A PREPARATION METHOD OF SILAGE

Abstract

The present disclosure relates to a preparation method of silage, and belongs to the technical field of microbial feeds. The present disclosure is intended to solve the problem that the existing silage has a low utilization rate due to anti-nutritional factors such as tannins and saponins. The present disclosure provides Lactiplantibacillus plantarum P91 with an accession number of CGMCC No. 27567. The Lactiplantibacillus plantarum P91 has acid resistance, a high growth rate, a strong carbon source-utilizing ability, and an excellent comprehensive acid-production ability, and can reduce a pH, well improve the palatability of silage, and reduce anti-nutritional factors in silage. Therefore, the present disclosure can effectively solve the problem that a silage raw material has a high content of anti-nutritional factors such as tannins and saponins, and overcome the adaptability problem of a lactobacillus to a raw material, thereby improving an activity of the lactobacillus and a quality of silage fermentation.

Claims

1-10. (canceled)

11. A preparation method of silage, comprising the following steps: S1: a raw material is chopped and thoroughly mixed; S2: the Lactiplantibacillus plantarum P91 is added to the raw material at a level of 1.010.sup.6 CFU/g or more; and S3: a resulting feed system is vacuum-sealed and stored; the accession number of the Lactiplantibacillus plantarum P91 is CGMCC No. 27567.

12. The preparation method of silage according to claim 1, wherein in the S1, the raw material includes Caragana korshinskii Kom. and Moringa oleifera Lam.

13. The preparation method of silage according to claim 2, wherein Caragana korshinskii Kom. and Moringa oleifera Lam. manually mowed are chopped to 2 cm to 3 cm.

14. The preparation method of silage according to claim 1, wherein in the S3, a vacuum-sealed feed system is stored at 20 C. to 25 C., and after the vacuum-sealed feed system is stored for 90 d, a pH of the vacuum-sealed feed system is reduced to 3.92.

15. The preparation method of silage according to claim 1, wherein the Lactiplantibacillus plantarum P91 is isolated from Broussonetia papyrifera silage.

16. The preparation method of silage according to claim 5, wherein before extraction and separation, the Broussonetia papyrifera silage is silage stored for 60 d.

17. The preparation method of silage according to claim 5, wherein a process of isolation and cultivation of the Lactiplantibacillus plantarum P91 includes: a bag with the Broussonetia papyrifera silage is opened, the Broussonetia papyrifera silage is thoroughly mixed in a clean basin, an appropriate amount of the Broussonetia papyrifera silage is taken and mixed with 0.85% normal saline, and a resulting supernatant is collected, transferred to an MRS medium, and cultivated.

18. The preparation method of silage according to claim 7, wherein a temperature for cultivation of the Lactiplantibacillus plantarum P91 is 15 C. to 45 C.

19. The preparation method of silage according to claim 7, wherein after the Lactiplantibacillus plantarum P91 is cultivated in the MRS medium for 24 h, a pH value of the MRS medium is reduced to 3.5 to 4.0.

20. The preparation method of silage according to claim 1, wherein the Lactiplantibacillus plantarum P91 comprises 16S rDNA shown in SEQ ID NO: 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are provided merely to illustrate the specific embodiments, rather than to limit the present disclosure. The same reference numerals represent the same components throughout the accompanying drawings.

[0022] FIG. 1 shows discoloration circles of the Lactiplantibacillus plantarum P91 for degradation of tannins in the present disclosure;

[0023] FIG. 2 shows a growth status of colonies of the Lactiplantibacillus plantarum P91 with saponins as an only carbon source in the present disclosure;

[0024] FIG. 3 shows acid-producing and growth rates of the Lactiplantibacillus plantarum P91 prepared in Example 1 of the present disclosure; and

[0025] FIG. 4 shows acid-producing and growth rates of the Lactiplantibacillus plantarum P87 prepared in Comparative Example 1 of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] Preferred embodiments of the present disclosure will be specifically described below with reference to the accompanying drawings. The accompanying drawings constitute a part of the present disclosure, and are used together with the embodiments of the present disclosure to explain the principles of the present disclosure rather than limit a scope of the present disclosure.

[0027] In a specific embodiment, the present disclosure provides Lactiplantibacillus plantarum P91, which was deposited in the China General Microbiological Culture Collection Center (CGMCC, Institute of Microbiology Chinese Academy of Sciences NO. 1 West Beichen Road, Chaoyang District, Beijing, China) on Jun. 6, 2023, with an accession number of CGMCC No. 27567.

[0028] In an embodiment, the Lactiplantibacillus plantarum P91 includes 16S rDNA shown in SEQ ID NO: 1.

[0029] In an embodiment, the Lactiplantibacillus plantarum P91 is isolated from Broussonetia papyrifera silage.

[0030] It should be noted that, before extraction and separation, the Broussonetia papyrifera silage is silage stored for 60 d, and as a preferred solution, Broussonetia papyrifera refers to hybrid Broussonetia papyrifera.

[0031] Specifically, a process of isolation and cultivation of the Lactiplantibacillus plantarum P91 includes: [0032] a bag with the Broussonetia papyrifera silage is opened, the Broussonetia papyrifera silage is thoroughly mixed in a clean basin, an appropriate amount of the Broussonetia papyrifera silage is taken and mixed with 0.85% normal saline, and a resulting supernatant is collected, transferred to an MRS medium, and cultivated.

