阅读说明：本技术 一种生物法利用牛血制备免疫球蛋白的工艺 (Process for preparing immune globulin by using bovine blood through biological method ) 是由 杜增鹏 杨金华 马宗瑞 于 2019-12-19 设计创作，主要内容包括：本发明公开了一种生物法利用牛血制备免疫球蛋白的工艺,属于生物技术领域。本申请以牛血为原料,集成混菌微生物发酵技术、现代生物分离技术,研制开发出高提取率的免疫球蛋白产品。本发明通过生物发酵法提升利用牛血制备免疫球蛋白的免疫活性和提取率,实现牛屠宰加工牛血废弃物的资源化再利用；本申请利用毕赤酵母、汉逊酵母和假丝酵母共同发酵牛血,充分利用微生物间的协同作用,提升免疫球蛋白得率；多菌种混合发酵不仅提高了免疫球蛋白素的得率,而且通过微生物间的发酵作用提升了免疫球蛋白的免疫活性；该工艺制备的免疫球蛋白产品提取率和活性保留率高,具有较好的转化价值,具有广阔的市场应用价值。(The invention discloses a process for preparing immunoglobulin by using bovine blood through a biological method, belonging to the technical field of biology. The method takes the bovine blood as a raw material, integrates a mixed microbial fermentation technology and a modern biological separation technology, and develops the immunoglobulin product with high extraction rate. According to the invention, the immunocompetence and the extraction rate of immunoglobulin prepared by using the cattle blood are improved by a biological fermentation method, and the resource recycling of cattle blood waste generated in cattle slaughtering and processing is realized; according to the method, the cow blood is fermented by using the pichia pastoris, the hansenula polymorpha and the candida, and the synergistic effect among microorganisms is fully utilized, so that the yield of immunoglobulin is improved; the multi-strain mixed fermentation not only improves the yield of the immunoglobulin, but also improves the immunocompetence of the immunoglobulin through the fermentation effect among microorganisms; the immunoglobulin product prepared by the process has high extraction rate and activity retention rate, better conversion value and wide market application value.)

1. A technology for preparing immunoglobulin by using bovine blood through a biological method is characterized by comprising the following steps:

(1) preparing plasma: preparing O.1M sodium squarate solution as an anticoagulant, uniformly mixing fresh bovine blood and the anticoagulant according to a ratio of 9:1, centrifuging for 10-20 minutes at a rotating speed of 2500-3000 rpm by using a centrifuge, removing red blood cells to obtain plasma, and placing the plasma at a temperature of-20 to-40 ℃ for later use;

(2) preparing fermentation liquor: dissolving the plasma in the step (1) in water, and then adding 2% glucose and 0.15% (NH) of the plasma by mass₄)₂SO₄、0.10% KH₂PO₄、0.1%MgSO₄Preparing a liquid fermentation culture medium; sterilizing at 121 deg.C for 15 min;

(3) aerobic fermentation: adding composite microorganisms accounting for 2% of the mass of the fermentation liquor into the fermentation liquor, and carrying out aerobic fermentation for 12 hours at the temperature of 28-35 ℃;

(4) and (3) filtering: filtering to remove thallus and insoluble solid after fermentation to obtain crude immunoglobulin solution;

(5) and (3) ultrafiltration: concentrating the crude immunoglobulin solution by an ultrafiltration membrane, washing and removing impurities to obtain a trapped phase;

(6) ultrasonic extracting, adding the trapped phase into ethanol, ultrasonic extracting for 2 times, and mixing extractive solutions;

(7) and (3) precipitation: adjusting the acid of the extracting solution, and centrifuging to obtain a precipitate;

(8) and (3) freeze drying: and (5) freezing and drying the precipitate to obtain the compound.

2. The process according to claim 1, wherein the ratio of water added in step (2) is plasma: the purified water is 1: 1.

3. The process according to claim 1, wherein the complex microorganism in step (3) is one or more of Pichia pastoris, Hansenula polymorpha, and Candida albicans.

4. The process of claim 3, wherein the inoculation amount ratio of Pichia pastoris, Hansenula polymorpha and Candida albicans is 2:1: 2.

