Sphingopyxis yunnanensis and application thereof

Abstract

The present application relates to the field of microbial technology, and more particularly to a sphingomonas and its application. The present application isolates a sphingomonas which can effectively degrade notoginseng autotoxic substance, namely saponin and phenolic acid. The strain can stably colonize in the root of notoginseng, inhibit notoginseng root rot pathogen, degrade crude saponin and generate new saponin, degrade phenolic acid, improve notoginseng survival rate and notoginseng dry weight, promote plant growth and dry matter accumulation, and has very important practical significance for relieving notoginseng continuous cropping obstacles and promoting plant growth.

Description

Technical Field

[0001] This invention relates to the field of microbial technology, and in particular to a strain of sphingosine box bacteria and its applications. Background Technology

[0002] Sanqi ( Panax. notoginseng Panax notoginseng (Burk.) FHChen is a perennial herb belonging to the genus Panax in the family Araliaceae. It is an important traditional Chinese medicine. However, due to the increasingly severe obstacles caused by continuous cropping of Panax notoginseng, the land resources suitable for its cultivation in traditional farmland have been significantly reduced. Root rot is the main manifestation of these obstacles, while autotoxicity may be the main contributing factor. Therefore, reducing the accumulation of autotoxic substances such as saponins in the soil after continuous cropping of Panax notoginseng is one of the effective ways to alleviate these obstacles.

[0003] Currently, the main strategies for addressing this problem include biochar adsorption, crop rotation, and microbial degradation. However, these measures to reduce autotoxic substances also have limitations. Specifically, the adsorption of autotoxic substances by biochar is mainly based on a reversible physical adsorption mechanism, which may lead to the re-release of adsorbed substances back into the soil environment under certain conditions, thus affecting its long-term effectiveness. On the other hand, while crop rotation can effectively mitigate autotoxicity, its practical application is often limited by a long implementation period, which may be detrimental to the efficient operation of agricultural production. Furthermore, although introducing exogenous microbial strains capable of degrading saponin-type autotoxic substances into continuously cropped soils is considered a highly promising biological strategy, it still faces many challenges in practical application. Specifically, the colonization efficiency of these exogenous strains in the soil may be low, resulting in insufficient surviving numbers and thus affecting their degradation efficiency. Moreover, even if successful colonization occurs, their degradation efficiency may be affected by various factors such as soil environment and competition from indigenous microorganisms, thus limiting their widespread application in actual production. Therefore, given the existing challenges in pathogen and autotoxic substance reduction strategies, exploring efficient and non-chemically dependent biological control methods has become an urgent need.

[0004] Sphingosine Box Bacteria ( Sphingopyxis The high adaptability of bacteria to adverse environments gives them a significant advantage in environmental remediation. They are widely used to degrade organic compounds. Previous studies have shown that strains of this genus can degrade chlorpyrifos, polyethylene glycol, microcystin, 1,2,3-trichloropropane, etc. However, there are no reports on their degradation of the autotoxic substances of Panax notoginseng, namely saponins and phenolic acids. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a strain of sphingosine box bacteria (Sphingosine box bacteria) Sphingopyxis sp. The strain is sphingosine sphingolipidae SPX122, with accession number CGMCC No. 31092.

[0006] The *Sphingosine Boxer* SPX122 strain of this invention was screened from the rhizosphere soil of *Panax notoginseng*. This strain was deposited on June 26, 2024, at the China General Microbiological Culture Collection Center (CGC-MSC), located at Institute of Microbiology, Chinese Academy of Sciences, No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, 100101, China. Its classification is *Sphingosine Boxer*. Sphingopyxis sp. The accession number is CGMCC No.31092.

[0007] Furthermore, the present invention provides a microbial inoculant comprising the aforementioned Sphingosine Box Bacterium SPX122.

[0008] Preferably, the microbial agent is a freeze-dried fermentation broth of Sphingosine Trichophyton spp. SPX122.

[0009] The freeze-dried fermentation broth contains Sphingosine Trichophyton spp. SPX122.

[0010] Preferably, the freeze-dried fermentation broth powder further includes a freeze-drying protectant.