[0033] In an embodiment, a temperature for cultivation of the Lactiplantibacillus plantarum P91 is 15 C. to 45 C., and further can be 30 C. to 35 C., such as 20 C., 25 C., 27 C., 33 C., 37 C., or 40 C.

[0034] In an embodiment, after the Lactiplantibacillus plantarum P91 is cultivated in the MRS medium for 24 h, a pH value of the MRS medium is reduced to 3.5 to 4.0.

[0035] In an embodiment, a pH for cultivation of the Lactiplantibacillus plantarum P91 is 4.5 to 7.0.

[0036] In an embodiment, a salt concentration for cultivation of the Lactiplantibacillus plantarum P91 is 3.0% to 6.5% NaCl.

[0037] It should be noted that the biological characteristics of the Lactiplantibacillus plantarum P91 in the present disclosure is a Gram-positive coccus allowing glucose homolactic fermentation. The Lactiplantibacillus plantarum P91 can grow normally at a pH of 4.5, indicating strong acid resistance. The Lactiplantibacillus plantarum P91 can grow well in environments with salt concentrations of 3.0% and 6.5%, respectively, indicating excellent salt resistance. After the Lactiplantibacillus plantarum P91 is cultivated in an MRS liquid medium at 37 C. for 48 h, OD.sub.600 nm is 1.6218, indicating a high growth rate. A test is conducted at 30 C. with Profile Index (API 50 CH, blomerieux, France) test strips. In addition to carbon sources that can be utilized by the Lactiplantibacillus plantarum P91, the Lactiplantibacillus plantarum P87 can well utilize D-fructose and dulcitol, as shown in Tables 6 and 8. It indicates that there is a difference in the utilization of carbon sources between the two strains.

[0038] In another specific embodiment, the present disclosure provides a silage additive including the Lactiplantibacillus plantarum P91 described above.

[0039] Further, the additive is a hybrid Broussonetia papyrifera silage additive.

[0040] In another specific embodiment, the present disclosure provides silage including the Lactiplantibacillus plantarum P91 described above.

[0041] In an embodiment, the silage further includes Caragana korshinskii Kom. silage and/or Moringa oleifera Lam. silage.

[0042] Further, the silage further includes Caragana korshinskii Kom. silage and Moringa oleifera Lam. silage.

[0043] In another specific embodiment, the present disclosure provides a preparation method of silage, including: a silage raw material is mixed with the Lactiplantibacillus plantarum P91 described above, and fermentation is allowed to obtain the silage.

[0044] In an embodiment, a mass ratio of the Lactiplantibacillus plantarum P91 to the silage raw material is 1.010.sup.5 CFU/g to 2.010.sup.6 CFU/g, for example, the mass ratio is 2.010.sup.5 CFU/g, 5.010.sup.5 CFU/g, 8.010.sup.5 CFU/g, 1.010.sup.6 CFU/g, or 1.510.sup.6 CFU/g.

[0045] Specifically, in an embodiment, the present disclosure provides a preparation method of silage, including the following steps: [0046] S1: a raw material is chopped and thoroughly mixed; [0047] S2: the Lactiplantibacillus plantarum P91 is added to the raw material at a level of 1.010.sup.6 CFU/g or more; and [0048] S3: a resulting feed system is vacuum-sealed and stored.

[0049] In an embodiment, in the S1, the raw material includes Caragana korshinskii Kom. and Moringa oleifera Lam., and further, Caragana korshinskii Kom. and Moringa oleifera Lam. manually mowed are chopped to 2 cm to 3 cm.

[0050] In an embodiment, in the S3, a vacuum-sealed feed system is stored at 20 C. to 25 C., and after the vacuum-sealed feed system is stored for 90 d, a pH of the vacuum-sealed feed system is reduced to 3.92.

[0051] In another specific embodiment, the present disclosure provides a use of the Lactiplantibacillus plantarum P91 in preparation of silage.

[0052] It should be noted that the Lactiplantibacillus plantarum P91 in the present disclosure has acid resistance, a high growth rate, a strong carbon source-utilizing ability, and an excellent comprehensive acid-production ability, and can reduce anti-nutritional factors in silage. Therefore, the present disclosure can effectively solve the problem that a silage raw material has a high content of anti-nutritional factors such as tannins and saponins, well improve the palatability of silage, and overcome the adaptability problem of a lactobacillus to a raw material, thereby improving an activity of the lactobacillus and a quality of silage fermentation.

[0053] Through the use of a plant epiphytic lactobacillus in silage, the present disclosure overcomes the problem that a lactobacillus exhibits low adaptability to a raw material during silage, and reduces the contents of tannins and saponins.

[0054] In the silage of the present disclosure, a lactobacillus is used to improve a fermentation quality of silage and reduce anti-nutritional factors in silage, which has advantages such as low cost, safety, reliability, and easy utilization.

[0055] The Lactiplantibacillus plantarum P91 and silage in an embodiment of the present disclosure are further described below in conjunction with the accompanying drawings and specific examples.

