Application of suspended biological filler in fermentation of vitamin B12

Abstract

The invention relates to the technical field of microbial fermentation, in particular to application of suspended biological filler in fermentation of vitamin B12. The suspended biological filler is prepared from the following raw materials in parts by weight: 30-50 parts of modified polyvinyl alcohol fiber; 10 to 20 parts of shell powder; 10 to 20 parts of activated carbon; 5 to 15 parts of rice husk; 5 to 10 parts of hydrogel; 1-3 parts of a cross-linking agent; and 1-5 parts of an activator. According to the present invention, with the microporous structure of the modified polyvinyl alcohol fiber, the modification enhancement of the cobalt selenide and the synergistic effect of the rice husk and the hydrogel, the efficient adsorption and purification of the impurities in the fermentation broth are achieved, and the impurity content is significantly reduced, such that the extraction process of the vitamin B12 is simplified, and the product purity is improved. Meanwhile, microorganisms on the filler and the adsorption performance of the microorganisms play an important role in wastewater treatment, so that the wastewater reaches the discharge standard. In addition, the addition of the shell powder and the activated carbon not only further purifies the fermentation liquor, but also constructs a dynamic pH value adjusting system together, and ensures that the fermentation environment is stable and appropriate.

Description

Technical Field

[0001] The present invention relates to the technical field of microbial fermentation, and particularly relates to the application of a suspended biological filler in vitamin B12 fermentation. Background Art

[0002] As an indispensable nutrient, vitamin B12 is used in the pharmaceutical field to treat diseases such as pernicious anemia, as a nutritional fortifier in the food industry, and plays a key role in the growth and development of animals in the feed industry, and its market demand continues to climb. However, the current fermentation production of vitamin B12 faces many challenges.

[0003] Traditional fermentation processes mostly rely on fixed reactors and simple stirring devices, and microorganisms grow in a dispersed state in the solution. This growth mode causes microorganisms to be easily restricted by the transfer of nutrients and oxygen. Due to the lack of effective attachment sites, it is difficult for microorganisms to form high-density aggregated communities. The diffusion rate of nutrients in the solution is limited and cannot meet the growth needs of microorganisms in a timely manner. Oxygen is also difficult to be fully supplied around each microbial cell, resulting in slow microbial growth, a significant extension of the fermentation cycle, and difficulty in increasing the yield. At the same time, the process of extracting fermentation products is complex and costly.

[0004] Furthermore, the wastewater generated during the fermentation process has complex components, and the concentrations of organic pollutants, nitrogen, phosphorus, etc. are extremely high. The presence of high-concentration organic pollutants not only increases the difficulty of wastewater treatment, but also the harmful substances therein may inhibit the microbial activity, further affecting the fermentation efficiency. If the wastewater is directly discharged without effective treatment, it will cause serious pollution to the ecological environment such as water bodies and soil, threatening the ecological balance and human health.

[0005] Although suspended biological fillers have shown potential in some wastewater treatment and biological reactions, there are still many technical problems to be solved in the application of vitamin B12 fermentation. For example, how to optimize the composition and performance of the filler according to the special requirements of vitamin B12 fermentation to make it better adapt to the fermentation process; how to ensure the stability and long-term effectiveness of the filler in the fermentation system to avoid adverse effects on the quality of fermentation products; and how to achieve efficient treatment of fermentation wastewater to meet the discharge standards and realize resource recovery and utilization, etc. Summary of the Invention

[0006] The present application provides an application of a suspended biological filler in vitamin B12 fermentation to solve problems such as low microbial growth efficiency, difficult extraction of fermentation products, and high difficulty in treating fermentation wastewater in related technologies.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows: The present invention provides an application of a suspended biological filler in vitamin B12 fermentation, and the suspended biological filler is made of the following raw materials in parts by weight: Modified polyvinyl alcohol fiber: 30 - 50 parts; Seashell powder: 10 - 20 parts; Activated carbon: 10 - 20 parts; Rice husk: 5 - 15 parts; Hydrogel: 5 - 10 parts; Crosslinking agent: 1 - 3 parts; Activator: 1 - 5 parts.

[0008] Furthermore, the modified polyvinyl alcohol fiber is made from the following raw materials in parts by weight: Polyvinyl alcohol fiber: 80 - 100 parts; Glycerol: 5 - 15 parts; Cobalt selenide: 0.1 - 3 parts; Maleic acid: 5 - 15 parts; Initiator: 0.5 - 2 parts; Glutaraldehyde: 1 - 3 parts; Terminator: 0.1 - 1 part.

[0009] Furthermore, the initiator is ammonium persulfate, and the terminator is hydroquinone.

[0010] Furthermore, the preparation process of the modified polyvinyl alcohol fiber includes: Weigh the raw materials; Pre-treat the polyvinyl alcohol fiber. Among them, the pre-treatment is to soak the polyvinyl alcohol fiber in deionized water to make the polyvinyl alcohol fiber fully swell; Put the swollen polyvinyl alcohol fiber into a reaction vessel, and sequentially add glycerol, cobalt selenide, maleic acid, initiator, and glutaraldehyde, continuously stir and keep the reaction temperature within the range of 60 - 80 °C, and control the reaction time within 2 - 4 hours to make it react fully; When the reaction reaches the predetermined time, add the terminator to terminate the reaction, take out the reaction product, wash it repeatedly with deionized water to remove unreacted raw materials and impurities, and then put it into a drying device for drying to obtain the finished product of modified polyvinyl alcohol fiber.

[0011] Furthermore, the crosslinking agent is N,N - methylenebisacrylamide, and the activator is sodium hydroxide solution with a mass fraction of 5% - 10%.

[0012] Furthermore, the preparation process of the suspended biological filler includes: Soak the rice husk in the activator, control the soaking temperature at 50 - 70 °C, and the soaking time is 2 - 4 hours; Put the modified polyvinyl alcohol fiber, shell powder, activated carbon, activated rice husk, hydrogel and cross-linking agent into a high-speed mixer and stir at a speed of 500 - 1000 revolutions per minute for 10 - 30 minutes to fully mix and homogenize all raw materials; Put the formed filler into an oven and carry out a post-crosslinking reaction for 12 - 24 hours under the conditions of 40 - 60 °C and 50% - 70% relative humidity to form a stable hydrogel network structure; After the post-crosslinking reaction is completed, continue to dry at 40 - 60 °C for 24 - 48 hours, and package and store the finished product of the suspended biological filler after drying.