[0011] Preferably, the freeze-drying protectant includes, but is not limited to, skim milk powder, dextrin, lactose, and sucrose.

[0012] Furthermore, the present invention provides the application of the aforementioned sphingosine-containing bacteria or the aforementioned microbial agent in inhibiting root rot pathogens.

[0013] Preferably, the root rot pathogen is pathogen LD ( Fusarium solani ).

[0014] Preferably, the inhibitory effect on root rot pathogens is enhanced by using Panax notoginseng crude saponins as a carbon source.

[0015] Furthermore, the present invention provides the application of the aforementioned sphingosine-containing bacteria or the aforementioned microbial agent in regulating the degradation or generation of crude saponins in Panax notoginseng.

[0016] Furthermore, the present invention provides the application of the aforementioned Sphingosine Box Bacterium or the aforementioned microbial agent in improving the survival rate or dry weight of Panax notoginseng seedlings.

[0017] Furthermore, the present invention provides the application of the aforementioned sphingosine-containing bacteria or the aforementioned microbial agent in the degradation of phenolic acids.

[0018] Preferably, the phenolic acid is p-hydroxybenzoic acid, ferulic acid, coumaric acid, or cinnamic acid.

[0019] Furthermore, the present invention provides the application of the aforementioned sphingosine-containing bacteria or the aforementioned microbial inoculant in promoting plant growth or dry matter accumulation; preferably, the plant is a plant with continuous cropping obstacles; preferably, the plant is lettuce, tomato, strawberry or soybean.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention has isolated a sphingosine-box bacterium that can effectively degrade the autotoxic substances of Panax notoginseng—saponins and phenolic acids. This strain can stably colonize the roots of Panax notoginseng, inhibit root rot pathogens, degrade crude saponins and generate new saponins, degrade phenolic acids, improve the survival rate and dry weight of Panax notoginseng, promote plant growth and dry matter accumulation, and has great practical significance for alleviating the obstacles of continuous cropping of Panax notoginseng and promoting plant growth. Attached Figure Description

[0021] Figure 1 This is a culture photograph of Sphingosine Box bacteria SPX122.

[0022] Figure 2 It is a phylogenetic tree.

[0023] Figure 3 This is a graph showing the results of the β-glucosidase production ability identification of Sphingosine Box Bacteria SPX122.

[0024] Figure 4 This is a diagram showing the results of an experiment on the inhibition of root rot pathogens by Sphingosine Box Bacterium SPX122.

[0025] Figure 5 This is a growth curve of Sphingosine Box Bacterium SPX122.

[0026] Figure 6 This is a graph showing the survival rate of seedlings in an indoor potted plant experiment.

[0027] Figure 7 This is a graph showing the results of the single-plant dry weight of the indoor potted plant experiment.

[0028] Figure 8 This is a diagram showing the degradation results of crude saponins in the culture medium by Sphingosine Box Bacterium SPX122.

[0029] Figure 9 This is a diagram showing the degradation results of saponins in continuously cropped soil by Sphingosine Box Bacterium SPX122.

[0030] Figure 10 This is a diagram showing the germination results of Panax notoginseng seedlings under forest cover after treatment with Sphingosine Box Bacterium SPX122.

[0031] Figure 11 This is a graph showing the degradation results of phenolic acids by Sphingosine Box Bacterium SPX122.

[0032] Figure 12 This is a graph showing the effect of Sphingosine Trichophyton spp. SPX122 on lettuce growth.

[0033] Figure 13 This is a graph showing the effect of Sphingosine Trichophyton spp. SPX122 on tomato growth.

[0034] Figure 14 This is a graph showing the effect of Sphingosine Trichophyton spp. SPX122 on strawberry growth.

[0035] Figure 15 This is a graph showing the effect of Sphingosine Trichophyton spp. SPX122 on soybean growth. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention are described clearly and completely below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. In statistical analysis, different asterisks represent significant differences, * p <0.05,** p <0.01, *** p <0.001.