[0056] The Caragana korshinskii Kom. material used comes from the Inner Mongolia Jinji Biotechnology Co., Ltd., Chifeng City, Inner Mongolia Autonomous Region (North Latitude: 43.97, East Longitude: 119.38, altitude: 687 m, average annual temperature: 5.8 C., and average annual precipitation: 314.5 mm). The Moringa oleifera Lam. material comes from the experimental base of the South China Agricultural University, Guangzhou City, Guangdong Province (North Latitude: 23.14, East Longitude: 113.32, altitude: 11 m, average annual temperature: 22.2 C., and average annual precipitation: 1,632 mm to 2,899 mm).

[0057] The Broussonetia papyrifera silage raw material comes from the Rongcheng Gouyang Modern Agriculture (Chongqing) Co., Ltd., Rongchang District, Chongqing: North Latitude: 29.42, East Longitude: 105.61, altitude: 380 m, relative humidity: 76%, average annual temperature: 17.8 C., and average annual precipitation: 1,099 mm. A specific preparation method of the Broussonetia papyrifera silage is as follows: the Broussonetia papyrifera silage raw material is chopped to 2 cm to 3 cm, an appropriate amount of a chopped raw material is uniformly taken and placed on a clean plastic sheet, and about 500 g of a fresh Broussonetia papyrifera sample is taken and placed in a double-sided twill silage bag (28 cm35 cm), and stored at room temperature (252 C.).

[0058] An MRS liquid medium used for the isolation and cultivation of the Lactiplantibacillus plantarum P91 and the determination of physiological and biochemical indexes such as growth rate and acid-producing rate includes the components shown in Table 1 below:

TABLE-US-00001 TABLE 1 Components of the MRS liquid medium Content Component (g) Peptone 10.0 Beef powder 5.0 Yeast powder 4.0 Glucose 20.0 Tween 80 1 mL Triammonium citrate 2.0 Sodium acetate 5.0 Magnesium sulfate 0.2 Manganese sulfate 0.05 Dipotassium phosphate 2.0 Distilled water 1000 mL

[0059] An MRS solid medium is obtained by adding 15 g of agar on the basis of the MRS liquid medium. The above media are sterilized at 121 C. in an autoclave for 15 min.

Example 1

Isolation and Primary Screening of Bacteria for Degrading Tannins and Saponins

1. Isolation and Purification of Strains

[0060] 20 g of Broussonetia papyrifera silage (which had been stored for 60 d) was taken and placed in a clean sealed bag filled with 180 mL of sterile normal saline (0.85% NaCl solution), then the sealed bag was fully shaken and placed in a 4 C. refrigerator to allow leaching for 4 h, and then 1 mL of a resulting supernatant (which was denoted as a 10.sup.1 concentration gradient) was taken and 10-fold diluted serially to a 10.sup.2 concentration gradient, a 10.sup.3 concentration gradient, and a 10.sup.4 concentration gradient. 100 L of a dilution at each gradient was spread on an MRS agar plate and cultivated in a 37 C. incubator for 48 h. According to the morphologies, colors, and sizes of single colonies, typical colonies were selected and purified at least twice by a plate streaking method until obtaining single colonies of lactobacilli. A lactobacillus was transferred to a 10% dimethyl sulfoxide-containing NB nutrient medium by a colony enrichment method, and stored in a 80 C. refrigerator. A composition of the MRS solid medium was as above.

2. Primary Screening of Lactobacilli Capable of Degrading Both Tannins and Saponins

[0061] A tannin-containing solid screening medium was equally divided into four parts, and a sterile Oxford cup was placed by sterile forceps on a surface of the medium at a corresponding position and pressed gently. An activated pure lactobacillus solution (100 L) was taken and spot-inoculated in the Oxford cup, and an inoculated medium was slowly placed in a 30 C. incubator and cultivated for 24 h to 48 h. A growth status of a colony and a size of a discoloration circle around a colony were observed. Colonies with transparent circles were preliminarily regarded as having an ability to degrade tannins, and this strain was selected and subsequently subjected to primary saponin-degradation screening by measuring a tannase-producing activity of this strain. Components of the medium for primary screening of tannin-degrading lactobacilli are shown in Table 2 below.

TABLE-US-00002 TABLE 2 Components of the medium for primary screening of tannin-degrading lactobacilli Percentage content Component (w/v) Tannic acid 1.00 Agar 2.50 NaNO.sub.3 0.30 K.sub.2HPO.sub.4 0.10 MgSO.sub.47H.sub.2O 0.05 KCl 0.05 FeSO.sub.47H.sub.2O 0.001 Bromophenol blue 0.004 pH 5.0

[0062] 100 L of a tannin-degrading pure bacterial solution screened above was added to a saponin-containing solid screening medium, and uniformly coated on a surface of the medium, and cultivated at 30 C. for 48 h. If colonies grew, it was preliminarily determined that a corresponding strain had an ability to utilize saponins, and the strain was stored and subjected to subsequent secondary screening. Components of the medium for preliminary screening of saponin-degrading lactobacilli are shown in Table 3 below.

