Lactiplantibacillus plantarum F57, its culture method, and its application

Abstract

The present application relates to the technical field of microbial engineering, and in particular to a Lactiplantibacillus plantarum F57, a culture method and application thereof.The Lactiplantibacillus plantarum F57 is preserved in the Guangdong Microbial Digital Culture Collection Center, with a preservation number of GDMCC No:66319, a preservation date of May 13, 2025, and a preservation address of No. 59, Building 5, 100, Middle Martyrs Road, Yuexiu District, Guangzhou City.The Lactiplantibacillus plantarum F57 has high antioxidant capacity, and when used to prepare fermented food, can effectively exert antioxidant effect in vivo; in addition, the strain has a certain adsorption effect on microplastics in vivo, and can expel microplastics out of the body with the consumption of fermented food; at the same time, the strain also shows excellent aroma-producing characteristics during fermentation, which can significantly improve the flavor quality of fermented food.

Description

Technical Field

[0001] This invention relates to the fields of microbial technology and food safety and health, and in particular to a Lactiplantibacillus plantarum F57 and its culture method and application. Background Technology

[0002] Microplastics refer to plastic residues smaller than 5 mm in size. Common microplastics currently include polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC) (Sharma, S., B. Sharma, and S. Dey Sadhu, Microplastic profusion in food and drinking water: are microplastics becoming a macroproblem? Environ Sci Process Impacts, 2022, 24(7): p. 992-1009.). Microplastics are increasingly attracting attention due to their widespread presence and potential pathogenicity. Extensive evidence indicates that food and water sources are generally contaminated with microplastics. Microplastics can enter the body through the respiratory and digestive tracts, and may even enter the human body through the skin. Accumulation of microplastics may affect the liver, kidneys, gastrointestinal tract, and even the heart.

[0003] Fermented products, an indispensable part of the human diet, are widely present in our lives. These foods, through a specific fermentation process, not only acquire unique flavor and texture, but more importantly, they contain abundant lactic acid bacteria. As a probiotic, lactic acid bacteria offer numerous health benefits. Studies have shown that lactic acid bacteria in fermented products can protect the human body and alleviate tissue damage caused by environmental pollutants. Existing research indicates that lactic acid bacteria have a certain adsorption capacity for microplastics of different particle sizes and possess antioxidant capabilities, effectively alleviating oxidative stress or inflammatory responses caused by long-term exposure to microplastics. Furthermore, lactic acid bacteria possess aroma-producing functions. Through processes such as sugar metabolism and fatty acid metabolism, they can produce various volatile aroma substances, such as isovaleraldehyde, C2 to C8 volatile acids, 3-hydroxybutanone, dimethyl ethyl ketone, acetaldehyde, and diacetyl. Among these, dimethyl ethyl ketone and 3-hydroxybutanone are the characteristic main components of fermented aromas, generated from the decomposition of the precursor α-acetolactate under the action of microorganisms. Under sufficient oxygen conditions, α-acetolactic acid decomposes into 3-hydroxybutanone, which is then further oxidized to dimethylbutanone. Both of these substances have a pleasant aroma. Consuming fermented foods in moderation in our daily diet not only allows us to enjoy their delicious taste but can also, to some extent, mitigate the adverse health effects of microplastic pollution.

[0004] Therefore, it is crucial to provide a new strain of lactic acid bacteria that combines efficient fermentation performance with microplastic adsorption capacity. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a *Lactiplantibacillus plantarum* F57 strain, its cultivation method, and its applications. In this invention, *Lactiplantibacillus plantarum* F57 possesses high antioxidant capacity, enabling it to effectively exert antioxidant effects in vivo when used in the preparation of fermented foods. Furthermore, this strain exhibits a certain adsorption capacity for microplastics in vivo and can excrete microplastics from the body through consumption of fermented foods. Simultaneously, this strain demonstrates excellent aroma-producing characteristics during fermentation, significantly enhancing the flavor and quality of fermented foods.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] The first objective of this invention is to provide a Lactiplantibacillus plantarum F57, which is deposited at the Guangdong Provincial Center for Microbial Culture Collection, with accession number GDMCC No:66319, deposit date May 13, 2025, and address 5th Floor, Building 59, No. 100 Xianlie Middle Road, Yuexiu District, Guangzhou.

[0008] In one embodiment of the present invention, the 16S rRNA gene sequence of Lactiplantibacillusplantarum F57 is shown in SEQ ID NO.1.

