Animal lactic acid bacteria ZS-1 and application thereof

Abstract

The invention relates to the technical field of microorganisms, and discloses an animal lactic acid bacterium ZS-1 and application thereof.The animal lactic acid bacterium ZS-1 has the characteristics of low temperature resistance, pH tolerance, salt tolerance and the like, can generate an excellent pesticide degradation effect, and particularly has high degradation capacity on cyhalothrin, metolachlor and chlorfenapyr.

Description

Technical Field

[0001] This application relates to the technical field of microorganisms, specifically to a strain of animal lactic acid bacteria ZS-1 and its applications. Background Technology

[0002] In the booming development of modern animal husbandry, silage has become an indispensable key component, serving as the cornerstone for ensuring the healthy growth and efficient breeding of livestock. After fermentation, silage has a sour and fragrant aroma and a soft texture, greatly increasing livestock feed intake and digestibility, making them more willing to eat and thus promoting their growth and development. Furthermore, the long shelf life of silage effectively solves the problem of uneven seasonal supply of green fodder, ensuring a continuous and stable supply of high-quality feed for animal husbandry, whether in seasons with abundant pasture or during periods of feed scarcity.

[0003] However, traditional silage technology reveals numerous insurmountable problems when faced with low-temperature environments, becoming a bottleneck restricting the wider application of silage in various regions and seasons. Traditional silage technology primarily relies on microorganisms naturally attached to the silage raw materials for fermentation. In low-temperature environments, the activity of these microorganisms is severely limited, especially lactic acid bacteria, which play a crucial role in silage fermentation. This results in a slow silage process, and may even prevent the normal fermentation process from starting, extending the silage production cycle and increasing production costs and management difficulties. Furthermore, under low-temperature conditions, the quality of silage is difficult to guarantee; silage may become too hard, have an unpleasant odor, poor palatability, and an increased risk of nutrient loss, further reducing livestock feed intake and digestibility, thus impacting farming efficiency.

[0004] The widespread use of pesticides inevitably leads to pesticide residues, which have serious impacts on the environment and human or animal health.

[0005] Therefore, it is of great significance to develop a strain that can efficiently carry out silage fermentation and effectively degrade pesticide residues. Summary of the Invention

[0006] To address the aforementioned technical problems, this application provides a strain of animal lactic acid bacteria ZS-1 and its applications. This strain exhibits characteristics such as low temperature tolerance, pH tolerance, and salt tolerance. Furthermore, this strain can produce excellent pesticide degradation effects, especially strong degradation capabilities for cyhalothrin, metolachlor, and chlorfenapyr.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: This application provides a strain of animal lactic acid bacteria ZS-1, which is classified as Lactobacillus animalis strain ZS-1 and was deposited at the China Center for Type Culture Collection on March 31, 2025, with accession number CCTCC NO: M 2025639.

[0008] A second aspect of the present invention provides the application of the above-mentioned animal lactic acid bacteria strain ZS-1 in reducing pesticide residues.

[0009] Preferably, the pesticide is a pyrethroid, amide, or pyrrole.

[0010] More preferably, the pesticide is at least one of cyhalothrin, metolachlor, and chlorfenapyr.

[0011] In a third aspect, this application provides the application of animal lactic acid bacteria strain ZS-1 in silage processing.

[0012] Further, this study provides information on the application of animal lactic acid bacteria strain ZS-1 in low-temperature silage processing.

[0013] One aspect of the applicant's research focuses on the use of compound bacteria in forage silage, resulting in the development of a novel type of Kobresia silage. This silage contains high levels of organic acids, crude protein, and nutrients. The compound bacteria provided in this application can increase the number of lactic acid bacteria in the silage while reducing the number of molds and yeasts, thereby effectively reducing the probability of spoilage during low-temperature silage and storage. This also improves the fermentation quality of Kobresia silage to a certain extent, promoting more efficient utilization of existing resources in high-altitude and cold regions where feed is scarce, and contributing to alleviating the winter and spring feed shortage in these areas. Simultaneously, in researching the degradation of pesticides by bacterial strains, it was unexpectedly discovered that animal lactic acid bacteria ZS-1, Leuconostoc mesenteroides XS-1, and plant lactic acid bacteria RL-5 all have certain pesticide degradation effects, especially animal lactic acid bacteria ZS-1, which exhibits significant pesticide degradation activity. Attached Figure Description

[0014] Figure 1 To prepare the colony morphology of the lactic acid bacteria in Example 1; where a represents animal lactic acid bacteria, b represents plant lactic acid bacteria, and c represents Leuconostoc mesenteroides.

