阅读说明：本技术 一种乳酸菌高密度发酵系统及发酵方法 (High-density fermentation system and fermentation method for lactic acid bacteria ) 是由 张其圣 吕鹏军 伍亚龙 杨恺 史梅莓 范智义 于 2021-09-30 设计创作，主要内容包括：一种乳酸菌高密度发酵系统及发酵方法,发酵系统包括发酵罐、补料罐、超滤装置、阴离子交换树脂装置、无菌阴离子交换柱以及三个泵,发酵罐通过管道连接于超滤装置上,超滤装置通过管道连接于阴离子交换树脂装置,阴离子交换树脂装置通过管道连接于发酵罐与无菌阴离子交换柱,无菌阴离子交换柱通过管道连接于发酵罐,补料罐通过管道连接于发酵罐,其中,第一个泵设于发酵罐与超滤装置的连接管道上,将超滤装置与离子交换偶联起来,使用超滤装置截留发酵液中的菌体及大分子物质,然后用离子交换法替换传统的采用碱中和调节pH的方式,改善了乳酸菌培养过程中所受的渗透压环境,提高了菌体的产量,增加了底物的利用率,减少了生产成本。(A high-density fermentation system and a fermentation method for lactic acid bacteria are disclosed, the fermentation system comprises a fermentation tank, a material supplementing tank, an ultrafiltration device, an anion exchange resin device, an aseptic anion exchange column and three pumps, the fermentation tank is connected to the ultrafiltration device through a pipeline, the ultrafiltration device is connected to the anion exchange resin device through a pipeline, the anion exchange resin device is connected to the fermentation tank and the aseptic anion exchange column through a pipeline, the aseptic anion exchange column is connected to the fermentation tank through a pipeline, the material supplementing tank is connected to the fermentation tank through a pipeline, wherein, the first pump is arranged on the connecting pipeline of the fermentation tank and the ultrafiltration device, the ultrafiltration device and the ion exchange are coupled, the bacteria and macromolecular substances in fermentation liquor of the ultrafiltration device are intercepted, then the traditional mode of adopting alkali neutralization and pH adjustment is replaced by the ion exchange method, and the osmotic pressure environment borne by the lactic acid bacteria in the culture process is improved, the yield of the thalli is improved, the utilization rate of the substrate is increased, and the production cost is reduced.)

1. The lactobacillus high-density fermentation system is characterized by comprising a fermentation tank (1), a material supplementing tank (7), an ultrafiltration device (3), an anion exchange resin device (4), a sterile anion exchange column (5) and three pumps (6), wherein the fermentation tank (1) is connected to the ultrafiltration device (3) through a pipeline, the ultrafiltration device (3) is connected to the anion exchange resin device (4) through a pipeline, the anion exchange resin device (4) is connected to the fermentation tank (1) and the sterile anion exchange column (5) through a pipeline, the sterile anion exchange column (5) is connected to the fermentation tank (1) through a pipeline, the material supplementing tank (7) is connected to the fermentation tank (1) through a pipeline, and the first pump (6) is arranged on a connecting pipeline between the fermentation tank (1) and the ultrafiltration device (3);

the second pump (6) is arranged on a connecting pipeline of the anion exchange resin device (4) and the fermentation tank (1);

the third pump (6) is arranged on a connecting pipeline of the fermentation tank (1) and the material supplementing tank (7);

the fermentation tank (1) is used for high-density fermentation of lactic acid bacteria;

the feed supplement tank (7) is used for supplementing a fresh culture medium and supplementing a culture solution lost due to ion exchange;

the ultrafiltration device (3) is used for filtering thalli and macromolecular organic matters;

the anion exchange resin device (4) is used for exchanging and adsorbing lactic acid in the fermentation liquid;

a sterile anion exchange column (5) is used to maintain the pH in the fermentor (1).

2. The lactobacillus high-density fermentation system according to claim 1, wherein the fermentation tank (1) comprises a tank body (10), the upper end of the tank body (10) is provided with a stirring mechanism (11), and an air inlet component (12) is arranged inside the tank body (10);

the tank body (10) comprises a shell (100), a conical cover (101) is arranged at the lower end of the shell (100), a communicating pipe head (102) is communicated with the lower end of the shell (100), an inner cylinder (103) is arranged in the shell (100), a funnel body (105) is arranged at the lower end of the inner cylinder (103), a discharge pipe (106) is communicated with the lower end of the funnel body (105), the conical cover (101) covers the funnel body (105), a plurality of heat conducting fins (104) are arranged on the outer walls of the inner cylinder (103) and the funnel body (105), the heat conducting fins (104) are made of copper alloy, a plurality of lantern rings (107) are arranged between the inner cylinder (103) and the shell (100), a plurality of through holes are formed in the lantern rings (107), a plurality of double-headed screws (108) are respectively penetrated through the lantern rings (107), a supporting wire sleeve (109) is respectively arranged between two adjacent double-headed screws (108), an inner embedded ring (1090) is arranged between the inner cylinder (103) and the upper end of the shell (100), the upper end of interior embedded ring (1090) is equipped with seal ring (1091), and the double-end screw (108) that are located the top layer all wear seal ring (1091), and the upper end that is located double-end screw (108) of top layer all connects on last seal ring (1091) through lock nut, and the upper end intercommunication of inner tube (103) has a plurality of feeding connecting pipe (1092).

3. The lactobacillus high-density fermentation system according to claim 2, wherein the stirring mechanism (11) comprises an upper extension cylinder (110) mounted on an upper sealing ring (1091), a sealing cover (111) is mounted at the upper end of the upper extension cylinder (110), a stirring motor (112) is mounted on the sealing cover (111), an output shaft of the stirring motor (112) is connected with a connecting disc (113), the connecting disc (113) is provided with folded connecting plates (114) in a circumferential array, folded plates (1140) are mounted at the lower ends of the folded connecting plates (114), a rotating ring (115) is arranged at the lower end of each folded plate (1140), a convex ring (116) is formed on the outer wall of each rotating ring (115), the convex ring (116) is located between the upper extension cylinder (110) and the sealing cover (111), the convex ring (116) extends to the lower end of the sealing cover (111), a rotating disc (117) penetrates through the rotating ring (115), and the lower end of the rotating disc (117) is provided with a lower limit ring, the lower limit ring is positioned at the lower side of the rotating ring (115), the upper disc is installed at the upper side of the rotating disc (117), the upper disc is provided with a plurality of overhanging support plates (118), the other ends of the overhanging support plates (118) are provided with upper limit rings, the upper limit rings are positioned at the upper side of the rotating ring (115), the folding plates (1140) are all sleeved on the upper limit rings, the upper disc is provided with upper extending columns in an upward extending manner, the outer sides of the upper extending columns are sleeved with rotating cylinders, the upper ends of the rotating cylinders are arranged on the connecting disc (113), the upper ends of the upper extending columns extend out of the output shaft of the stirring motor (112), the upper ends of the upper extending columns are fixed on the sealing cover (111), the lower layer of the rotating disc (117) is formed with annular grooves (119), the annular grooves (119) are provided with convex grooves in a circumferential array manner, the lower wall of the rotating ring (115) is provided with connecting rods (1190) in a circumferential array manner, the lower ends of the connecting rods (1191) are all hinged with connecting plates (1195), the other ends of the connecting plates (1191) are penetrated by lower extending rods (1195), the upper ends of the lower extension rods (1195) are respectively provided with a rolling ring (1194), the rolling rings (1194) are respectively positioned in the ring groove (119), the lower ends of the lower extension rods (1195) are respectively provided with a stirring plate (1196), the stirring plates (1196) penetrate through the inner cylinder (103), the connecting plates (1191) are respectively provided with a lower extension rod (1192) in a downward extending manner, and the lower ends of the lower extension rods (1192) are respectively provided with a scraper (1193);

the air inlet component (12) comprises an air inlet ring pipe (120) arranged on the inner side of an upper extension barrel (110), the air inlet ring pipe (120) is communicated with an air inlet pipe (121), the air inlet pipe (121) extends out of the upper extension barrel (110), the air inlet pipe (121) extends downwards and is provided with a plurality of connecting pipes (122) in a communicated manner, the lower end of each connecting pipe (122) is provided with a relay ring (123), the relay ring (123) extends downwards and is communicated with a plurality of air outlet pipes (124), the air outlet pipes (124) are provided with a plurality of air vent holes, and the air outlet nozzles (2) are arranged at the air vent holes.

