Porcine bacillus velezensis YB-X-733 and application thereof

Abstract

The invention discloses swine bacillus velezensis YB-X-733 and application thereof, and relates to the technical field of microorganisms. The swine-derived bacillus velezensis YB-X-733 is preserved in the China General Microbiological Culture Collection Center on September 24, 2024, the preservation number is CGMCC No.32057, the preservation address is No.3, Yard 1, Beichen West Road, Chaoyang District, Beijing, and the swine-derived bacillus velezensis YB-X-733 is classified and named as bacillus velezensis. The swine bacillus velezensis YB-X-733 disclosed by the invention has a good inhibition effect on escherichia coli, staphylococcus aureus and salmonella, and can be used for preparing a piglet inflammation resisting product. The swine-origin bacillus velezensis YB-X-733 disclosed by the invention can be used for obviously improving the metabolic capability of weaned piglets and improving the physiological status of the piglets; the immunocompetence of weaned piglets is improved, and inflammation is reduced; the microbial flora in the intestinal tracts of the weaned piglets can be obviously improved, the growth of harmful bacteria is inhibited, and the growth of beneficial bacteria is promoted.

Description

Technical Field

[0001] The invention relates to the technical field of microorganisms, in particular to a strain of swine-derived Bacillus Velez subtilis YB-X-733 and application thereof. Background Art

[0002] In the process of pig farming, the weaned piglet stage is a turning point in the growth process of pigs, and the farming at this stage is also a difficult point. This is because: First, newborn piglets obtain maternal antibodies from colostrum, but as the age increases, the titer of maternal antibodies gradually decreases, and active immunity is not yet perfect, so weaned piglets are prone to disease. Second, the digestive tract of weaned piglets is not fully mature, especially the acid environment in the stomach and the concentration of digestive enzymes in the small intestine are low, resulting in limited digestion of protein in the diet. In addition, after weaning, the pH value in the stomach increases due to the loss of lactic acid in breast milk, further affecting the digestive ability. Third, weaned piglets leave the sow and the familiar environment, and are prone to stress reactions, such as screaming and looking for sows, which not only affects the piglets' feeding and growth, but also leads to the occurrence of diseases. At the same time, the temperature, humidity, ventilation and other conditions of the new environment may also have an adverse effect on piglets. Fourth, after weaning, piglets need to gradually transition from breast milk to solid feed. If the feed conversion is not appropriate during this process, it is easy to cause problems such as indigestion and diarrhea.

[0003] In order to solve the above problems, farms usually add antibiotics to feed to enhance the immunity and resistance of piglets and reduce stress response. Due to the excessive use of antibiotics in the aquaculture industry, problems such as drug residues and bacterial resistance have emerged one after another, which has brought extremely adverse effects on human health and the ecological environment. With the comprehensive "ban on antibiotics" on the feed side in 2020 and the implementation of the "antibiotic reduction and restriction" policy on the aquaculture side, "antibiotic alternatives" products have developed rapidly. Among them, probiotics are considered to be one of the best antibiotic alternatives, and Bacillus Velezii ( Bacillus velezensis ) is a new type of Bacillus, which can be used as a substitute for antibiotics. However, the currently available Bacillus Velezii can only be used to improve the production performance of chickens, and cannot achieve good results when used to improve the production performance of pigs. At present, no Bacillus Velezii that is good at inhibiting bacteria and promoting the growth performance of piglets has been found specifically for weaned piglets. Summary of the invention

[0004] The invention aims to provide a strain of swine-derived Bacillus Velez subtilis YB-X-733 and application thereof.

[0005] In order to solve the problems existing in the prior art, the technical solution adopted by the present invention is: In the first aspect, the present invention provides a strain of porcine Bacillus Velezii YB-X-733, which was deposited in the General Microbiological Center of China Microbiological Culture Collection Committee on September 24, 2024, with a deposit number of CGMCC No.32057, and a deposit address of No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, and was classified and named Bacillus Velezii ( Bacillus velezensis .

[0006] Furthermore, the sequence of the porcine-derived Bacillus Velez subtilis YB-X-733 is shown in SEQ ID NO.1.