[0015] Figure 2 Gel electrophoresis image of the DNA of the lactic acid bacteria strain in Example 1.

[0016] Figure 3 The image shows a PCR electrophoresis diagram of the 16S rRNA nucleotide sequence amplified from the DNA of the lactic acid bacteria strain in Example 1.

[0017] Figure 4To prepare a phylogenetic tree of the 16S rDNA sequence of the lactic acid bacteria strain in Example 1. Detailed Implementation

[0018] The present application will be further described in detail below with reference to embodiments, comparative examples and performance test results. These embodiments should not be construed as limiting the scope of protection claimed in this application.

[0019] Preparation Example 1 provides an animal lactic acid bacteria, a plant lactic acid bacteria, Leuconostoc mesenteroides, and a method for their preparation.

[0020] (1) Isolation and identification of lactic acid bacteria strains Kobresia spp. (collected in June from pastoral areas of Tibet) were aseptically cut into 1-2 cm sections and 10 g was weighed and placed in an Erlenmeyer flask containing 100 g of sterile water. The mixture was shaken at 180 rpm for 2 hours, and the supernatant was diluted to 10 g. -1 -10 -5 Five gradients were prepared, with 20 μL of each sample spread onto MRS solid medium using the dilution plate method, and then incubated in an anaerobic incubator at 30°C for 48 h inverted position.

[0021] Kobresia spp. (collected in September from pastoral areas of Tibet) were aseptically cut into 1-2 cm sections and 10 g was weighed and placed in an Erlenmeyer flask containing 100 g of sterile water. The mixture was shaken at 180 rpm for 2 hours, and the supernatant was diluted to 10 g. -1 -10 -5 Five gradients were prepared, with 20 μL of each sample spread onto MRS solid medium using the dilution plate method, and then incubated in an anaerobic incubator at 30°C for 48 h inverted position.

[0022] Take 10g of cheese (sampled from a farmer's home in Damxung County, Lhasa) and place it in an Erlenmeyer flask containing 100g of sterile water. Shake at 180rpm for 2 hours. Take the supernatant and dilute it to 10. -1 -10 -5 Five gradients were prepared, with 20 μL of each sample spread onto MRS solid medium using the dilution plate method, and then incubated in an anaerobic incubator at 30°C for 48 h inverted position.

[0023] Single bacterial strains were isolated based on colony morphology characteristics, purified for two generations, and then freeze-dried for preservation. Subsequently, physiological and biochemical tests, including Gram staining and catalase activity assays, were performed to screen strains conforming to the physiological and biochemical characteristics of lactic acid bacteria. Total DNA was extracted from the strains using a bacterial extraction kit. The 16S rRNA target gene fragment was amplified by PCR using universal primers for 16S rRNA. After verification by 1% agarose gel electrophoresis, the PCR amplification products were sent to a biotechnology company for sequencing. The 16S rRNA sequence was then analyzed for homology using BLAST alignment to construct a phylogenetic tree and identify the strain species.

[0024] (2) Isolation of lactic acid bacteria Thirty-three bacterial strains were isolated from Kobresia edulis and cheese samples using MRS medium. Among them, 16 strains were Gram-positive and catalase-negative (as shown in Table 1). These 16 strains were preliminarily identified as suspected lactic acid bacteria.