4. The lactobacillus high-density fermentation system according to claim 3, wherein the air outlet nozzle (2) comprises a connector (20) arranged in the vent hole, an end cap (21) is arranged at the outer side end of the connector (20), a spring (22) is arranged in the end cap (21), a sealing bead (23) is arranged at the other end of the spring (22), and the sealing bead (23) is positioned in the connector (20);

the connector (20) comprises a connecting column body (200), one end of the connecting column body (200) is provided with a connecting column (201), the connecting column (201) is arranged in a vent hole, a vent hole (203) is formed in the connecting column (201), the other end of the vent hole (203) extends to the connecting column body (200), the other end of the vent hole (203) is provided with a conical cavity (204), a sealing bead (23) is positioned in the conical cavity (204), and the other end of the connecting column body (200) is provided with an inner wire ring (202);

an outer screw ring (212) is arranged at the inner end of the end cover (21), the outer screw ring (212) is arranged on the inner screw ring (202), an inner groove (210) is formed on the end cover (21), an air outlet hole (211) is formed at the bottom of the inner groove (210), and the spring (22) is arranged in the inner groove (210).

5. The lactobacillus high-density fermentation system according to claim 1, wherein the ultrafiltration device (3) comprises a plurality of ultrafiltration modules and a circulation system, the ultrafiltration modules comprise filter tubes (30), both ends of the filter tubes (30) are provided with feed heads (31), the filter tubes (30) are connected to the filter tubes (30) through a plurality of connecting members (32), and ultrafiltration members (33) are arranged in the filter tubes (30);

end rings (300) are arranged at two ends of the filter tube (30), positioning rods (301) are arranged on the end rings (300) in a circumferential array mode, a sealing ring (302) is arranged on the outer wall of each end ring (300), assembly ring grooves are formed in the end portions of the end rings (300), the filter tube (30) is communicated with a plurality of filtrate discharge tubes (303), filtrate connecting tubes (304) are arranged at the other ends of the filtrate discharge tubes (303), and liquid outlet header pipes (305) are arranged at the outer side ends of the filtrate connecting tubes (304);

the feeding head (31) comprises a connecting ring (310) arranged at the end part of the end ring (300), the sealing ring (302) penetrates through the connecting ring (310), the connecting ring (310) is provided with a conical feeding shell (311) in an outward extending mode, the diameter of the inner side end of the conical feeding shell (311) is larger than that of the outer side end of the conical feeding shell, the outer side end of the conical feeding shell (311) is communicated with a feeding connecting pipe (312), and the outer side end of the feeding connecting pipe (312) is provided with a mounting flange (313);

the connecting component (32) comprises a hinge seat (320) arranged on the connecting ring (310), the hinge seat (320) is hinged with a pair of L-shaped plates (321), a connecting seat (323) is arranged at the root part between the L-shaped plates (321), an end plate (322) is arranged at the other end of the L-shaped plate (321), a connecting screw rod (324) is arranged between the connecting seat (323) and the end plate (322), a rotating head (325) is arranged at one end of the connecting screw rod (324), an inner pressing plate (326) is arranged on the connecting screw rod (324), and the positioning rod (301) penetrates through the lower end of the inner pressing plate (326);

the ultrafiltration component (33) comprises a plurality of ultrafiltration tubes (330) penetrating in the filter tubes (30), two ends of each ultrafiltration tube (330) are respectively sleeved with a sleeve cap (331), the outer side ends of the sleeve caps (331) are respectively provided with an outer convex ring (332), the outer wall of each outer convex ring (332) is provided with sealing rubber, the groove bottom of each assembly ring groove is provided with two sealing rubber strips (3300), a sealing end cover (333) is arranged in each assembly ring groove, the sealing end cover (333) is fixed in the assembly ring groove through a plurality of screws (335), a plurality of through holes (334) are formed in the sealing end cover (333), the outer convex rings (332) are respectively penetrating at the inner sides of the sealing end covers (333), the through holes (334) are concentric and communicated with the corresponding outer convex rings (332), the ultrafiltration tubes (330) are sleeved with inner support discs (336), the inner support discs (336) penetrate through fixedly connected lead screws (337) in a circumferential array manner, and two adjacent fixedly connected through connecting wire sleeves (338), the filtrate discharge pipe (303) is positioned between two adjacent inner supporting discs (336);

the outer layer of the ultrafiltration tube (330) is made of alumina honeycomb ceramic material, and the inner layer of the ultrafiltration tube (330) is made of polyvinylidene fluoride and polysulfone membrane material.

6. The lactic acid bacteria high-density fermentation system according to claim 1, wherein:

the pH value of the fermentation tank (1) is controlled between 6 and 8;

the stirring speed of the fermentation tank (1) is 0-200 rpm;

the fermentation temperature of the fermentation tank (1) is 30-42 ℃;

and sterile air is introduced into the fermentation tank (1) during fermentation.

7. The high-density fermentation system of lactic acid bacteria according to claim 1, wherein the materials supplemented into the fermentation tank (1) by the supplement tank (7) are glucose, yeast powder and ammonium sulfate;

when in material supplement, the material supplement tank (7) adds one or more of glucose, yeast powder and ammonium sulfate to the fermentation tank (1);

when the material supplementing tank (7) is used for supplementing material, an SBA-40E biosensing analyzer is used for measuring the concentration of glucose in the fermentation tank, and the standard of supplementing material is that the concentration of glucose in the fermentation tank (1) is lower than 5 g/L.

8. The lactic acid bacteria high-density fermentation system according to claim 1, wherein:

the aperture of the ultrafiltration tube (330) is 0.01-0.001 μm, and the cut-off molecular weight is more than 10000D;

the ultrafiltration device (3) adopts a hydrogen peroxide sterilization mode, and the concentration of the hydrogen peroxide is 2-8%;

the resin in the anion exchange resin device (4) is one or more of D319, D311 and D301.