[0009] A second objective of this invention is to provide a method for culturing Lactiplantibacillus plantarum F57, comprising the following steps:

[0010] (S1) Inoculate Lactiplantibacillus plantarum F57 into MRS liquid medium for activation culture;

[0011] (S2) Inoculate the activated Lactiplantibacillus plantarum F57 into MRS medium and continue culturing.

[0012] A third objective of this invention is to provide an application of Lactiplantibacillus plantarum F57 in microplastic adsorption.

[0013] In this invention, Lactiplantibacillus plantarum F57 exhibits high adsorption capacity for polypropylene microplastic spheres of different particle sizes.

[0014] The fourth objective of this invention is to provide an application of Lactiplantibacillus plantarum F57 in the field of microbial antioxidants.

[0015] In one embodiment of the present invention, the field of microbial antioxidants includes food preservation, preparation of antioxidant products, drug development, or bioremediation.

[0016] In this invention, Lactiplantibacillus plantarum F57 exhibits high scavenging ability against DPPH and ABTS free radicals.

[0017] The fifth objective of this invention is to provide an application of Lactiplantibacillus plantarum F57 in the field of microbial acid production.

[0018] In one embodiment of the present invention, the field of microbial acid production includes fermented food production, acidulant production, organic acid production, plastic production, wastewater treatment, soil remediation, drug production, or microbial preparation production.

[0019] In this invention, Lactiplantibacillus plantarum F57 has strong acid and bile resistance and can survive for a long time in the human gastrointestinal tract.

[0020] The sixth objective of this invention is to provide an application of Lactiplantibacillus plantarum F57 in the field of microbial ketone production.

[0021] In one embodiment of the present invention, the field of microbial ketone production includes the production of ketone flavoring agents, the production of ketone food additives, wastewater treatment, or the production of pharmaceutical intermediates.

[0022] In this invention, Lactiplantibacillus plantarum F57 has a high aroma-producing ability in fermented milk.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) Safe, healthy, and low cost: The Lactiplantibacillus plantarum F57 provided by this invention is a safe strain that can be used in food and is screened from kimchi. The method of this invention has no chemical additives, is green and natural, and is nutritious and healthy.

[0025] (2) The Lactiplantibacillus plantarum F57 of the present invention has strong antioxidant capacity, and the bacterial cell concentration is 10. 9 After incubation at 37°C for 12 hours, the bacterial cells at CFU / mL showed a scavenging rate of 65.06±0.23% and 60.10±0.63% for DPPH and ABTS free radicals, respectively. Compared with the traditional method, this not only has the advantages of highly efficient biological antioxidants, but also, due to its own characteristics, it belongs to probiotics and has greater advantages in the food industry.

[0026] (3) The Lactiplantibacillus plantarum F57 of the present invention has a strong adsorption capacity for microplastic PP, and the bacterial concentration is 10. 9 CFU / mL of bacterial cells, after incubation at 37°C for 4 hours, can achieve an adsorption rate of 72.37±2.60% for 5μm PP. The Lactiplantibacillus plantarum F57 of this invention has a certain mitigating effect on the adverse effects of human exposure to microplastics.

[0027] (4) The plant lactobacillus plantarum F57 of the present invention has been used in biological experiments and has produced a significant effect on the adsorption of microplastics. Its high antioxidant effect also brings certain probiotic effects to the organism.

[0028] (5) The Lactiplantibacillus plantarum F57 provided by the present invention has a certain aroma-producing ability, which is of great significance for developing fermented products with probiotic and flavor characteristics. Attached Figure Description

[0029] Figure 1 The adsorption effect of different plant lactobacilli on microplastic PP-MP beads of different particle sizes is shown in the figure.

[0030] Figure 2The image shows the monitoring data of microplastic content in zebrafish feces in Example 5; where * indicates p < 0.05 and ** indicates p < 0.01. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0032] Unless otherwise specified, all reagents used in the following embodiments are commercially available reagents, and all means and methods used are conventional means and methods in the art.

[0033] Example 1

[0034] This embodiment provides the isolation, purification, morphological identification, molecular identification, and culture methods for Lactobacillus plantarum F57, as detailed below:

[0035] (1) Isolation and purification of the strain:

[0036] (A1) Serially diluted with sterile saline to 10 -6 Each dilution gradient was sequentially plated on MRS plates and incubated at 37°C for 72 hours. After incubation, colonies with different morphologies were selected using an inoculation needle and streaked onto MRS plates until uniform single colonies of consistent size and morphology appeared.