[0025] Table 1. Initial screening results of lactic acid bacteria

[0026] (3) Identification of lactic acid bacteria Total DNA was extracted from 16 bacterial strains and verified by 1% agarose gel electrophoresis. The electrophoresis results of the total DNA extraction of the strains are shown in the figure below. Figure 2 The 16S rRNA nucleotide sequence was amplified and verified by 1% agarose gel electrophoresis. The PCR electrophoresis results of the strain after amplifying the 16S rRNA nucleotide sequence are shown in the figure. Figure 3 Compared with the Mark (nucleic acid marker), the DNA of each bacterium was 23,000 bp, and the 16S rDNA fragment was located at around 1,500 bp, consistent with expectations. The PCR amplification products were sent to a biotechnology company for sequencing. The sequences were aligned using NCBIL Blast and a phylogenetic tree was constructed. The results are as follows: Figure 4As shown. The results showed that strains ZS-7 and XS-6 shared 99% gene sequence similarity with *pediococcus acidilactici* strain NRCC1, RL-15 with *pediococcus acidilactici* strains B1104, RL-10, and XS-15 with *pediococcus acidilactici* strains UL5, XS-1, and RL-13 with *pediococcus acidilactici* strain Uga 146-3; strain ZS-10 shared 98% homology with *Enterococcus faecalis* strain DPNS2; strains ZS-1 and RL-5 shared 100% homology with *Lactobacillus animalis* strain JCM 7708; strains RL-6 and XS-2 shared over 97% kinship with *Lactobacillus Plantarum* strains HM1 and XS-11 with *Lactobacillus Plantarum* strain JCM 11056; and strains ZS-3 and RL-2 shared over 97% kinship with *Lactococcus* strains. The homology between sp. TP1MJ and strain RL-12 was 98% and 99%, respectively; strain RL-12 showed 100% homology with Lactobacillus ghanensis DSM 18630. Based on the combined results of bacterial morphology, physiological and biochemical tests, and 16S rDNA sequence analysis, strains ZS-7, XS-6, RL-15, RL-10, XS-15, XS-1, and RL-13 were identified as Pediococcus lactis; strain ZS-10 was Enterococcus faecalis; strains ZS-1 and RL-5 were animal lactic acid bacteria; strains RL-6, XS-2, and XS-11 were Lactobacillus plantarum; strains ZS-3 and RL-2 were Lactococcus; and strain RL-12 was Lactobacillus.

[0027] Experimental Example 1 (1) Detection of biological characteristics of lactic acid bacteria strains Candidate lactic acid bacteria strains were inoculated into MRS liquid medium and anaerobically cultured in anaerobic incubators at 5℃ and 10℃ for 5 days, and in anaerobic incubators at 40℃ and 50℃ for 3 days. The absorbance was measured at a wavelength of 560nm using a UV spectrophotometer to determine the growth ability of the lactic acid bacteria strains to withstand high and low temperature stress.

[0028] Candidate lactic acid bacteria strains were inoculated into MRS liquid medium with different pH values ​​(3.0, 3.5, 8.0, 9.0) and anaerobic cultured at 30°C for 72 h. The absorbance was measured at 560 nm to determine the acid and alkali stress tolerance of the lactic acid bacteria strains.

[0029] Candidate lactic acid bacteria strains were inoculated into MRS liquid medium with different salt concentrations (3wt%, 6wt%, 9wt%) and cultured anaerobically at 30℃ for 72h. The absorbance was measured at 560nm to determine the salt stress tolerance of the lactic acid bacteria strains.

[0030] Test results are shown in Table 2.

[0031] (1.1) Temperature tolerance test According to the temperature tolerance test results of the lactic acid bacteria strains in Table 2, all lactic acid bacteria strains have a wide growth temperature range and can grow at 10℃ and 40℃. Among them, strains XS-1, ZS-1, ZS-3, RL-5, RL-10 and RL-12 have strong low temperature tolerance and can grow weakly at 5℃ and grow well at 10℃. However, they have weak high temperature tolerance, grow slowly at 40℃ and cannot grow at 50℃.

[0032] Table 2 Results of biological characteristics detection of lactic acid bacteria

[0033] (1.2) pH tolerance test Based on the pH tolerance test results of the lactic acid bacteria strains in Table 2, it can be seen that most lactic acid bacteria strains have a pH tolerance range of 3.5 to 8. At strongly acidic (pH=4) or weakly alkaline (pH=8) pH levels, the vast majority of lactic acid bacteria grow normally or thrive. However, when pH < 4 or pH > 8, the growth of most lactic acid bacteria strains is inhibited. Specifically, at pH = 3, only strains XS-1, XS-6, ZS-1, and RL-2 can grow weakly, while other strains cannot grow at all. At pH = 9, strains XS-15, RL-10, and RL-12 can grow normally, while strains XS-1, XS-2, ZS-7, RL-6, and RL-15 can grow weakly.

[0034] (1.3) Salt tolerance test Based on the salt tolerance test results of the lactic acid bacteria strains in Table 2, it can be seen that all strains except ZS-10, which could not grow at a 9% NaCl salt concentration, could grow. Most strains grew well at a 3% NaCl salt concentration and grew normally or well at a 6% NaCl salt concentration. As the salt concentration increased, the growth of the strains was inhibited; at a 9% NaCl salt concentration, most strains showed weak growth.

