A, and continue to culture the 5 groups of samples at point B at point B;

[0057] S3, microplastic recovery: after changing the position of migrating microplastics, 5 continuous incubation times were reset. After migration, the microplastics stayed at point B according to the continuous incubation time. The simulated migrating microplastics were recovered at point B, and the control group microplastics were recovered at points A and B respectively.

[0058] S3-1. Setting the recovery time of microplastics: setting 5 different retention times for the continued cultivation (retention) of microplastics after simulated migration, with each group continuing to cultivate for 2, 4, 8, 16, and 32 days, respectively, and recovering samples on days (14+2)=16, (14+4)=18, (14+8)=22, (14+16)=30, and (14+32)=46;

[0059] S3-2. Recovery of microplastics after simulated migration: On the 16th, 18th, 22nd, 30th and 46th days, recover at point B one group of samples that were pre-cultured at point A for 1, 3, 7 and 14 days, respectively, that is, a total of 4 groups of samples were recovered at each time. For example, on the 16th day, 4 groups of samples were recovered at point B, including those that were pre-cultured at point A for 1 day and continued to be cultured at point B for 2 days, those that were pre-cultured at point A for 3 days and continued to be cultured at point B for 2 days, those that were pre-cultured at point A for 7 days and continued to be cultured at point B for 2 days, and those that were pre-cultured at point A for 14 days and continued to be cultured at point B for 2 days. After the samples were recovered, gently rinse the surface of the samples with filtered water from point B and store them with ice packs during transportation;

[0060] S3-3. Recover microplastics in the control group: On the 16th, 18th, 22nd, 30th, and 46th days, recover one group of samples at Point A and Point B respectively after pre-culturing at the point for 1, 3, 7, and 14 days, and then continuing to culture at the point, that is, a total of 4 groups of samples are recovered at each point at each time. For example, on the 16th day, 4 groups of samples were recovered at Point A after being cultured for a total of (2+1)=3, (2+3)=5, (2+7)=9, and (2+14)=16 days. After the samples are recovered, use the filtered water from the current point to gently rinse the surface of the samples, and use ice packs to preserve them during transportation;

[0061] S4. Conduct microbial data analysis: Recover microplastics after being cultured in the environment and analyze the surface microorganisms, and compare the simulated migration microplastics with the control group;

[0062] S4-1. Isolation and extraction of microorganisms on the surface of microplastics: On the 14th, 16th, 18th, 22nd, 30th, and 46th days of the experiment, after the samples were recovered and transported to the laboratory, the microorganisms on the surface of microplastics were isolated and extracted as soon as possible;

[0063] S4-2, set the control group: the microplastics migrated from point A to point B are the migration group, and the microplastics that are always cultured at point A or point B with the same pre-culture time and the same continued culture time are the control groups of the original environment before migration and the new environment after migration. For example, a sample pre-cultured at point A for 3 days and migrated to point B for 8 days, the control group in the original environment before migration is the sample cultured at point A for (3+8)=11 days, and the control group in the new environment after migration is the sample cultured at point B for (3+8)=11 days;

[0064] S4-3. Comparative analysis: Compare the differences in surface microorganisms of the simulated migration samples with different continued culture times recovered in S3-2 and the samples recovered at point A in S2-1, so as to obtain the microbial situation of the simulated migration microplastics continuing to colonize at point B after the environment is changed;

[0065] In the S4-2, the microorganisms on the surface of the simulated migrating microplastics and the control group microplastics recovered at the same time are compared to obtain the changing characteristics of the microorganisms on the surface of the migrating microplastics at different residence times at points A and B before and after the simulated migration.