[0037] (A2) After step (A1) is completed, the selected single colony is Gram stained. Select strains that stain purple with Gram, are catalase negative, and do not form spores, and tentatively identify them as lactic acid bacteria (the isolated strains are labeled as F57, XC4, F15, XC22, and WJ105, respectively).

[0038] (A3) After step (A2) is completed, the strains that were temporarily identified as lactic acid bacteria were activated for 3 generations in MRS liquid medium and then subjected to physiological and biochemical identification and molecular biological identification.

[0039] (2) Morphological identification of strains

[0040] The strain obtained in step (1) was streaked on an MRS plate and cultured at 37°C for 48 hours. The strain was found to grow well, with round, raised colonies, neat edges, milky white color, opaque, moist and smooth surface, and the colonies could be drawn into strands when picked up.

[0041] Gram staining of strain F57 was performed using the Gram staining method. The results showed that the bacteria were non-motile rod-shaped, mostly arranged in chains of varying lengths, and also scattered individually. They did not produce spores and were Gram-positive.

[0042] (3) Molecular identification

[0043] The 16S rRNA of the isolated strain F57 was cloned and sequenced. The nucleotide sequence of its 16S rRNA gene is shown in SEQ ID No. 1. The 16S rRNA gene sequence of this strain was compared with the sequence of Lactiplantibacillus plantarum from NCBI and it was found that the 16S rRNA gene sequence of the strain had a similarity of 98.03% with the sequence of Lactiplantibacillus plantarum.

[0044] Furthermore, this strain was deposited at the Guangdong Provincial Microbial Culture Collection Center, with the taxonomic name *Lactiplantibacillus plantarum*, specifically *Lactiplantibacillus plantarum* F57; its accession number is GDMCC No:66319; the deposit date is May 13, 2025; and the deposit address is 5th Floor, Building 59, No. 100 Xianlie Middle Road, Yuexiu District, Guangzhou.

[0045] Specifically, SEQ ID No. 1 is as follows:

[0046]

[0047] (4) Culture methods of the strain

[0048] (S1) Lactiplantibacillus plantarum F57 was inoculated into MRS liquid medium for activation culture (37℃, 24h);

[0049] (S2) Inoculate the activated Lactiplantibacillus plantarum F57 into MRS medium and continue culturing (37℃, 16-24h).

[0050] Example 2

[0051] This embodiment provides a determination of the survival of Lactiplantibacillus plantarum F57 in a simulated gastrointestinal tract, as detailed below:

[0052] Pepsin (Sangon Biotech (Shanghai) Co., Ltd., 1:10000) was dissolved in sterile physiological saline (0.9% w / v) to a final concentration of 3 g / L, and the pH of the solution was adjusted to 3.0 with hydrochloric acid. Finally, the solution was filtered through a 0.22 μm sterile filter membrane and prepared immediately before use. This is the simulated gastric juice.

[0053] After centrifuging the cultured Lactiplantibacillus plantarum F57 at 5000×g for 10 min, the precipitate was resuspended in simulated gastric fluid to achieve a bacterial concentration of 1×10⁻⁶. 9 CFU / mL; then incubated in a 37℃ incubator, and after 3 hours, 0.1 mL was taken out for viable bacterial count and its survival rate in simulated gastric fluid was calculated.

[0054] Trypsin (1:250) was resuspended in sterile 0.9% (w / v) physiological saline to a concentration of 1 g / L (i.e., 0.1 g of trypsin was added to 100 mL). Then, 0.3% (w / v) bile salts were added and the pH was adjusted to 8.0. Finally, the mixture was filtered through a 0.22 μm sterile filter membrane and prepared immediately before use. This is the simulated intestinal fluid.

[0055] After centrifuging the cultured Lactiplantibacillus plantarum F57 at 5000×g for 10 min, the precipitate was resuspended in simulated gastric fluid to achieve a bacterial concentration of 1×10⁻⁶. 9CFU / mL; then incubate in a 37℃ incubator. After 3 hours, take 0.5 mL of the incubated suspension and transfer it to 5 mL of simulated intestinal fluid. Shake well and continue incubating at 37℃ for 2 hours or 4 hours. Take 0.1 mL for viable count and calculate its survival rate in the simulated intestinal fluid.