9. A high-density fermentation method of lactic acid bacteria, comprising the step of using the high-density fermentation system of lactic acid bacteria according to any one of claims 1 to 8, comprising:

fermentation: inoculating the lactobacillus plantarum seed liquid which is activated for two generations into a fermentation tank (1) for fermentation;

and (3) pH adjustment: when lactobacillus plantarum is fermented, automatically adding sterile resin through the sterile anion exchange column (5) to control the pH value in the fermentation tank (1) and maintain the pH value in the fermentation tank (1) between 6.5 and 6.9, and when the pH value in the fermentation tank (1) is lower than 6.5, automatically adding the sterile anion resin into the fermentation tank (1) through the sterile anion exchange column (5);

and (3) removing lactic acid: after fermentation enters a logarithmic phase, pumping lactobacillus plantarum fermentation liquor into an ultrafiltration device (3) at an interval of 2-3h, wherein the filtration pressure is 0.1-0.3MPa, filtering to remove lactobacillus plantarum and macromolecular substances, exchanging lactic acid from filtrate passing through the ultrafiltration device (3) through an anion exchange resin device (4), and returning culture solution into a fermentation tank (1) for continuous culture;

and (3) finishing fermentation: after the lactobacillus plantarum is fermented for 18-24 hours, the lactobacillus plantarum is pumped out, and thalli of the lactobacillus plantarum are separated out through centrifugation and collected.

10. The high-density fermentation method of lactic acid bacteria according to claim 9, wherein the resin treatment method comprises:

s1, washing the resin with sterile pure water until the effluent is clear and free of impurities;

s2, soaking the resin in a saturated sodium chloride solution with the volume being 3 times that of the resin for 18-20 hours, and then rinsing the resin with clear water;

s3, sequentially soaking in 4-5% NaOH solution and HCl solution in exchange resin for 2-4h, washing with a large amount of sterile pure water until the effluent is neutral, and repeating for 2-3 times;

s4 is soaked in 4-5% NaOH solution and rinsed to neutrality by sterile pure water.

Technical Field

The invention relates to the technical field related to microbial fermentation, in particular to a high-density fermentation system and a fermentation method of lactic acid bacteria.

Background

Lactic acid bacteria are probiotics which are widely distributed in nature, have important probiotic effects in intestinal tracts and oral cavities of human bodies, such as promoting the growth of the human bodies, regulating normal flora of the gastrointestinal tracts and maintaining microecological balance, thereby improving the functions of the gastrointestinal tracts, improving the digestibility and the biological value of food, reducing serum cholesterol, controlling endotoxin, inhibiting the growth of putrefying bacteria in the intestinal tracts, improving the immunity of the organisms and the like. In the food industry, lactic acid bacteria have a wide range of uses, such as fermenting dairy products, fermenting vegetables, fermenting meat products, seasonings, producing lactic acid, and the like. At present, the difference between the domestic probiotic production aspect and the foreign world is still large, in the lactic acid bacteria culture process, cells can be metabolized to generate a large amount of organic acids such as lactic acid and the like, the organic acids can inhibit the growth of the lactic acid bacteria in turn, and the alkaline solution is generally adopted for neutralization in the industry, so that the lactic acid bacteria can be maintained at the optimal pH value for growth in the fermentation process. But due to the alkali used for neutralization during the growth of lactic acid bacteria, such as Na in NaOH solution⁺Etc. can affect the osmotic pressure of the cells, resulting in a decrease in the quality of the final target product. Secondly, most of the existing lactobacillus fermentation is batch fermentation, excessive substrate is added at one time, so that the utilization rate of the substrate is low, and the centrifuged supernatant still contains a large amount of nutrients which are not absorbed and utilized by the thalliGenerally, it is considered that the treatment of waste water causes an increase in production cost and waste of raw materials, and therefore, it is necessary to solve these problems in order to achieve high-density culture of lactic acid bacteria.

Disclosure of Invention

The invention provides a high-density fermentation system and a fermentation method for lactic acid bacteria, aiming at solving the defects of the prior art, an ultrafiltration device is coupled with ion exchange, the ultrafiltration device is used for intercepting thalli and macromolecular substances in fermentation liquor, then the ion exchange method is used for replacing the traditional mode of adopting alkali neutralization to adjust pH, the osmotic pressure environment borne by the lactic acid bacteria in the culture process is improved, the yield of thalli is improved, the utilization rate of a substrate is increased, the production cost is reduced, and the high-density fermentation system and the fermentation method have stronger practicability.

In order to achieve the purpose of the invention, the following technology is adopted:

a lactobacillus high-density fermentation system comprises a fermentation tank, a material supplementing tank, an ultrafiltration device, an anion exchange resin device, an aseptic anion exchange column and three pumps, wherein the fermentation tank is connected to the ultrafiltration device through a pipeline;

the second pump is arranged on the connecting pipeline of the anion exchange resin device and the fermentation tank;

the third pump is arranged on a connecting pipeline of the fermentation tank and the material supplementing tank;

the fermentation tank is used for high-density fermentation of lactic acid bacteria;

the feed supplement tank is used for supplementing a fresh culture medium and supplementing a culture solution lost due to ion exchange;

the ultrafiltration device is used for filtering thalli and macromolecular organic matters;

the anion exchange resin device is used for exchanging and adsorbing lactic acid in the fermentation liquid;

a sterile anion exchange column was used to maintain the pH in the fermentor.

Further, the fermentation tank comprises a tank body, wherein the upper end of the tank body is provided with a stirring mechanism, and an air inlet component is arranged in the tank body;

the tank body comprises a shell, a conical cover is arranged at the lower end of the shell, the lower end of the shell is communicated with a communicating pipe head, an inner barrel is arranged in the shell, a funnel body is arranged at the lower end of the inner barrel, a discharging pipe is communicated with the lower end of the funnel body, the conical cover covers the funnel body, a plurality of heat conducting fins are arranged on the outer walls of the inner barrel and the funnel body, the heat conducting fins are made of copper alloy, a plurality of lantern rings are arranged between the inner barrel and the shell, a plurality of through holes are formed in the lantern rings, a plurality of double-headed screws penetrate through the lantern rings, a supporting wire sleeve is arranged between every two adjacent double-headed screws, an inner embedded ring is arranged between the upper ends of the inner barrel and the shell, an upper sealing ring is arranged at the upper end of the inner embedded ring, the double-headed screws located on the top layer penetrate through the upper sealing ring, the upper ends of the double-headed screws located on the top layer are connected to the upper sealing ring through locking nuts, and a plurality of feeding connecting pipes are communicated with the upper end of the inner barrel;

the stirring mechanism comprises an upper extension cylinder arranged on an upper sealing ring, a sealing cover is arranged at the upper end of the upper extension cylinder, a stirring motor is arranged on the sealing cover, an output shaft of the stirring motor is connected with a connecting disc, the connecting disc is provided with folded connecting plates in a circumferential array manner, folded plates are arranged at the lower ends of the folded connecting plates, rotating rings are arranged at the lower ends of the folded plates, convex rings are formed on the outer walls of the rotating rings, the convex rings are positioned between the upper extension cylinder and the sealing cover and extend to the lower ends of the sealing cover, a rotating disc penetrates through the rotating rings, a lower limit ring is arranged at the lower end of the rotating disc and is positioned at the lower side of the rotating rings, an upper disc is arranged at the upper side of the rotating disc, the upper disc is provided with a plurality of overhanging support plates, the other ends of the overhanging support plates are provided with upper limit rings, the upper limit rings are positioned at the upper limit rings, upper extension columns are arranged on the upper disc in an upward extending manner, the rotating cylinders are sleeved at the outer sides of the upper extension columns, the upper end of the rotating cylinder is arranged on the connecting disc, the upper end of the upper extension column extends out of an output shaft of the stirring motor, the upper end of the upper extension column is fixed on the sealing cover, a ring groove is formed in the lower layer of the rotary table, convex grooves are formed in the ring groove in a circumferential array mode, connecting rods are arranged on the lower wall of the rotating ring in a circumferential array mode, the lower ends of the connecting rods are hinged with connecting plates, lower extension rods penetrate through the other ends of the connecting plates, rolling rings are arranged at the upper ends of the lower extension rods and are located in the ring groove, stirring plates are arranged at the lower ends of the lower extension rods and penetrate through the inner cylinder, lower extension rods are arranged on the connecting plates in a downward extending mode, and scraping plates are arranged at the lower ends of the lower extension rods;