[0013] Furthermore, the application process of the suspended biological filler in vitamin B12 fermentation includes: Add 50 - 100 g of the pre-prepared suspended biological filler to the fermenter, and at the same time add a fermentation medium containing plant triterpenoids and make the suspended biological filler evenly dispersed in the medium by low-speed stirring to form a stable suspension system; Prepare a vitamin B12 fermentation medium, adjust its pH value to the appropriate range, and at the same time, under sterile conditions, inoculate the vitamin B12-producing strain into the fermenter; During the fermentation process, the temperature is maintained between 28 - 32 °C, the stirring speed is set at 150 - 250 revolutions per minute, the ventilation volume is controlled at 0.5 - 1 vvm, and after the fermentation lasts for 72 - 96 hours, when the content of vitamin B12 in the fermentation broth no longer increases significantly and the microbial cell concentration begins to decline, it is judged that the fermentation is over; Adopt separation and purification techniques to remove microbial cells and impurities in the fermentation broth to obtain a vitamin B12 product with a higher purity; concentrate and dry the purified vitamin B12 to obtain the finished vitamin B12.

[0014] Furthermore, the plant triterpenoids are prepared by the Triple - MAX triple glycolysis, "Multi - Point" enzymatic oligopeptide, and "Bio - Synthesis biosynthesis" processes. Among them, the plant triterpenoids include 38 mesoparticles with targeting functions, 32 high-quality particles with higher activity, and 28 colloidal particles with comprehensive nutrition.

[0015] Furthermore, the components of the vitamin B12 fermentation medium are glucose, yeast extract, peptone, inorganic salts, and trace elements.

[0016] Furthermore, after obtaining the finished vitamin B12, it also includes: Select a wastewater treatment reactor, clean and inspect it, and then load the suspended biological filler into the wastewater treatment reactor; Collect vitamin B12 fermentation wastewater, adjust its pH value and temperature to a suitable range, and then introduce it into a wastewater treatment reactor to provide a suitable growth environment for microorganisms by controlling the hydraulic retention time and using intermittent aeration; After a period of operation, when the wastewater treatment effect reaches the discharge standard, the wastewater can be discharged directly. At the same time, the residual sludge generated during the treatment process is regularly treated.

[0017] Furthermore, the wastewater treatment reactor is a biological contact oxidation tank or a sequencing batch activated sludge reactor.

[0018] The beneficial effects achieved by adopting the above-mentioned present invention are as follows: 1. The present invention prepares a suspended biological filler for use in vitamin B12 fermentation. Due to the efficient adsorption and purification of impurities by the suspended biological filler during the fermentation process, the impurity content in the fermentation liquid is greatly reduced after the fermentation is completed, so that the subsequent separation and purification technology is used to extract vitamin B12, and the operation is simpler and the product purity is easier to improve. At the same time, in the wastewater treatment link, the wastewater treatment reactor filled with used suspended biological fillers can quickly start the purification of fermentation wastewater by virtue of the residual microorganisms on the filler and its own adsorption properties. Through intermittent aeration and other methods, the microorganisms use the organic matter in the wastewater as a nutrient source to carry out secondary metabolic activities, further degrade pollutants, and enable the wastewater to meet the emission standards in a relatively short time, greatly reducing the burden of wastewater treatment and realizing the green and efficient connection between the fermentation and wastewater treatment processes; 2. Secondly, in the preparation of suspended biological fillers, modified polyvinyl alcohol fibers have a unique microporous structure. This is because polyvinyl alcohol fibers swell in deionized water, and the distance between molecular chains increases, providing a spatial basis for the entry and reaction of subsequent reactants. When glycerol is added, glycerol molecules are interspersed between the molecular chains of polyvinyl alcohol fibers, which to a certain extent stretch the molecular chains; the addition of maleic acid further promotes the formation of microporous structures. Maleic acid molecules contain double bonds and carboxyl groups. Under the action of free radicals generated by the initiator, their double bonds can participate in polymerization reactions and be embedded in the fiber cross-linking network that is being formed. At the same time, carboxyl groups undergo esterification reactions with hydroxyl groups on the surface of the fibers. Since maleic acid molecules are relatively large and have a certain degree of rigidity, they stretch the surrounding molecular chains during the reaction, causing the local pores to further expand and interconnect; these micropores provide a rapid diffusion channel for the substrate in the fermentation medium, greatly shortening the distance that the substrate diffuses to the surface of microbial cells, and accelerating the rate of microbial uptake of the substrate. According to Fick's law, the mass transfer rate is proportional to the concentration gradient and the diffusion coefficient. The microporous structure effectively increases the diffusion coefficient of the substrate, so that a high substrate concentration can always be maintained around the microorganisms, ensuring that the microorganisms continue to carry out metabolic activities efficiently, thereby significantly improving the fermentation efficiency. 3. Cobalt selenide is also added in the preparation of the modified polyvinyl alcohol fiber of the present invention. Cobalt selenide has a unique crystal structure and surface charge distribution characteristics. During the fiber modification reaction process, it can be embedded on the fiber surface, changing the charge density and distribution on the fiber surface. The surface of microbial cells usually carries negative charges. After being modified with cobalt selenide, the surface charge of the fiber shows an appropriate positive and negative distribution. Through electrostatic attraction, the adsorption between microorganisms and the fiber is further enhanced, enabling microorganisms to adsorb on the fiber surface, significantly increasing the concentration and activity of microorganisms in the fermentation system. Secondly, as a composite supply source of selenium and cobalt, cobalt selenide can fully meet the needs of microorganisms for these two key elements, stimulate the metabolic vitality of microorganisms, and promote their vigorous growth in the fermentation system. Among them, selenium can participate in the intracellular antioxidant defense system to protect microbial cells from oxidative damage and maintain the normal physiological functions of cells. Cobalt directly participates in the construction of the molecular structure of vitamin B12; 4. In the process of preparing the suspended biological filler of the present invention, after the rice husk is soaked and treated with an activator, the chemical bonds between the internal cellulose and hemicellulose are broken by the weak acidic substances or enzymes in the activator, resulting in partial hydrolysis of these nutrient components. During the subsequent fermentation process, as the microbial metabolic activities continue to progress, the environment of the fermentation broth changes, and these hydrolyzed nutrients such as sugars will be slowly released according to the concentration difference, providing a continuous and stable carbon source for microorganisms. At the same time, as a three-dimensional network-structured polymer, the hydrogel has hydrophilic groups such as hydroxyl and carboxyl groups inside it, which can bind a large amount of water molecules to form a "nutrient reservoir" to store water and dissolved nutrients. When the local nutrient concentration in the fermentation broth decreases, the hydrogel will use the nutrient concentration difference between it and the external environment to slowly release the stored nutrients, jointly ensuring that microorganisms obtain sufficient nutrients throughout the fermentation cycle with the nutrient source released by the rice husk, preventing growth stagnation or metabolic disorders caused by nutrient deficiency. In addition, the density and buoyancy characteristics of the rice husk itself, as well as the elasticity and viscosity of the hydrogel, enable the system formed by their cross-linking to be evenly dispersed and maintain a stable suspended state for a long time under the condition of low-speed stirring in the fermentation tank. This stable suspension system not only ensures sufficient and continuous contact between the filler, microorganisms, and substrates, but also provides a suitable growth environment and nutrient source for microorganisms, while promoting the rapid diffusion of substrate molecules and avoiding the negative impacts that may be brought by the precipitation and accumulation of the filler; 5. In the present invention, the shell powder can effectively adsorb large particulate impurities and some heavy metal ions in the fermentation broth, and the activated carbon can adsorb tiny impurities, harmful metabolic by-products, pigments and organic small molecules in all directions, further purifying the fermentation broth, significantly reducing the impurity content, and greatly optimizing the extraction process of the fermentation product. In addition, the shell powder slowly releases calcium ions during the fermentation process, which not only serves as a nutrient element for the growth of microorganisms, but also participates in various physiological activities. At the same time, it combines with hydrogen ions in an acidic environment to prevent the pH value from dropping excessively, playing a protective role for the microorganisms. The functional groups on the surface of the activated carbon can flexibly adjust the acidity and alkalinity of the fermentation broth within a wide pH range, and cooperate with the shell powder to form a dynamic pH value adjustment system, ensuring that the pH value during the fermentation process is stably within the range suitable for the growth of microorganisms and the synthesis of vitamin B12. Detailed implementation mode