[0007] In a second aspect, the present invention provides use of the Bacillus Velez subtilis YB-X-733 described in the first aspect in the preparation of a probiotic.

[0008] In a third aspect, the present invention provides a probiotic comprising the Bacillus Velez subtilis YB-X-733 described in the first aspect.

[0009] Preferably, the viable count of the Bacillus Velezii YB-X-733 in the probiotic is 1×10 10 CFU / g.

[0010] In a fourth aspect, the present invention provides a method for preparing the probiotic agent according to the third aspect, comprising the following steps: The strain was inoculated into LB medium for activation for three generations, and then inoculated into a fermenter for further culture. The bacterial solution after overnight culture was inoculated into LB broth medium at a ratio of 1-3% (V / V) to obtain a probiotic solution, and the probiotic solution was mixed with wheat bran to ensure that the number of live bacteria of the Velez subtilis YB-X-733 after mixing was 1×10 10 CFU / g, freeze-dried for later use.

[0011] The solid-liquid ratio of the probiotic solution to wheat bran is (0.5-2.0) L: (0.20-0.30) kg, preferably 1.0 L: 0.25 kg.

[0012] In a fifth aspect, the present invention provides the use of the Bacillus Velez subtilis YB-X-733 described in the first aspect or the probiotic described in the third aspect or the probiotic prepared according to the method described in the fourth aspect in the preparation of a product for improving the production performance of piglets.

[0013] In a sixth aspect, the present invention provides the use of the Bacillus Velez subtilis YB-X-733 described in the first aspect or the probiotic agent described in the third aspect or the probiotic agent prepared according to the method described in the fourth aspect in preparing piglet feed.

[0014] Preferably, the viable count of the Bacillus Velez subtilis YB-X-733 in the piglet feed is 1×10 8 CFU / g.

[0015] In a seventh aspect, the present invention provides use of the Bacillus Velez subtilis YB-X-733 described in the first aspect or the probiotic described in the third aspect or the probiotic prepared according to the method described in the fourth aspect in inhibiting harmful bacteria.

[0016] Furthermore, the harmful bacteria are Escherichia coli, Salmonella and Staphylococcus aureus.

[0017] The advantages and beneficial effects of the present invention are: The porcine-derived Bacillus Velez subtilis YB-X-733 of the present invention has a good inhibitory effect on Escherichia coli, Staphylococcus aureus and Salmonella, and can be used to prepare anti-piglet inflammation products. The porcine-derived Bacillus Velez subtilis YB-X-733 of the present invention can significantly improve the metabolic capacity of weaned piglets, improve the physiological state of piglets, improve the immune capacity of weaned piglets, and reduce the occurrence of inflammation; it can significantly improve the microbial flora in the intestines of weaned piglets, inhibit the growth of harmful bacteria, and promote the growth of beneficial bacteria. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The following is the effect diagram of the inhibition zone, where A is Escherichia coli, B is Salmonella, and C is Staphylococcus aureus. Figure 2 The Gram staining result of the porcine Bacillus YB-X-733 of the present invention (×1000); Figure 3 The spore staining result of the porcine Bacillus YB-X-733 of the present invention (×1000); Figure 4 It is a schematic diagram of the growth state of the porcine-derived Bacillus YB-X-733 of the present invention; Figure 5 is the genetic evolution tree of the porcine Bacillus YB-X-733 of the present invention; Figure 6 This is the growth curve of the porcine Bacillus YB-X-733 of the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0020] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial channels.

[0021] Example 1: 1. Screening and Isolation of Swine-derived Bacillus YB-X-733 Fresh feces of healthy adult antibiotic-free local pigs in Mianyang, Sichuan Province were used as samples. 1 g of feces sample was aseptically weighed and placed in 10 mL of sterile PBS buffer. The sample was shaken to mix thoroughly and placed in a 90°C water bath for 10 min to kill other non-spore-forming bacteria. Then, the sample was diluted 10 times with sterile water and 100 μL of the dilution was spread on a soybean casein agar (TSA) plate. The plate was placed in a 37°C incubator and inverted for 48 h. The growth of the plate colonies was observed and a single colony was streaked and inoculated on a new plate. LB medium was added and aerobic culture was carried out at 37°C and pH = 7.0 ± 0.1 for 8 h. Figure 4 As shown, a Bacillus strain was finally screened and isolated, numbered YB-X-733, and submitted to the General Microbiology Center of China Microorganism Culture Collection Administration with a deposit number of CGMCC No.32057.