[0056] The results are shown in Table 1. Table 1 shows that the survival rate of Lactiplantibacillus plantarum F57 was 88.89±1.57% after 3 hours of incubation in simulated gastric fluid; the survival rate was 66.42±0.81% after 2 hours of incubation in simulated intestinal fluid; and the survival rate was 53.09±3.75% after 4 hours of incubation.

[0057] Table 1. Survival ability of different *Lactobacillus plantarum* species in simulated human gastrointestinal environment.

[0058]

[0059] Example 3

[0060] This embodiment provides the determination of the antioxidant capacity of Lactiplantibacillus plantarum F57, as detailed below:

[0061] (1) Determination of DPPH scavenging rate

[0062] After inoculating Lactiplantibacillus plantarum F57 into liquid culture medium and activating it for 2 generations, the bacterial suspension was centrifuged at 5000 rpm for 12 min, the supernatant was discarded, the bacterial cells were washed once with PBS solution, and centrifuged again at 5000 rpm for 12 min, the supernatant was discarded, and the bacterial cells were left for testing.

[0063] DPPH free radical scavenging rate determination: 0.5 mL PBS was mixed with bacterial cells to prepare a sample solution of Lactiplantibacillus plantarum F57 (bacterial cell concentration 1×10⁻⁶). 9 (CFU / mL); Take 0.5 mL of DPPH (0.2 mmol / L) solution and 0.5 mL of Lactiplantibacillus plantarum F57 sample solution, mix well, and let stand at room temperature for 30 minutes. Then, use a spectrophotometer to measure the absorbance (A1) of the solution after the reaction at 517 nm; at the same time, measure the absorbance (A0) of 0.5 mL of DPPH solution mixed with 0.5 mL of PBS as a control.

[0064] Calculate the clearance rate: The clearance rate of DPPH by Lactiplantibacillus plantarum F57 was calculated using the following formula:

[0065] Clearance rate = [(A0-A1) / A0] × 100%

[0066] Where A0 is the absorbance of the control solution and A1 is the absorbance of the solution after the reaction.

[0067] (2) ABTS free radical scavenging rate determination

[0068] The ABTS method is a widely used method for detecting the in vitro antioxidant capacity of substances. ABTS reacts with K₂S₂O₈ to generate stable free radical ABTS. + This free radical exhibits maximum absorption at 734 nm and displays a blue-green color. As the free radical is removed, its quantity decreases, causing the solution color to lighten, thus reducing the absorbance at 734 nm. This can be used to determine if the sample has been free of ABTS. + The ability.

[0069] Preparation of 7 mM ABTS (2,2-azino-bis(3-ethyl-benzothiazole-6-sulfonic acid) diammonium salt): The molecular weight of ABTS is approximately 548.68 g / mol. Dissolve 0.0384 g of ABTS powder in a certain amount of PBS and make up to 10 mL to obtain a 7 mM ABTS solution.

[0070] Preparation of potassium persulfate solution: Weigh 0.0134 g of potassium persulfate powder, dissolve it in deionized water and make up to 10 mL to obtain a 2.45 mM potassium persulfate solution.

[0071] Preparation of ABTS free radical working solution: Mix 7 mM ABTS solution with 2.45 mM potassium persulfate solution in equal volumes, and store the mixture in the dark for 12 hours or overnight.

[0072] Dilution of ABTS radical working solution: Dilute ABTS radical working solution to the required concentration using PBS with pH 7.4 (specifically, dilute 20 times with PBS with pH 7.4 before use).

[0073] Mix 0.5 mL of PBS with the bacterial cells to prepare a sample solution of Lactiplantibacillus plantarum F57 (bacterial concentration of 1 × 10⁻⁶). 9(CFU / mL); Mix 0.5 mL of ABTS radical working solution with 0.5 mL of Lactiplantibacillus plantarum F57 sample solution and let stand at room temperature for 30 minutes. Then, measure the absorbance (A1) of the solution after reaction at 734 nm using a spectrophotometer. At the same time, measure the absorbance (A0) of 0.5 mL of ABTS radical working solution mixed with 0.5 mL of PBS as a control.

[0074] Calculate the scavenging rate: The scavenging rate of ABTS free radicals by Lactiplantibacillus plantarum F57 is calculated according to the following formula:

[0075] Clearance rate = [(A0-A1) / A0] × 100%

[0076] Where A0 is the absorbance of the control solution and A1 is the absorbance of the solution after the reaction.