5. The process of claim 3, wherein the activating method for Pichia pastoris, Hansenula polymorpha, Candida albicans is as follows: under the aseptic operation condition, two rings of strains are picked from the inclined plane of the yeast YDP by using an inoculating ring, inoculated into a 500mL triangular flask containing 300mLPDA liquid culture medium, subjected to shaking culture at the temperature of between 28 and 32 ℃ and at the speed of 140r/min for 24 hours, and then inoculated into a seed tank for expanded culture according to the process to prepare the yeast seed liquid, wherein the effective viable count of the seed liquid is required to be more than or equal to 10⁹cfu/mL。

6. The process according to claim 1, wherein the ultrafiltration membrane in the step (5) is a porous fiber ultrafiltration membrane with a molecular weight cut-off of 3000-10000D.

7. The process according to claim 1, wherein the amount of the extraction solvent used in the step (6) is 10-15 times (V/W), the extraction time is 20-30min, and the process is performed at room temperature.

8. The process according to claim 1, wherein the acid in step (7) is hydrochloric acid or sulfuric acid, and the pH after acidification is 7.3-7.7.

Technical Field

The invention relates to a process for preparing immunoglobulin by using bovine blood through a biological method, in particular to a process for preparing the immunoglobulin with high purity and high activity retention rate by using a biological fermentation technology and a low-temperature drying technology, belonging to the technical field of biology.

Background

Animal husbandry is the agricultural backbone industry in our country. With the rapid development of intensive livestock and poultry industry in China, the byproducts of livestock and poultry product processing are increased greatly, wherein the blood of livestock and poultry is the largest byproduct, and the resources are increasingly abundant. Nearly 2 hundred million bull cattle and sheep are bred in China every year, the number of cattle stock-keeping in China at the end of 2018 is 10576.0 ten thousand, slaughtered beef cattle is 1363 ten thousand, the total bleeding amount of the cattle is 4.2% of the physical quantity of live cattle, the blood collection amount of each cattle is 11-15 kg, the calf is about 2.7kg, and 57.25 million tons of cattle blood can be obtained in China every year. The development and utilization of pig blood are good, but the utilization of cattle blood has not been greatly developed and paid attention. Because the bovine blood has heavier fishy smell, poor digestibility and palatability, poor color and luster sense, extremely difficult preservation of raw material blood and other factors, a large amount of blood is discarded after a small amount of the bovine blood is processed into food, and the comprehensive utilization of bovine blood resources is severely restricted. At present, the utilization rate and the deep processing degree of livestock and poultry blood are generally low in China and difficult to industrialize, and products are mainly primary processed products such as feeding blood powder and edible blood bean curd, so that the comprehensive development and utilization of bovine blood resources have extremely important significance and are a current and future development trend.

A large number of researches prove that the immunoglobulin can agglutinate bacteria, neutralize bacterial toxins, thoroughly kill bacteria and viruses, activate complement and enhance the immune function of the body under the participation of other factors in the body. Wherein IgG content is the highest, accounting for about 75% of total Ig in serum, and is the main antibody in humoral immunity; IgM accounts for about 10%, and has higher hemolysis, bacteriolysis, sterilization, phagocytosis promotion and aggregation than IgG, and is a highly effective antimicrobial antibody. 10g of immune protein can be extracted per kilogram of blood. At present, the immunoglobulin has increasingly prominent clinical effect, and the application field, variety and adaptation condition are expanded. The immunoglobulin can be isolated by salting out with saturated ammonium sulfate, organic solvent precipitation, column chromatography, ultrafiltration, etc. The salting-out method and the organic solvent method have low cost, simple and quick operation and wide application. The Qinghai province uses a large amount of blood generated by slaughtering yaks as a characteristic resource, proposes a technology for preparing immune protein by utilizing yak blood, and completes a plurality of projects for developing and producing immunoglobulin products with high added values by utilizing blood resources. For example, patent 2011101193811 discloses a method for extracting immunoglobulin from cattle hairy blood, which comprises adding anticoagulant into fresh bright cattle blood, and centrifuging to obtain plasma. Removing impurities from blood plasma by ultrafiltration membrane, and concentrating. The trapped phase is extracted by ethanol ultrasound, and is obtained by freeze drying, and the method has the advantages of simple extraction method, rapidness, safety, no pollution, low cost, low carbon and no public nuisance.

In the prior art, although industrialization of preparing immunoglobulin from bovine blood is realized at present, the preparation of immunoglobulin from bovine blood still has the technical disadvantages of low activity retention rate, low industrialization economic benefit and the like, and the integration and application of key technologies are urgently needed.

