Method and device for improving fish quality by utilizing probiotic bioreactor

Abstract

The invention belongs to the technical field of aquaculture, and particularly relates to a method and device for improving fish quality by utilizing a probiotic bioreactor, and the method comprises the following steps: S1, taking a high polymer material membrane as a carrier, fixing probiotics on the high polymer material membrane, and manufacturing the bioreactor; and S2, fixing the constructed probiotic bioreactor into a culture water body. According to the method, the concentration of main fishy smell substances such as trimethylamine in a water body can be reduced by 70%-80%, fishy smell substances in fish bodies and water are effectively removed, the fish quality is improved, the pollution of a traditional chemical method to the water body and the fish bodies is avoided by utilizing the biodegradation effect of probiotics, meanwhile, the probiotics can improve the micro-ecological environment of the water body in the metabolic process, and the ecological environment of the water body is improved. The balance of a breeding ecological system is promoted, and good environmental protection and sustainability are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of aquaculture, and in particular relates to a method and a device for improving fish quality by utilizing a probiotic bioreactor. Background Art

[0002] In aquaculture, the fishy odor of fish has always been a key factor affecting its quality and market acceptance. The fishy odor mainly comes from volatile compounds produced by the fish's own metabolism, such as trimethylamine and hexahydropyridine, as well as some odorous substances present in the water. Traditional methods for removing fishy odor include improving water quality during the breeding process, such as regular water changes and the use of water purifiers, but these methods are limited in effectiveness and are costly. In addition, processing the fish after fishing, such as washing and soaking in special solutions, is not only cumbersome but can also damage the fish, affecting its freshness and taste. Currently, the market lacks a technology that is efficient, environmentally friendly, and can continue to work during the breeding process to fundamentally reduce fishy odor and improve fish quality. Summary of the Invention

[0003] The purpose of the present invention is to address the above-mentioned technical problems and provide a method and device for improving fish quality by using a probiotic bioreactor, thereby effectively removing fishy substances in fish bodies and water and improving fish quality.

[0004] In view of this, the present invention provides a method for improving fish quality using a probiotic bioreactor: The following steps are involved: S1: Using a polymer film as a carrier, immobilizing probiotics on the polymer film to produce a bioreactor; S2: Fix the constructed probiotic bioreactor into the aquaculture water body.

[0005] In this technical solution, during the breeding process, the fishy substances in the water enter the membrane pores of the bioreactor through diffusion and come into contact with the probiotics fixed on the membrane. The probiotics use the fishy substances as a carbon source or nitrogen source for metabolic activities, decomposing them into harmless small molecules such as carbon dioxide, water and inorganic salts, thereby reducing the concentration of fishy substances in the water. At the same time, when the fish are swimming, the fishy substances on the surface of the body will also be affected by the surrounding water containing probiotics. Some fishy substances are decomposed and removed, which can reduce the concentration of major fishy substances such as trimethylamine in the water by 70%-80%, effectively removing fishy substances in the fish and water, improving the quality of the fish, and utilizing the biodegradation effect of probiotics to avoid the pollution of water and fish by traditional chemical methods. At the same time, probiotics can also improve the microecological environment of the water during metabolism, promote the balance of the breeding ecosystem, and have good environmental protection and sustainability.

[0006] Furthermore, the probiotics in step S1 are probiotic strains isolated and screened from natural water bodies or the intestines of healthy fish, which have the ability to efficiently decompose fishy substances.

[0007] Furthermore, the screened probiotic strain is Bacillus subtilis or lactic acid bacteria.

[0008] In this technical solution, it has been verified experimentally that Bacillus subtilis or lactic acid bacteria have a significant degradation effect on odorous substances such as trimethylamine and hexahydropyridine.

[0009] Furthermore, the polymer material film in step S1 is a polyvinylidene fluoride (PVDF) film or a polyacrylonitrile (PAN) film.

[0010] In this technical solution, the porosity of the polyvinylidene fluoride (PVDF) membrane can reach 70%-80%, which can provide sufficient attachment space and good mass transfer performance for probiotics.

[0011] Furthermore, in step S1, the screened probiotics are fixed on the carrier membrane by an adsorption method or a covalent binding method.

[0012] In this technical solution, taking the adsorption method as an example, the carrier membrane is immersed in a bacterial solution containing a high concentration of probiotics, and oscillated and adsorbed for a certain period of time (such as 12-24 hours) under suitable temperature (such as 30℃-35℃) and pH value (such as pH 6.5-7.5) conditions to make the probiotics firmly attached to the membrane surface and pores. The probiotic loading after fixation can reach 10^8-10^9 colony-forming units (CFU / cm²) per square centimeter of membrane area. Furthermore, in step S2, a hanging or floating method is adopted to ensure that the membrane is in full contact with the water body.