[0077] The results are shown in Table 2. Table 2 shows that, compared with the antioxidant capacity of vitamin C (0.1 mg / mL), the scavenging capacity of Lactiplantibacillus plantarum F57 against DPPH and ABTS free radicals was 65.06±0.23% and 60.10±0.63%, respectively. As can be seen from the figure, its antioxidant capacity is basically the same as that of vitamin C (0.1 mg / mL equivalent) or even shows a better ability.

[0078] Table 2 Comparison of antioxidant capacity of strain F57 and vitamin C

[0079]

[0080] Note: Welch's t-test (t = -7.30, p = 0.0005)

[0081] Example 4

[0082] This embodiment provides a determination of the adsorption capacity of Lactiplantibacillus plantarum F57 for PP microplastics of different particle sizes, as detailed below:

[0083] Preparation of working solution for microplastic particles (PP-MPs): 5 μm PP-MPs were dispersed in water and diluted to 60 μg / mL to prepare the PP-MPs working solution.

[0084] Approximately 1.0 × 10 9CFU / mL of *Lactobacillus plantarum* strains (F57, XC4, F15, XC22, and WJ105, respectively) were suspended in 1.0 mL of 60 μg / mL working solution of different PP-MPs; incubated at 37 °C for 4 h, followed by centrifugation at 6000 × g for 15 min at 4 °C. The supernatant (500 μL) was collected for microscopic counting analysis.

[0085] A suspension of PP-MPs was dropped onto a glass slide. The number of unbound PP-MPs in 20 random fields of view was quantified using a microscope. The results are expressed as the average number of unbound PP-MPs in bacterial cells.

[0086] Calculation of PP-MP adsorption rate: A bacteria-free PP-MP solution (10 μg / mL) was used as a control. The adsorption rate was calculated using the formula: Adsorption rate (%) = (Number of MPs in control group - Number of MPs in supernatant) / Number of MPs in control group × 100%.

[0087] The results are shown in Table 3 and Figure 1 As shown, *Lactiplantibacillus plantarum* F57 exhibited an adsorption rate of 72.37 ± 2.60% for 5 μm PP, 81.82 ± 5.25% for 50 μm PP, and 86.67 ± 3.85% for 500 μm PP. The phenomenon of "higher adsorption rate with larger microplastic particle size" observed in *Lactiplantibacillus plantarum* F57 is likely a result of the synergistic effect of its unique physiological and biochemical characteristics (excellent surface adhesion ability, preference for flat / low curvature surfaces) and environmental behavior (utilizing large particle sedimentation and aggregation). This groundbreaking discovery strongly demonstrates the high efficiency and broad application prospects of strain F57 in the field of microplastic adsorption, particularly in the remediation of microplastic pollution of various particle sizes that are most prevalent in the environment.

[0088] Table 3. Determination of the adsorption capacity of *Lactobacillus plantarum* F57 for three different particle sizes of PP microplastics.

[0089]

[0090] Example 5

[0091] This embodiment provides a determination of the adsorption effect of Lactiplantibacillus plantarum F57 on microplastics in organisms (using zebrafish for microplastic exposure and monitoring the adsorption effect of Lactiplantibacillus plantarum F57 on microplastics), as detailed below:

[0092] Specific exposure model: 6 zebrafish per tank were exposed to 60 mg / L polypropylene (50 μm) plastic beads. Simultaneously, the treatment group received 0.0012 g of Lactiplantibacillus plantarum F57 bacterial powder (ensuring a bacterial concentration of 1 × 10⁻⁶). 7 In the drug group, vitamin C (0.1 mg / mL) was added, and fecal samples were collected and the microplastic content was measured on days 0, 5, and 15 of the experiment. Figure 2 As shown, on day 0 of exposure, 6 microplastic particles were observed in the water under a microscope; on day 5, 5 feces of zebrafish were collected and resuspended in deionized water before being observed under a microscope. The model group (i.e., the blank control) had 21 microplastic particles, the F57 group had 39 microplastic particles, and the Vc group had 18 microplastic particles; on day 15, the model group had 47 microplastic particles, the F57 group had 69 microplastic particles, and the Vc group had 35 microplastic particles. It can be seen that F57 has the greatest impact on the amount of microplastic excretion in zebrafish feces.