TABLE-US-00003 TABLE 3 Components of the medium for primary screening of saponin-degrading lactobacilli Thousandth content Component (w/v) Saponin 10.00 Agar 20.00 (NH.sub.4).sub.2SO.sub.4 1.00 K.sub.2HPO.sub.4 1.50 KH.sub.2PO.sub.4 0.50 NaCl 1.00 MgSO.sub.4 0.20 FeSO.sub.4 0.05 pH 7.00

Secondary Screening of Bacteria Capable of Degrading Both Tannins and Saponins

[0063] Determination of tannase: A bacterial solution capable of degrading both tannins and saponins that was primarily screened above and activated for 24 h was inoculated into a tannase-production medium (a composition of the tannase-production medium was shown in Table 4) and cultivated in a constant-temperature shaker at 150 rpm and 30 C. for 24 h, and a resulting bacterial solution was centrifuged at 10,000 rpm and 4 C. for 10 min to obtain a supernatant, which was a crude tannase solution. A propyl gallate (PG) solution required by the experiment and a crude tannase solution to be tested each were incubated in a 30 C. water bath for 5 min to 10 min. 0.25 mL of the PG solution was added to each test tube; 0.25 mL of a crude tannase solution was added to an experimental tube, and 0.25 mL of a citric acid buffer was added to a blank tube; each test tube was thoroughly vortexed and then incubated in a 30 C. water bath for 5 min; then 0.3 mL of a rhodanine methanol solution was added to each tube, and each test tube was incubated for 5 min; then 0.4 mL of a KOH solution was added to each test tube; 3.8 mL of distilled water was added to each test tube to dilute a reaction system, and a diluted reaction system was incubated at 30 C. for 5 min to 10 min; and with distilled water as a blank, an appropriate amount of a final reaction solution was taken and tested by a microplate reader for absorbance at 520 nm, and a tannase activity was calculated. The tannase activity was calculated as follows: A.sub.520=(A.sub.testA.sub.blank)(A.sub.controlA.sub.blank). With gallic acid as a standard, a standard curve was plotted, where a standard equation was y=0.001 x+0.051 and R.sup.2=0.9917. A tannase activity was 183.47 mol/min.Math.mL.

TABLE-US-00004 TABLE 4 Tannase-production medium Percentage content Component (w/v) Tannic acid 2.00 Sucrose 1.00 NaNO.sub.3 0.30 K.sub.2HPO.sub.4 0.10 KCl 0.05 MgSO.sub.47H.sub.2O 0.05

[0064] Determination of a degradation rate of saponins: The degradation rate of saponins was used as an index for the secondary screening. Preparation of a crude saponin fermentation broth: A strain to be tested was inoculated into a saponin primary screening medium without agar, and fermentation was conducted in a shaking flask for 24 h (until the medium was turbid); a resulting bacterial solution was frozen-centrifuged at 4 C. (8,000 rpm, 10 min) to obtain a supernatant; the bacterial precipitate was washed 3 times with sterile water; the supernatant was collected and diluted to 250 mL to obtain the crude saponin fermentation broth; and 5 mL of the crude saponin fermentation broth was diluted to 100 mL, and a diluted crude saponin fermentation broth was stored in a refrigerator at 4 C. for later use. 0.5 mL of the diluted crude saponin fermentation broth was taken and tested for absorbance at 550 nm, with distilled water as a blank. Degradation rate of saponins (W)=1C/C.sub.0100%, where W represents a degradation rate of saponins, C represents a content of saponins after fermentation, and C.sub.0 represents a content of saponins before fermentation. A degradation rate of saponins by degradation bacteria was 51.52%.

[0065] A strain with a tannase activity of 183.47 mol/min mL and a saponin degradation rate of 51.52% was selected as a degradation strain, and the degradation strain was subjected to the following morphological identification and physiological and biochemical tests.

Morphological Identification of the Degradation Strain

[0066] Processes of Gram staining, cell shape observation, and a catalase experiment were as follows:

[0067] Gram staining: A specified amount of water was picked to a center of a glass slide, then a small amount of the strain was picked with an inoculation loop and thoroughly mixed with water droplets on the glass slide, and a resulting mixture was coated to form a thin bacterial film and then naturally dried. The glass slide was fixed upwards above a slight fire, initially stained with crystal violet for 1 min, and then rinsed with water thoroughly (which should be gentle to prevent a water flow from directly impacting bacterial blocks). An iodine solution was added dropwise to the glass slide to allow mordant-staining for 1 min to 2 min, and then the glass slide was decolorized with 95% ethanol and washed with water. The glass slide was counter-stained with safranin for 1 min to 2 min, then washed with water, naturally dried, and then observed under a 1,000-amplification oil immersion lens. Bacteria stained blue-purple were Gram-positive bacteria, and bacteria stained red were Gram-negative bacteria.

[0068] Catalase experiment: A 3% (volume fraction) hydrogen peroxide solution was pipetted with a pipette tip and added to a plate, a small amount of bacteria was picked with an inoculation loop and thoroughly mixed with the hydrogen peroxide solution, and 2 min to 3 min later, the plate was observed. If it was observed that there were bubbles, the bacteria were positive, and if it was observed that there were no bubbles, the bacteria were negative.