[0019] The technical solutions of the present invention are illustrated below by specific examples. It should be understood that one or more method steps mentioned in the present invention do not exclude the existence of other method steps before and after the combined steps, or the insertion of other method steps between these clearly mentioned steps; it should also be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention. Moreover, unless otherwise specified, the numbers of each method step are only convenient tools for identifying each method step, rather than limiting the arrangement order of each method step or the scope in which the present invention can be implemented. The change or adjustment of their relative relationship, without substantial change in technical content, should also be regarded as the scope in which the present invention can be implemented.

[0020] In order to better understand the above technical solutions, the exemplary embodiments of the present invention are described in more detail below. Although the exemplary embodiments of the present invention are shown, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0021] The present invention is further described below in conjunction with the following embodiments.

[0022] Example 1 An application of a suspended biological filler in the fermentation of vitamin B12, and the suspended biological filler is made of the following raw materials in parts by weight: Modified polyvinyl alcohol fiber: 30 parts; Shell powder: 10 parts; Activated carbon: 10 parts; Rice husk: 5 parts; Hydrogel: 5 parts; Cross-linking agent: 1 part; Activator: 1 part.

[0023] In the embodiments of the present application, the modified polyvinyl alcohol fiber is made from the following raw materials by weight: Polyvinyl alcohol fiber: 80 parts; Glycerol: 5 parts; Cobalt selenide: 0.1 part; Maleic acid: 5 parts; Initiator: 0.5 part; Glutaraldehyde: 1 part; Terminator: 0.1 part.

[0024] In the embodiments of the present application, the initiator is ammonium persulfate, and the terminator is hydroquinone.

[0025] In the embodiments of the present application, the preparation process of the modified polyvinyl alcohol fiber includes: Weigh the raw materials; Pretreat the polyvinyl alcohol fiber. Among them, the pretreatment is to soak the polyvinyl alcohol fiber in deionized water to make the polyvinyl alcohol fiber fully swell; Put the swollen polyvinyl alcohol fiber into a reaction vessel, and sequentially add glycerol, cobalt selenide, maleic acid, initiator and glutaraldehyde, continuously stir and keep the reaction temperature within the range of 70 °C, and control the reaction time at 3 hours to make it react fully; When the reaction reaches the predetermined time, add the terminator to terminate the reaction, take out the reaction product and wash it repeatedly with deionized water to remove the unreacted raw materials and impurities, and then put it into a drying device for drying to obtain the finished product of the modified polyvinyl alcohol fiber.

[0026] In the embodiments of the present application, the crosslinking agent is N,N-methylenebisacrylamide, and the activator is a sodium hydroxide solution with a mass fraction of 7.5%.

[0027] In the embodiments of the present application, the preparation process of the suspended biological filler includes: Soak the rice husk in the activator, control the soaking temperature at 60 °C, and the soaking time is 3 hours; Put the modified polyvinyl alcohol fiber, shell powder, activated carbon, activated rice husk, hydrogel and crosslinking agent into a high-speed mixer and stir at a speed of 750 revolutions per minute for 20 minutes to make the raw materials fully mixed and uniform; Put the formed filler into an oven and carry out a post-crosslinking reaction at 50 °C and 60% relative humidity for 18 hours to form a stable hydrogel network structure; After the post-crosslinking reaction is completed, continue to dry at 50 °C for 36 hours, and package and store the dried finished product of the suspended biological filler.

[0028] In the embodiments of the present application, the application process of the suspended biological filler in vitamin B12 fermentation includes: Add 50 g of pre-prepared suspended biological filler into the fermenter, and at the same time, add the fermentation medium with plant tricin and evenly disperse the suspended biological filler in the medium by low-speed stirring to form a stable suspension system; Prepare the vitamin B12 fermentation medium, adjust its pH value to the appropriate range. At the same time, under aseptic conditions, inoculate the vitamin B12-producing strain into the fermenter; During the fermentation process, maintain the temperature between 30 °C, set the stirring speed at 200 revolutions per minute, control the aeration volume at 0.75 vvm. After 84 hours of fermentation, when the content of vitamin B12 in the fermentation broth no longer increases significantly and the microbial cell concentration begins to decline, judge that the fermentation is over; Adopt separation and purification technology to remove microbial cells and impurities in the fermentation broth to obtain a vitamin B12 product with higher purity; concentrate and dry the purified vitamin B12 to obtain the finished vitamin B12.

[0029] In the embodiment of the present application, the components of the vitamin B12 fermentation medium are glucose, yeast extract, peptone, inorganic salts and trace elements.

[0030] In the embodiment of the present application, plant tricin is prepared by Triple - MAX triple glycolysis, "Multi - Point" enzymatic oligopeptide, and "Bio - Synthesis" biosynthesis process. Among them, plant tricin includes 38 mesogens with targeting functions, 32 high-quality elements with higher activity, and 28 glutinous elements with comprehensive nutrition.

[0031] In the embodiment of the present application, after obtaining the finished vitamin B12, it further includes: Select a wastewater treatment reactor, clean and inspect it, and then load the suspended biological filler into the wastewater treatment reactor; Collect the vitamin B12 fermentation wastewater, adjust its pH value and temperature to the appropriate range, and then introduce it into the wastewater treatment reactor. By controlling the hydraulic retention time and adopting intermittent aeration, provide a suitable growth environment for microorganisms; After a period of operation, when the wastewater treatment effect reaches the discharge standard, the wastewater can be directly discharged. At the same time, regularly treat the excess sludge generated during the treatment process.