Disclosure of Invention

In order to overcome the defects of the prior art and realize the high-efficiency preparation of high-purity immunoglobulin by using bovine blood, the invention provides a process for preparing immunoglobulin by using bovine blood through a biological method, integrates a modern biological separation technology, a mixed bacteria microbial fermentation technology and the like, realizes the high-efficiency extraction and high-valued resource comprehensive utilization of bovine blood immunoglobulin, and meets the market demand of immunoglobulin. The immunoglobulin product prepared by the process has high extraction rate and activity retention rate, and has good conversion value.

The invention realizes the technical effects through the following technical scheme:

a biological method for preparing immunoglobulin by using bovine blood specifically comprises the following steps:

(1) preparing plasma: preparing O.1M sodium squarate solution as an anticoagulant, uniformly mixing fresh bovine blood and the anticoagulant according to a ratio of 9:1, centrifuging for 10-20 minutes at a rotating speed of 2500-3000 rpm by using a centrifuge, removing red blood cells to obtain plasma, and placing the plasma at a temperature of-20 to-40 ℃ for later use;

(2) preparing fermentation liquor: dissolving the plasma in the step (1) in water, and then adding 2% glucose and 0.15% (NH) of the plasma by mass₄)₂SO₄、0.10% KH₂PO₄、0.1%MgSO₄Preparing a liquid fermentation culture medium; sterilizing at 121 deg.C for 15 min;

(3) aerobic fermentation: adding composite microorganisms accounting for 2% of the mass of the fermentation liquor into the fermentation liquor, and carrying out aerobic fermentation for 12 hours at the temperature of 28-35 ℃;

(4) and (3) filtering: filtering to remove thallus and insoluble solid after fermentation to obtain crude immunoglobulin solution;

(5) and (3) ultrafiltration: concentrating the crude immunoglobulin solution by an ultrafiltration membrane, washing and removing impurities to obtain a trapped phase;

(6) ultrasonic extracting, adding the trapped phase into ethanol, ultrasonic extracting for 2 times, and mixing extractive solutions;

(7) and (3) precipitation: adjusting the acid of the extracting solution, and centrifuging to obtain a precipitate;

(8) and (3) freeze drying: and (5) freezing and drying the precipitate to obtain the compound.

Preferably, the water adding ratio in the step (2) is plasma: the purified water is 1: 1.

Preferably, the complex microorganism in the step (3) is one or a mixture of pichia pastoris, hansenula polymorpha and candida.

Optimally, the inoculation amount ratio of the pichia, the hansenula and the candida is 2:1: 2.

Further, the activation method of the pichia, hansenula and candida comprises the following steps: under the aseptic operation condition, two rings of strains are picked from the inclined plane of the yeast YDP by using an inoculating ring, inoculated into a 500mL triangular flask containing 300mLPDA liquid culture medium, subjected to shaking culture at the temperature of between 28 and 32 ℃ and at the speed of 140r/min for 24 hours, and then inoculated into a seed tank for expanded culture according to the process to prepare the yeast seed liquid, wherein the effective viable count of the seed liquid is required to be more than or equal to 10⁹cfu/mL。

Preferably, the ultrafiltration membrane in the step (5) is a porous fiber ultrafiltration membrane with the cut-off molecular weight of 3000-10000D.

Preferably, the amount of the extraction solvent used in the step (6) is 10-15 times (V/W), the extraction time is 20-30min, and the operation is performed at room temperature.

Preferably, the acid in the step (7) is one of hydrochloric acid and sulfuric acid, and the pH after acidification is 7.3-7.7.

The invention provides a process for preparing immunoglobulin by using bovine blood through a biological method, which has the following remarkable advantages compared with the prior art:

(1) according to the invention, the immunocompetence and the extraction rate of immunoglobulin prepared by using the cattle blood are improved by a biological fermentation method, the resource recycling of cattle blood waste generated by cattle slaughtering and processing is realized, and no report that the immunoglobulin extraction rate is improved by using yeast fermentation is found in the prior art;

(2) according to the method, the cow blood is fermented by using the pichia pastoris, the hansenula polymorpha and the candida, and the synergistic effect among microorganisms is fully utilized, so that the yield of immunoglobulin is improved; the multi-strain mixed fermentation not only improves the yield of the immunoglobulin, but also improves the immunocompetence of the immunoglobulin through the fermentation effect among microorganisms;

(3) the immunoglobulin product prepared by the process has high extraction rate and activity retention rate, better conversion value and wide market application value.

