BIFIDOBACTERIUM ANIMALIS SUBSP. LACTIS I797, METHOD FOR SEPARATION AND PURIFICATION THEREOF, AND USE THEREOF

Abstract

Provided are a Bifidobacterium animalis subsp. lactis i797, a method for the separation and purification thereof, and a use thereof. The strain was is deposited in the China General Microbiological Culture Collection Center on Aug. 20, 2019, wherein the deposit address is Building 3, No. 1 Beichen West Road, Chaoyang District, Beijing, and the deposit number is CGMCC NO. 18403. The Bifidobacterium animalis subsp. lactis i797 can adjust the balance of intestinal flora, improve stool characteristics, and has a better survival rate in simulated digestive juice; in addition, after being stored at 37° C., a relatively high temperature which is suitable for the growth of lactic acid bacteria, same can successfully control post-acidification.

Claims

1. A Bifidobacterium animalis subsp. lactis i797, characterized in that, the strain of Bifidobacterium animalis subsp. lactis i797 is preserved in the China General Microbiological Culture Collection Center, the preservation address is: No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, the preservation date is Aug. 20, 2019, and the preservation number is CGMCC No. 18403.

2. The Bifidobacterium animalis subsp. lactis i797 according to claim 1, characterized in that, it is screened out from the intestinal flora of infants or babies.

3. The Bifidobacterium animalis subsp. lactis i797 according to claim 1, characterized in that, its 16SrRNA sequence is as follows: TABLE-US-00013 ACGGCTCCCCCACAAGGGTCGGGCCACCGGCTTCGGGTGCTACCCACTTT CATGACTTGACGGGCGGTGTGTACAAGGCCCGGGAACGCATTCACCGCGG CGTTGCTGATCCGCGATTACTAGCGACTCCGCCTTCACGCAGTCGAGTTG CAGACTGCGATCCGAACTGAGACCGGTTTTCAGCGATCCGCCCCACGTCA CCGTGTCGCACCGCGTTGTACCGGCCATTGTAGCATGCGTGAAGCCCTGG ACGTAAGGGGCATGATGATCTGACGTCATCCCCACCTTCCTCCGAGTTGA CCCCGGCGGTCCCACATGAGTTCCCGGCATCACCCGCTGGCAACATGCGG CGAGGGTTGCGCTCGTTGCGGGACTTAACCCAACATCTCACGACACGAGC TGACGACGACCATGCACCACCTGTGAACCGGCCCCGAAGGGAAACCGTGT CTCCACGGCGATCCGGCACATGTCAAGCCCAGGTAAGGTTCTTCGCGTTG CATCGAATTAATCCGCATGCTCCGCCGCTTGTGCGGGCCCCCGTCAATTT CTTTGAGTTTTAGCCTTGCGGCCGTACTCCCCAGGCGGGATGCTTAACGC GTTGGCTCCGACACGGGACCCGTGGAAAGGGCCCCACATCCAGCATCCAC CGTTTACGGCGTGGACTACCAGGGTATCTAATCCTGTTCGCTCCCCACGC TTTCGCTCCTCAGCGTCAGTGACGGCCCAGAGACCTGCCTTCGCCATTGG TGTTCTTCCCGATATCTACACATTCCACCGTTACACCGGGAATTCCAGTC TCCCCTACCGCACTCCAGCCCGCCCGTACCCGGCGCAGATCCACCGTTAG GCGATGGACTTTCACACCGGACGCGACGAACCGCCTACGAGCCCTTTACG CCCAATAAATCCGGATAACGCTCGCACCCTACGTATTACCGCGGCTGCTG GCACGTAGTTAGCCGGTGCTTATTCGAACAATCCACTCAACACGGCCGAA ACCGTGCCTTGCCCTTGAACAAAAGCGGTTTACAACCCGAAGGCCTCCAT CCCGCACGCGGCGTCGCTGCATCAGGCTTGCGCCCATTGTGCAATATTCC CCACTGCTGCCTCCCGTAGGAGTCTGGGCCGTATCTCAGTCCCAATGTGG CCGGTCACCCTCTCAGGCCGGCTACCCGTCAACGCCTTGGTGGGCCATCA CCCCGCCAACAAGCTGATAGGACGCGACCCCATCCCATGCCGCAAAAGCA TTTCCCACCCCACCATGCGATGGAGCGGAGCATCCGGTATTACCACCCGT TTCCAGGAGCTATTCCGGTGCACAGGGCAGGTTGGTCACGCATTACTCAC CCGTTCGCCACTCTCACCCGACAGCAAGCTGCCAGGGATCCCGTTCGACT GCATGTGTAAG.