[0013] In this technical solution, for pond farming, the bioreactor is hung in the pond by ropes to ensure that the membrane is in full contact with the water body; for the recirculating aquaculture system, the bioreactor is installed in the water circulation pipe to ensure that the water can continuously flow through the bioreactor. The bioreactor has a simple structure and is easy to install and maintain. It only requires regular inspection and replacement of some aging biofilm components. Compared with traditional methods such as frequent water changes and the use of large amounts of chemical agents, it greatly reduces production costs and labor intensity.

[0014] Furthermore, a device for improving fish quality using a probiotic bioreactor comprises: A carrier membrane component, wherein the carrier membrane component includes a polymer material membrane for fixing probiotics; The supporting frame is used to fix and support the carrier membrane assembly, and the supporting frame is made of corrosion-resistant material. Furthermore, the carrier membrane assembly is in sheet shape, the support frame is arranged around the carrier membrane assembly, and a connecting ring is provided on the support frame.

[0015] In this technical solution, for pond aquaculture, the bioreactor is suspended in the pond by ropes so that the membrane is in full contact with the water body. The connecting ring is used to connect ropes, hooks and connectors, etc., to ensure that the bioreactor can be conveniently and firmly placed in a suitable position in the aquaculture water body.

[0016] Furthermore, the carrier membrane assembly is cylindrical, and a support frame is provided at each end of the carrier membrane assembly. The support frame is annular, and the outer diameter is less than or equal to the diameter of the water pipe. The inner diameter is conical and includes a first conical surface. Threads are provided on the outer periphery of both ends of the water pipe, and an annular connecting sleeve is provided at both ends of the water pipe. A positioning groove is provided between the inner diameter and outer diameter of the connecting sleeve, and the outer wall of the positioning groove is threadedly connected to the outer wall of the water pipe. The inner wall of the positioning groove is a second conical surface that matches the angle of the first conical surface.

[0017] In this technical solution, for the recirculating aquaculture system, the bioreactor is installed in the water circulation pipe to ensure that water can continuously flow through the bioreactor. The carrier membrane assembly and the support frame are connected and placed in the water pipe. The connecting sleeves are screwed on both ends of the water pipe. The support frame is located in the positioning groove of the connecting sleeve. As the connecting sleeve is gradually screwed in, the second conical surface will gradually approach the first conical surface until it is completely close to the first conical surface. In this way, the support frame is fixed by the connecting sleeve.

[0018] Furthermore, the connecting sleeve is used to connect water pipes.

[0019] The beneficial effects of the present invention are: 1. During the breeding process, the fishy substances in the water enter the membrane pores of the bioreactor through diffusion and come into contact with the probiotics fixed on the membrane. The probiotics use the fishy substances as a carbon or nitrogen source for metabolic activities, decomposing them into harmless small molecules such as carbon dioxide, water and inorganic salts, thereby reducing the concentration of fishy substances in the water. At the same time, when the fish are swimming, the fishy substances on the surface of the body will also be affected by the surrounding water containing probiotics. Some fishy substances are decomposed and removed, which can reduce the concentration of major fishy substances such as trimethylamine in the water by 70%-80%, effectively removing fishy substances in fish and water, and improving fish quality. The biodegradation effect of probiotics avoids the pollution of water and fish by traditional chemical methods. At the same time, probiotics can also improve the microecological environment of the water during metabolism, promote the balance of the aquaculture ecosystem, and have good environmental protection and sustainability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a perspective view of the bioreactor in Example 1; Figure 2 is a three-dimensional diagram of the bioreactor in Example 2; Figure 3 yes Figure 2 Exploded diagram; Figure 4 yes Figure 2 Half-section view; Figure 5 yes Figure 4 A partial enlarged view of point A in the middle; The marks in the figure are: 1. Polymer material membrane; 2. Support frame; 3. Connecting ring; 4. First conical surface; 5. Connecting sleeve; 6. Positioning groove; 7. Second conical surface; 8. Water pipe. DETAILED DESCRIPTION