[0037] The culture medium formulation using crude saponins as the sole carbon source in the following examples is as follows: 3g NaNO3, 1g KH2PO4, 0.5g KCl, 0.5g MgSO4•7H2O, 0.01g FeSO4•7H2O, 10g Panax notoginseng crude saponins, 17g agar, 1000mL distilled water. Dissolve and mix well, then adjust the pH to 7.0 with 1mol / L NaOH solution. The crude Panax notoginseng saponins were purchased from Shaanxi Jinkangtai Biotechnology Co., Ltd.

[0038] Example 1: Isolation of Sphingosine Box Bacteria SPX122 Soil microorganisms were isolated from the rhizosphere soil of *Panax notoginseng* stored at 4°C using a culture-isolation method. Fungi were isolated using Bengal Red and PDA media, while bacteria were isolated using LB, NA, R2A, and modified Gao's No. 1 media (Wang et al., 2020; van der Linde et al., 1999; Lin et al., 2012). Following the principles of cultinomy, four media—NA, LB, R2A, and PDA—were selected for the isolation and culture of *Panax notoginseng* rhizosphere soil microorganisms. 1 g of each soil sample stored at 4°C was placed in a 15 mL sterile centrifuge tube, and 9 mL of sterile distilled water was added. The mixture was shaken at 120 rpm for 30 min and then allowed to stand for 2 min to prepare a soil microbial suspension. The soil microbial suspension was diluted to 10⁻¹⁰ with sterile water. 3 10 4 and 10 5100 μL of each culture medium was added to the surface of different solid culture media, spread evenly with a spreader, and incubated in a 28°C incubator. Single colonies were picked from the corresponding plates at different incubation times (3-7 days) and purified on NA (bacteria) / PDA (fungi) medium. After three purifications, when no contaminating bacteria appeared, single colonies were picked, preserved, and sequenced. Fungi were amplified and sequenced using ITS (Guo Penghao et al., 2012), and bacteria were amplified and sequenced using 16S rDNA (Cai et al., 2012). The sequencing results were compared using BLAST in the NCBI database (https: / / www.ncbi.nlm.nih.gov / ).

[0039] A microorganism was isolated, and the streak isolation photo is shown below. Figure 1 As shown, the 16S sequence of this bacterium was determined, and after alignment on the NCBI platform, a phylogenetic tree was constructed, as follows. Figure 2 As shown, the bacterium was identified as *Sphingosine Box Bacteria*. Sphingopyxis sp. It was named Sphingosine Box Bacterium SPX122, with accession number CGMCC No.31092.

[0040] Furthermore, the ability to produce β-glucosidase was identified. Aescin is a white needle-like crystal that is hydrolyzed by β-glucosidase produced by microbial metabolism, yielding aescin and glucose. Aescin reacts with iron ions in the culture medium to form a black substance. The experimental results are shown below. Figure 3 This indicates that *Sphingosine monocytogenes* SPX122 can produce β-glucosidase, and CK is the sterile water control group.

[0041] Example 2: Inhibition of pathogens by *Sphingosine Boxerella sphingolipidae* SPX122 on crude saponin plates. This embodiment observed the inhibitory effect of *Sphingosine Trichophyton mentagrophytes* SPX122 on root rot pathogens on plates with different concentrations of crude saponins. The test results are as follows: Figure 4 As shown, the pathogenic bacteria LD ( Fusarium solani The colony radius was significantly inhibited on plates with different concentrations of crude saponin, and the inhibitory effect increased with increasing crude saponin concentration. Co-culture experiments of *Sphingosine Boxerella* SPX122 and *LD* showed that SPX122 had a strong antagonistic effect on LD, and the colony diameter decreased significantly with increasing crude saponin concentration, indicating that SPX122's inhibitory effect on LD increased.

[0042] To investigate the degradation effect of Sphingosine Box Bacterium SPX122 on crude saponins, an experiment was also conducted using crude saponins as the sole carbon source. The results are as follows: Figure 4 As shown, crude saponins significantly promoted the growth of Sphingosine Trichophyton spp. SPX122, with CK being the sterile water control group.