Detailed Description

The activation method of the compound microbial agent in the following examples is prepared by adopting the following processes: under the aseptic operation condition, two rings of strains are picked from the inclined plane of the yeast YDP by using an inoculating ring, inoculated into a 500mL triangular flask containing 300mLPDA liquid culture medium, subjected to shaking culture at the temperature of between 28 and 32 ℃ and at the speed of 140r/min for 24 hours, and then inoculated into a seed tank for expanded culture according to the process to prepare the yeast seed liquid, wherein the effective viable count of the seed liquid is required to be more than or equal to 10⁹cfu/mL; then uniformly mixing the pichia pastoris, the hansenula polymorpha and the candida according to the inoculation amount ratio of 2:1: 2.

Example 1

A biological method for preparing immunoglobulin by using bovine blood specifically comprises the following steps:

(1) preparing plasma: preparing O.1M sodium squarate solution as an anticoagulant, uniformly mixing fresh bovine blood and the anticoagulant according to a ratio of 9:1, centrifuging for 10-20 minutes at a rotating speed of 2500-3000 rpm by using a centrifuge, removing red blood cells to obtain plasma, and placing the plasma at a temperature of-20 to-40 ℃ for later use;

(2) preparing fermentation liquor: dissolving the plasma in the step (1) in water, wherein the water adding proportion is that the plasma: the purified water is 1: 1; then adding 2 percent of glucose and 0.15 percent (NH) of the plasma mass ratio₄)₂SO₄、0.10% KH₂PO₄、0.1%MgSO₄Preparing a liquid fermentation culture medium; sterilizing at 121 deg.C for 15 min;

(3) aerobic fermentation: adding composite microorganisms accounting for 2% of the mass of the fermentation liquor into the fermentation liquor, and carrying out aerobic fermentation for 12 hours at the temperature of 28-35 ℃; the composite microorganism is a mixture of pichia pastoris, hansenula polymorpha and candida, and the inoculation amount ratio of the pichia pastoris, the hansenula polymorpha and the candida is 2:1: 2;

(4) and (3) filtering: filtering to remove thallus and insoluble solid after fermentation to obtain crude immunoglobulin solution;

(5) and (3) ultrafiltration: concentrating the crude immunoglobulin solution by an ultrafiltration membrane, washing and removing impurities to obtain a trapped phase; wherein the ultrafiltration membrane is a porous fiber ultrafiltration membrane with the cut-off molecular weight of 3000-10000D;

(6) ultrasonic extracting, adding the trapped phase into ethanol, ultrasonic extracting for 2 times, and mixing extractive solutions; the amount of extraction solvent is 10-15 times (V/W), the extraction time is 20-30min, and the operation is carried out at room temperature;

(7) and (3) precipitation: adjusting the acid of the extracting solution, and centrifuging to obtain a precipitate; the acid is hydrochloric acid, and the pH value after acidification is 7.3-7.7;

(8) and (3) freeze drying: and (5) freezing and drying the precipitate to obtain the compound.

Example 2

A biological method for preparing immunoglobulin by using bovine blood specifically comprises the following steps:

(1) preparing plasma: preparing O.1M sodium squarate solution as an anticoagulant, uniformly mixing fresh bovine blood and the anticoagulant according to a ratio of 9:1, centrifuging for 10-20 minutes at a rotating speed of 2500-3000 rpm by using a centrifuge, removing red blood cells to obtain plasma, and placing the plasma at a temperature of-20 to-40 ℃ for later use;

(2) preparing fermentation liquor: dissolving the plasma in the step (1) in water, wherein the water adding proportion is that the plasma: the purified water is 1: 1; then adding 2 percent of glucose and 0.15 percent (NH) of the plasma mass ratio₄)₂SO₄、0.10% KH₂PO₄、0.1%MgSO₄Preparing a liquid fermentation culture medium; sterilizing at 121 deg.C for 15 min;

(3) aerobic fermentation: adding composite microorganisms accounting for 2% of the mass of the fermentation liquor into the fermentation liquor, and carrying out aerobic fermentation for 12 hours at the temperature of 28-35 ℃; the composite microorganism is a mixture of pichia pastoris, hansenula polymorpha and candida, and the inoculation amount ratio of the pichia pastoris, the hansenula polymorpha and the candida is 1:2: 1;