[0093] Example 6

[0094] This embodiment provides the following details regarding the aroma-producing ability of Lactiplantibacillus plantarum F57:

[0095] Lactiplantibacillus plantarum F57 was inoculated into MRS liquid medium (bacterial suspension / medium volume ratio of 2:100) and cultured at 37°C for 12 h. A second activation was then performed at an inoculation rate of 2% (v / v). After 12 h of activation, the bacterial suspension was centrifuged at 4500 rpm for 12 min at 4°C, washed twice with physiological saline, and then mixed with sterile water to obtain the bacterial suspension.

[0096] The prepared bacterial suspension was inoculated into sterilized milk at an inoculation rate of 2%, and fermented at a constant temperature of 43°C. When the pH of the system reached 4.45–4.5, the fermentation process was terminated. Then, mechanical stirring was used to break the emulsion. After the temperature was lowered to room temperature through a cooling system, it was transferred to a low-temperature environment of 4°C for post-ripening treatment. The post-ripening time was controlled at 12–16 hours, thereby obtaining the fermented milk product.

[0097] Sterilized light cream was cooled to room temperature and then inoculated with a 1% inoculum of *Lactiplantibacillus plantarum* F57 bacterial suspension. Fermentation was carried out at 30°C for 20 hours to obtain fermented sour cream. 5.00 mL (accurate to 0.01 mL) of the fermented milk sample after 12 hours of refrigeration was transferred to a 20 mL headspace solid-phase microextraction (HS-SPME) vial, sealed, and stored for analysis. The vial was placed in a 55°C water bath, and the aged extraction head (50 / 30 μm DVB / CAR / PDMS) was inserted. Headspace adsorption was performed for 40 minutes. After extraction, the extraction head was subjected to GC-MS analysis for 5 minutes to complete sample injection.

[0098] The GC-MS program conditions were as follows: HP-INNOWAX column (60m × 0.25mm × 0.25mm); injection port temperature: 230℃; temperature program: 40℃ for 3 min, then increased at 4℃ / min to 120℃, and finally increased at 5℃ / min to 230℃, held for 10 min; carrier gas: He; flow rate: 1 mL / min; injection mode: splitless injection. Mass spectrometry conditions were as follows: ion source temperature: 230℃; ion source: EI; electron energy: 70 eV; scan range: 30–300 amu; full ion scan mode. The flavor compounds shown in the table below were obtained.

[0099] Table 3. Determination of aroma production capacity of Lactobacillus plantarum F57

[0100]

[0101] Comparative Example 1

[0102] The difference between this comparative example and Example 4 is that Lactiplantibacillus plantarum F57 was replaced with Lactiplantibacillus plantarum XC6, HLB2, WJ102, GM-6 (Screening of goaty flavor-inhibiting lactic acid bacteria and their effects on the flavor profiles of goat milk cakes[J].Food Bioscience,2023,53:102504.) as the control sample group.

[0103] The results are shown in Table 4. The DPPH scavenging rate of XC6 was 49.95±0.33%; HLB2 was 51.48±0.82%; WJ102 was 46.67±0.17%; and GM-6 was 56.29±0.47%. This indicates that the DPPH scavenging rate of Lactiplantibacillus plantarum F57 (65.06±0.23%) was higher than that of the three Lactiplantibacillus plantarum strains, further highlighting the superiority of Lactiplantibacillus plantarum F57 in the relevant indicators.

[0104] Table 4 Comparison of DPPH removal capabilities

[0105]

[0106] Comparative Example 2

[0107] The difference between this comparative example and Example 4 is that *Lactiplantibacillus plantarum* F57 was replaced with *Lactiplantibacillus plantarum* F15 and GM-6 (Screening of goaty flavor-inhibiting lactic acid bacteria and their effects on the flavor profiles of goat milkcakes[J]. Food Bioscience, 2023, 53:102504.). Their adsorption capacity for three different particle sizes of polypropylene (PP) was measured. The results show that the adsorption rates of F15 and GM-6 for 5 μm PP are shown in the table below. Compared with the adsorption capacity of *Lactiplantibacillus plantarum* F57 (5 μm PP adsorption rate: 72.37±2.60%), the adsorption capacity of F15 and GM-6 is much lower than that of *Lactiplantibacillus plantarum* F57.

[0108] Table 5 Comparison of the adsorption capacity of different plant-derived Lactobacillus species for microplastics (PP) of different particle sizes.