4. The Bifidobacterium animalis subsp. lactis i797 according to claim 1, characterized in that, its tuf gene sequence is as follows: TABLE-US-00014 GGATCTCGATGAGAGCAGCGTGGTATCACCATCAACATTGCCCACATCGA GTACCAGACGGCCAAGCGTCACTACGCCCACGTCGACTGCCCGGGCCACG CCGACTTCGTGAAGAACATGATCACCGGCGCTGCCCAGATGGATGGCGCC ATCCTCGTTGTGGCCGCCACCGACGGCCCGATGGCCCAGACCCGCGAGCA CGTGCTGCTCGCCCGTCAGGTCGGCGTCCCGAAGATCCTCGTCGCTCTGA ACAAGTGCGATATGGTCGATGACGAAGAGCTCATCGAGCTCGTCGAAGAA GAGGTCCGCGACCTCCTCGACGAGAACGGCTTCGACCGCGACTGCCCGGT CGTGCACACCTCCGCTTACGGCGCTCTGCATGACGACGCTCCCGGATCAC GACAAGTGGGTTGCCACCATCAAGGAGCTCATGGACGACGTCGACGAGTA CATCCCGACCCCGGTCCACGACCTCGACAAGCCGTTCCTGATGCCGATCG AGGACGTCTTCACCATCTCCGGCCGTGGCACCGTCGTCACCGGTCGTGTC GAGCGCGGCAAGCTGCCGATCAACACGAACGTCGAGATCGTCGGCATCCG CCCGACCCAGACCACCACCGTCACCTCCATCGAGACCTTCCACAAGCAGA TGGATGAGTGCGAGGCCGGCGACAACACCGGTCTGCTGCTCCGCGGCATC AACCGCACCGACGTCGAGCGTGGCCAGGTCGTGGCTGCTCCGGGTTCGGT CACCCCGCACACCAAGTTCGAAGGCGAAGTCTACGTCCTTACCAAGGATG AGGGCGGCCGTCACTCGCCGTTCTTCTCGAACTACCGTCCGCAGTTCTAC TTCCGCACCACCGACGTCACCGGCGTCATCACGCTGCCGGAAGGCGTCGA GATGGTTCAGCCTGGCGATCACGCGACCTTCACGGTTGAGCTGATCCAGC CGATCGCTATGGAAGAGGGCTTCACCTTCCCAGTGCTTGAAGGC.

5. A method for separating and purifying the Bifidobacterium animalis subsp. lactis i797 according to claim 1, characterized in that, it comprises the following steps which are carried out in sequence: I. sample collection obtaining intestinal feces of infants or babies, then adding the intestinal feces into normal saline and mix thoroughly to obtain a sample A; II. sample enrichment adding the sample A into a modified MRS liquid culture medium, and culturing in an anaerobic environment at 35-40° C. for 62-82 hours to obtain a culture solution B; the modified MRS liquid culture medium is an MRS liquid culture medium added with 0.5 wt % cysteine; the volume ratio of the sample A to the modified MRS liquid culture medium is 1:10-100; III. strain separation and screening diluting the culture solution B with 0.9% sterile normal saline by ten-time gradient multiplication, i.e., diluting to 10.sup.−1, 10.sup.−2, 10.sup.−3, 10.sup.−4 and 10.sup.−5 times sequentially, thus obtaining bacterial suspensions C.sub.1-C.sub.5 correspondingly; melting modified MRS solid culture medium and pouring it into the first to fifth culture dishes, thus obtaining culture media D.sub.1-D.sub.5 after cooling and complete solidification; drawing 0.1 mL bacterial suspensions C.sub.1-C.sub.5 and spreading them on the culture media D.sub.1-D.sub.5 respectively in one-to-one correspondence, then turning the plates upside down and culturing them in an anaerobic environment at 35-40° C. for 62-82 hours, and observing the growth of the colonies; the modified MRS solid culture medium is a solid culture medium obtained by adding 15 wt % agar per 1,000 mL modified MRS liquid culture medium; after typical colonies appear on the plates, picking corresponding single colony E; IV. strain purification picking a selected single colony E and streak-inoculating the single colony E culture on the modified MRS solid culture medium, and culturing in anaerobic environment at 35-40° C. for 62-82 hours to obtain a single colony F; streak-inoculating the single colony F further on the modified MRS solid culture medium, and culturing in an anaerobic environment at 35-40° C. for 62-82 hours to obtain a single colony G; streak-inoculating the single colony G further on the modified MRS solid culture medium, and culturing in an anaerobic environment at 35-40° C. for 62-82 hours to obtain a pure culture H, which is the strain of Bifidobacterium animalis subsp. lactis i797.