[0032] In the embodiment of the present application, the wastewater treatment reactor is a biological contact oxidation tank or a sequencing batch activated sludge reactor.

[0033] Example 2 An application of a suspended biological filler in vitamin B12 fermentation, and the suspended biological filler is made from the following raw materials in parts by weight: Modified polyvinyl alcohol fiber: 35 parts; Seashell powder: 12 parts; Activated carbon: 12 parts; Rice husk: 7 parts; Hydrogel: 6 parts; Crosslinking agent: 1.5 parts; Activator: 2 parts.

[0034] In the embodiment of the present application, the modified polyvinyl alcohol fiber is made from the following raw materials by weight: Polyvinyl alcohol fiber: 85 parts; Glycerol: 7 parts; Cobalt selenide: 0.8 part; Maleic acid: 7 parts; Initiator: 0.9 part; Glutaraldehyde: 1.5 parts; Terminator: 0.3 part.

[0035] In the embodiment of the present application, the initiator is ammonium persulfate, and the terminator is hydroquinone.

[0036] In the embodiment of the present application, the preparation process of the modified polyvinyl alcohol fiber includes: Weigh the raw materials; Pretreat the polyvinyl alcohol fiber. Among them, the pretreatment is to soak the polyvinyl alcohol fiber in deionized water to make the polyvinyl alcohol fiber fully swell; Put the swollen polyvinyl alcohol fiber into a reaction vessel, and successively add glycerol, cobalt selenide, maleic acid, initiator and glutaraldehyde, continuously stir and keep the reaction temperature within the range of 70 °C, and control the reaction time at 3 hours to make it react fully; When the reaction reaches the predetermined time, add the terminator to terminate the reaction, take out the reaction product and wash it repeatedly with deionized water to remove the unreacted raw materials and impurities, and then put it into a drying device to dry to obtain the finished modified polyvinyl alcohol fiber.

[0037] In the embodiment of the present application, the crosslinking agent is N,N-methylenebisacrylamide, and the activator is a sodium hydroxide solution with a mass fraction of 7.5%.

[0038] In the embodiment of the present application, the preparation process of the suspended biological filler includes: Soak the rice husk in the activator, control the soaking temperature at 60 °C, and the soaking time is 3 hours; Put the modified polyvinyl alcohol fiber, seashell powder, activated carbon, activated rice husk, hydrogel and crosslinking agent into a high-speed mixer, and stir at a speed of 750 revolutions per minute for 20 minutes to make the raw materials fully mixed and uniform; Put the formed packing material into an oven and carry out a post-crosslinking reaction for 18 hours under the conditions of 50°C and 60% relative humidity to form a stable hydrogel network structure; After the post-crosslinking reaction is completed, continue to dry at 50°C for 36 hours, and package and store the finished product of the suspended biological packing material after drying.

[0039] In the embodiment of the present application, the application process of the suspended biological packing material in vitamin B12 fermentation includes: Add 60 g of the pre-prepared suspended biological packing material into a fermenter, and at the same time add a fermentation medium with phytohormones and evenly disperse the suspended biological packing material in the medium through low-speed stirring to form a stable suspension system; Prepare a vitamin B12 fermentation medium, adjust its pH value to an appropriate range, and at the same time, inoculate a vitamin B12-producing strain into the fermenter under sterile conditions; During the fermentation process, the temperature is maintained between 30°C, the stirring speed is set at 200 revolutions per minute, the ventilation volume is controlled at 0.75 vvm, and after the fermentation lasts for 84 hours, when the content of vitamin B12 in the fermentation broth no longer increases significantly and the microbial cell concentration begins to decline, it is judged that the fermentation is over; Adopt separation and purification techniques to remove microbial cells and impurities in the fermentation broth to obtain a vitamin B12 product with higher purity; concentrate and dry the purified vitamin B12 to obtain the finished vitamin B12.

[0040] In the embodiment of the present application, the components of the vitamin B12 fermentation medium are glucose, yeast extract, peptone, inorganic salts, and trace elements.

[0041] In the embodiment of the present application, phytohormones are prepared by Triple - MAX triple glycolysis, "Multi - Point" enzymatic oligopeptides, and "Bio - Synthesis" biosynthesis processes. Among them, phytohormones include 38 mesogens with targeted functions, 32 high-quality elements with higher activity, and 28 collagens with comprehensive nutrition.

[0042] In the embodiment of the present application, after obtaining the finished vitamin B12, it further includes: Select a wastewater treatment reactor, clean and inspect it, and then load the suspended biological packing material into the wastewater treatment reactor; Collect vitamin B12 fermentation wastewater, adjust its pH value and temperature to an appropriate range, and then introduce it into the wastewater treatment reactor. By controlling the hydraulic retention time and adopting an intermittent aeration method, provide a suitable growth environment for microorganisms; After a period of operation, when the wastewater treatment effect reaches the discharge standard, the wastewater can be directly discharged. At the same time, the excess sludge generated during the treatment process is treated regularly.

[0043] In the embodiment of the present application, the wastewater treatment reactor is a biological contact oxidation tank or a sequencing batch reactor.

[0044] Example 3 An application of a suspended biological filler in vitamin B12 fermentation, the suspended biological filler is made from the following raw materials in parts by weight: Modified polyvinyl alcohol fiber: 40 parts; Seashell powder: 15 parts; Activated carbon: 15 parts; Rice husk: 10 parts; Hydrogel: 7 parts; Crosslinking agent: 2 parts; Activator: 3 parts.

[0045] In the embodiment of the present application, the modified polyvinyl alcohol fiber is made from the following raw materials in parts by weight: Polyvinyl alcohol fiber: 90 parts; Glycerol: 10 parts; Cobalt selenide: 1.5 parts; Maleic acid: 10 parts; Initiator: 1.3 parts; Glutaraldehyde: 2 parts; Terminator: 0.5 part.

[0046] In the embodiment of the present application, the initiator is ammonium persulfate and the terminator is hydroquinone.

[0047] In the embodiment of the present application, the preparation process of the modified polyvinyl alcohol fiber includes: Weigh the raw materials; Pretreat the polyvinyl alcohol fiber, wherein the pretreatment is to soak the polyvinyl alcohol fiber in deionized water to make the polyvinyl alcohol fiber fully swell; Put the swollen polyvinyl alcohol fiber into a reaction vessel, and sequentially add glycerol, cobalt selenide, maleic acid, initiator and glutaraldehyde, continuously stir and keep the reaction temperature within the range of 70 °C, and control the reaction time at 3 hours to make it react fully; When the reaction reaches the predetermined time, add the terminator to terminate the reaction, take out the reaction product and wash it repeatedly with deionized water to remove the unreacted raw materials and impurities, and then put it into a drying device for drying to obtain the finished product of the modified polyvinyl alcohol fiber.