Physiological and Biochemical Tests of the Degradation Strain

[0069] The degradation strain was tested according to growth temperatures (4 C., 15 C., 30 C., 35 C., and 45 C.) and growth pH values (3.0, 3.5, 4.0, 4.5, and 9.0), and a process was as follows:

[0070] Determination and screening of acid productions and growth rates of the degradation strain: An isolated and purified strain was inoculated into 3 mL of an MRS liquid medium and cultivated overnight on a shaker at 30 C. and 250 rpm for about 14 h to 16 h. A resulting bacterial solution was inoculated at an inoculum size of 1% (V/V) into 3 mL of a fresh MRS liquid medium and cultivated on a shaker at 30 C. and 250 rpm, and at 0 h, 2 h, 4 h, 6 h, 8 h, 10 h, 12 h, 14 h, 16 h, 18 h, 20 h, 22 h, 24 h, and 48 h after the inoculation, a pH value of the MRS liquid medium was measured and an absorbance value was measured at a wavelength of 600 nm. 3 replicates needed to be set for each strain at each time point, and test tubes for cultivating bacteria needed to be of a same specification.

[0071] Temperature resistance test: A strain was inoculated at an inoculum size of 1% (V/V) into a fresh MRS liquid medium, and cultivated for 2 d at constant temperatures of 4 C., 15 C., 30 C., 35 C., and 45 C.

[0072] pH resistance test: A strain was inoculated at an inoculum size of 1% (V/V) into MRS liquid media with pH values of 3.0, 3.5, 4.0, 4.5, and 9.0, respectively, and cultivated for 2 d at 30 C. (a pH was adjusted with 2.0 M NaOH or 1.0 M HCl).

[0073] Salt resistance: The degradation strain was inoculated into MRS liquid media with NaCl contents of 3% and 6.5%, respectively, and then cultivated in a 30 C. incubator for 2 d, and then a growth status of the degradation strain was observed.

[0074] According to results of the above tests, a temperature for cultivation of the degradation strain is 15 C. to 45 C., a pH for cultivation of the degradation strain is 4.5 to 7.0, and a salt concentration for cultivation of the degradation strain is 3.0% to 6.5% NaCl. The degradation strain can grow normally under the above conditions.

[0075] The morphology and physiological and biochemical characteristics of the degradation strain are shown in Table 5, and the acid-producing and growth rates of the degradation strain are shown in FIG. 3.

TABLE-US-00005 TABLE 5 Morphology and physiological and biochemical characteristics of the degradation strain Strain Degradation strain Source Broussonetia papyrifera silage Morphology Rod-shaped Gram staining + Catalase Fermentation type Homolactic 4 C. 15 C. ++ 35 C. +++ 45 C. ++ 3.0 3.5 4.0 4.5 ++ 5.0 + 5.5 ++ 6.0 +++ 7.0 +++ 3% NaCl +++ 6.5% NaCl ++ Notes: In Table 5, the , +, ++, and +++ in the resistance tests have the following meanings: : OD.sub.600 nm < 0.5; +: 0.5 OD.sub.600 nm < 1.0; ++: 1.0 OD.sub.600 nm < 1.5; and +++: 1.5 OD.sub.600 nm.

TABLE-US-00006 TABLE 6 Carbon sources utilized by the degradation strain Degradation Degradation Item strain Item strain CK Control ESC Esculin + ferric citrate GLY Glycerol W SAL Salicin + EERY Erythritol CEL D-cellobiose + DARA D-arabinose W MAL D-maltose + LARA L-arabinose + LAC D-lactose + RIB D-ribose + MEL D-melibiose + DXYL D-xylose + SAC D-sucrose + LXYL L-xylose W TRE D-trehalose + ADO D-adonitol W INU Inulin + MDX Methyl--D W MLZ D-melezitose + xylopyranoside GAL D-galactose + RAF D-raffinose + GLU D-glucose + AMD Starch W FRU D-fructose + GLYG Glycogen W MNE D-mannose + XLT Xylitol W SBE L-sorbose W GEN D-gentiobiose + RHA L-rhamnose W TUR D-Turanose + DUL Dulcitol W LYX D-lyxose W INO Inositol W TAG D-tagatose + MAN Mannitol + DFUC D-fucose W SOR Sorbitol + LFUC L-fucose W MDM Methyl--D- + DARL D-arbaitol W mannopyranoside MDG Methyl--D- + LARL L-arbaitol W glucopyranoside NAG N-Acetyl + GNT Potassium + glucosamine gluconate AMY Amygdalin + 2KG 2-Keto-potassium gluconate ARB Arbulin + 5KG 5-Keto-potassium W gluconate Notes: W, +, and in Table 6 have the following meanings: w: weakly positive, +: positive, and : negative.

[0076] The results in Tables 5 and 6 show that the degradation strain is a Gram-positive bacillus allowing homolactic fermentation, and has strong acid and salt resistance, a high growth rate, and a strong comprehensive acid-production ability.

Comparative Example 1

[0077] A bag with the Broussonetia papyrifera silage was opened, the Broussonetia papyrifera silage was thoroughly mixed in a clean basin, 20 g of the Broussonetia papyrifera silage (which had been stored for 60 d) was taken and mixed with 180 mL of 0.85% normal saline (NaCl), a resulting mixture was placed in a 4 C. refrigerator to allow leaching for 4 h, and then a resulting supernatant was collected and 10-fold diluted serially to a 10.sup.4 concentration gradient and a 10.sup.5 concentration gradient. 100 L of a dilution at each gradient was coated on a plate with an MRS medium and cultivated in a 30 C. incubator for 48 h. After bacterial colonies grew, bacterial colonies were picked and separated through at least 2 times of plate streaking to obtain single colonies A, and the single colonies A were stored with dimethyl sulfoxide in a 80 C. refrigerator.