[0022] 2. Antagonistic properties of swine-derived Bacillus subtilis YB-X-733 against pathogens In order to further test its antibacterial effect, the candidate bacteria were tested for inhibiting pathogens: Preparation of swine Bacillus suspension: After the strain was activated, the grown single colony was inoculated into LB broth medium and cultured at 37°C for 12 h. Then, 2 mL of bacterial solution was taken, centrifuged and the supernatant was discarded. 2 mL of sterile PBS buffer was added and shaken evenly to obtain a suspension of Bacillus suis from pigs. The number of viable bacteria in the suspension was 1×10 8 CFU·mL -1 .

[0023] Experimental methods: After the LB broth solid medium is sterilized and cooled to about 50°C, it is poured into a sterile culture dish. After the plate is naturally dried, 0.1 mL of the swine Bacillus suspension (10 8 CFU / mL) was evenly spread on the plate, and after natural drying, holes were punched on the plate, and 0.1 mL of the test bacterial solution YB-X-733 was added to the hole. After the bacterial solution penetrated into the plate, it was cultured at 37 °C for 24 h, and the size of the inhibition zone was measured. The results showed that YB-X-733 had a good inhibitory effect on Escherichia coli, Staphylococcus aureus and Salmonella.

[0024] Test results: Swine-derived Bacillus subtilis YB-X-733 has a good inhibitory effect on Escherichia coli (O157:H7 is enterohemorrhagic Escherichia coli), Staphylococcus aureus and Salmonella. The antibacterial results are shown in Table 1. Figure 1 .

[0025] Table 1 Results of antibacterial test of candidate bacteria:

[0026] 3. Screening of acid and bile resistance of swine-derived Bacillus subtilis YB-X-733 In order to further explore the tolerance of porcine Bacillus YB-X-733 to the digestive tract environment, acid and bile resistance tests were conducted: 3.1 Bile salt tolerance test: The bacteria to be tested were inoculated into LB liquid culture medium. After culturing for 12-24 h, 5% of the bacterial solution was inoculated into LB liquid culture medium with different bile salt levels (0.15% and 0.3%) and placed at 37°C for 2 h or 4 h. 100 μL of the bacterial solution was diluted 10-fold at 0, 2, and 4 h, and 100 μL of the bacterial solution was diluted 10-fold at 0, 2, and 4 h. -5 The gradient dilutions were spread on LB plates, cultured at 37°C for 24 h, and colonies were counted. Each sample was replicated 3 times. The survival rate was calculated as follows: Survival rate (%) = number of colonies at “2 h or 4 h” / number of colonies at “0 h” × 100%.

[0027] 3.2 Acid resistance test: The bacteria to be tested were inoculated into LB liquid culture medium. After culturing for 12-24 h, 5% of the bacterial solution was inoculated into LB liquid culture medium with different bile salt levels (0.15% and 0.3%) and placed at 37°C for 2 h or 4 h. 100 μL of the bacterial solution was diluted 10-fold at 0, 2, and 4 h, and 100 μL of the bacterial solution was diluted 10-fold at 0, 2, and 4 h. -5 The gradient dilutions were spread on LB plates, cultured at 37°C for 24 h, and colonies were counted. Each sample was replicated 3 times. The survival rate was calculated as follows: Survival rate (%) = number of colonies at “2 h or 4 h” / number of colonies at “0 h” × 100%.

[0028] The test results are shown in Table 2. The results show that in the environment of pH 2 and 3, the survival rate of strain YB-X-733 reached more than 80% after 2 hours of treatment, and more than 70% after 4 hours of treatment. In the environment of 0.15% and 0.3% bile salt, the survival rate of strain YB-X-733 was more than 80% after 2 hours of treatment, and more than 67% after 4 hours of treatment. Based on the results of acid and bile salt resistance, strain YB-X-733 has strong acid and bile salt resistance.