6. The method for separating and purifying the Bifidobacterium animalis subsp. lactis i797 according to claim 5, wherein the strain of Bifidobacterium animalis subsp. lactis i797 is preserved as follows: mixing the pure culture H with 50 wt % sterile glycerol at a ratio of 1:1, placing the mixture in a strain preservation tube, mixing homogeneously and then preserving at −80-70° C.; at the same time, inoculating on test-tube slant of the modified MRS solid culture medium for temporary storage.

7. The method for separating and purifying the Bifidobacterium animalis subsp. lactis i797 according to claim 4, wherein the components of the modified MRS liquid culture medium include: casein peptone, beef extract, yeast extract, glucose, sodium acetate, diamine citrate, Tween-80, K.sub.2HPO.sub.4, MgSO.sub.4.7H.sub.2O, MnSO.sub.4.7H.sub.2O, cysteine and distilled water; wherein the dosage ratio of casein peptone:beef extract:yeast extract:glucose:sodium acetate:diamine citrate:Tween-80:K.sub.2HPO.sub.4:MgSO.sub.4.7H.sub.2O:MnSO.sub.4.7H.sub.2O:cysteine:distilled water is 10 g:10 g:5 g:20 g:5 g:2 g:1 g:2 g:0.2 g:0.05 g: 0.5 g:1,000 mL.

8. Use of the Bifidobacterium animalis subsp. lactis i797 according to claim 1 in preparation of drinks, foods or medicines.

9. The use of the Bifidobacterium animalis subsp. lactis i797 according to claim 8, wherein the drinks are beverages or fermented milk drinks; the foods are cereals, cereal derivatives, fermented meat products, probiotics or milk foods; the medicines are in dosage forms of capsule, tablet, pill or powder.

10. The use of the Bifidobacterium animalis subsp. lactis i797 according to claim 9, wherein the probiotics are compound probiotics.

Description

IV. EMBODIMENTS

[0031] Hereunder some preferred examples of the present invention will be detailed. It should be understood that the preferred examples described here are only used to describe and explain the present invention, but not intended to limit the present invention.

Example 1. A Bifidobacterium animalis Subsp. Lactis i797

[0032] In this example, a Bifidobacterium animalis subsp. lactis i797, which is separated and screened from the feces of breast-fed infants or babies, and preserved in the China General Microbiological Culture Collection Center (address: No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing) on Aug. 20, 2019, with a preservation number of CGMCC No. 18403, is provided.

[0033] The 16SrRNA sequence of above Bifidobacterium animalis subsp. lactis i797 is as follows:

TABLE-US-00003 ACGGCTCCCCCACAAGGGTCGGGCCACCGGCTTCGGGTGCTACCCACTTT CATGACTTGACGGGCGGTGTGTACAAGGCCCGGGAACGCATTCACCGCGG CGTTGCTGATCCGCGATTACTAGCGACTCCGCCTTCACGCAGTCGAGTTG CAGACTGCGATCCGAACTGAGACCGGTTTTCAGCGATCCGCCCCACGTCA CCGTGTCGCACCGCGTTGTACCGGCCATTGTAGCATGCGTGAAGCCCTGG ACGTAAGGGGCATGATGATCTGACGTCATCCCCACCTTCCTCCGAGTTGA CCCCGGCGGTCCCACATGAGTTCCCGGCATCACCCGCTGGCAACATGCGG CGAGGGTTGCGCTCGTTGCGGGACTTAACCCAACATCTCACGACACGAGC TGACGACGACCATGCACCACCTGTGAACCGGCCCCGAAGGGAAACCGTGT CTCCACGGCGATCCGGCACATGTCAAGCCCAGGTAAGGTTCTTCGCGTTG CATCGAATTAATCCGCATGCTCCGCCGCTTGTGCGGGCCCCCGTCAATTT CTTTGAGTTTTAGCCTTGCGGCCGTACTCCCCAGGCGGGATGCTTAACGC GTTGGCTCCGACACGGGACCCGTGGAAAGGGCCCCACATCCAGCATCCAC CGTTTACGGCGTGGACTACCAGGGTATCTAATCCTGTTCGCTCCCCACGC TTTCGCTCCTCAGCGTCAGTGACGGCCCAGAGACCTGCCTTCGCCATTGG TGTTCTTCCCGATATCTACACATTCCACCGTTACACCGGGAATTCCAGTC TCCCCTACCGCACTCCAGCCCGCCCGTACCCGGCGCAGATCCACCGTTAG GCGATGGACTTTCACACCGGACGCGACGAACCGCCTACGAGCCCTTTACG CCCAATAAATCCGGATAACGCTCGCACCCTACGTATTACCGCGGCTGCTG GCACGTAGTTAGCCGGTGCTTATTCGAACAATCCACTCAACACGGCCGAA ACCGTGCCTTGCCCTTGAACAAAAGCGGTTTACAACCCGAAGGCCTCCAT CCCGCACGCGGCGTCGCTGCATCAGGCTTGCGCCCATTGTGCAATATTCC CCACTGCTGCCTCCCGTAGGAGTCTGGGCCGTATCTCAGTCCCAATGTGG CCGGTCACCCTCTCAGGCCGGCTACCCGTCAACGCCTTGGTGGGCCATCA CCCCGCCAACAAGCTGATAGGACGCGACCCCATCCCATGCCGCAAAAGCA TTTCCCACCCCACCATGCGATGGAGCGGAGCATCCGGTATTACCACCCGT TTCCAGGAGCTATTCCGGTGCACAGGGCAGGTTGGTCACGCATTACTCAC CCGTTCGCCACTCTCACCCGACAGCAAGCTGCCAGGGATCCCGTTCGACT GCATGTGTAAG.