[0078] Strains of the single colonies A were subjected to primary screening, secondary screening, identification, and tests according to the methods in Example 1 to finally obtain a strain B capable of degrading both tannins and saponins. Relevant results of the strain B are shown in Tables 7 and 8.

TABLE-US-00007 TABLE 7 Morphology and physiological and biochemical characteristics of the strain B Strain Strain B Source Broussonetia papyrifera silage Morphology Rod-shaped Gram staining + Catalase Fermentation type Heterolactic 4 C. 15 C. ++ 35 C. +++ 45 C. + 3.0 3.5 4.0 + 4.5 ++ 5.0 ++ 5.5 +++ 6.0 + 7.0 +++ 3% NaCl +++ 6.5% NaCl ++ Notes: In Table 7, the , +, ++, and +++ in the resistance tests have the following meanings: : OD.sub.600 nm < 0.5; +: 0.5 OD.sub.600 nm < 1.0; ++: 1.0 OD.sub.600 nm < 1.5; and +++: 1.5 OD.sub.600 nm.

TABLE-US-00008 TABLE 8 Carbon sources utilized by the strain B Strain Strain Item B Item B CK Control ESC Esculin + ferric citrate GLY Glycerol SAL Salicin + EERY Erythritol CEL D-cellobiose + DARA D-arabinose MAL D-maltose + LARA L-arabinose + LAC D-lactose + RIB D-ribose + MEL D-melibiose + DXYL D-xylose W SAC D-sucrose + LXYL L-xylose TRE D-trehalose + ADO D-adonitol 1 INU Inulin + MDX Methyl-- MLZ D-melezitose + D xylopyranoside GAL D-galactose + RAF D-raffinose + GLU D-glucose + AMD Starch W FRU D-fructose + GLYG Glycogen W MNE D-mannose + XLT Xylitol W SBE L-sorbose W GEN D-gentiobiose + RHA L-rhamnose + TUR D- Turanose + DUL Dulcitol + LYX D-lyxose W INO Inositol W TAG D-tagatose W MAN Mannitol + DFUC D-fucose W SOR Sorbitol + LFUC L-fucose MDM Methyl--D- + DARL D-arbaitol W mannopyranoside MDG Methyl--D- + LARL L-arbaitol W glucopyranoside NAG N-Acetyl + GNT Potassium + glucosamine gluconate AMY Amygdalin + 2KG 2-Keto-potassium gluconate ARB Arbulin + 5KG 5-Keto-potassium W gluconate Notes: W, +, and in Table 8 have the following meanings: w: weakly positive, +: positive, and : negative.

[0079] The results in Tables 7 and 8 show that the strain B is a Gram-positive coccus allowing heterolactic fermentation, and has strong salt resistance, a high growth rate, and a strong comprehensive acid-production ability. Acid-production and growth rates of the strain B are shown in FIG. 4.

the Degradation Strain Obtained in Example 1 and the Strain B Obtained in Comparative Example 1 were Subjected to Homology Analysis with a 16S rDNA Gene

[0080] A strain was cultivated overnight at 35 C. in 5 mL of an MRS medium, a resulting bacterial solution was then transferred to a 1.5 mL centrifuge tube and centrifuged at 10,000 rpm/min for 3 min to 5 min to obtain a bacterial pellet, the bacterial pellet was washed twice with TE 0.1 (10 mmol/L Tris-HCL, 0.1 mmol/L EDTA, pH 8.0) and then subjected to DNA extraction with a TIANamp Bacteria DNA Kit (TIANGEN BIOTECH CO., LTD., Beijing, China), and the absorbance OD.sub.600 nm was detected.

[0081] Then PCR amplification was conducted. Amplification primers for 16S rDNA were 27f and 1492r (Monis et al., 2005), and a PCR procedure was as follows: 95 C. (5 min), 94 C. (30 s), 55 C. (1 min), 72 C. (1.5 min), and 72 C. (10 min), where there were 30 cycles of 94 C. (30 s), 55 C. (1 min), and 72 C. (1.5 min). Amplification products were sent to Shenzhen Huada gene Technology Co., Ltd. (China) for sequencing. Sequencing results were subjected to alignment in the gene bank of NCBI to find out a standard Lactiplantibacillus plantarum strain with a close relationship to a corresponding strain. Through the DNAman software, a screened strain was subjected to similarity analysis with a standard strain in terms of a partial sequence (about 1,400 bp to 1,500 bp) of 16S rDNA (16S rDNA of the degradation strain was shown in SEQ ID NO: 1, and 16S rDNA of the strain B was shown in SEQ ID NO: 2), and the similarity between the degradation strain or the strain B and Lactiplantibacillus plantarum was more than 99%. Thus, in combination with physiological and biochemical indexes, it was determined that the degradation strain and the strain B both were the same species as Lactiplantibacillus plantarum. In the present disclosure, the degradation strain is the Lactiplantibacillus plantarum P91 of the present disclosure, and the strain B is the Lactiplantibacillus plantarum P87 of the present disclosure.

[0082] Discoloration circles of the Lactiplantibacillus plantarum P91 for degradation of tannins are shown in FIG. 1, and colonies of the Lactiplantibacillus plantarum P91 with saponins as an only carbon source are shown in FIG. 2.