[0021] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0022] In the description of this application, it should be noted that the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the exemplary embodiments according to this application. For ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The techniques, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0023] It should be noted that the terms "first," "second," etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than those illustrated or described herein, and that the objects distinguished by "first," "second," etc. are generally of the same type, and do not limit the number of objects. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0024] It should be noted that, in the description of this application, the directions or positional relationships indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. Unless otherwise specified, these directional terms do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of this application; the directional terms "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0025] It should be noted that, in the present application, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the opposite order according to the functions involved. For example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0026] Example 1: A method for improving fish quality using a probiotic bioreactor comprises the following steps: Pond aquaculture applications (1) Bioreactor construction Bacillus subtilis and lactic acid bacteria were isolated and screened from the intestines of healthy crucian carp. After culture and amplification, the bacterial solution concentration reached 10^10 CFU / mL. A polymer membrane 1, such as a polyvinylidene fluoride (PVDF) membrane, was cut into 20 cm squares and placed in the bacterial solution. The probiotics were immobilized by oscillation at 32°C and pH 7.0 for 18 hours. The PVDF membrane with immobilized probiotics was mounted on a stainless steel support frame 2 to form the bioreactor body. (2) Application process In a crucian carp breeding pond with an area of ​​1,000 square meters, a bioreactor is hung every 50 square meters, for a total of 20. The bioreactor is 0.5 meters above the water surface and is fixed to wooden stakes around the pond with ropes and hooks. During the six-month aquaculture cycle, the concentration of odorous substances in the water and the sensory quality of the fish were regularly tested. The results showed that the trimethylamine concentration in the water was 50 μg / L in the early stages of aquaculture, dropping to 15 μg / L after three months and to 10 μg / L after six months. The professional evaluation panel evaluated the crucian carp caught in the later stages of aquaculture as having a significantly reduced fishy odor and significantly improved tenderness and taste. A device for improving fish quality using a probiotic bioreactor corresponding to the first embodiment, such as Figure 1 As shown, including: A carrier membrane component, the carrier membrane component comprising a polymer material membrane 1 for fixing probiotics; The support frame 2 is used to fix and support the carrier membrane assembly. The support frame 2 is made of corrosion-resistant material. The carrier membrane assembly is in sheet shape, and the support frame 2 is arranged around the carrier membrane assembly. A connecting ring 3 is provided on the support frame 2 .

[0027] For pond farming, the bioreactor is suspended in the pond by ropes so that the membrane is in full contact with the water. The connecting ring 3 is used to connect ropes, hooks and connectors to ensure that the bioreactor can be conveniently and firmly placed in a suitable position in the aquaculture water.

[0028] Example 2: A method for improving fish quality using a probiotic bioreactor comprises the following steps: Application of recirculating aquaculture system (1) Bioreactor construction Photosynthetic bacteria with high odor-degrading properties were selected from natural water bodies and cultured to a bacterial concentration of 10^11 CFU / mL. The bacteria were covalently immobilized on a tubular polymer membrane (1), such as a polyacrylonitrile (PAN) membrane, with an inner diameter of 3 cm and a length of 50 cm. The PAN membrane tubes, immobilized with the photosynthetic bacteria, were mounted within a support frame (2) made of engineering plastics to form a bioreactor assembly equipped with a valve to adjust the water flow rate.

[0029] (2) Application process The bioreactor is installed in the filtration pipes of the recirculating aquaculture system, allowing aquaculture water to continuously flow through the bioreactor. A valve adjusts the water flow rate to keep the water's residence time within the bioreactor at approximately 30 minutes. Quality monitoring of farmed seabass revealed a 75% reduction in the main odorous substances in the water after four months of cultivation. This significantly reduced the amount of odorous substances on the seabass' surface and muscles, significantly improving the quality of the fish meat. The market price for this fish is 20% higher than that of conventional farmed seabass.

[0030] The second embodiment corresponds to a device for improving fish quality by using a probiotic bioreactor, such as Figure 2-5 As shown, including: A carrier membrane component, the carrier membrane component comprising a polymer material membrane 1 for fixing probiotics; The support frame 2 is used to fix and support the carrier membrane assembly. The support frame 2 is made of corrosion-resistant material. The carrier membrane assembly is cylindrical, with a support frame 2 at each end. The support frame 2 is annular, with an outer diameter less than or equal to the diameter of the water pipe 8 and a tapered inner diameter including a first tapered surface 4. Threads are provided on the outer circumference of each end of the water pipe 8, and an annular connecting sleeve 5 is provided at each end of the water pipe 8. The connecting sleeve 5 is used to connect the water pipes 8. A positioning groove 6 is defined between the inner and outer diameters of the connecting sleeve 5. The outer wall of the positioning groove 6 is threadedly connected to the outer wall of the water pipe 8, and the inner wall of the positioning groove 6 is a second tapered surface 7 that matches the angle of the first tapered surface 4.