[0034] Its tuf gene sequence is as follows:

TABLE-US-00004 GGATCTCGATGAGAGCAGCGTGGTATCACCATCAACATTGCCCACATCGA GTACCAGACGGCCAAGCGTCACTACGCCCACGTCGACTGCCCGGGCCACG CCGACTTCGTGAAGAACATGATCACCGGCGCTGCCCAGATGGATGGCGCC ATCCTCGTTGTGGCCGCCACCGACGGCCCGATGGCCCAGACCCGCGAGCA CGTGCTGCTCGCCCGTCAGGTCGGCGTCCCGAAGATCCTCGTCGCTCTGA ACAAGTGCGATATGGTCGATGACGAAGAGCTCATCGAGCTCGTCGAAGAA GAGGTCCGCGACCTCCTCGACGAGAACGGCTTCGACCGCGACTGCCCGGT CGTGCACACCTCCGCTTACGGCGCTCTGCATGACGACGCTCCCGGATCAC GACAAGTGGGTTGCCACCATCAAGGAGCTCATGGACGACGTCGACGAGTA CATCCCGACCCCGGTCCACGACCTCGACAAGCCGTTCCTGATGCCGATCG AGGACGTCTTCACCATCTCCGGCCGTGGCACCGTCGTCACCGGTCGTGTC GAGCGCGGCAAGCTGCCGATCAACACGAACGTCGAGATCGTCGGCATCCG CCCGACCCAGACCACCACCGTCACCTCCATCGAGACCTTCCACAAGCAGA TGGATGAGTGCGAGGCCGGCGACAACACCGGTCTGCTGCTCCGCGGCATC AACCGCACCGACGTCGAGCGTGGCCAGGTCGTGGCTGCTCCGGGTTCGGT CACCCCGCACACCAAGTTCGAAGGCGAAGTCTACGTCCTTACCAAGGATG AGGGCGGCCGTCACTCGCCGTTCTTCTCGAACTACCGTCCGCAGTTCTAC TTCCGCACCACCGACGTCACCGGCGTCATCACGCTGCCGGAAGGCGTCGA GATGGTTCAGCCTGGCGATCACGCGACCTTCACGGTTGAGCTGATCCAGC CGATCGCTATGGAAGAGGGCTTCACCTTCCCAGTGCTTGAAGGC.

Example 2. A Method for Separating and Purifying Bifidobacterium animalis Subsp. Lactis i797

[0035] In this example, a method for separating and purifying the Bifidobacterium animalis subsp. lactis i797 described in the example 1 is provided, including the following steps which are carried out in sequence:

I. Sample Collection

[0036] 1 g intestinal feces of infants or babies is obtained and then added into 9 mL normal saline for thorough mixing to obtain a sample A;

II. Sample Enrichment

[0037] 2 mL (V.sub.1) sample A is added into 100 mL (V.sub.2) modified MRS liquid culture medium, and cultured in an anaerobic environment at 37° C. (T.sub.1) for 72 hours (t.sub.1) to obtain a culture solution B;

III. Strain Separation and Screening

[0038] 1 mL culture solution B.sub.1 is diluted with 0.9% sterile normal saline by ten-time gradient multiplication, i.e., diluting to 10.sup.−1, 10.sup.−2, 10.sup.−3, 10.sup.−4 and 10.sup.−5 times sequentially, thus obtaining bacterial suspensions C1.sub.1-C1.sub.5 correspondingly;

[0039] A modified MRS solid culture medium is melted and poured into the first to fifth culture dishes, thus culture media D.sub.1-D.sub.5 are obtained after cooling and complete solidification; 0.1 mL bacterial suspensions C.sub.1-C.sub.5 are drawn and spread on the culture media D.sub.1-D.sub.5 respectively in one-to-one correspondence, then the plates are turned upside down and cultured in an anaerobic environment at 37° C. (T.sub.2) for 72 hours (t.sub.2), and the growth of the colonies is observed;