(4) and (3) filtering: filtering to remove thallus and insoluble solid after fermentation to obtain crude immunoglobulin solution;

(5) and (3) ultrafiltration: concentrating the crude immunoglobulin solution by an ultrafiltration membrane, washing and removing impurities to obtain a trapped phase; wherein the ultrafiltration membrane is a porous fiber ultrafiltration membrane with the cut-off molecular weight of 3000-10000D;

(6) ultrasonic extracting, adding the trapped phase into ethanol, ultrasonic extracting for 2 times, and mixing extractive solutions; the amount of extraction solvent is 10-15 times (V/W), the extraction time is 20-30min, and the operation is carried out at room temperature;

(7) and (3) precipitation: adjusting the acid of the extracting solution, and centrifuging to obtain a precipitate; the acid is hydrochloric acid, and the pH value after acidification is 7.3-7.7;

(8) and (3) freeze drying: and (5) freezing and drying the precipitate to obtain the compound.

Example 3

A biological method for preparing immunoglobulin by using bovine blood specifically comprises the following steps:

(1) preparing plasma: preparing O.1M sodium squarate solution as an anticoagulant, uniformly mixing fresh bovine blood and the anticoagulant according to a ratio of 9:1, centrifuging for 10-20 minutes at a rotating speed of 2500-3000 rpm by using a centrifuge, removing red blood cells to obtain plasma, and placing the plasma at a temperature of-20 to-40 ℃ for later use;

(2) preparing fermentation liquor: dissolving the plasma in the step (1) in water, wherein the water adding proportion is that the plasma: the purified water is 1: 1; then adding 2 percent of glucose and 0.15 percent (NH) of the plasma mass ratio₄)₂SO₄、0.10% KH₂PO₄、0.1%MgSO₄Preparing a liquid fermentation culture medium; sterilizing at 121 deg.C for 15 min;

(3) aerobic fermentation: adding composite microorganisms accounting for 2% of the mass of the fermentation liquor into the fermentation liquor, and carrying out aerobic fermentation for 12 hours at the temperature of 28-35 ℃; the compound microorganism is pichia pastoris;

(4) and (3) filtering: filtering to remove thallus and insoluble solid after fermentation to obtain crude immunoglobulin solution;

(5) and (3) ultrafiltration: concentrating the crude immunoglobulin solution by an ultrafiltration membrane, washing and removing impurities to obtain a trapped phase; wherein the ultrafiltration membrane is a porous fiber ultrafiltration membrane with the cut-off molecular weight of 3000-10000D;

(6) ultrasonic extracting, adding the trapped phase into ethanol, ultrasonic extracting for 2 times, and mixing extractive solutions; the amount of extraction solvent is 10-15 times (V/W), the extraction time is 20-30min, and the operation is carried out at room temperature;

(7) and (3) precipitation: adjusting the acid of the extracting solution, and centrifuging to obtain a precipitate; the acid is hydrochloric acid, and the pH value after acidification is 7.3-7.7;

(8) and (3) freeze drying: and (5) freezing and drying the precipitate to obtain the compound.

Example 4

A biological method for preparing immunoglobulin by using bovine blood specifically comprises the following steps:

(1) preparing plasma: preparing O.1M sodium squarate solution as an anticoagulant, uniformly mixing fresh bovine blood and the anticoagulant according to a ratio of 9:1, centrifuging for 10-20 minutes at a rotating speed of 2500-3000 rpm by using a centrifuge, removing red blood cells to obtain plasma, and placing the plasma at a temperature of-20 to-40 ℃ for later use;

(2) preparing fermentation liquor: dissolving the plasma in the step (1) in water, wherein the water adding proportion is that the plasma: the purified water is 1: 1; then adding 2 percent of glucose and 0.15 percent (NH) of the plasma mass ratio₄)₂SO₄、0.10% KH₂PO₄、0.1%MgSO₄Preparing a liquid fermentation culture medium; sterilizing at 121 deg.C for 15 min;

(3) aerobic fermentation: adding composite microorganisms accounting for 2% of the mass of the fermentation liquor into the fermentation liquor, and carrying out aerobic fermentation for 12 hours at the temperature of 28-35 ℃; the compound microorganism is Hansenula polymorpha;