the air inlet component comprises an air inlet ring pipe arranged on the inner side of the upper extension cylinder, the air inlet ring pipe is communicated with an air inlet pipe, the air inlet pipe extends out of the upper extension cylinder, the air inlet pipe extends downwards and is provided with a plurality of connecting pipes in a communicating manner, the lower end of each connecting pipe is provided with a relay ring, the relay ring is communicated with a plurality of air outlet pipes in a downward extending manner, the air outlet pipes are provided with a plurality of air outlet holes, and air outlet nozzles are arranged at the air outlet holes;

the air outlet nozzle comprises a connector arranged in the air vent, an end cover is arranged at the outer side end of the connector, a spring is arranged in the end cover, and a sealing bead is arranged at the other end of the spring and is positioned in the connector;

the connector comprises a connecting column body, one end of the connecting column body is provided with a connecting column, the connecting column is arranged in a vent hole, a vent hole is formed in the connecting column, the other end of the vent hole extends into the connecting column body, a conical cavity is formed at the other end of the vent hole, a sealing bead is positioned in the conical cavity, and the other end of the connecting column body is provided with an inner screw ring;

the end cover is provided with an outer screw ring at the inner side end, the outer screw ring is arranged in the inner screw ring, the end cover is provided with an inner groove, the bottom of the inner groove is provided with an air outlet hole, and the spring is arranged in the inner groove.

Furthermore, the ultrafiltration device comprises a plurality of ultrafiltration modules and a circulating system, wherein each ultrafiltration module comprises a filter tube, both ends of each filter tube are provided with feed heads, the filter tubes are connected to the filter tubes through a plurality of connecting components, and an ultrafiltration component is arranged in each filter tube;

the two ends of the filter tube are provided with end rings, the end rings are provided with positioning rods in a circumferential array manner, the outer walls of the end rings are provided with sealing rings, assembling ring grooves are formed in the end parts of the end rings, the filter tube is communicated with a plurality of filtrate discharge tubes, filtrate connecting tubes are arranged at the other ends of the filtrate discharge tubes, and liquid outlet header pipes are arranged at the outer side ends of the filtrate connecting tubes;

the feeding head comprises a connecting ring arranged at the end part of the end ring, the sealing ring penetrates through the connecting ring, a conical feeding shell is arranged on the connecting ring in an outward extending mode, the diameter of the inner side end of the conical feeding shell is larger than that of the outer side end of the conical feeding shell, the outer side end of the conical feeding shell is communicated with a feeding connecting pipe, and a mounting flange is arranged at the outer side end of the feeding connecting pipe;

the connecting component comprises a hinge seat arranged on the connecting ring, the hinge seat is hinged with a pair of L-shaped plates, a connecting seat is arranged at the root part between the L-shaped plates, an end plate is arranged at the other end of each L-shaped plate, a connecting lead screw is arranged between the connecting seat and the end plate, a rotating head is arranged at one end of the connecting lead screw, an inner pressing plate is arranged on the connecting lead screw, and the positioning rod penetrates through the lower end of the inner pressing plate;

the ultrafiltration component comprises a plurality of ultrafiltration tubes penetrating through the filtration tubes, sleeve caps are sleeved at two ends of each ultrafiltration tube, outer side ends of the sleeve caps are provided with outer convex rings, the outer walls of the outer convex rings are provided with sealing rubber, two sealing rubber strips are arranged at the bottoms of the assembly ring grooves, sealing end covers are arranged in the assembly ring grooves and are fixed in the assembly ring grooves through a plurality of screws, a plurality of through holes are formed in the sealing end covers, the outer convex rings penetrate through the inner sides of the sealing end covers, the through holes are concentric and communicated with the corresponding outer convex rings, the ultrafiltration tube sleeves are provided with inner support discs, the inner support discs penetrate through fixedly connected screw rods in a circumferential array manner, two adjacent fixedly connected screw rods are connected through connecting screw sleeves, and a filtrate discharge tube is positioned between two adjacent inner support discs;

the outer layer of the ultrafiltration tube is made of alumina honeycomb ceramic material, and the inner layer of the ultrafiltration tube is made of polyvinylidene fluoride and polysulfone membrane material.

Further, the pH value of the fermentation tank is controlled between 6.0 and 8.0;

the stirring speed of the fermentation tank is 0-200 rpm;

the fermentation temperature of the fermentation tank is 30-42 ℃;

and sterile air is introduced into the fermentation tank during fermentation.

Further, the material supplemented into the fermentation tank by the supplementing tank is one or more of glucose, yeast powder and ammonium sulfate;

when the material supplementing tank adds glucose, yeast powder and ammonium sulfate to the fermentation tank, the ratio of glucose to yeast powder to ammonium sulfate is 1: 0.1-0.5;

and when the material is supplemented in the material supplementing tank, an SBA-40E biosensing analyzer is adopted to measure the concentration of the glucose in the fermentation tank, and the standard of material supplement is that the concentration of the glucose in the fermentation tank is lower than 5 g/L.

Furthermore, the aperture of the ultrafiltration tube is 0.01-0.001 μm, and the cut-off molecular weight is more than 10000D;

the ultrafiltration device adopts a hydrogen peroxide sterilization mode, and the concentration of the hydrogen peroxide is 2 to 8 percent;

the resin in the anion exchange resin device is one or more of D319, D311 and D301.

A high-density fermentation method of lactic acid bacteria comprises the following steps:

first-stage seed liquid: activating a glycerol tube containing lactobacillus plantarum, sucking bacterial liquid in 0.5-1ml of glycerol tube, injecting the bacterial liquid into an MRS culture medium, wherein the capacity of a conical flask containing the MRS culture medium is 250-500ml, the liquid loading capacity of the conical flask is 100-300ml, the sterilization temperature is 121 ℃, and the time is 15 min;

secondary seed liquid: injecting 40-60% of the first-stage seed solution into a culture medium of a second-stage seed solution, wherein the culture medium of the second-stage seed solution is an MRS culture medium, the conical flask of the second-stage seed solution is 1-3L, the liquid loading amount is 600-2000 ml, the sterilization temperature is 121 ℃, and the time is 15 min;

fermentation: inoculating the lactobacillus plantarum seed liquid which is activated for two generations into a fermentation tank for fermentation;

and (3) pH adjustment: when lactobacillus plantarum is fermented, automatically adding sterile resin through a sterile anion exchange column to control the pH value in the fermentation tank, maintaining the pH value in the fermentation tank between 6.5 and 6.9, and when the pH value in the fermentation tank is lower than 6.5, automatically adding the sterile anion exchange resin into the fermentation tank through the sterile anion exchange column;

and (3) removing lactic acid: after fermentation enters a logarithmic phase, pumping lactobacillus plantarum fermentation liquor into an ultrafiltration device at an interval of 2-3h, wherein the filtration pressure is 0.1-0.3MPa, filtering to remove lactobacillus plantarum and macromolecular substances, exchanging lactic acid from filtrate passing through the ultrafiltration device through an anion exchange resin device, and returning culture solution to a fermentation tank for continuous culture;

and (3) finishing fermentation: after the lactobacillus plantarum is fermented for 18-24 hours, the lactobacillus plantarum is pumped out, and thalli of the lactobacillus plantarum are separated out through centrifugation and collected.