[0040] After typical colonies appear on the plates, corresponding single colony E is selected according to the colony characteristics of standard Bifidobacterium with reference to images in relevant literature;

IV. Strain Purification

[0041] A selected single colony E is picked and its culture is streak-inoculated on the modified MRS solid culture medium, and cultured in anaerobic environment at 37° C. (T.sub.3) for 72 hours (t.sub.3) to obtain a single colony F;

[0042] The single colony F is further streak-inoculated on the modified MRS solid culture medium, and cultured in an anaerobic environment at 37° C. (T.sub.4) for 72 hours (t.sub.4) to obtain a single colony G;

[0043] The single colony G is further streak-inoculated on the modified MRS solid culture medium, and cultured in an anaerobic environment at 37° C. (T.sub.5) for 72 hours (t.sub.5) to obtain a pure culture H, which is the strain of Bifidobacterium animalis subsp. lactis i797;

V. Preservation

[0044] The pure culture H is mixed with 50 wt % sterile glycerol at a ratio of 1:1, the mixture is placed in a strain preservation tube, mixed homogeneously and then preserved at −70° C. (T.sub.6); at the same time, it is inoculated on the test-tube slant of the modified MRS solid culture medium for temporary storage.

[0045] In this example, the raw materials of the modified MRS liquid culture medium include: casein peptone, beef extract, yeast extract, glucose, sodium acetate, diamine citrate, Tween-80, K.sub.2HPO.sub.4, MgSO.sub.4.7H.sub.2O, MnSO.sub.4.7H.sub.2O, cysteine and distilled water; wherein a dosage ratio of casein peptone:beef extract:yeast extract:glucose:sodium acetate:diamine citrate:Tween-80:K.sub.2HPO.sub.4:MgSO.sub.4-7H.sub.2O:MnSO.sub.4.7H.sub.2O:cysteine:distilled water is 10 g:10 g:5 g:20 g:5 g:2 g:1 g:2 g:0.2 g:0.05 g:0.5 g:1,000 mL; the modified MRS solid culture medium is obtained by adding 15 wt % agar per 1,000 mL modified MRS liquid culture medium.

Examples 3-6. A Method for Separating and Purifying the Bifidobacterium animalis Subsp. lactis i797

[0046] The examples 3-6 provide a separation and purification method of the example 1 respectively, which is essentially the same as that of the example 2, except that the technical parameters of the separation and purification process are different. The specific parameters are shown in Table 1:

TABLE-US-00005 TABLE 1 Separation and Purification Process and Parameters in Examples 3-6 Example Step Parameter 3 4 5 6 II V.sub.1 (ml) 2 2 2 2 V.sub.2 (ml) 20 70 200 154 T.sub.1 (° C.) 35 36.4 40 38 t.sub.1 (h) 82 78 62 69 III T.sub.2 (° C.) 39 40 36 35 t.sub.2 (h) 69.5 82 62 75.4 IV T.sub.3 (° C.) 40 35 36.3 37.5 t.sub.3 (h) 70 82 63 62 T.sub.4 (° C.) 35 38.1 39.6 40 t.sub.4 (h) 62 80 69 82 T.sub.5 (° C.) 37.2 35 40 35.9 t.sub.5 (h) 76 62 82 81 V T.sub.6 (° C.) −80 −73 −75.8 −78

Example 7. Basic Bacteriological Characteristics of the Bifidobacterium animalis Subsp. lactis i797

[0047] This example illustrates the basic bacteriological characteristics of the Bifidobacterium animalis subsp. lactis i797 in the example 1, which are shown in Table 2:

TABLE-US-00006 TABLE 2 Basic Characteristics of the Bifidobacterium Animalis Subsp. Lactis i797 Test item Result Test item Result Gram staining Positive Cell morphology Polymorphic rod shape Oxidase — Catalase —

Example 8. Sugar Fermentation Characteristics of the Bifidobacterium Animalis Subsp. Lactis i797

[0048] This example illustrates the sugar fermentation characteristics of the strain of Bifidobacterium animalis subsp. lactis i797 in the example 1. The experimental method for sugar fermentation characteristics is as follows: a single colony of the strain of Bifidobacterium animalis subsp. lactis i797 obtained with the separation and purification method in the example 3 is inoculated into a sterilized modified MRS liquid culture medium, and cultured at 37° C. for 24 hours, then the bacterial suspension is inoculated into a sugar fermentation tube, and cultured under anaerobic condition at 37° C. for 48 hours, and the color change is observed. The identification result of the sugar fermentation characteristics is shown in Table 3:

TABLE-US-00007 TABLE 3 Identification Result of Sugar Fermentation Characteristics of the Bifidobacterium Animalis Subsp. Lactis i797 Test item Result Test item Result Test item Result Glycerol − Mannitol − Melezitose − Erythritol − Sorbitol − Raffinose + D-arabinose − α-methyl-mannoside − Starch − L-arabinose − α-methyl-glucoside − Glycogen − D-ribose + N-acetyl-glucosamine − Xylitol − D-xylose + Amygdalin + Gentiobiose − L-xylose − Arbutin − D-turanose − Adonitol − Esculin + D-lyxose − β-methyl-D-xyloside − Salicin + D-tagatose − D-galactose − Cellobiose + D-fucose − D-glucose + Maltose + L-fucose − D-fructose − Lactose + D-arabitol − D-mannose − Melibiose + L-arabitol − L-sorbose − Sucrose + Gluconate − L-rhamnose − Trehalose + 2-keto-gluconate − Dulcitol − Inulin − Inositol − Note: ″+″ means utilization through fermentation; ″−″ means no utilization with fermentation.

[0049] The modified MRS liquid culture medium used in this example has the same composition as the modified MRS liquid culture medium in the example 2.

Example 9. Molecular Biological Identification of the Strain of Bifidobacterium animalis subsp. lactis i797

[0050] The strain of Bifidobacterium animalis subsp. lactis i797 obtained with the separation and purification method in the example 5 is subjected to molecular biological identification, and through DNA extraction, PCR amplification, 16SrRNA sequencing, and NCBI Online Blast, it is finally determined as a Bifidobacterium animalis subsp. lactis.

[0051] Its 16SrRNA sequencing result is as follows:

TABLE-US-00008 ACGGCTCCCCCACAAGGGTCGGGCCACCGGCTTCGGGTGCTACCCACTTT CATGACTTGACGGGCGGTGTGTACAAGGCCCGGGAACGCATTCACCGCGG CGTTGCTGATCCGCGATTACTAGCGACTCCGCCTTCACGCAGTCGAGTTG CAGACTGCGATCCGAACTGAGACCGGTTTTCAGCGATCCGCCCCACGTCA CCGTGTCGCACCGCGTTGTACCGGCCATTGTAGCATGCGTGAAGCCCTGG ACGTAAGGGGCATGATGATCTGACGTCATCCCCACCTTCCTCCGAGTTGA CCCCGGCGGTCCCACATGAGTTCCCGGCATCACCCGCTGGCAACATGCGG CGAGGGTTGCGCTCGTTGCGGGACTTAACCCAACATCTCACGACACGAGC TGACGACGACCATGCACCACCTGTGAACCGGCCCCGAAGGGAAACCGTGT CTCCACGGCGATCCGGCACATGTCAAGCCCAGGTAAGGTTCTTCGCGTTG CATCGAATTAATCCGCATGCTCCGCCGCTTGTGCGGGCCCCCGTCAATTT CTTTGAGTTTTAGCCTTGCGGCCGTACTCCCCAGGCGGGATGCTTAACGC GTTGGCTCCGACACGGGACCCGTGGAAAGGGCCCCACATCCAGCATCCAC CGTTTACGGCGTGGACTACCAGGGTATCTAATCCTGTTCGCTCCCCACGC TTTCGCTCCTCAGCGTCAGTGACGGCCCAGAGACCTGCCTTCGCCATTGG TGTTCTTCCCGATATCTACACATTCCACCGTTACACCGGGAATTCCAGTC TCCCCTACCGCACTCCAGCCCGCCCGTACCCGGCGCAGATCCACCGTTAG GCGATGGACTTTCACACCGGACGCGACGAACCGCCTACGAGCCCTTTACG CCCAATAAATCCGGATAACGCTCGCACCCTACGTATTACCGCGGCTGCTG GCACGTAGTTAGCCGGTGCTTATTCGAACAATCCACTCAACACGGCCGAA ACCGTGCCTTGCCCTTGAACAAAAGCGGTTTACAACCCGAAGGCCTCCAT CCCGCACGCGGCGTCGCTGCATCAGGCTTGCGCCCATTGTGCAATATTCC CCACTGCTGCCTCCCGTAGGAGTCTGGGCCGTATCTCAGTCCCAATGTGG CCGGTCACCCTCTCAGGCCGGCTACCCGTCAACGCCTTGGTGGGCCATCA CCCCGCCAACAAGCTGATAGGACGCGACCCCATCCCATGCCGCAAAAGCA TTTCCCACCCCACCATGCGATGGAGCGGAGCATCCGGTATTACGACCCGT TTCCAGGAGCTATTCCGGTGCACAGGGCAGGTTGGTCACGCATTACTCAC CCGTTCGCCACTCTCACCCGACAGCAAGCTGCCAGGGATCCCGTTCGACT GCATGTGTAAG.