Use Example

1. Preparation of Silage

[0083] Caragana korshinskii Kom. from the Inner Mongolia Jinji Biotechnology Co., Ltd., Chifeng City, Inner Mongolia Autonomous Region and Moringa oleifera Lam. from the experimental base of the South China Agricultural University, Guangzhou City, Guangdong Province were cut to 2 cm to 3 cm and thoroughly mixed to obtain a mixed material, and the Lactiplantibacillus plantarum P91 (P91 treatment group) in Example 1 and the Lactiplantibacillus plantarum P87 (P87 treatment group) in Comparative Example 1 each were inoculated into the mixed material at an amount of about 110.sup.6 CFU/g. A resulting mixture in each treatment group was thoroughly mixed and then packed in three 28 cm35 cm polyethylene silage bags with about 500 g of the mixture in each bag, and the polyethylene silage bags were vacuumed by a vacuum sealing machine for sealing and then stored at a temperature of 20 C. to 25 C. to allow fermentation for 90 d.

2. Tests of Caragana korshinskii Kom. And Moringa Oleifera Lam. Raw Materials and Silage

[0084] Samples were taken to analyze anti-nutritional components in the Caragana korshinskii Kom. and Moringa oleifera Lam. raw materials and the silage obtained after a silage treatment with an additive for 90 d. Specific results are shown in Tables 9 and 10. Test processes are as follows:

[0085] Dry matter (DM) contents in the raw materials and the silage each were determined by a lyophilization method as follows: a sample was thoroughly mixed and then lyophilized in a lyophilizer for 5 d or more until a mass of the sample was constant, and a dry matter content in the sample was determined. An oven-dried sample was crushed by a plant crusher, sieved through a 40-mesh sieve, and then tested for anti-nutritional components.

[0086] A determination method of tannins was obtained through an appropriate adjustment with reference to Zhang Yingchao (2019, Screening of Excellent Lactobacilli and Research on Action Mechanisms of Lactobacilli in Typical Woody Forage Silage). 0.2 g of a lyophilized and crushed sample was weighed and added to a 25 mL round-bottom centrifuge tube, 5 mL of 70% acetone was added to the round-bottom centrifuge tube to obtain a first mixture, and the first mixture was ultrasonically-treated at room temperature for 20 min and then centrifuged at 4 C. and 8,000 rpm for 10 min. The above process was repeated once, and a final extraction system was diluted to 25 mL and stored in an ice bath to obtain an extraction solution. 0.1 mL of the extraction solution was added to a 15 mL centrifuge tube, distilled water was added to the centrifuge tube to allow a total volume of 1.0 mL, and then 0.5 mL of a Folin reagent and 2.5 mL of a 20% sodium carbonate reagent were added to obtain a second mixture; and the second mixture was thoroughly mixed and shaken at room temperature for 40 min to obtain a reaction solution, an appropriate amount of the reaction solution was taken and tested by a microplate reader for absorbance at 720 nm, and a total phenol content was calculated. With gallic acid as a standard, a standard curve was plotted. 0.1 g of insoluble polyvinylpyrrolidone was taken and added to a 10 mL centrifuge tube, 1 mL of distilled water and the extracting solution were added to the centrifuge tube, and the centrifuge tube was thoroughly vortexed, allowed to stand at 4 C. for 15 min, and then centrifuged at 8,000 rpm for 10 min to obtain a supernatant; 0.1 mL of the supernatant was collected in a test tube, 0.9 mL of distilled water was added to the test tube, and then 0.5 mL of a Folin reagent and 2.5 mL of a 20% sodium carbonate reagent were added successively to obtain a mixture; and the mixture was thoroughly mixed and shaken at room temperature for 40 min to obtain a reaction solution, an appropriate amount of the reaction solution was taken and tested by a microplate reader for absorbance at 720 nm, and a total phenol content was calculated. With gallic acid as a standard, a standard curve was plotted. A hydrolytic tannin content was a difference between a total phenol content and a simple phenol content. A condensed tannin content was determined by a Vanilli-HCl method. 0.1 g of a lyophilized and crushed sample was accurately weighed and added to a 15 mL round-bottom centrifuge tube, 5 mL of a 1% hydrochloride methanol solution was added to the centrifuge tube, and the centrifuge tube was shaken at room temperature for 20 h and then centrifuged at 8,000 rpm for 10 min to obtain a supernatant, and the supernatant was collected and diluted to 5 mL to obtain a condensed tannin leaching liquor. 1 mL of the condensed tannin leaching liquor was taken and added to a test tube, 5 mL of a vanillin chromogenic solution was added to the test tube, and the test tube was vortexed for thorough mixing and then allowed to stand at room temperature for 20 min to obtain a reaction solution. An appropriate amount of the reaction solution was taken and tested by a microplate reader for absorbance at 495 nm, and a condensed tannin content was calculated. With catechin as a standard, a standard curve was plotted. A sum of a hydrolytic tannin content and a condensed tannin content was a total tannin content.