[0043] Example 3: Effects of crude saponins on the growth and biofilm formation of Sphingosine Box Bacteria SPX122 In this embodiment, *Sphingosine Boxerella sphingosine* SPX122 was cultured in a medium with crude saponins as the sole carbon source. *Sphingosine Boxerella sphingosine* SPX122 was cultured in LB medium, and the OD590 value was measured using a microplate reader. The medium was diluted to approximately 0.4, and 100 μL of the bacterial culture was added to 200 mL of liquid medium with crude Panax notoginseng saponins as the sole carbon source (10 mg / L). A control group without added bacterial culture was used. The plates were incubated on a shaker (28℃, 150 r / min). Every 3 hours, 200 μL of the culture was transferred to 96-well plates, and the OD600 was measured at 600 nm using a microplate reader. Bacterial growth curves were plotted. Simultaneously, the effect of crude saponins on bacterial biofilm was determined using the crystal violet method (Wang Lijun et al., 2019).

[0044] Bacterial growth curves as follows Figure 5 As shown, with prolonged culture time, the bacterial strain grew, and the OD value of the bacterial solution increased, indicating that crude saponins promoted the growth of *Sphingosine Box Bacteria* SPX122. This suggests that *Sphingosine Box Bacteria* SPX122 can tolerate crude saponins, and that crude saponins from *Panax notoginseng* can promote the vegetative growth of the strain, allowing it to occupy a larger ecological niche in the *Panax notoginseng* root system.

[0045] Furthermore, *Sphingosine Trichophyton* SPX122 was inoculated into a 96-well plate with a culture medium containing crude saponins as the sole carbon source. After incubation at 28°C for 52 hours, the biofilm content was determined using the crystal violet method, and the OD490 value was read. Figure 5 As shown, the biofilm amount of *Sphingosine Boxerella sphingosine* SPX122 was significantly higher than that of CK (0 g / L, sterile water), indicating that crude saponins promoted the biofilm formation of *Sphingosine Boxerella sphingosine* SPX122 and enhanced its colonization in the roots of Panax notoginseng.

[0046] Example 4: Effect of Sphingosine Box Bacterium SPX122 on the growth of Panax notoginseng A certain amount of crude Panax notoginseng saponins was added to a small basin containing 1 kg of forest soil and mixed thoroughly to achieve a saponin content of 10 ppm in the soil, simulating the total saponin concentration in three-year-old Panax notoginseng soil (Wang Luotao, 2020). The mixture was left to stand for 3 days to obtain exogenously added crude Panax notoginseng saponin soil. Soil from continuous cropping (where Panax notoginseng had been grown for three years in a greenhouse in Xundian) was mixed with treated unplanted forest soil at a 1:1 ratio and left to stand for 3 days to obtain continuous cropping soil.

[0047] Select healthy Panax notoginseng seeds, surface disinfect them with 1.5% NaClO for 5 minutes, rinse them three times with sterile water, and blot dry with sterile filter paper. Use 10 seeds per pot, with 10 replicates per treatment. In the laboratory, NA liquid culture medium of *Sphingosine Box Bacteria* SPX122 was prepared and cultured by shaking until the bacterial OD value was approximately 0.4. After complete germination, each pot was irrigated with 50 mL of culture medium (culture medium = 1 part 5 mL bacterial suspension : 9 parts sterile water). Sterile water was used as the control group (CK). The treatment groups included four groups, as follows: Forest soil from unplanted *Panax notoginseng* was collected and divided into two portions. One portion was sterilized by steam at 100℃ for 4 hours and then allowed to cool (referred to as sterilized); the other portion was not sterilized (referred to as unsterilized). Both soil portions were further treated. One portion was treated with crude saponins at a concentration of 10 mg / kg, mixed thoroughly, and then potted (15 cm diameter pots, approximately 1 kg of soil per pot) (referred to as saponin). The other portion was treated with a mixture of 50% *Panax notoginseng* continuously cropped soil (soil from *Panax notoginseng* continuously planted for three years) and 50% of the above-treated forest soil (sterilized / unsterilized), mixed thoroughly, and then potted (15 cm diameter pots, approximately 1 kg of soil per pot) (referred to as 50% continuously cropped soil). *Panax notoginseng* seeds were then planted. After the potted plants were planted, they were randomly placed in the greenhouse at the Xundian base and managed routinely. They were irrigated with nutrient solution once a week for two consecutive months. The survival rate of seedlings was then recorded. After the Panax notoginseng continued to grow for another two months, the potted Panax notoginseng were sampled, cleaned, sterilized at 115℃ for 30 minutes, dried at 60℃ for 3 days, weighed, and the dry weight of each plant was calculated.