[0048] In the embodiment of the present application, the crosslinking agent is N,N-methylenebisacrylamide, and the activator is a sodium hydroxide solution with a mass fraction of 7.5%.

[0049] In the embodiment of the present application, the preparation process of the suspended biological filler includes: Soak the rice husk in the activator at a soaking temperature controlled at 60°C for 3 hours; Put the modified polyvinyl alcohol fiber, shell powder, activated carbon, activated rice husk, hydrogel and crosslinking agent into a high-speed mixer and stir at a speed of 750 revolutions per minute for 20 minutes to fully mix and homogenize the raw materials; Put the formed filler into an oven and carry out a post-crosslinking reaction at 50°C and 60% relative humidity for 18 hours to form a stable hydrogel network structure; After the post-crosslinking reaction is completed, continue to dry at 50°C for 36 hours, and package and store the dried suspended biological filler finished product.

[0050] In the embodiment of the present application, the application process of the suspended biological filler in vitamin B12 fermentation includes: Add 70 g of the pre-prepared suspended biological filler to the fermenter, and at the same time add a fermentation medium with plant triterpenoids and make the suspended biological filler evenly dispersed in the medium by low-speed stirring to form a stable suspension system; Prepare a vitamin B12 fermentation medium, adjust its pH value to an appropriate range, and at the same time, inoculate the vitamin B12-producing strain into the fermenter under sterile conditions; During the fermentation process, the temperature is maintained between 30°C, the stirring speed is set at 200 revolutions per minute, the ventilation volume is controlled at 0.75 vvm. After 84 hours of fermentation, when the content of vitamin B12 in the fermentation broth no longer increases significantly and the microbial cell concentration begins to decline, it is judged that the fermentation is over; Adopt separation and purification techniques to remove microbial cells and impurities in the fermentation broth to obtain a vitamin B12 product with higher purity; concentrate and dry the purified vitamin B12 to obtain the finished vitamin B12.

[0051] In the embodiment of the present application, the components of the vitamin B12 fermentation medium are glucose, yeast extract, peptone, inorganic salts and trace elements.

[0052] In the embodiment of the present application, the plant triterpenoids are prepared by the Triple - MAX triple glycolysis, "Multi - Point" enzymatic oligopeptide, and "Bio - Synthesis biosynthesis" processes. Among them, the plant triterpenoids include 38 mesoprotons with targeted functions, 32 high-quality protons with higher activity, and 28 collagens with comprehensive nutrition.

[0053] In the embodiment of the present application, after obtaining the finished vitamin B12, it further includes: Select a wastewater treatment reactor, clean and inspect it, and then load suspended biological fillers into the wastewater treatment reactor; Collect the vitamin B12 fermentation wastewater, adjust its pH value and temperature to an appropriate range, and then introduce it into the wastewater treatment reactor. By controlling the hydraulic retention time and adopting the intermittent aeration method, provide a suitable growth environment for microorganisms; After running for a period of time, when the wastewater treatment effect reaches the discharge standard, the wastewater can be directly discharged. At the same time, regularly treat the excess sludge generated during the treatment process.

[0054] In the embodiment of the present application, the wastewater treatment reactor is a biological contact oxidation tank or a sequencing batch activated sludge reactor.

[0055] Example 4 An application of suspended biological fillers in vitamin B12 fermentation, and the suspended biological fillers are made from the following raw materials in parts by weight: Modified polyvinyl alcohol fiber: 45 parts; Seashell powder: 18 parts; Activated carbon: 18 parts; Rice husk: 13 parts; Hydrogel: 8 parts; Crosslinking agent: 2.5 parts; Activator: 4 parts.

[0056] In the embodiment of the present application, the modified polyvinyl alcohol fiber is made from the following raw materials in parts by weight: Polyvinyl alcohol fiber: 95 parts; Glycerol: 13 parts; Cobalt selenide: 2.2 parts; Maleic acid: 13 parts; Initiator: 1.7 parts; Glutaraldehyde: 2.5 parts; Terminator: 0.8 part.

[0057] In the embodiment of the present application, the initiator is ammonium persulfate, and the terminator is hydroquinone.

[0058] In the embodiment of the present application, the preparation process of the modified polyvinyl alcohol fiber includes: Weigh the raw materials; Pretreat the polyvinyl alcohol fiber, wherein the pretreatment is to soak the polyvinyl alcohol fiber in deionized water to make the polyvinyl alcohol fiber fully swell; Put the swollen polyvinyl alcohol fibers into a reaction vessel, and successively add glycerol, cobalt selenide, maleic acid, initiator, and glutaraldehyde. Continuously stir and keep the reaction temperature within the range of 70 °C, and control the reaction time at 3 hours to allow sufficient reaction; When the reaction reaches the predetermined time, add a terminator to terminate the reaction. Take out the reaction product and wash it repeatedly with deionized water to remove unreacted raw materials and impurities, and then put it into a drying device for drying to obtain the finished product of modified polyvinyl alcohol fibers.

[0059] In the embodiment of the present application, the cross-linking agent is N,N-methylenebisacrylamide, and the activator is a sodium hydroxide solution with a mass fraction of 7.5%.

[0060] In the embodiment of the present application, the preparation process of the suspended biological filler includes: Soak the rice husk in the activator, control the soaking temperature at 60 °C, and the soaking time at 3 hours; Put the modified polyvinyl alcohol fibers, shell powder, activated carbon, activated rice husk, hydrogel, and cross-linking agent into a high-speed mixer and stir at a speed of 750 revolutions per minute for 20 minutes to make the raw materials fully mixed and uniform; Put the formed filler into an oven and carry out a post-crosslinking reaction at 50 °C and 60% relative humidity for 18 hours to form a stable hydrogel network structure; After the post-crosslinking reaction is completed, continue to dry at 50 °C for 36 hours, and package and store the finished product of the suspended biological filler after drying.

[0061] In the embodiment of the present application, the application process of the suspended biological filler in the fermentation of vitamin B12 includes: Add 80 g of the pre-prepared suspended biological filler to the fermenter, and at the same time add a fermentation medium with phytohormones and make the suspended biological filler evenly dispersed in the medium by low-speed stirring to form a stable suspension system; Prepare a vitamin B12 fermentation medium, adjust its pH value to the appropriate range, and at the same time, inoculate the vitamin B12-producing strain into the fermenter under sterile conditions; During the fermentation process, the temperature is maintained between 30 °C, the stirring speed is set at 200 revolutions per minute, the ventilation volume is controlled at 0.75 vvm. After 84 hours of fermentation, when the content of vitamin B12 in the fermentation broth no longer increases significantly and the microbial cell concentration begins to decline, it is judged that the fermentation is over; Adopt separation and purification techniques to remove microbial cells and impurities in the fermentation broth to obtain a vitamin B12 product with a higher purity; concentrate and dry the purified vitamin B12 to obtain the finished vitamin B12.