Further, the resin treatment method comprises the following steps:

s1, washing the resin with sterile pure water until the effluent is clear and free of impurities;

s2, soaking the resin in a saturated sodium chloride solution with the volume being 3 times that of the resin for 18-20 hours, and then rinsing the resin with clear water;

s3, sequentially soaking in 4-5% NaOH solution and HCl solution in exchange resin for 2-4h, washing with a large amount of sterile pure water until the effluent is neutral, and repeating for 2-3 times;

s4 is soaked in 4-5% NaOH solution and rinsed to neutrality by sterile pure water.

Further, the culture temperature of the first-stage seed liquid and the second-stage seed liquid is 35-37 ℃, and the culture time is 18-24 h.

Further, the lactobacillus plantarum culture medium is: glucose: 10-30g/L, yeast powder: 10-40g/L, peptone: 8-20g/L, ammonium sulfate: 10-15g/L, sodium acetate: 1-3g/L, diammonium citrate 0.5-1.5 g/L, magnesium sulfate: 0.1-0.3 g/L, manganese sulfate: 0.1-0.2 g/L.

The technical scheme has the advantages that:

the invention couples the ultrafiltration device with ion exchange, firstly uses the ultrafiltration device to intercept macromolecular substances in the fermentation liquor, and then uses the ion exchange method to replace the traditional mode of adopting alkali to neutralize and regulate pH, thereby improving the osmotic pressure environment borne by the lactobacillus in the culture process, improving the yield of thalli, increasing the utilization rate of a substrate and reducing the production cost. Correspondingly, the special fermentation tank is adopted to ensure the temperature required in the fermentation process, and the culture solution is convenient to stir in the fermentation process. Correspondingly, the ultrafiltration module with longer service life is adopted, the ultrafiltration effect is improved, and the practicability is stronger.

Drawings

FIG. 1 shows a block diagram of a high-density fermentation system of lactic acid bacteria.

FIG. 2 shows the growth curve of Lactobacillus plantarum in a conventional fermentation system.

FIG. 3 shows the growth curve of Lactobacillus plantarum in a lactic acid bacteria high-density fermentation system.

FIG. 4 shows a perspective view of the fermenter.

FIG. 5 shows a first sectional perspective view of the fermenter.

FIG. 6 shows a sectional perspective view of the second embodiment of the fermentation tank.

FIG. 7 shows an enlarged view of the fermenter at A.

FIG. 8 shows an enlarged view of the fermenter at point B.

Figure 9 shows a gas outlet nozzle structure.

Fig. 10 shows a perspective view of the ultrafiltration module.

Fig. 11 shows a front view of an ultrafiltration module.

FIG. 12 shows a cross-sectional view at E-E of the ultrafiltration module.

Fig. 13 shows an enlarged view of the ultrafiltration module at D.

Fig. 14 shows an enlarged view of the ultrafiltration module at F.

Fig. 15 shows a partial cut-away view of an ultrafiltration module.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or the orientations or positional relationships that the products of the present invention are conventionally placed in use, and are only used for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

The terms "first," "second," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

The terms "parallel", "perpendicular", etc. do not require that the components be absolutely parallel or perpendicular, but may be slightly inclined. For example, "parallel" merely means that the directions are more parallel relative to "perpendicular," and does not mean that the structures are necessarily perfectly parallel, but may be slightly tilted.

Furthermore, the terms "substantially", and the like are intended to indicate that the relative terms are not necessarily strictly required, but may have some deviation. For example: "substantially equal" does not mean absolute equality, but because absolute equality is difficult to achieve in actual production and operation, certain deviations generally exist. Thus, in addition to absolute equality, "substantially equal" also includes the above-described case where there is some deviation. In this case, unless otherwise specified, terms such as "substantially", and the like are used in a similar manner to those described above.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

EXAMPLE 1

As shown in fig. 1, a lactobacillus high-density fermentation system comprises a fermentation tank 1, a material supplementing tank 7, an ultrafiltration device 3, an anion exchange resin device 4, a sterile anion exchange column 5 and three pumps 6, wherein the fermentation tank 1 is connected to the ultrafiltration device 3 through a pipeline, the ultrafiltration device 3 is connected to the anion exchange resin device 4 through a pipeline, the anion exchange resin device 4 is connected to the fermentation tank 1 and the sterile anion exchange column 5 through a pipeline, the sterile anion exchange column 5 is connected to the fermentation tank 1 through a pipeline, and the material supplementing tank 7 is connected to the fermentation tank 1 through a pipeline. Wherein, the first pump 6 is arranged on the connecting pipeline of the fermentation tank 1 and the ultrafiltration device 3, the second pump 6 is arranged on the connecting pipeline of the anion exchange resin device 4 and the fermentation tank 1, and the third pump 6 is arranged on the connecting pipeline of the fermentation tank 1 and the feeding tank 7. The fermentation tank 1 is used for high-density fermentation of lactic acid bacteria, the feed supplement tank 7 is used for supplementing a fresh culture medium and a culture solution lost due to ion exchange, the ultrafiltration device 3 is used for filtering thalli and macromolecular organic matters, the anion exchange resin device 4 is used for exchanging and adsorbing lactic acid in a fermentation solution, and the sterile anion exchange column 5 is used for maintaining the pH value in the fermentation tank 1.

The system can culture lactobacillus plantarum at high density through a fermentation tank 1, a feed supplement tank 7, an ultrafiltration device 3, an anion exchange resin device 4, a sterile anion exchange column 5, three pumps 6, pipelines for connecting all components, an opening and closing valve for controlling the opening and closing of all the components and related determination components for determining parameters of all the components.

In order to perform high-density culture of lactobacillus plantarum, sterile air is required to be introduced into the fermentation tank 1 during fermentation, and when the sterile air is introduced, the air is stored in a gas storage bottle through an air compressor, then moisture in the air is removed through a freeze dryer, then foreign bacteria in the air are filtered out through an air filter with a filter pore size of 0.22 μm, and finally the air is introduced into the fermentation tank 1. The pH value in the fermentation tank 1 is specifically controlled between 6.5 and 6.9, which is the optimal propagation interval for Lactobacillus plantarum. The fermentation tank 1 stirs the culture solution and the bacterial solution at a stirring speed of 50-100rpm, so that the lactobacillus plantarum can fully absorb the culture solution, and the propagation rate of the lactobacillus plantarum is increased. The fermentation tank 1 also provides a proper fermentation temperature of 35-37 ℃ for the propagation of the lactobacillus plantarum. The fermentation mode of the fermentation tank 1 and the fermentation mode of the traditional fermentation tank 1 have the advantages that moisture in the air entering the fermentation tank 1 is removed, and a filter membrane with smaller aperture is selected, so that the risk that the fermentation tank 1 is infected by bacteria caused by the fact that air containing moisture is brought into mixed bacteria is reduced.