[0029] Table 2 Acid and bile salt tolerance of candidate strains

[0030] 4. Identification of swine-derived Bacillus subtilis YB-X-733 After a single colony of pure swine Bacillus is isolated, the colony is identified. The identification process of swine Bacillus YB-X-733 in the present application is as follows: the colony of swine Bacillus obtained after separation and purification is processed, and the cell morphology, physiological and biochemical characteristics, and 16SrRNA gene sequence of the separated and purified swine Bacillus are identified as swine Bacillus Velezii, and named as Bacillus Velezii ( Bacillus velezensis . It is deposited in the General Microbiology Center of China Microbiological Culture Collection Administration Committee, with the deposit number CGMCC No.32057, the deposit address is No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, and the deposit date is September 24, 2024. The identification data are as follows: 4.1 Morphological identification The colony morphology of the swine-derived Bacillus subtilis YB-X-733 strain is shown in Table 3. Figure 2 , 3 As shown, Gram staining observation revealed that the strain was a Gram-positive bacillus, and spore staining was positive.

[0031] Table 3 Colony morphology

[0032] 5. Identification of physiological and biochemical characteristics of YB-X-733 strain The physiological and biochemical characteristics of strain YB-X-733 are shown in Table 4. The comparative analysis was carried out with reference to the Manual of Identification of Common Bacterial Systems and the Bergey's Manual of Identification of Bacteria, which was consistent with the physiological and biochemical characteristics of Bacillus.

[0033] Table 4 Physiological and biochemical identification results of YB-X-733

[0034] Note: + indicates positive; - indicates negative.

[0035] 6. Molecular biological identification of YB-X-733 strain PCR amplification was performed using universal primers (27F and 1492R) for bacterial identification of 16S rDNA: ‌First, the strain DNA was extracted and the 16S rDNA was amplified using universal primers (27F and 1492R). The PCR products were detected by electrophoresis to ensure the size and specificity of the amplified fragments, and then the amplified products were sequenced. The 16S rDNA primer sequences were 27F (5'-AGAGTTTGATCCTGGCTCAG -3') (SEQ ID NO.2) and 1492R (5' -TACGGCTACCTTGTTACGACTT-3') (SEQ ID NO.3). The primers were synthesized by Shanghai Bioengineering Co., Ltd.

[0036] The PCR amplification template was 2 μL, the system was 50 μL, and the amplification system was: 10×PCR Buffer 5 μL, 2.5 mmoldNTPs 5 μL, Forword Primers (10 pmol) 5 μL, ReversePrimers (10 pmol) 5 μL, Polymerase (2.5 U / μL) 1 μL, template 2 μL, ddH2O 27 μL.

[0037] The PCR amplification program was as follows: 94 °C pre-denaturation for 3 min; 94 °C denaturation for 30 s, 58 °C annealing for 30 s, 72 °C extension for 3 min, a total of 32 cycles; 72 °C extension for 10 min, and storage at 4 °C. The sequencing results were analyzed by BLAST in GenBank, and the 16S rDNA gene sequence of Bacillus suis YB-X-733 is shown in SEQ ID NO.1.

[0038] By performing BLAST comparison in GenBank and drawing a genetic evolutionary tree, the results showed that the swine-derived Bacillus YB-X-733 and Bacillus Velezii ( Bacillus velezensis On the same branch, the closest affinity is 99% ( Figure 5 ), so it can be determined that YB-X-733 is Bacillus Velezii, so it is named Bacillus Velezii ( Bacillus velezensis) .

[0039] SEQ ID NO.1 7. Analysis of biological characteristics of YB-X-733 strain After the strain was activated for one generation, it was inoculated into 100 mL LB liquid culture medium at a 2% (V / V) inoculation rate and cultured at 37°C with shaking. 5 mL of the bacterial solution was taken for testing every 2 h, and the concentration (OD value) of the bacterial solution was measured at a wavelength of 600 nm using an ultraviolet spectrophotometer for a total of 14 h.

[0040] like Figure 6 As shown in the figure, by measuring the growth curve of porcine Bacillus Velezii YB-X-733, it can be found that YB-X-733 enters the logarithmic growth phase after 2 hours and enters the stable phase after 8 hours.