[0087] A total saponin content was determined with reference to Zhang Jiming (2015, Study on Total Saponin Contents in Medicago sativa L. of Different Varieties Treated with Additive at Mowing Stage) as follows: 0.5 g of a lyophilized and crushed sample was accurately weighed and placed in a 50 mL centrifuge tube, 15 mL of 70% ethanol was added to the centrifuge tube to obtain a first mixture, the first mixture was ultrasonically treated at room temperature for 15 min, then incubated in a 75 C. water bath for 15 min, and centrifuged at 8,000 rpm for 10 min to obtain a supernatant, and the supernatant was diluted to 25 mL to obtain a total saponin leaching liquor. 0.1 mL of the total saponin leaching liquor was taken and added to a glass test tube, and then the glass test tube was placed in an 80 C. water bath for evaporation to dryness, and cooled; then 0.2 mL of a 5% vanillin-glacial acetic acid solution and 0.8 mL of perchloric acid were added at one time to the glass test tube, and the glass test tube was vortexed for thorough mixing, heated in a 75 C. water bath for 20 min, and then quickly cooled in an ice bath; 5 mL of glacial acetic acid was added to the glass test tube, and the glass test tube was vortexed and allowed to stand for 10 min to obtain a reaction solution; and an appropriate amount of the reaction solution was taken and tested by a microplate reader for absorbance at 545 nm, and a total saponin content was calculated. With oleanolic acid as a standard, a standard curve was plotted.

[0088] Contents of hydrolytic tannins, condensed tannins, total tannins, and total saponins in the Caragana korshinskii Kom. raw material are 2.30 g/kg DM, 5.52 g/kg DM, 7.67 g/kg DM, and 141.53 g/kg DM, respectively. Contents of hydrolytic tannins, condensed tannins, total tannins, and total saponins in the Moringa oleifera Lam. raw material are 0.15 g/kg DM, 9.54 g/kg DM, 9.69 g/kg DM, and 51.41 g/kg DM, respectively.

[0089] Anti-nutritional factor contents in Caragana korshinskii Kom. and Moringa oleifera Lam. each after silage are shown in Table 10. Compared with the raw materials, the addition of P91 significantly reduces the contents of condensed tannins, total tannins, and total saponins in the Caragana korshinskii Kom. and Moringa oleifera Lam. raw materials (P<0.05). Compared with CK (silage produced after 90 d of silage without an additive), the addition of P91 significantly reduces the contents of hydrolytic tannins, condensed tannins, total tannins, and total saponins in Caragana korshinskii Kom., and corresponding degradation rates are 41.94%, 14.48%, 26.60%, and 47.19%, respectively (P<0.05). The addition of P91 reduces the contents of hydrolytic tannins, condensed tannins, total tannins, and total saponins in Moringa oleifera Lam., and corresponding degradation rates are 8.81%, 33.51%, 28.33%, and 72.51%, respectively (P<0.05). Therefore, the Lactiplantibacillus plantarum P91, as a novel additive for effectively degrading anti-nutritional factors (tannins and total saponins) in a feed, can significantly improve a quality of Caragana korshinskii Kom. and Moringa oleifera Lam. silage.

TABLE-US-00009 TABLE 9 Anti-nutritional components in Caragana korshinskii Kom. and Moringa oleifera Lam. raw materials Caragana Moringa Item korshinskii Kom. oleifera Lam. DMs (g/kg FM) 635.85 2.88 203.86 3.63 Hydrolytic tannins (g/kg DM) 2.15 0.03 0.15 0.03 Condensed tannins (g/kg DM) 5.52 0.47 9.54 1.53 Total tannins (g/kg DM) 7.67 0.43 9.69 1.56 Total saponins (g/kg DM) 141.53 6.35 51.41 21.86

TABLE-US-00010 TABLE 10 Impacts of additives P91 and P87 on tannins and total saponins in Caragana korshinskii Kom. and Moringa oleifera Lam. Silage Index Material CK P91 P87 Hydrolytic tannins Caragana korshinskii Kom. 4.65 0.74 a 2.70 0.41 b 4.34 0.31 a (g/kg DM) Moringa oleifera Lam. 2.61 0.77 a 2.38 0.51 a 2.37 0.63 a Condensed tannins Caragana korshinskii Kom. 5.80 0.39a 4.96 0.25 a 4.97 0.41 a (g/kg DM) Moringa oleifera Lam. 9.70 1.86 a 6.45 0.81 b 6.61 0.36 b Total tannins Caragana korshinskii Kom. 10.45 1.11 a 7.67 0.65 b 9.31 0.47 a (g/kg DM) Moringa oleifera Lam. 12.32 2.21 a 8.83 1.15 b 8.98 0.83 b Total saponins Caragana korshinskii Kom. 126.59 29.93 a 66.85 6.74 b 113.35 9.23 a (g/kg DM) Moringa oleifera Lam. 88.89 30.16 a 24.44 4.39 b 49.74 10.21 b

[0090] It can be seen from the above analysis that amounts of total tannins and total saponins degraded by the Lactiplantibacillus plantarum P91 are greater than amounts of total tannins and total saponins degraded by the Lactiplantibacillus plantarum P87. Therefore, the Lactiplantibacillus plantarum P91, as a novel silage additive, can significantly improve a quality of silage fermentation.

[0091] The above are merely preferred specific implementations of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any modification or replacement easily conceived by those skilled in the art within the technical scope of the present disclosure should fall within the protection scope of the present disclosure.