[0048] The seedling survival rate results of the indoor pot experiment are as follows: Figure 6 As shown, *Sphingosine Boxerella sphingosine* SPX122 significantly improved the survival rate of potted plants in all four treatments, with better results in continuously cropped soil and unsterilized soil. This indicates that *Sphingosine Boxerella sphingosine* SPX122 can promote the growth of Panax notoginseng in soil containing initial microorganisms, especially when saponins are present in the soil. This suggests that *Sphingosine Boxerella sphingosine* SPX122 can not only degrade saponins, but may also perform more of the function of recruiting beneficial microorganisms.

[0049] The results of the single-plant dry weight of the indoor potted plant experiment are as follows: Figure 7 As shown, Sphingosine Box Bacterium SPX122 significantly increased the dry weight of individual plants in all four treatments. Sphingosine Box Bacterium SPX122 can significantly promote the accumulation of Panax notoginseng dry matter, especially when the continuous cropping is heavy.

[0050] Example 5: Study on the degradation of crude saponins in culture medium by *Sphingosine Boxer* SPX122 500 μL of NA culture medium of *Sphingosine Boxerella* SPX122 was added to 50 mL of a single carbon source culture medium containing 1 g / L crude saponins. After incubation on a shaker at room temperature for 72 h, 2 mL of the liquid was taken and freeze-dried for 48 h (-40℃, 0.12 kPa). An equal volume of 75% chromatographic methanol was added to the freeze-dried material to dissolve it, and the mixture was thoroughly mixed by pipetting. 1 mL of the methanol solution was placed in a 1.5 mL centrifuge tube and centrifuged at 14000 rpm for 15 min. The supernatant was collected and analyzed by HPLC. The contents of 12 saponins (R1, Rg1, Re, Rb1, Rd, Rf, Rb2, Rh1, Rc, Rh2, Rb3, and Rg3) in the crude saponins were determined by HPLC. The HPLC detection steps are as follows: (1) HPLC detection conditions were as follows: column (4.6 mm × 150 mm, 4 µm, Agilent Poroshell 120EC-C18); mobile phase A: acetonitrile; mobile phase B: water; flow rate 1.0 mL / min; column temperature 30℃; detection wavelength 203 nm; injection volume 10 µL. Elution gradient: 0-20 min, 82% B; 20-40 min, 82-57% B; 40-48 min, 57-45% B; 48-54 min, 45% B; 54-56 min, 45-5% B; 56-71 min, 5% B; 71-72 min, 5-82% B; 72-74 min, 82% B. Under these conditions, baseline separation of 12 major saponins could be achieved. (2) Prepare standard solutions of 12 saponins. Accurately weigh the corresponding standard into a 2 mL volumetric flask and dilute to volume. Dilute the solution with methanol in a certain proportion to prepare standard solutions of 5 ppm, 10 ppm, 25 ppm, 50 ppm, 100 ppm, 200 ppm and 500 ppm. Filter the obtained standard solutions through a 0.22 μm filter membrane for later use. (3) Determination of linearity. HPLC was used for detection, and a standard curve was plotted with the peak area (Y) as the ordinate and the sample concentration (X) as the abscissa.

[0051] (4) Weigh 0.2 g of crude saponin, dissolve it in 75% chromatographic methanol, sonicate for 30 min, centrifuge at 10000 rpm for 10 min, filter the solution through a 0.22 μm filter membrane, detect it by HPLC, and determine the concentration of each monomer saponin in the crude saponin according to the standard curve. Calculate the saponin conversion rate based on the concentration of each monomer saponin in the uninoculated bacteria.