[0041] Example 2 1. Preparation of probiotic preparations When using the screened probiotics to prepare probiotic preparations, the strains were first inoculated into LB medium for activation for three generations. After activation, they were inoculated into a fermenter for continued cultivation. The bacterial solution after overnight culture was inoculated into a 20 L automatic fermenter with LB broth culture medium at a ratio of 2% (V / V) to obtain a probiotic solution. The number of viable bacteria in the produced bacterial solution was calculated by the plate count method, and the number of viable bacteria was adjusted. 1.0 L of the probiotic solution was mixed with 0.25 kg of wheat bran to ensure that the content of Bacillus velezensis YB-X-733 was 1×10 10 CFU / g, and then freeze-dried for later use.

[0042] 2. Animal Experimentation A total of 108 healthy 28-day-old weaned piglets (Du Changda) were selected and divided into three groups (control group, Bacillus group, comparative group) according to the block design principle, with 6 replicates in each group and 6 pigs in each replicate. The control group was fed a basic diet, and the Bacillus group was supplemented with YB-X-733 Bacillus probiotic preparation in the basic diet, and the live bacteria count in the feed was adjusted to 1×10 8 CFU / g. The probiotics used in the comparative group were Bacillus Velezii, which was published in the Chinese invention patent with patent number 201911416772.2 and the invention name was a strain of Bacillus Velezii and its application in preventing and treating swine diarrhea. The comparative group added a probiotic preparation prepared by the Bacillus Velezii to the basic feed and adjusted the number of live bacteria in the feed to 1×10 8 CFU / g, pre-feeding period of 3 days, formal test period of 28 days. The test pigs were managed according to the routine breeding of the pig farm, and the immunization, deworming and disinfection procedures during the test were carried out according to the normal procedures of the pig farm. At the end of the test feeding, 5 mL of blood was collected from the anterior vena cava of each group, placed in a serum tube for coagulation, centrifuged at 3000r / min for 10 min, and the serum was separated and stored at -20℃ for testing.

[0043] 4. Effect of YB-X-733 on the growth performance of weaned piglets Table 5 shows the growth performance of weaned piglets in each group. As can be seen from Table 5, there is no difference in initial weight among the groups, and the weights of the piglets in each group are relatively close. After 28 days of feeding, the average daily weight gain of the YB-X-733 group was significantly higher than that of the control group and the comparative group ( P <0.05). The results showed that the addition of YB-X-733 could significantly improve the growth performance of piglets.

[0044] Table 5 Effect of YB-X-733 on growth performance of weaned piglets

[0045] Note: Different letters in the same row represent significant differences (P<0.05). The same below.

[0046] 2. Effects of YB-X-733 on blood biochemical parameters of weaned piglets Serum biochemical indicators can directly reflect the physiological state of animals. Higher levels of total protein, albumin and globulin in serum indicate that the animal is in good health and has good protein synthesis and metabolism capabilities; the level of lactate dehydrogenase reflects the animal's level of carbohydrate metabolism.

[0047] The liver is an important digestive organ of the body and also has immune function. When the liver function of an animal is damaged, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase in the liver are released into the blood, leading to increased enzyme activity in the blood.

[0048] As shown in Table 6, the globulin of weaned piglets in the YB-X-733 group increased significantly ( P <0.05), although the globulin in the control group also increased, it was still lower than that in the YB-X-733 group. Alanine aminotransferase, alkaline phosphatase and aspartate aminotransferase in the blood of piglets in the YB-X-733 group were all reduced to a certain extent. Although the control group also decreased, it was still lower than that in the YB-X-733 group. This shows that the addition of YB-X-733 can significantly improve the metabolic capacity of weaned piglets and improve the physiological state of piglets.

[0049] Table 6 Effects of YB-X-733 on blood biochemical parameters of weaned piglets

[0050] Note: Different letters in the same row represent significant differences (P<0.05).