[0062] In the embodiments of the present application, the components of the vitamin B12 fermentation medium are glucose, yeast extract, peptone, inorganic salts, and trace elements.

[0063] In the embodiments of the present application, the plant trinity is prepared by Triple - MAX triple glycolysis, "Multi - Point" enzymatic oligopeptide, and "Bio - Synthesis biosynthesis" process. Among them, the plant trinity includes 38 mesophores with targeted functions, 32 high - activity quality elements, and 28 comprehensive - nutrition collagens.

[0064] In the embodiments of the present application, after obtaining the finished vitamin B12, it further includes: Select a wastewater treatment reactor, clean and inspect it, and then load the suspended biological filler into the wastewater treatment reactor; Collect the vitamin B12 fermentation wastewater, adjust its pH value and temperature to the appropriate range, and then introduce it into the wastewater treatment reactor. By controlling the hydraulic retention time and adopting the intermittent aeration method, provide a suitable growth environment for microorganisms; After running for a period of time, when the wastewater treatment effect reaches the discharge standard, the wastewater can be directly discharged. At the same time, regularly treat the excess sludge generated during the treatment process.

[0065] In the embodiments of the present application, the wastewater treatment reactor is a biological contact oxidation tank or a sequencing batch reactor.

[0066] Example 5 An application of a suspended biological filler in vitamin B12 fermentation. The suspended biological filler is made from the following raw materials in parts by weight: Modified polyvinyl alcohol fiber: 50 parts; Shell powder: 20 parts; Activated carbon: 20 parts; Rice husk: 15 parts; Hydrogel: 10 parts; Cross - linker: 3 parts; Activator: 5 parts.

[0067] In the embodiments of the present application, the modified polyvinyl alcohol fiber is made from the following raw materials in parts by weight: Polyvinyl alcohol fiber: 100 parts; Glycerol: 15 parts; Cobalt selenide: 3 parts; Maleic acid: 15 parts; Initiator: 2 parts; Glutaraldehyde: 3 parts; Terminator: 1 part.

[0068] In the embodiments of the present application, the initiator is ammonium persulfate and the terminator is hydroquinone.

[0069] In the embodiments of the present application, the preparation process of the modified polyvinyl alcohol fiber includes: Weigh the raw materials; Pre-treat the polyvinyl alcohol fiber. Among them, the pre-treatment is to soak the polyvinyl alcohol fiber in deionized water to make the polyvinyl alcohol fiber fully swell; Put the swollen polyvinyl alcohol fiber into a reaction vessel, and successively add glycerol, cobalt selenide, maleic acid, initiator and glutaraldehyde, continuously stir and keep the reaction temperature within the range of 70°C, and control the reaction time at 3 hours to make it react fully; When the reaction reaches the predetermined time, add a terminator to terminate the reaction, take out the reaction product and wash it repeatedly with deionized water to remove unreacted raw materials and impurities, and then put it into a drying device for drying to obtain the finished modified polyvinyl alcohol fiber.

[0070] In the embodiments of the present application, the cross-linking agent is N,N-methylenebisacrylamide, and the activator is a sodium hydroxide solution with a mass fraction of 7.5%.

[0071] In the embodiments of the present application, the preparation process of the suspended biological filler includes: Soak the rice husk in the activator, control the soaking temperature at 60°C, and the soaking time is 3 hours; Put the modified polyvinyl alcohol fiber, shell powder, activated carbon, activated rice husk, hydrogel and cross-linking agent into a high-speed mixer and stir at a speed of 750 revolutions per minute for 20 minutes to make the raw materials fully mixed and uniform; Put the formed filler into an oven and carry out a post-crosslinking reaction at 50°C and 60% relative humidity for 18 hours to form a stable hydrogel network structure; After the post-crosslinking reaction is completed, continue to dry at 50°C for 36 hours, and package and store the finished suspended biological filler after drying.

[0072] In the embodiments of the present application, the application process of the suspended biological filler in the fermentation of vitamin B12 includes: Add 100 g of the pre-prepared suspended biological filler to the fermentation tank, and at the same time add a fermentation medium with phytohormones and make the suspended biological filler evenly dispersed in the medium by low-speed stirring to form a stable suspension system; Prepare a vitamin B12 fermentation medium, adjust its pH value to the appropriate range. At the same time, under aseptic conditions, inoculate the vitamin B12-producing strain into the fermentation tank; During the fermentation process, the temperature is maintained between 30°C, the stirring speed is set at 200 revolutions per minute, the aeration rate is controlled at 0.75 vvm. After 84 hours of fermentation, when the content of vitamin B12 in the fermentation broth no longer increases significantly and the microbial cell concentration begins to decline, the fermentation is judged to be over; Separation and purification techniques are used to remove microbial cells and impurities from the fermentation broth to obtain a vitamin B12 product with a higher purity; the purified vitamin B12 is concentrated and dried to obtain the finished vitamin B12.

[0073] In the embodiment of the present application, the components of the vitamin B12 fermentation medium are glucose, yeast extract, peptone, inorganic salts, and trace elements.

[0074] In the embodiment of the present application, the plant trinity is prepared by the Triple - MAX triple glycolysis, "Multi - Point" enzymatic oligopeptide, and "Bio - Synthesis biosynthesis" processes. Among them, the plant trinity includes 38 mesophores with targeting functions, 32 high - quality mesophores with higher activity, and 28 collagens with comprehensive nutrition.

[0075] In the embodiment of the present application, after obtaining the finished vitamin B12, it further includes: Select a wastewater treatment reactor, clean and inspect it, and then load the suspended biological filler into the wastewater treatment reactor; Collect the vitamin B12 fermentation wastewater, adjust its pH value and temperature to the appropriate range, and then introduce it into the wastewater treatment reactor. By controlling the hydraulic retention time and adopting the intermittent aeration method, a suitable growth environment is provided for the microorganisms; After running for a period of time, when the wastewater treatment effect reaches the discharge standard, the wastewater can be directly discharged. At the same time, the excess sludge generated during the treatment process is treated regularly.

[0076] In the embodiment of the present application, the wastewater treatment reactor is a biological contact oxidation tank or a sequencing batch reactor.

[0077] Comparative Example 1 An application of a suspended biological filler in vitamin B12 fermentation, the difference from Example 1 is only that the polyvinyl alcohol fiber is not modified, and the addition amount of the modified polyvinyl alcohol fiber is changed to the addition amount of polyvinyl alcohol fiber, and the components of the remaining suspended biological filler are the same as those in Example 1.