[0109]

[0110] Comparative Example 3

[0111] The difference between this comparative example and Example 4 is that Lactobacillus plantarum F57 was replaced with Lactobacillus plantarum CCFM1373 (Lactobacillus plantarum reduces polystyrene microplastic induced toxicity via multiple pathways: A potentially effective and safe dietary strategy to counteract microplastic harm[J]. Journal of Hazardous Materials, 2025, 489: 137669.). The adsorption rate of Lactobacillus plantarum F57 for 5μm PS microplastics was 57.99%, while Lactobacillus plantarum F57 showed a higher adsorption rate (72.37%) for 5μm PP microplastics.

[0112] Comparative Example 4

[0113] The difference between this comparative example and Example 6 is that *Lactiplantibacillus plantarum* F57 was replaced with *Lactiplantibacillus plantarum* XC 12, and its aroma-producing ability in yogurt was measured. The results are shown in Table 6. No characteristic volatile metabolites, such as acetic acid and dimethylglyoxal, were detected in the yogurt fermented with *Lactiplantibacillus plantarum* XC 12.

[0114] Table 6. Aroma production capacity determination of Lactobacillus plantarum GM-6 (OAV>1)

[0115]

[0116] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the interpretation of the present invention, without departing from the scope of the invention, should be within the protection scope of the present invention.

Claims

1. A plant lactobacillus ( Lactiplantibacillus plantarum F57, characterized in that, The plant lactobacillus ( Lactiplantibacillus plantarum F57 is deposited at the Guangdong Provincial Center for Microbial Culture Collection, with accession number GDMCC No: 66319, deposit date May 13, 2025, and address 5th Floor, Building 59, No. 100 Xianlie Middle Road, Yuexiu District, Guangzhou.

2. The *Lactobacillus plantarum* according to claim 1 (… Lactiplantibacillus plantarum F57, characterized in that, The plant lactobacillus ( Lactiplantibacillus plantarum The 16S rRNA gene sequence of F57 is shown in SEQ ID NO.

1.

3. A plant lactobacillus as described in any one of claims 1 to 2 ( Lactiplantibacillus plantarum The cultivation method of F57 is characterized by, Includes the following steps: (S1) Bacterium plantarum ( Lactiplantibacillus plantarum F57 cells were inoculated into MRS liquid medium for activation culture; (S2) The activated cultured Lactobacillus plantarum ( Lactiplantibacillus plantarum F57 can be inoculated into MRS medium and cultured for a while.

4. A *Lactobacillus plantarum* strain as described in any one of claims 1 to 2 (… Lactiplantibacillus plantarum The application of F57 in the preparation of microplastic adsorption products is characterized by, This application is for purposes other than disease treatment and diagnosis.

5. A *Lactobacillus plantarum* strain as described in any one of claims 1 to 2 (… Lactiplantibacillus plantarum The application of F57 in the field of microbial antioxidants is characterized by, The field of microbial antioxidants includes food preservation, preparation of antioxidant products, drug development, or bioremediation. This application is for purposes other than disease treatment and diagnosis.

6. A *Lactobacillus plantarum* strain as described in any one of claims 1 to 2 (… Lactiplantibacillus plantarum The application of F57 in the field of microbial acid production is characterized by, The acid is acetic acid, butyric acid, hexanoic acid, octanoic acid, or n-decanoic acid; This application is for purposes other than disease treatment and diagnosis.

7. The application according to claim 6, characterized in that, The fields of microbial acid production include fermented food production, acidulant production, organic acid production, drug production, or microbial preparation production.

8. A *Lactobacillus plantarum* strain as described in any one of claims 1 to 2 (… Lactiplantibacillus plantarum The application of F57 in the field of microbial ketone production is characterized by, The ketone is 2-heptanone, 2-octanone, 2-nonanone, 2,3-butanedione, 6-methyl-5-hepten-2-one, or acetoin; This application is for purposes other than disease treatment and diagnosis.

9. The application according to claim 8, characterized in that, The field of microbial ketone production includes the production of ketone flavoring agents and ketone food additives.

10. A plant lactobacillus as described in any one of claims 1 to 2 ( Lactiplantibacillus plantarum The application of F57 in the field of microbial ketone production is characterized by, The ketone is acetylacetone; The field of microbial ketone production is the production of pharmaceutical intermediates.

Images