[0031] For the recirculating aquaculture system, the bioreactor is installed in the water circulation pipeline to ensure that water can continuously flow through the bioreactor. The carrier membrane assembly and the support frame 2 are connected and placed in the water pipe 8. The connecting sleeves 5 are screwed on both ends of the water pipe 8. The support frame 2 is located in the positioning groove 6 of the connecting sleeve 5. As the connecting sleeve 5 is gradually screwed in, the second conical surface 7 will gradually approach the first conical surface 4 until it is completely close to the first conical surface 4. In this way, the support frame 2 is fixed by the connecting sleeve 5.

[0032] During the breeding process, the fishy substances in the water enter the membrane pores of the bioreactor through diffusion and come into contact with the probiotics fixed on the membrane. The probiotics use the fishy substances as a carbon source or nitrogen source for metabolic activities, and decompose them into harmless small molecules, such as carbon dioxide, water and inorganic salts, thereby reducing the concentration of fishy substances in the water. At the same time, when the fish are swimming, the fishy substances on the surface of the body will also be affected by the surrounding water containing probiotics. Some fishy substances are decomposed and removed, which can reduce the concentration of major fishy substances such as trimethylamine in the water by 70%-80%, effectively removing fishy substances in fish and water, and improving fish quality. The biodegradation effect of probiotics avoids the pollution of water and fish by traditional chemical methods. At the same time, probiotics can also improve the microecological environment of the water during metabolism, promote the balance of the aquaculture ecosystem, and have good environmental protection and sustainability.

[0033] The embodiments of the present application are described above in conjunction with the accompanying drawings. Unless there is a conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.

Claims

1. A method for improving fish quality using a probiotic bioreactor, characterized in that , including the following steps: S1: Using the polymer material membrane (1) as a carrier, immobilizing the probiotics on the polymer material membrane (1) to produce a bioreactor; S2: Fix the constructed probiotic bioreactor into the aquaculture water body.

2. The method for improving fish quality using a probiotic bioreactor according to claim 1, characterized in that: The probiotics in step S1 are probiotic strains isolated and screened from natural water bodies or the intestines of healthy fish, which have the ability to efficiently decompose fishy substances.

3. The method for improving fish quality using a probiotic bioreactor according to claim 2, characterized in that: The screened probiotic strains are Bacillus subtilis or lactic acid bacteria.

4. The method for improving fish quality using a probiotic bioreactor according to claim 1, characterized in that: The polymer material film (1) in step S1 is a polyvinylidene fluoride (PVDF) film or a polyacrylonitrile (PAN) film.

5. The method for improving fish quality using a probiotic bioreactor according to claim 1, characterized in that: In step S1, the screened probiotics are fixed on the carrier membrane by an adsorption method or a covalent binding method.

6. The method for improving fish quality using a probiotic bioreactor according to claim 1, characterized in that: In step S2, a hanging or floating method is used to ensure that the membrane is in full contact with the water.

7. A device for improving fish quality using a probiotic bioreactor, suitable for the method for improving fish quality using a probiotic bioreactor according to claim 1, characterized in that ,include: A carrier membrane component, the carrier membrane component comprising a polymer material membrane (1) for fixing probiotics; A support frame (2) is used to fix and support the carrier membrane assembly, and the support frame (2) is made of corrosion-resistant material.

8. The device for improving fish quality using a probiotic bioreactor according to claim 7, characterized in that: The carrier membrane assembly is in the form of a sheet, the support frame (2) is arranged around the carrier membrane assembly, and a connecting ring (3) is provided on the support frame (2).

9. The device for improving fish quality using a probiotic bioreactor according to claim 7, characterized in that: The carrier membrane assembly is cylindrical, and a support frame (2) is provided at each end of the carrier membrane assembly. The support frame (2) is annular, and its outer diameter is less than or equal to the diameter of the water pipe (8). Its inner diameter is conical and includes a first conical surface (4). Threads are provided at the outer periphery of both ends of the water pipe (8). An annular connecting sleeve (5) is provided at both ends of the water pipe (8). A positioning groove (6) is provided between the inner diameter and the outer diameter of the connecting sleeve (5). The outer wall of the positioning groove (6) is threadedly connected to the outer wall of the water pipe (8), and the inner wall of the positioning groove (6) is a second conical surface (7) that matches the angle of the first conical surface (4).

10. The device for improving fish quality using a probiotic bioreactor according to claim 9, characterized in that: The connecting sleeve (5) is used to connect the water pipes (8).

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