(4) and (3) filtering: filtering to remove thallus and insoluble solid after fermentation to obtain crude immunoglobulin solution;

(5) and (3) ultrafiltration: concentrating the crude immunoglobulin solution by an ultrafiltration membrane, washing and removing impurities to obtain a trapped phase; wherein the ultrafiltration membrane is a porous fiber ultrafiltration membrane with the cut-off molecular weight of 3000-10000D;

(6) ultrasonic extracting, adding the trapped phase into ethanol, ultrasonic extracting for 2 times, and mixing extractive solutions; the amount of extraction solvent is 10-15 times (V/W), the extraction time is 20-30min, and the operation is carried out at room temperature;

(7) and (3) precipitation: adjusting the acid of the extracting solution, and centrifuging to obtain a precipitate; the acid is hydrochloric acid, and the pH value after acidification is 7.3-7.7;

(8) and (3) freeze drying: and (5) freezing and drying the precipitate to obtain the compound.

Example 5

A biological method for preparing immunoglobulin by using bovine blood specifically comprises the following steps:

(1) preparing plasma: preparing O.1M sodium squarate solution as an anticoagulant, uniformly mixing fresh bovine blood and the anticoagulant according to a ratio of 9:1, centrifuging for 10-20 minutes at a rotating speed of 2500-3000 rpm by using a centrifuge, removing red blood cells to obtain plasma, and placing the plasma at a temperature of-20 to-40 ℃ for later use;

(2) preparing fermentation liquor: dissolving the plasma in the step (1) in water, wherein the water adding proportion is that the plasma: the purified water is 1: 1; then adding 2 percent of glucose and 0.15 percent (NH) of the plasma mass ratio₄)₂SO₄、0.10% KH₂PO₄、0.1%MgSO₄Preparing a liquid fermentation culture medium; sterilizing at 121 deg.C for 15 min;

(3) aerobic fermentation: adding composite microorganisms accounting for 2% of the mass of the fermentation liquor into the fermentation liquor, and carrying out aerobic fermentation for 12 hours at the temperature of 28-35 ℃; the compound microorganism is candida;

(4) and (3) filtering: filtering to remove thallus and insoluble solid after fermentation to obtain crude immunoglobulin solution;

(5) and (3) ultrafiltration: concentrating the crude immunoglobulin solution by an ultrafiltration membrane, washing and removing impurities to obtain a trapped phase; wherein the ultrafiltration membrane is a porous fiber ultrafiltration membrane with the cut-off molecular weight of 3000-10000D;

(6) ultrasonic extracting, adding the trapped phase into ethanol, ultrasonic extracting for 2 times, and mixing extractive solutions; the amount of extraction solvent is 10-15 times (V/W), the extraction time is 20-30min, and the operation is carried out at room temperature;

(7) and (3) precipitation: adjusting the acid of the extracting solution, and centrifuging to obtain a precipitate; the acid is hydrochloric acid, and the pH value after acidification is 7.3-7.7;

(8) and (3) freeze drying: and (5) freezing and drying the precipitate to obtain the compound.

Example 6 Effect of different Process conditions on the Retention (%) of immunoglobulin Activity

1. Index measuring method

The immunoglobulin activity retention (%) was determined according to the method described in "optimization of conditions for extraction of immunoglobulin from pig blood" by Zhang Gao et al.

2. Grouping method

The experiment is divided into experiment groups of examples 1-5, a control group does not contain a fermentation process, and the rest processes are the same as those of example 1;

3. test results

TABLE 1 Effect of different Process conditions on the Retention (%) of immunoglobulin Activity

Test group	Immunoglobulin Activity Retention (%)
		Control group	76.42
Example 1 test group	95.26
		Example 2 test group	87.91
Example 3 test group	80.84
		Example 4 test group	82.08
Example 5 test group	82.27

The experimental results show that the embodiments of the invention have better immunoglobulin activity retention rate, which indicates that the process of the invention obtains better extraction effect; in addition, the test results also show that the composition and inoculation ratio of the complex microorganisms have a significant influence on the retention rate of the immunoglobulin activity. Example 1 is the most preferred embodiment of the present invention.

The above embodiments are only used for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof; such modifications and substitutions do not depart from the spirit and scope of the present invention as set forth in the appended claims.