The feed supplement tank 7 continuously provides nutrient solution for the fermentation tank 1, the nutrient solution is glucose, and simultaneously provides stable carbon source and nitrogen source for the fermentation tank 1, specifically carbon source and nitrogen source substances are yeast powder and ammonium sulfate, and the proportion of the feed supplement rule between glucose and the yeast powder and the ammonium sulfate is 1: 0.1-0.5. And during the specific feeding operation, measuring the concentration of the glucose in the fermentation tank 1 by using an SBA-40E biosensing analyzer, and when the concentration of the glucose in the fermentation tank 1 is less than 5-10g/L, supplementing the glucose, a carbon source and a nitrogen source into the fermentation tank 1 so as to keep the concentration of the glucose in the fermentation tank 1 between 5-10 g/L. The system and the traditional feeding mode have the advantages that accurate feeding can be carried out according to the concentration of the substrate in the fermentation tank 1, the substrate is controlled to be at a lower level, the inhibition effect of the substrate on the thallus can be reduced, the thallus content is increased, meanwhile, the waste of the substrate can be reduced, the substrate utilization rate is increased, and the cost of a subsequent sewage treatment link is reduced.

The aperture of the ultrafiltration membrane in the ultrafiltration device 3 is 0.01-0.001 μm, and the cut-off molecular weight is more than 10000D. And the ultrafiltration membrane is made of polyvinylidene fluoride and polysulfone membrane materials, and the ultrafiltration membrane material has the advantages of acid and alkali resistance, high temperature resistance, cleaning resistance and good pollution resistance, so that the service time of the ultrafiltration membrane is prolonged, and the use cost is reduced. Ultrafiltration device 3 adopts hydrogen peroxide solution to soak, the sterilization mode of washing, wherein, hydrogen peroxide solution concentration is 2% -8%, soak time 0.5h, wash time 0.5h, then wash with aseptic water, wash remaining hydrogen peroxide solution for use after repeating twice with aseptic water, its advantage lies in that the zymotic fluid can be withheld thallus and macromolecular substance wherein before carrying out ion exchange, only allow micromolecular substance and salt through being used for ion exchange, can prolong the life of resin among the ion exchange system greatly like this, and the production cost is reduced.

The resin used in the anion exchange resin device 4 is D319, the device can ensure that the fermentation liquor after passing through the ultrafiltration device 3 enters the device and is exchanged and adsorbed by the device to generate lactic acid in the fermentation liquor, the fermentation liquor after ion exchange is pumped into the fermentation tank 1 through the pump 6 to be continuously cultured, the utilization rate of the substrate is improved in the mode, the cost is saved, meanwhile, compared with the traditional fermentation, the method removes the lactic acid in the fermentation liquor through the ion exchange resin, the stability of pH is maintained, the alkali liquor for neutralization is replaced, and Na in the neutralization liquor is removed⁺，K⁺The inhibition caused by the bacteria can increase the yield of the bacteria.

The sterile anion exchange column 5 is mainly used for controlling the pH value in the fermentation tank 1, when the pH value in the fermentation tank 1 is lower than the set 6.5, anion exchange resin in the sterile anion exchange column 5 can enter the fermentation tank 1, so that the pH in the fermentation tank is kept constant, compared with the traditional alkali solution neutralization mode, the regulation mode relieves the use of alkali solution in the traditional fermentation, relieves the rise of the osmotic pressure of fermentation liquor caused by neutralizing salt ions in the alkali solution, improves the cell osmotic pressure environment in the fermentation process of lactic acid bacteria, and improves the yield and the efficiency of the lactic acid bacteria.

EXAMPLE 2

As shown in fig. 4-8, the fermentation tank 1 includes a tank 10, a stirring mechanism 11 is disposed at the upper end of the tank 10, and an air inlet member 12 is disposed inside the tank 10. Compared with the traditional fermentation tank, the fermentation tank 1 can ensure the fermentation temperature during fermentation, can stably stir culture solution and the like during the fermentation process, and can stably convey air to the fermentation tank 1 during fermentation, thereby facilitating the fermentation of lactic acid bacteria.

The tank body 10 comprises a shell 100, a conical cover 101 is arranged at the lower end of the shell 100, a communicating pipe head 102 is communicated with the lower end of the shell 100, an inner cylinder 103 is arranged in the shell 100, a funnel body 105 is arranged at the lower end of the inner cylinder 103, a discharge pipe 106 is communicated with the lower end of the funnel body 105, the conical cover 101 covers the funnel body 105, a plurality of heat conducting fins 104 are arranged on the outer walls of the inner cylinder 103 and the funnel body 105, the heat conducting fins 104 are made of copper alloy, a plurality of lantern rings 107 are arranged between the inner cylinder 103 and the shell 100, a plurality of through holes are arranged on the lantern rings 107, a plurality of double-headed screws 108 are respectively penetrated through the lantern rings 107, a supporting thread sleeve 109 is respectively arranged between every two adjacent double-headed screws 108, an embedded ring 1090 is arranged between the inner cylinder 103 and the upper end of the shell 100, an upper seal ring 1091 is arranged at the upper end of the embedded ring 1090, the double-headed screws 108 on the top layer are respectively penetrated through upper seal rings 1091, and the upper ends of the double-headed screws 108 on the top layer are respectively connected to the upper seal ring 1091 through locking nuts, the upper end of the inner cylinder 103 is communicated with a plurality of feeding connecting pipes 1092. The shell 100 and the conical cover 101 in the tank body 1 provide a cavity for water bath heating, the temperature control is simple, the heat preservation effect is excellent, and the temperature consistency can be ensured during heat preservation. In order to improve the efficiency of heat transfer or heat exchange, a heat conductive sheet 104 made of a copper alloy having excellent heat conductivity is provided on the inner tube 103. The embedded rings 1090 between the inner cylinder 103 and the housing 100 play a role in stably supporting the inner cylinder 103, and meanwhile, the double-threaded screws 108 and the supporting thread sleeves 109 fix the embedded rings 1090, so that the supporting stability and the supporting strength are improved.

The stirring mechanism 11 comprises an upper extension cylinder 110 arranged on an upper seal ring 1091, a seal cover 111 is arranged at the upper end of the upper extension cylinder 110, a stirring motor 112 is arranged on the seal cover 111, an output shaft of the stirring motor 112 is of a hollow structure, the output shaft of the stirring motor 112 is connected with a connecting disc 113, the connecting disc 113 is provided with fold-shaped connecting plates 114 in a circumferential array manner, fold-shaped plates 1140 are arranged at the lower ends of the fold-shaped connecting plates 114, a rotating ring 115 is arranged at the lower end of the fold-shaped plates 1140, a convex ring 116 is formed on the outer wall of the rotating ring 115, the convex ring 116 is positioned between the upper extension cylinder 110 and the seal cover 111, the convex ring 116 extends to the lower end of the seal cover 111, a turntable 117 penetrates through the rotating ring 115, a lower limit ring is arranged at the lower end of the rotating ring 117, an upper disc is arranged at the upper side of the turntable 117, a plurality of overhanging support plates 118 are arranged, an upper limit ring is arranged at the other end of the support plates 118, the upper limit ring is arranged at the upper side of the rotating ring 115, the folding plates 1140 are all sleeved on the upper limit ring, the upper disc is provided with an upper extension column in an upward extending manner, the outer side of the upper extension column is sleeved with a rotating cylinder, the upper end of the rotating cylinder is arranged on the connecting disc 113, the upper end of the upper extension column extends out of the output shaft of the stirring motor 112, and the upper end of the upper extension column is fixed on the sealing cover 111 through a fixed disc and a plurality of fixed screw rods, a ring groove 119 is formed in the lower layer of the turntable 117, the ring groove 119 is provided with convex grooves in a circumferential array, the lower wall of the rotating ring 115 is provided with connecting rods 1190 in a circumferential array, the lower ends of the connecting rods 1190 are hinged with connecting plates 1191, the other ends of the connecting plates 1191 are respectively penetrated with a lower extension rod 1195, the upper ends of the lower extension rods 1195 are respectively provided with a rolling ring 1194, the rolling rings 1194 are respectively positioned in the ring groove 119, the lower ends of the lower extension rods 1195 are respectively provided with a stirring plate 1196, the stirring plates 1196 are penetrated in the inner cylinder 103, the connecting plates 1191 are respectively provided with a lower extension rod 1192 in a downward extending manner, and the lower ends of the lower extension rods 1192 are provided with scraping plates 1193. The working principle is that the stirring motor 112 is started, the connecting disc 113 is driven by the stirring motor 112 to rotate, the connecting disc 113 drives the rotating ring 115 to rotate through the folded connecting plate 114 when rotating, the rotating ring 115 drives each connecting plate 1191 to rotate in the rotating process, and the connecting plates 1191 enable the scraping plates 1193 to act on the inner wall of the inner cylinder 103 periodically under the limiting of the annular groove 119 and the convex groove in the rotating process, and finally, thalli or culture solution adhered to the inner cylinder 103 drops, so that the utilization rate of the culture solution is improved, and the fermentation cost is reduced. And the connecting plate 1191 not only drives the stirring plate 1196 to rotate around the axial direction of the rotating ring 115 in the rotating process, but also drives the stirring plate 1196 to rotate under the driving of the rolling ring 1194, so that the stirring effect is improved, and the fermentation speed is increased. Wherein the upper limit ring and the lower limit ring are provided to ensure the stability of the rotation ring 115.