[0052] Its tuf gene sequencing result is as follows:

TABLE-US-00009 GGATCTCGATGAGAGCAGCGTGGTATCACCATCAACATTGCCCACATCGA GTACCAGACGGCCAAGCGTCACTACGCCCACGTCGACTGCCCGGGCCACG CCGACTTCGTGAAGAACATGATCACCGGCGCTGCCCAGATGGATGGCGCC ATCCTCGTTGTGGCCGCCACCGACGGCCCGATGGCCCAGACCCGCGAGCA CGTGCTGCTCGCCCGTCAGGTCGGCGTCCCGAAGATCCTCGTCGCTCTGA ACAAGTGCGATATGGTCGATGACGAAGAGCTCATCGAGCTCGTCGAAGAA GAGGTCCGCGACCTCCTCGACGAGAACGGCTTCGACCGCGACTGCCCGGT CGTGCACACCTCCGCTTACGGCGCTCTGCATGACGACGCTCCCGGATCAC GACAAGTGGGTTGCCACCATCAAGGAGCTCATGGACGACGTCGACGAGTA CATCCCGACCCCGGTCCACGACCTCGACAAGCCGTTCCTGATGCCGATCG AGGACGTCTTCACCATCTCCGGCCGTGGCACCGTCGTCACCGGTCGTGTC GAGCGCGGCAAGCTGCCGATCAACACGAACGTCGAGATCGTCGGCATCCG CCCGACCCAGACCACCACCGTCACCTCCATCGAGACCTTCCACAAGCAGA TGGATGAGTGCGAGGCCGGCGACAACACCGGTCTGCTGCTCCGCGGCATC AACCGCACCGACGTCGAGCGTGGCCAGGTCGTGGCTGCTCCGGGTTCGGT CACCCCGCACACCAAGTTCGAAGGCGAAGTCTACGTCCTTACCAAGGATG AGGGCGGCCGTCACTCGCCGTTCTTCTCGAACTACCGTCCGCAGTTCTAC TTCCGCACCACCGACGTCACCGGCGTCATCACGCTGCCGGAAGGCGTCGA GATGGTTCAGCCTGGCGATCACGCGACCTTCACGGTTGAGCTGATCCAGC CGATCGCTATGGAAGAGGGCTTCACCTTCCCAGTGCTTGAAGGC.

Example 10. Tolerance of the Bifidobacterium animalis Subsp. Lactis i797 to Gastric Fluid and Intestinal Fluid

[0053] After the strain of Bifidobacterium animalis subsp. lactis i797 to be tested is activated for 3 generations, 1 mL strain is injected in 9 mL filtered and sterilized artificial gastric fluid with a pH of 3.0, the mixture is shaken homogeneously and cultured in an anaerobic environment at 37° C.; samples are taken at the beginning of culturing and after 2 hours culturing respectively, and the viable counts are determined respectively. Then, 1 mL culture solution which has been digested in the artificial gastric fluid with 3.0 pH for 2 hours is inoculated into 9 mL filtered and sterilized artificial intestinal fluid with a pH of 8.0, and is further cultured at 37° C.; the viable count is measured at 0 hour, 4 hours and 6 hours respectively.

[0054] Bifidobacterium BB-12 is used as a standard strain for a control experiment, and the experimental parameters are the same as those of the experiment for the strain of Bifidobacterium animalis subsp. lactis i797.

Survival rate (%)=(cfu N.sub.1/cfu N.sub.0)×100%

where, N.sub.1—the viable count after treatment with the artificial digestive fluid for 6 hours; N.sub.0—the viable count after treatment with the artificial digestive fluid for 0 hour.
b. Intestinal fluid: 0.9 g Bile Salts (Difco) per 100 mL, the pH is adjusted to 8.0, and the fluid is filtered and sterilized for later use.

TABLE-US-00010 TABLE 4 Result of Tolerance of Bifidobacterium Animalis Lactis Subsp. i797 to Simulated Gastric Fluid and Intestinal Fluid Survival Survival Survival rate in rate in rate in gastric intestinal digestive Strain 0 h 2 h 6 h fluid fluid fluid i797 5.0 × 10.sup.8 3.2 × 10.sup.6 3.7 × 10.sup.5 6.4%  116% 7.4% BB-12 2.6 × 10.sup.8 1.8 × 10.sup.6 1.2 × 10.sup.5 6.8% 66.7% 4.5%

[0055] The experiment demonstrates that BB-12 has strong tolerance to gastric acid and poor tolerance to intestinal fluid, while the Bifidobacterium animalis subsp. lactis i797 has poor tolerance to gastric acid and strong tolerance to intestinal fluid. By comprehensive comparison, the Bifidobacterium animalis subsp. lactis i797 achieves a better survival rate in the simulated digestive fluid, which is 7.4% and superior to that of BB-12.