[0078] Comparative Example 2 A preparation method of fermented organic fertilizer, the difference from Example 1 is only that no suspended biological filler is added in the vitamin B12 fermentation, and the remaining process of preparing vitamin B12 is the same as that in Example 1.

[0079] Performance Test Examples 1 - 5 were compared and analyzed with Comparative Example 1 and Comparative Example 2. The test indicators covered key aspects such as fermentation efficiency, product purity, and wastewater treatment effect, as follows: I. Fermentation Efficiency Test During the fermentation process, the microbial cell concentration in the fermentation broth was measured every 12 hours using the hemocytometer method. The change curves of the microbial cell numbers in each example and comparative example at different time points were recorded, and the results showed that: Example 1: In the early stage of fermentation, the microbial cell concentration increased rapidly, starting from 0.5×10 6 cells / mL, reaching 2.0×10 6 cells / mL after 12 hours, increasing to 5.0×10 6 cells / mL after 24 hours, and reaching 8.0×10 6 cells / mL after 36 hours; Example 2: Starting from 0.6×10 6 cells / mL, reaching 2.2×10 6 cells / mL after 12 hours, increasing to 5.5×10 6 cells / mL after 24 hours, and reaching 8.5×10 6 cells / mL after 36 hours.

[0080] Example 3: Starting from 0.7×10 6 cells / mL, reaching 2.5×10 6 cells / mL after 12 hours, increasing to 6.0×10 6 cells / mL after 24 hours, and reaching 9.0×10 6 cells / mL after 36 hours.

[0081] Example 4: Starting from 0.8×10 6 cells / mL, reaching 2.8×10 6 cells / mL after 12 hours, increasing to 6.5×10 6 cells / mL after 24 hours, and reaching 9.5×10 6 cells / mL after 36 hours.

[0082] Example 5: Starting from 0.9×10 6 cells / mL, reaching 3.0×10 6 cells / mL after 12 hours, increasing to 7.0×10 6 cells / mL after 24 hours, and reaching 10.0×10 6 cells / mL after 36 hours.

[0083] Comparative Example 1: Since the polyvinyl alcohol fiber was not modified, the microbial adhesion ability was limited, starting from 0.3×10 6CFU / mL, reaching 1.2×10 6 CFU / mL at 12 hours, increasing to 3.0×10 6 CFU / mL at 24 hours, reaching 5.0×10 6 CFU / mL at 36 hours, with a relatively slow growth rate.

[0084] Comparative Example 2: Without adding suspended biological fillers, the microorganisms are unevenly dispersed in the solution and are easily affected by environmental factors. Initially 0.2×10 6 CFU / mL, reaching 1.0×10 6 CFU / mL at 12 hours, increasing to 2.5×10 6 CFU / mL at 24 hours, reaching 4.0×10 6 CFU / mL at 36 hours, with low growth efficiency.

[0085] II. Determination of vitamin B12 production: After fermentation, the content of vitamin B12 in the fermentation broth was determined by high performance liquid chromatography. The vitamin B12 production of Examples 1 - 5 increased successively, reaching 150, 170, 190, 210, and 230 μg / mL respectively, showing a significant increase compared to Comparative Example 2, which was only 100 μg / mL. Although there were some unmodified fibers in Comparative Example 1, due to the lack of various synergistic effects brought by modification, the vitamin B12 production was 130 μg / mL, indicating that modification plays a key role in improving fermentation efficiency.

[0086] III. Product purity test Analysis of impurity content: After fermentation, the same volume of fermentation broth was taken, and the content of heavy metal ions was detected by inductively coupled plasma mass spectrometry, and the content of pigments and organic small molecule impurities was determined by ultraviolet - visible spectrophotometer. The results are as follows: Example 1: Lead ion content 0.05 mg / L, absorbance of pigments and organic small molecule impurities 0.02.

[0087] Example 2: Lead ion content 0.04 mg / L, absorbance of pigments and organic small molecule impurities 0.018.

[0088] Example 3: Lead ion content 0.03 mg / L, absorbance of pigments and organic small molecule impurities 0.015.

[0089] Example 4: Lead ion content 0.02 mg / L, absorbance of pigments and organic small molecule impurities 0.012.

[0090] Example 5: Lead ion content 0.01 mg / L, absorbance of pigments and organic small molecule impurities 0.01.

[0091] Comparative Example 1: Due to the unmodified fibers, the adsorption performance is insufficient. The lead ion content is 0.1 mg / L, and the absorbance of pigments and organic small molecule impurities is 0.03.

[0092] Comparative Example 2: Without filler adsorption, the lead ion content is 0.2 mg / L, and the absorbance of pigments and organic small molecule impurities is 0.05, seriously affecting the purity of the subsequent product extraction.

[0093] Determination of the purity of the separated and purified product: After the fermentation broths of Examples 1 - 5 and Comparative Examples 1 and 2 were treated with the same separation and purification technology, the purity of the vitamin B12 product was measured again by HPLC. The purities of the vitamin B12 products finally obtained in Examples 1 - 5 reached 95%, 96%, 97%, 98%, and 99%, far higher than the 90% purity of Comparative Example 2. This fully demonstrates the excellent efficacy of the suspended biological filler in improving the product purity and lays a foundation for the industrial production of high-quality vitamin B12. Although unmodified fibers were partially used in Comparative Example 1, its product purity was only 93%, still lower than that of the example group, further highlighting the key role of the modification treatment.

[0094] IV. Wastewater treatment effect test Determination of the chemical oxygen demand (COD) removal rate: The fermentation wastewater was introduced into a wastewater treatment reactor filled with the suspended biological fillers used in Examples 1 - 5 and Comparative Examples 1 and 2. After operating for 72 hours under the same intermittent aeration conditions, the COD values of the influent and effluent were measured, and the COD removal rate was calculated. The COD removal rates of Examples 1 - 5 reached 80%, 82%, 85%, 88%, and 90% respectively, showing good wastewater treatment capabilities. In Comparative Example 1, due to the unmodified fibers, the performance of the filler was limited, and the COD removal rate was 70%, lower than that of the examples. In Comparative Example 2, without the participation of the filler, the removal of wastewater COD mainly relied on natural degradation, with extremely low efficiency, only 40%, making it difficult to meet the discharge standards.