The air inlet member 12 includes an air inlet ring pipe 120 installed inside the upper extending cylinder 110, the air inlet ring pipe 120 is communicated with an air inlet pipe 121, the air inlet pipe 121 extends out of the upper extending cylinder 110, the air inlet pipe 121 extends downward and is provided with a plurality of connecting pipes 122 in a communicating manner, the lower end of the connecting pipe 122 is provided with a relay ring 123, the relay ring 123 is communicated with a plurality of air outlet pipes 124 in a downward extending manner, the air outlet pipes 124 are provided with a plurality of air vents, and the air vents 2 are arranged at the air vents. Wherein the air inlet ring pipe 120 conveniently and uniformly introduces sterile air into the inner cylinder 103, and the air can be uniformly filled in the inner cylinder 103 by filling the relay ring 123 with filter cotton and further filtering the mixed bacteria through the filter cotton, so as to provide the air outlet pipe 124.

As shown in fig. 9, the air outlet nozzle 2 includes a connector 20 disposed in the air vent, an end cap 21 is disposed at an outer end of the connector 20, a spring 22 is disposed in the end cap 21, a sealing bead 23 is disposed at another end of the spring 22, and the sealing bead 23 is disposed in the connector 20. The connector 20 comprises a connecting column body 200, one end of the connecting column body 200 is provided with a connecting column 201, the connecting column 201 is arranged in a vent hole, a vent hole 203 is formed in the connecting column 201, the other end of the vent hole 203 extends into the connecting column body 200, the other end of the vent hole 203 is formed with a conical cavity 204, the sealing bead 23 is positioned in the conical cavity 204, and the other end of the connecting column body 200 is provided with an inner wire ring 202. The end cover 21 is provided with an outer wire ring 212 at the inner end, the outer wire ring 212 is arranged on the inner wire ring 202, the end cover 21 is formed with an inner groove 210, the bottom of the inner groove 210 is formed with an air outlet 211, and the spring 22 is arranged in the inner groove 210. The arrangement of the air outlet nozzle 2 mainly considers that when the fermentation is stopped, the culture solution easily enters the air outlet pipe 124, so that the air outlet pipe 124 is easily blocked, and meanwhile, the cleaning is also inconvenient. When air enters the connector 20 at high pressure and high speed during the venting process, the sealing bead 23 is moved toward the end cap 21 by the impact force, and the spring 22 is compressed while the sealing bead 23 is moved, and air is finally ejected from the air outlet 211 through the vent hole 203. When the air supply is stopped, the air pressure inside the fermentation tank 1 is obviously higher than the external air pressure due to the lack of the external air pressure, and meanwhile, the sealing beads 23 are positioned in the conical cavity 204 under the action of the spring 22 and seal the conical cavity 204, so that the ventilation holes are sealed finally, foreign bacteria are prevented from entering the fermentation tank 1, and the culture solution and the like can be prevented from entering the air outlet pipe 124.

EXAMPLE 3

As shown in fig. 11-15, the ultrafiltration device 3 includes a plurality of ultrafiltration modules and a circulation system, the ultrafiltration modules include filter tubes 30, feed heads 31 are disposed at two ends of the filter tubes 30, the filter tubes 30 are connected to the filter tubes 30 through a plurality of connection members 32, and ultrafiltration members 33 are disposed in the filter tubes 30.

The two ends of the filter tube 30 are provided with end rings 300, the end rings 300 are provided with positioning rods 301 in a circumferential array mode, the outer wall of each end ring 300 is provided with a sealing ring 302, assembling ring grooves are formed in the end portions of the end rings 300, the filter tube 30 is communicated with a plurality of filtrate discharge tubes 303, the other ends of the filtrate discharge tubes 303 are provided with filtrate connecting tubes 304, and the outer side ends of the filtrate connecting tubes 304 are provided with liquid outlet header pipes 305. Provides a filtering space for the ultrafiltration component 33 and also provides protection for the ultrafiltration component 33, and the filtrate outlet pipe 303, the filtrate connecting pipe 304 and the liquid outlet main pipe 305 discharge the filtered small-molecule bacterium liquid.

The feeding head 31 comprises a connecting ring 310 arranged at the end of the end ring 300, the sealing ring 302 penetrates through the connecting ring 310, the connecting ring 310 is provided with a conical feeding shell 311 extending outwards, the diameter of the inner end of the conical feeding shell 311 is larger than that of the outer end thereof, the outer end of the conical feeding shell 311 is communicated with a feeding connecting pipe 312, and the outer end of the feeding connecting pipe 312 is provided with a mounting flange 313. The feeding head 31 is provided with a conical structure, so that the fluid can be prevented from causing vibration of the ultrafiltration member 33 during the filtration process, and damage to the ultrafiltration member 33 can be avoided. In order to improve the sealing effect between the filter tube 30 and the feed head 31, a corresponding sealing ring 302 is provided.

The connecting member 32 includes a hinge base 320 mounted on the connecting ring 310, the hinge base 320 is hinged with a pair of L-shaped plates 321, a connecting base 323 is arranged at the root between the L-shaped plates 321, an end plate 322 is arranged at the other end of the L-shaped plate 321, a connecting screw rod 324 is arranged between the connecting base 323 and the end plate 322, a rotating head 325 is arranged at one end of the connecting screw rod 324, an inner pressing plate 326 is arranged on the connecting screw rod 324, and the positioning rod 301 penetrates through the lower end of the inner pressing plate 326. This component 32 conveniently connects chimney filter 30 and feed head 31, dismantlement when also being convenient for overhaul simultaneously, when dismantling, rotates connecting screw 324 through rotating head 325, and connecting screw 324 will drive interior clamp plate 326 outwards when rotating to break away from with locating lever 301, then rotate L shaped plate 321 around articulated seat 320, then carry out the operation of demolising of chimney filter 30 and feed head 31.