[0035] (2) Construction of high-efficiency silage compound microbial system Candidate lactic acid bacteria strains were co-cultured in pairs, and the biological characteristics of the co-cultures were tested. Strains with antagonistic effects were eliminated, and strains with better stress resistance and antibacterial activity than single strains in the co-culture state were selected. An optimized combination was then used to construct a high-efficiency silage compound microbial system: ZS-1, XS-1, and RL-5. For example... Figure 1 To prepare the colony morphology of the lactic acid bacteria in Example 1; where a represents animal lactic acid bacteria, b represents plant lactic acid bacteria, and c represents Leuconostoc mesenteroides. The colony morphology of animal lactic acid bacteria is milky white, round, with a smooth surface and regular edges; the colony morphology of plant lactic acid bacteria (b) is light yellow, round, with regular edges, a smooth and raised surface; and the colony morphology of Leuconostoc mesenteroides (c) is white, round, with regular edges, and a smooth and moist surface.

[0036] The applicant has deposited the above three bacteria, with the following details: * *Lactobacillus animalis* strain ZS-1, classified as an animal lactic acid bacterium, was deposited at the China Center for Type Culture Collection (CCTCC) on March 31, 2025, with accession number CCTCC NO: M 2025639; * *Lactobacillus plantarum* strain RL-5, classified as a plant lactic acid bacterium, was deposited at the CCTCC on July 1, 2025, with accession number CCTCC NO: M 20251503; * *Leuconostoc mesenteroides* strain XS-1, classified as a mesenteroides, was deposited at the CCTCC on July 1, 2025, with accession number CCTCC NO: M 20251504.

[0037] Example Examples 1-4 Examples 1-4 provide a compound microbial strain for low-temperature silage.

[0038] The difference between the above embodiments lies in the composition of the compound bacteria, as shown below.

[0039] In Example 1: The compound bacteria consisted of animal lactic acid bacteria, plant lactic acid bacteria, and Leuconostoc mesenteroides in a live bacteria ratio of 7:5:0.4.

[0040] In Example 2: The compound bacteria consisted of animal lactic acid bacteria, plant lactic acid bacteria, and Leuconostoc mesenteroides in a live bacteria ratio of 9:3:0.6.

[0041] In Example 3: The compound bacteria consisted of animal lactic acid bacteria, plant lactic acid bacteria, and Leuconostoc mesenteroides mixed together in a live bacteria ratio of 11:1:0.8.

[0042] In Example 4: The compound bacteria consisted of animal lactic acid bacteria, plant lactic acid bacteria, and Leuconostoc mesenteroides in a live bacteria ratio of 3:9:0.6.

[0043] Experimental Example 2 This study used fully mature Kobresia spp. as the silage raw material and employed a 2×3 experimental design (two temperatures: 25℃ and 10℃, and three levels of silage microbial culture addition) for silage experiments, with three replicates for each treatment. After 60 days of silage, samples were collected and analyzed to determine the fermentation quality parameters (pH, organic acids), the content of common nutrients (crude protein, neutral detergent fiber, acid detergent fiber, acid detergent lignin), and the number of microorganisms (lactic acid bacteria, molds, yeasts). The study aimed to elucidate the mechanism by which temperature affects the silage effect of Kobresia spp. and to determine the optimal silage microbial culture for Kobresia spp. ...

[0044] 1. Experimental Design: Fully mature Kobresia was chopped to 1-2 cm, and the moisture content was adjusted to 65%. Experiments were conducted with no additives and with low-level additives (1×10⁻⁶). 6 CFU / g) and high levels (1×10) 9 The CFU / g silage compound microbial strains were labeled CK, L and H groups in sequence. After being mixed evenly, they were placed in sterile bags and vacuum sealed. The bags were then placed in constant temperature incubators at 10℃ and 25℃ for silage experiments, with 3 replicates for each treatment.

[0045] 2. Silage quality evaluation After 60 days of silage, samples were collected and analyzed for fermentation quality indicators, content of conventional nutrients, number of microorganisms, and in vitro fermentation indicators.

[0046] (2.1) Fermentation quality analysis: The pH value of the sample leachate was determined by a pH meter; the contents of organic acids such as lactic acid, acetic acid, propionic acid and butyric acid were determined by a Shimadzu LC-20A high performance liquid chromatograph.

[0047] (2.2) Routine nutritional composition analysis: Crude protein (CP) content was determined by Kjeldahl method; the contents of neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) were determined by Paraná fiber analysis method.

[0048] (2.3) Microbial quantity determination: The microbial quantity was determined by plate counting method.