[0095] Evaluation of the excess sludge production: After the wastewater treatment was completed, the excess sludge generated in each reactor was collected and weighed. The excess sludge production in Examples 1 - 5 was relatively small and stable, being 50 g, 45 g, 40 g, 35 g, and 30 g respectively. This is because the filler had adsorbed some impurities during the fermentation process, reducing the generation of sludge in the subsequent wastewater treatment. In Comparative Example 2, due to the lack of the purification effect of the pre - filler, a large amount of impurities in the wastewater were converted into sludge, and the excess sludge production was 80 g, significantly higher than that of the examples, increasing the cost and difficulty of sludge treatment. Similarly, the excess sludge production in Comparative Example 1 was 60 g, also higher than that of the example group.

[0096] In summary, the present application proposes an application of suspended biological fillers in vitamin B12 fermentation. By means of efficient adsorption and purification technologies, impurities in the fermentation broth are reduced, the extraction operation of vitamin B12 is simplified, and the purity is improved. In wastewater treatment, the used fillers can rapidly purify the fermentation wastewater. The suspended biological fillers are made of modified polyvinyl alcohol fibers and cobalt selenide, which accelerate the uptake of substrates by microorganisms and enhance the fermentation efficiency and microbial activity. The rice husk hydrolysate and hydrogel provide a stable carbon source and nutrients, maintaining the suspended state to ensure sufficient contact. The shell powder and activated carbon synergistically purify the fermentation broth, reduce impurities, optimize extraction, and dynamically adjust the pH value to ensure suitable microbial growth and vitamin B12 synthesis. Thus, the problems in the related technologies such as low microbial growth efficiency, difficult extraction of fermentation products, and high difficulty in treating fermentation wastewater are solved.

[0097] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. Application of a suspended biological filler in vitamin B12 fermentation, characterized in that, The floating biological filler is made from the following raw materials in parts by weight: Modified polyvinyl alcohol fiber: 30 - 50 parts; Shell powder: 10 - 20 parts; Activated carbon: 10 - 20 parts; Rice husk: 5 - 15 parts; Hydrogel: 5 - 10 parts; Crosslinking agent: 1 - 3 parts; Activator: 1 - 5 parts.

2. The application of a suspended biological filler in vitamin B12 fermentation according to claim 1, characterized in that, The modified polyvinyl alcohol fiber is made from the following raw materials in parts by weight: Polyvinyl alcohol fiber: 80 - 100 parts; Glycerol: 5 - 15 parts; Cobalt selenide: 0.1 - 3 parts; Maleic acid: 5 - 15 parts; Initiator: 0.5 - 2 parts; Glutaraldehyde: 1 - 3 parts; Terminator: 0.1 - 1 part.

3. The application of a suspended biological filler in vitamin B12 fermentation according to claim 2, wherein The initiator is ammonium persulfate, and the terminator is hydroquinone.

4. Use of a suspended biological filler according to claim 2 in the fermentation of vitamin B12, characterized in that, The preparation process of the modified polyvinyl alcohol fiber includes: Weigh the raw materials; Pre-treat the polyvinyl alcohol fiber. The pre-treatment is to soak the polyvinyl alcohol fiber in deionized water to make the polyvinyl alcohol fiber fully swell; Put the swollen polyvinyl alcohol fiber into a reaction vessel, and sequentially add glycerol, cobalt selenide, maleic acid, initiator, and glutaraldehyde. Continuously stir and keep the reaction temperature within the range of 60 - 80 °C, and control the reaction time at 2 - 4 hours to make it react fully; When the reaction reaches the predetermined time, add the terminator to terminate the reaction. Take out the reaction product and wash it repeatedly with deionized water to remove the unreacted raw materials and impurities, and then put it into a drying device for drying to obtain the finished product of modified polyvinyl alcohol fiber.

5. The application of a suspended biological filler in vitamin B12 fermentation according to claim 1, wherein The crosslinking agent is N,N - methylenebisacrylamide, and the activator is a sodium hydroxide solution with a mass fraction of 5% - 10%.

6. The application of a suspended biological filler in vitamin B12 fermentation according to claim 1, wherein The preparation process of the floating biological filler includes: Soak the rice husk in the activator, control the soaking temperature at 50 - 70 °C, and the soaking time at 2 - 4 hours; Put the modified polyvinyl alcohol fiber, shell powder, activated carbon, activated rice husk, hydrogel, and crosslinking agent into a high-speed mixer and stir at a speed of 500 - 1000 revolutions per minute for 10 - 30 minutes to make the raw materials fully mixed and uniform; Put the formed filler into an oven and carry out a post-crosslinking reaction at 40 - 60 °C and 50% - 70% relative humidity for 12 - 24 hours to form a stable hydrogel network structure; After the post-crosslinking reaction is completed, continue to dry at 40 - 60 °C for 24 - 48 hours. The dried floating biological filler finished product is packaged and stored.

7. Use of a suspended biological filler in vitamin B12 fermentation according to claim 1, characterized in that The application process of the floating biological filler in vitamin B12 fermentation includes: Add 50 - 100 g of the pre-prepared floating biological filler to the fermentation tank, and at the same time add a fermentation medium with phytohormones, and make the floating biological filler evenly disperse in the medium by low-speed stirring to form a stable suspension system; Prepare a vitamin B12 fermentation medium, adjust its pH value to the appropriate range. At the same time, under aseptic conditions, inoculate the vitamin B12-producing strain into the fermentation tank; During the fermentation process, the temperature is maintained between 28 - 32 °C, the stirring speed is set at 150 - 250 revolutions per minute, the aeration rate is controlled at 0.5 - 1 vvm. After the fermentation lasts for 72 - 96 hours, when the content of vitamin B12 in the fermentation broth no longer increases significantly and the microbial cell concentration begins to decline, the fermentation is judged to be completed; Using separation and purification techniques, the microbial cells and impurities in the fermentation broth are removed to obtain a vitamin B12 product with a higher purity; the purified vitamin B12 is concentrated and dried to obtain the finished vitamin B12.

8. The application of a suspended biological filler in vitamin B12 fermentation according to claim 1, wherein, The components of the vitamin B12 fermentation medium are glucose, yeast extract, peptone, inorganic salts, and trace elements.

9. Use of a suspended biological filler according to claim 7 in the fermentation of vitamin B12, characterized in that, After obtaining the finished vitamin B12, it further includes: Select a wastewater treatment reactor, clean and inspect it, and then load the suspended biological filler into the wastewater treatment reactor; Collect the vitamin B12 fermentation wastewater, adjust its pH value and temperature to the appropriate range, and then introduce it into the wastewater treatment reactor. By controlling the hydraulic retention time and adopting the intermittent aeration method, a suitable growth environment is provided for the microorganisms; After a period of operation, when the wastewater treatment effect reaches the discharge standard, the wastewater can be directly discharged. At the same time, the excess sludge generated during the treatment process is treated regularly.

10. Use of a suspended biological filler according to claim 9 in vitamin B12 fermentation, characterized in that, The wastewater treatment reactor is a biological contact oxidation tank or a sequencing batch reactor.