The ultrafiltration member 33 comprises a plurality of ultrafiltration tubes 330 penetrating through the filter tubes 30, two ends of each ultrafiltration tube 330 are respectively sleeved with a sleeve cap 331, the outer side end of each sleeve cap 331 is provided with an outer convex ring 332, the outer wall of each outer convex ring 332 is provided with sealing rubber, two sealing rubber strips 3300 are arranged at the bottom of each assembly ring groove, a sealing end cover 333 is arranged in each assembly ring groove, each sealing end cover 333 is fixed in each assembly ring groove through 335 of a plurality of screws, each sealing end cover 333 is provided with a plurality of through holes 334, each outer convex ring 332 penetrates through the inner side of each sealing end cover 333, each through hole 334 is concentric with and communicated with the corresponding outer convex ring 332, each ultrafiltration tube 330 is sleeved with an inner support disc 336, each inner support disc 336 is provided with fixedly connected lead screws 337 in a circumferential array mode, each adjacent two fixedly connected lead screws 337 are connected through a connecting wire sleeve 338, a filtrate discharge pipe 303 is arranged between each adjacent two inner support discs 336, the outer layer of each ultrafiltration tube 330 is made of alumina honeycomb ceramic material, and the inner layer of each ultrafiltration tube 330 is made of polyvinylidene fluoride and polysulfone membrane material. The ultrafiltration tube 330 is mainly made of alumina honeycomb ceramic materials, and plays an external protection role for the ultrafiltration tube 330, so that the strength of the ultrafiltration tube 330 is improved, and meanwhile, the oxidation resistance, corrosion resistance and other characteristics of the ultrafiltration tube 330 are improved, so that the service life of the ultrafiltration tube 330 is prolonged. The ultrafiltration membrane material of polyvinylidene fluoride and polysulfone membrane material has the advantages of acid and alkali resistance, high temperature resistance, cleaning resistance and good pollution resistance, thereby improving the service time of the ultrafiltration membrane and reducing the use cost. In order to avoid the vibration of the ultrafiltration tube 330 caused by the inconsistent density of the fluid on the inner wall and the outer wall of the ultrafiltration tube 330 during the filtration process, the damage to the ultrafiltration tube 330 is caused during the vibration, an inner supporting disc 336 is arranged, the ultrafiltration tube 330 is supported by the inner supporting disc 336, and the inner supporting disc 336 is connected with a connecting screw rod 337 and a connecting screw sleeve 338. Wherein, the arrangement of the sleeve cap 331 and the convex ring 332 and the sealing end cover 333 can seal the two ends of the ultrafiltration tube 330, thereby preventing macromolecules from entering into small molecules during the filtration process, and improving the filtration effect. And the sealing rubber strip 3300 is arranged to improve the sealing effect between the sealing end cover 333 and the filter tube 30.

EXAMPLE 4

A high-density fermentation method of lactic acid bacteria comprises the following steps:

first-stage seed liquid: activating a glycerol tube containing lactobacillus plantarum, sucking bacterial liquid in 0.5-1ml of glycerol tube, injecting the bacterial liquid into an MRS culture medium, wherein the capacity of a conical flask containing the MRS culture medium is 250-500ml, the liquid loading capacity of the conical flask is 100-300ml, the sterilization temperature is 121 ℃, the time is 15min, the culture temperature is 35-37 ℃, and the culture time is 18-24 h.

Secondary seed liquid: injecting 40-60% of the volume of the first-stage seed solution into a culture medium of a second-stage seed solution, wherein the culture medium of the second-stage seed solution is an MRS culture medium, the conical flask of the second-stage seed solution is 1-3L, the liquid loading amount is 600-2000 ml, the sterilization temperature is 121 ℃, the time is 15min, the culture temperature is 35-37 ℃, and the culture time is 18-24 h.

Fermentation: inoculating the lactobacillus plantarum seed solution activated for two generations into a fermentation tank 1 for fermentation, wherein the pH value of the fermentation tank 1 is controlled to be 6.5-6.9, and the rotation speed is 50-100 rpm. The lactobacillus plantarum culture medium comprises: glucose: 10-30g/L, yeast powder: 10-40g/L, peptone: 8-20g/L, ammonium sulfate: 10-15g/L, sodium acetate: 1-3g/L, diammonium citrate 0.5-1.5 g/L, magnesium sulfate: 0.1-0.3 g/L, manganese sulfate: 0.1-0.2 g/L.

And (3) pH adjustment: when lactobacillus plantarum is fermented, sterile resin is automatically added through the sterile anion exchange column 5 to control the pH value in the fermentation tank 1 and maintain the pH value in the fermentation tank 1 between 6.5 and 6.9, and when the pH value in the fermentation tank 1 is lower than 6.5, the sterile anion exchange column 5 automatically adds the sterile anion resin to the fermentation tank 1.

And (3) removing lactic acid: after fermentation enters a logarithmic phase, lactobacillus plantarum fermentation liquor is pumped into an ultrafiltration device 3 at intervals of 2-3h, the filtration pressure is 0.1-0.3MPa, lactobacillus plantarum and macromolecular substances are removed through filtration, the filtrate passing through the ultrafiltration device 3 exchanges lactic acid through an anion exchange resin device 4, the culture solution returns to a fermentation tank 1 to be continuously cultured, the lactobacillus plantarum and the macromolecular substances are removed through filtration, the phenomenon that some protein molecules are attached to ion exchange resin to cause the reduction of the efficiency of ion exchange is avoided, and the service life of the resin is shortened.

And (3) finishing fermentation: after the lactobacillus plantarum is fermented for 18-24 hours, the lactobacillus plantarum is pumped out, and thalli of the lactobacillus plantarum are separated out through centrifugation and collected.

The resin treatment method comprises the following steps:

step 1, washing the resin with sterile pure water until the effluent is clear and free of impurities;

step 2, soaking the resin in a saturated sodium chloride solution with the volume of 3 times that of the resin for 18-20 hours, and then rinsing with clear water;

step 3, sequentially soaking 4-5% NaOH solution and HCl solution in exchange resin for 2-4h, washing with a large amount of sterile pure water until the effluent is neutral, and repeating for 2-3 times;

and 4, soaking the mixture in 4-5% NaOH solution, and leaching the mixture to be neutral through sterile pure water.

In combination with fig. 2 and fig. 3 and the following table, it can be seen that the method is compared with the conventional fermentation method:

firstly, compared with the traditional method, the system prolongs the logarithmic growth phase of the lactobacillus plantarum, namely prolongs the growth time of the bacteria, and avoids the early entering of the stationary phase in the fermentation process. Finally, the OD620 value of the lactobacillus plantarum reaches 2.3 times of the original value, larger and more efficient lactobacillus yield is obtained, and the culture efficiency of the lactobacillus plantarum is obviously improved.

The utilization rate of the substrate is obviously improved in the embodiment, and is mainly reflected in the obvious reduction of salinity, total phosphorus and COD (chemical oxygen demand), and the indexes show that the utilization rate of the fermentation substrate can be improved, the resources can be utilized more efficiently, the cost of subsequent sewage treatment is reduced, and the energy is saved, so that the aim of green production is fulfilled.

Through the analysis, the fermentation level of the lactobacillus plantarum is obviously improved, the fermentation cost is reduced, and the environmental protection pressure is relieved.

	Salinity (mg/L)	COD(mg/L)	Total phosphorus (mg/L)
				Conventional methods	12000	40000	80
This example	5000	15000	36

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and it is apparent that those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.