[0049] (2.4) In vitro fermentation indicators: Rumen fluid samples from yaks were collected 1 hour before morning feeding, filtered, and kept in a 39°C water bath while continuously aerating with CO2 to maintain an anaerobic environment. 0.5 g of Kobresia silage sample was weighed and placed in a fermentation bottle, along with 25 mL of rumen fluid and 50 mL of preheating buffer. After mixing thoroughly, N2 was introduced to expel air from the bottle. Gas production was recorded over 48 hours using a microbial fermentation gas recorder, and dry matter digestibility was calculated using the nylon bag method.

[0050] 3. Results Analysis (3.1) Fermentation quality of Kobresia silage Table 3 shows the test results of the fermentation quality of Kobresia silage (%FM represents the percentage of fresh weight). It can be seen that after 60 days of silage, under conditions of 10℃ and 25℃, the contents of lactic acid, acetic acid, and butyric acid in groups L and H were higher than those in group CK, and increased with increasing concentration of the compound microbial strain. The pH in groups L and H was lower than that in group CK, and decreased with increasing concentration of the compound microbial strain. At the same addition level, the contents of lactic acid, acetic acid, and butyric acid in the 25℃ treatment were higher than those in the 10℃ treatment, while the pH was lower than that in the 10℃ treatment. By comparing the test results under silage temperatures of 10℃ and 25℃, the contents of lactic acid, acetic acid, and butyric acid in Example 4 were lower than those in Examples 1-3; while the pH was lower than that in Examples 1-3. These results indicate that the low-temperature silage compound microbial strain can increase the contents of lactic acid, acetic acid, and butyric acid and decrease the pH level in Kobresia silage at both low and normal temperatures, and is significantly affected by temperature and the type of compound microbial strain.

[0051] Table 3. Detection results of fermentation quality of Kobresia silage

[0052] (3.2) Nutritional components of Kobresia silage Table 4 shows the results of nutrient composition analysis of *Sophora flavescens* silage (%DM represents percentage under dry matter). It can be seen that at 10℃ and 25℃, the CP content in groups L and H was higher than that in group CK; and the CP content showed an increasing trend with increasing concentration of the compound microbial strain. The NDF, ADF, and ADL contents in groups L and H were lower than those in group CK, and the NDF, ADF, and ADL contents showed a decreasing trend with increasing concentration of the compound microbial strain. At the same addition level, the CP content in the 25℃ treatment was higher than that in the 10℃ treatment, while the NDF, ADF, and ADL contents in the 25℃ treatment were lower than those in the 10℃ treatment. By comparing the results under silage temperatures of 10℃ and 25℃, the crude protein content in Example 4 was lower than that in Examples 1-3; while the NDF, ADF, and ADL contents were higher than those in Examples 1-3. These results indicate that the compound microbial strain can increase the crude protein content and decrease the NDF, ADF, and ADL contents in *Sophora flavescens* silage at both low and normal temperatures, and is significantly affected by temperature level and the type of compound microbial strain.

[0053] Table 4. Detection results of nutritional components in Kobresia silage

[0054] (3.3) Microorganisms in Kobresia Silage Table 5 shows the detection results of microorganisms in Kobresia silage (lg cfu / g FW represents the commonly used logarithmic value of the number of culturable viable bacteria per gram of fresh weight). It can be seen that at 10℃ and 25℃, the number of lactic acid bacteria in groups L and H was higher than that in group CK; and the number of lactic acid bacteria showed an increasing trend with the increase of the concentration of the compound microbial system. Conversely, the number of yeasts in groups L and H was lower than that in group CK. At 10℃, the number of molds in groups L and H was lower than that in group CK, and showed a decreasing trend with the increase of the concentration of the compound microbial system; at 25℃, the number of molds in groups L and H was higher than that in group CK. At the same addition level, the number of lactic acid bacteria in the 25℃ treatment was higher than that in the 10℃ treatment, while the number of yeasts in the 25℃ treatment was lower than that in the 10℃ treatment. These results indicate that the compound microbial system provided in this application can increase the number of lactic acid bacteria and decrease the number of molds and yeasts in Kobresia silage at low temperatures; and can increase the number of lactic acid bacteria and decrease the number of yeasts in Kobresia silage at room temperature.

[0055] Table 5. Detection results of microorganisms in Kobresia silage (lg cfu / g FW)

[0056] Through the above experiments, this application has constructed a highly efficient compound microbial system suitable for low-temperature silage. This silage contains a high content of organic acids, crude protein, and nutrients. The compound microbial system provided by this application can increase the number of lactic acid bacteria in silage and reduce the number of molds and yeasts, thereby effectively reducing the probability of spoilage during low-temperature silage and storage, and improving the fermentation quality of Kobresia silage to a certain extent.