[0051] 3. Effect of YB-X-733 on the immune level of weaned piglets The levels of related cytokines were detected using commercially available ELISA kits. Interleukin-2 (IL-2), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) are all pro-inflammatory factors. From the data in Table 7, it can be seen that compared with the control group and the comparative group, the IL-2 content in the serum of weaned piglets in the YB-X-733 group was significantly reduced ( P <0.05), IL-6 and TNF-α in the YB-X-733 group showed a certain downward trend. The pro-inflammatory factor interleukin-10 (IL-10) was significantly reduced in the YB-X-733 group ( P <0.05). This indicates that the addition of YB-X-733 can improve the immune capacity of weaned piglets and reduce the occurrence of inflammation.

[0052] Table 7 Effect of YB-X-733 on the immune level of weaned piglets

[0053] Note: Different letters in the same column represent significant differences ( P <0.05).

[0054] 4. Effect of YB-X-733 on fecal flora of weaned piglets The effect of YB-X-733 on fecal flora of weaned piglets is shown in Table 8. The number of lactobacilli in the feces of weaned piglets in the YB-X-733 group was significantly higher than that in the control group and the comparative group, while the number of Escherichia coli and Salmonella was significantly lower than that in the control group and the comparative group ( P <0.05). This suggests that YB-X-733 can significantly improve the microbial flora in the intestines of weaned piglets, inhibit the growth of harmful bacteria, and promote the growth of beneficial bacteria.

[0055] Table 8 Effect of YB-X-733 on fecal flora of weaned piglets

[0056] Note: Different letters in the same column represent significant differences ( P <0.05).

[0057] According to the above experimental results, the YB-X-733 of the present invention can significantly improve the growth performance of piglets, improve the metabolic capacity of weaned piglets, improve the physiological state of piglets, improve the immunity of weaned piglets, reduce the occurrence of inflammation, significantly improve the microbial flora in the intestines of weaned piglets, inhibit the growth of harmful bacteria, and promote the growth of beneficial bacteria.

[0058] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A strain of porcine Bacillus Velezii YB-X-733, characterized in that: The porcine Bacillus Velezii YB-X-733 was deposited in the General Microbiology Center of the China Microbiological Culture Collection Administration on September 24, 2024, with a deposit number of CGMCC No.32057 and a deposit address of No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing. It was classified and named Bacillus Velezii ( Bacillus velezensis .

2. The porcine Bacillus Velez subtilis YB-X-733 according to claim 1, characterized in that: The sequence of the porcine Bacillus Velez subtilis YB-X-733 is shown in SEQ ID NO.

1.

3. Use of the Bacillus Velez subtilis YB-X-733 according to claim 1 or 2 in the preparation of a probiotic.

4. A probiotic agent, characterized in that: Contains the Bacillus Velezii YB-X-733 according to claim 1 or 2.

5. A probiotic according to claim 4, characterized in that The viable bacteria count of the Bacillus Velez YB-X-733 in the probiotic is 1×10 10 CFU / g.

6. The method for preparing a probiotic according to claim 4 or 5, characterized in that The following steps are involved: The strain was inoculated into LB medium for activation for three generations, and then inoculated into a fermenter for further culture. The bacterial solution after overnight culture was inoculated into LB broth medium at a ratio of 1-3% (V / V) to obtain a probiotic solution, and the probiotic solution was mixed with wheat bran to ensure that the number of live bacteria of the Velez subtilis YB-X-733 after mixing was 1×10 10 CFU / g, freeze-dried for later use.

7. The method for preparing a probiotic according to claim 6, characterized in that: The solid-liquid ratio of the probiotic liquid to the wheat bran is (0.5-2.0) L: (0.20-0.30) kg.

8. Use of the Bacillus Velez YB-X-733 according to any one of claims 1 to 2, the probiotic according to any one of claims 4 to 5, or the probiotic prepared according to the method according to any one of claims 6 to 7 in the preparation of a product for improving the production performance of piglets.

9. Use of the Bacillus Velez YB-X-733 according to any one of claims 1 to 2, the probiotic according to any one of claims 4 to 5, or the probiotic prepared according to the method according to any one of claims 6 to 7 in preparing piglet feed.

10. Use of the Bacillus Velez YB-X-733 according to any one of claims 1 to 2, the probiotic according to any one of claims 4 to 5, or the probiotic prepared according to the method according to any one of claims 6 to 7 in inhibiting harmful bacteria.

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