[0066] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

Claims

1. A method for dynamically realizing changes in microbial communities on the surface of microplastics during environmental migration, characterized in that: include: At different time points, multiple groups of microplastics with no microorganisms attached to the surface were placed at various locations for pre-culture, and the pre-culture time of each group of microplastics at the original location before simulated migration was set. The formal definition includes: setting the maximum pre-culture time of microplastics before simulated migration to x n The pre-culture time of each group of microplastics is x a Days, pre-culture time index sequence a = 1, 2...(n-2), (n-1), n, n represents the index of each group of microplastics, the time for placing the first group of microplastics is set as day 0, and the time for simulating migration is set as day x. n Days, the time for placing each group of microplastics for pre-cultivation is (x n –x a ) days; select each group of microplastic pre-cultivation environments at each point before simulating migration, and place multiple groups of microplastics at each point for in situ pre-cultivation; The migration process of microplastics with microorganisms colonized on the surface after pre-culture at the origin is simulated, and some microplastics are kept at the origin as a control group; according to the pre-culture time of each group of microplastics, (2m+1) groups of microplastics are placed at the origin before migration at each time point, and (m+1) groups of microplastics are placed at the new point after migration, simulating m different continued culture times after migration; at the xth time point, n Days later, microplastics with different pre-culture times were recovered at the original point before migration and the new point after migration. Pre-culture x a There are 1 group of microplastics for each day, and a total of n groups at each point, representing the microorganisms on the surface of microplastics with different in situ pre-culture time at each point; simulate the migration process, recycle the m groups of microplastics from the previous point, and gently rinse the surface of the microplastics with filtered water from the current point, use ice bags to preserve them during transportation to protect the microorganisms, carry them to the next point on the migration path, and place them in the same environmental conditions as the microplastics pre-cultured at the next point; set up a control group of microplastics, and keep the m groups of microplastics incubated at each point. After the simulated migration, the continued cultivation time is reset. After the migration, the microorganisms stay in the new environment according to the continued cultivation time. The simulated migration microplastics are recovered at the next point, and the control group microplastics are recovered at the previous point and the next point respectively. The microplastics were recovered after being cultured in the environment, and the simulated migrated microplastics were compared with the control group for analysis: comparative analysis was conducted to compare the differences in the surface microorganisms of the simulated migrated microplastics recovered at the next point and the microplastics before simulated migration recovered at the previous point, so as to obtain the microbial situation of the simulated migrated microplastics continuing to colonize in the new environment after the environment was changed; and to compare the surface microorganisms of the simulated migrated microplastics and the control group microplastics recovered at the same time, so as to study the changing characteristics of the microorganisms on the surface of the migrated microplastics under different residence times in the original environment and the new environment before and after the simulated migration.

2. The method for dynamically realizing changes in microbial communities on the surface of microplastics during environmental migration according to claim 1, characterized in that: Microplastics are obtained through processing to be placed at various points for pre-culture before simulated migration. The processing steps include rinsing the surface of the microplastics three times with 95% ethanol before placing the microplastics, and then rinsing the surface of the microplastics three times with ultrapure water to ensure that there are no microorganisms attached to the surface of the microplastics before culture.

3. The method for realizing dynamic changes of microbial communities on the surface of microplastics during environmental migration according to claim 1, characterized in that: The microplastic recycling further includes the following processing: Set the microplastic recycling time, that is, set the maximum time for microplastics to continue to be cultivated after simulated migration to y m The cultivation time of each group is y b Days, continue to cultivate the time index sequence b = 1, 2... (m-2), (m-1), m, the recovery time of each group of microplastics is (x n +y b ) days, the corresponding culture time of each group of microplastics is (x a +y b ) days, the last recycling time is (x n +y m )sky; To recover the microplastics after simulated migration, that is, according to the recovery time of each group of microplastics (x n +y b ) days, and then collect the cultured x at the previous point at the next point. a After 10 days, simulate the migration of microplastics to the next point, collect n groups at each time point, and use filtered water from the current point to gently rinse the surface of the microplastics. Use ice packs to store them during transportation; The control group microplastics were collected, that is, the microplastics in each group were collected according to the time (x n +y b ) days, the cultured x at the previous point and the next point were recovered respectively. a Days later, continue to cultivate y at this point b For the control group of microplastics, n groups of microplastics were collected at the previous point and the next point at each time point. After collection, the surface of the microplastics was gently rinsed with filtered water from the current point and stored in ice packs during transportation.

4. The method for realizing the dynamic changes of microbial communities on the surface of microplastics during environmental migration according to claim 1, characterized in that: Further including: A control group was set up, and the microplastics that migrated from the previous point to the next point were the migration group. The microplastics that were always cultured at the previous point or the next point with the same pre-culture time and the same continued culture time were respectively the control group of the original environment before migration and the new environment after migration. a Day, cultivate y at the next point b The surface microorganisms of the migration group on the day of the migration and the control group in the original environment before the simulated migration were cultured at the previous point (x a +y b ) days, the control group in the new environment after migration was cultured at the next point (x a +y b ) days of microorganisms on the surface of microplastics.

5. The method for dynamically realizing changes in microbial communities on the surface of microplastics during environmental migration according to claim 1, characterized in that: in, x a ,y b is a non-arithmetic sequence or an arithmetic sequence, and x a ,y b The values ​​are the same or different.

6. The method for realizing dynamic changes of microbial communities on the surface of microplastics during environmental migration according to claim 1, characterized in that: The culture environment includes but is not limited to water, sediment, and the interface between water and sediment.

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