Example 11. Study on the Intestinal Regulation of the Bifidobacterium animalis Subsp. lactis i797

[0056] A drink containing the Bifidobacterium animalis subsp. lactis i797 is given to the testers for drinking, and statistics on the drinking result of 10 testers is carried out.

[0057] The statistical result is shown in Table 5:

TABLE-US-00011 TABLE 5 Analysis of Difference of Indexes after Drinking the Drink Containing Bifidobacterium Animalis Subsp. Lactis i797 Drinking for a week Drinking for two weeks Is there a Is there a Item P value difference P value difference Frequency of 0.024 Yes 0.009 Yes defecation Difficulty in 0.087 No 0.042 Yes defecation Feeling after 0.250 No 0.179 No defecation Hardness of feces 0.023 Yes 0.091 No Amount of feces 0.655 No 0.281 No Odor of feces 0.909 No 0.159 No Color of feces 0.336 No 0.095 No Shape of feces 0.016 Yes 0.107 No Gastrointestinal 0.923 No 0.637 No condition Note: Any significant change (statistically significant, P < 0.05) means there is a difference.

[0058] In the statistical process: [0059] (1) Through analysis on the differences, it is found that there are significant differences in the frequency of defecation, difficulty in defecation, hardness of feces, and shape of feces; [0060] (2) Through conversation with the drinkers, it is found that after drinking, the frequency of defecation is increased, the color of the feces turns yellow, and the feces became softer, indicating obvious change of indexes.

[0061] It can be seen from Table 5: among all indexes, four indexes (frequency of defecation, difficulty in defecation, hardness of feces, and shape of feces) have changed significantly (statistically significant, P<0.05), which indicates that Bifidobacterium animalis subsp. lactis i797 has a regulating effect on the intestinal tracts.

Example 12. Analysis on Post-Acidification of the Strain of Bifidobacterium animalis subsp. lactis i797

[0062] Fresh milk of 97-98 parts and white sugar of 2-3 parts are mixed and blended evenly, homogenized at 65° C. and 15 MPa, sterilized at 95° C. for 300 seconds, and then cooled down to 37° C. to obtain sterilized milk; the Bifidobacterium animalis subsp. lactis i797 is inoculated into the sterilized milk with an inoculation amount of 3 wt % of the sterilized milk, and then fermented at 36° C., and the pH change is detected.

[0063] Standard strain of Bifidobacterium BB-12 is used as a control strain for control experiment, and the experimental parameters are the same as those of the above experiment for the strain of Bifidobacterium animalis subsp. lactis i797.

[0064] The result of acid production is shown in Table 6.

TABLE-US-00012 TABLE 6 Change of the Acidity of the Bifidobacterium Animalis Subsp. Lactis i797 Fermentation time BB-12 JMCC0025  0 h 6.4 6.32 18 h 6.13 6.06 24 h 5.55 4.66 42 h 3.97 3.92 49 h 3.86 3.87 66 h 3.82 3.87 90 h 3.82 3.88

[0065] It can be seen from Table 6: the Bifidobacterium animalis subsp. lactis i797 can control the post-acidification well under a storage condition suitable for the growth of lactic acid bacteria at a higher temperature of 37° C.

Example 13. Use of the Strain of Bifidobacterium animalis Subsp. Lactis i797

[0066] This example provides use of the Bifidobacterium animalis subsp. lactis i797 in Example 1, which can be used to prepare drinks, foods or medicines. For example, the strain can be used to prepare cereals and their derivatives, fermented meat products, probiotics and formula milk powder, which have an intestinal regulation function; it can also be used to prepare beverages and fermented yogurts that have an intestinal regulation function; in addition, it can be used to prepare medicines with an intestinal regulation function, in a dosage form of capsule, powder, pill, oral liquid or spray, etc.

Example 14. Use of the Strain of Bifidobacterium animalis Subsp. Lactis i797

[0067] The probiotics in the example 13 may be probiotics that only contain the Bifidobacterium animalis subsp. lactis i797; or the probiotics may be compound probiotics prepared by mixing Bifidobacterium animalis subsp. lactis i797, Lactobacillus paracasei N1115, Lactobacillus plantarum N3117 and Streptococcus thermophilus JMCC0003, and the dosage of the compound probiotics may be compound probiotic microcapsule powder.