[0057] Experimental Example 3: Study on pesticide degradation characteristics of lactic acid bacteria strains ZS-1, XS-1, and RL-5 ZS-1, XS-1, and RL-5 were inoculated into MRS liquid medium for activation, and the inoculation was repeated three times, with each inoculation at 37°C for 24 hours, using an inoculation amount of 1×10⁻⁶. 7 CFU / mL were inoculated into MRS medium containing 5 mg / kg metolachlor, cyhalothrin, and chlorfenapyr, respectively, and cultured at 37℃ for 72 h. The fermentation broth was centrifuged at 5000×g for 15 min, and the supernatant was filtered through a 0.22 μm membrane and stored at -20℃ for later use. A blank control (CK) was set up, and the experiment was repeated three times.

[0058] (2) Take 20g of the MRS medium after fermentation of the test strain in step (1) and place it in a 50 mL centrifuge tube. Add 75 mL of acetonitrile-ultrapure water (2:1, v / v) mixture and place it in a high-speed homogenizer. Homogenize and extract for 2 min. Transfer it to a stoppered graduated cylinder containing 15 g of sodium chloride (the amount of sodium chloride should be sufficient to saturate the volume). Shake vigorously for about 30 s and let it stand at room temperature for 30 min to separate the organic phase and the aqueous phase.

[0059] Pipette 10.00 mL of solution from a stoppered graduated cylinder into a 15 mL glass test tube. Blow the extract to near dryness with nitrogen at 80°C. Add 2 mL of n-hexane and vortex for 30 s, then allow to purify. Pre-wash the Florisil solid-phase extraction column sequentially with 5 mL of acetone + n-hexane (10+90) and then with 5 mL of n-hexane. When the solution level reaches the surface of the column adsorption layer, immediately pour in the above-mentioned purification solution. Collect the eluent in a 15 mL graduated centrifuge tube. Rinse the test tube with 5 mL of acetone + n-hexane (10+90) and then rinse the Florisil column, repeating this process three times. Collect the eluent and slowly blow it down to approximately 5 mL using a nitrogen blower at 50°C. Make up to 5 mL with n-hexane, mix well, filter through a 0.22 μm organic filter membrane, and transfer to a sample vial for analysis.

[0060] GC-2010PLUS gas chromatograph. Injector temperature: 200℃. Detector temperature: 320℃. Column temperature conditions: initial temperature 150℃, hold for 2 min, ramp up to 270℃ at 6℃ / min, hold for 18 min. Gas flow rate: 14 mL / min. Injection volume: 1 μL. Split ratio: 10:1.

[0061] The results are shown in Table 6 below: Table 6. Degradation rate of pesticides by three strains

[0062] Strain ZS-1 exhibited the strongest degradation ability for the three pesticides, with the highest degradation rate for cyhalothrin (70.76% ± 2.4%), followed by metolachlor (61.14% ± 3.1%), and also showing a high degradation rate for chlorfenapyr. Strain XS-1 also showed a high degradation rate for cyhalothrin (60.56% ± 1.8%) and metolachlor (52.23% ± 4.5%). Strain RL-5 showed relatively weaker degradation ability, with a degradation rate of 55.72% ± 2.9% for cyhalothrin and 42.17% ± 3.8% for metolachlor. Overall, strain ZS-1 demonstrated the best degradation performance for the three pesticides.

[0063] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A strain of animal lactic acid bacteria ZS-1 and its application, characterized in that, The animal lactic acid bacteria is classified as Lactobacillus animalis strain ZS-1 and was deposited at the China Center for Type Culture Collection on March 31, 2025, with accession number CCTCC NO: M 2025639.

2. The application of the animal lactic acid bacteria ZS-1 strain according to claim 1 in reducing pesticide residues.

3. The application according to claim 2, characterized in that, The pesticides mentioned are pyrethroids, amides, and / or pyrroles.

4. The application according to claim 2, characterized in that, The pesticide is at least one of cyhalothrin, metolachlor, and chlorfenapyr.

5. The application of the animal lactic acid bacteria strain ZS-1 as described in claim 1 in silage processing.

6. The application of the animal lactic acid bacteria strain ZS-1 as described in claim 1 in low-temperature silage processing.

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