[0052] Test results are as follows Figure 8As shown, the saponin content in the solution changed after inoculation with *Sphingosine Boxerella sphingosine* SPX122, indicating that *Sphingosine Boxerella sphingosine* SPX122 significantly degraded the crude saponins of Panax notoginseng. The total saponin content was significantly lower than that of the blank treatment. Detailed results are as follows: Among *Sphingosine Boxerella sphingosine* SPX122, the average degradation rates of Re (107%), Rc (95.68%), Rg1 (92.33%), Rf (53.06%), Rh1 (50.62%), Rd (14.52%), Rb1 (12.55%), R1 (10.83%), and Rb2 (4.79%) were above 10%. Rg2 was also generated (89.23%). Furthermore, two new saponins were generated in the *Sphingosine Boxerella* SPX122 treatment group: Rh2 (concentration of 0.09 mg / g) and Rb3 (concentration of 1.48 mg / g). Comprehensive analysis results show that *Sphingosine Boxerella* SPX122 can not only degrade saponins but also generate new saponins.

[0053] Example 6: Study on the effects of Sphingosine Box Bacterium SPX122 on saponin degradation in continuously cropped soil and on the emergence rate of Panax notoginseng seedlings under forest cover. To investigate the role of *Sphingosine Boxerella sphingosine* SPX122 in soil, a study on soil saponin degradation was conducted. Soil under trees that had been continuously cropped with *Panax notoginseng* for three years was selected for bacterial treatment. The detailed treatment process was as follows: A liquid culture of *Sphingosine Boxerella sphingosine* SPX122 was prepared in the laboratory and cultured by shaking until the bacterial OD value was approximately 0.4. Then, the culture was prepared at a concentration of 200 mL / m³. 3 The bacterial count was used to irrigate the soil under the continuous forest. After irrigation, the treated soil was mixed evenly. The treatment was carried out once a week for 8 consecutive weeks, for a total of two months. Before each treatment, soil samples were taken for quantitative analysis of soil saponins to calculate the saponin degradation rate.

[0054] The results are as follows Figure 9As shown (CK represents the sterile water treatment group, 3-3 represents the Sphingosine Boxerella SPX122 treatment group), Sphingosine Boxerella SPX122 degraded all five major saponins in the soil after continuous cropping of Panax notoginseng to varying degrees. Specifically, in the degradation of R1, Sphingosine Boxerella SPX122 showed a significantly higher degradation effect than CK in the later stages. In the degradation of Rg1, the degradation trend was similar to R1, but the phenomenon of Sphingosine Boxerella SPX122 treatment significantly outperforming CK began in the second week after treatment, earlier than R1 (4-5 weeks). In the degradation of Rb1, Sphingosine Boxerella SPX122... The degradation effect of the treated bacteria was significantly higher than that of the control (CK). In the degradation of Rd, the degradation effect of the treated bacteria SPX122 was significantly higher than that of the control, and this difference was more obvious in the early stage of treatment. In the degradation of Re, the treatment of SPX122 was significantly higher than that of the control in the later stage. The results of the five saponins showed that SPX122 was significantly higher than the control after a period of treatment. The soil saponin degradation effect clearly demonstrated the ability of SPX122 to degrade saponins, providing important evidence for the study of the degradation ability of SPX122.

[0055] Furthermore, the soil treated for two months was used to plant one-year-old Panax notoginseng twigs and Panax notoginseng seeds under the forest canopy to study the germination of Panax notoginseng seedlings under the forest canopy after treatment with Sphingosine monocytogenes SPX122. The results showed that ( Figure 10 Treatment with *Sphingosine Boxerella salina* SPX122 significantly improved the germination rate of two-year-old *Panax notoginseng* seedlings under forest cover. In the germination of one-year-old *Panax notoginseng*, the SPX122 treatment group was slightly higher than the control group (CK was the sterile water control group), but the difference was not statistically significant. Therefore, in the forest understory environment, treatment with *Sphingosine Boxerella salina* SPX122 can significantly improve the germination rate of both one-year-old and two-year-old *Panax notoginseng*, with a more significant effect on promoting the germination of two-year-old *Panax notoginseng*, indicating that *Sphingosine Boxerella salina* SPX122 has greater application potential in actual production.

[0056] Example 7: Degradation effect of Sphingosine Box Bacterium SPX122 on phenolic acids Numerous studies have reported that the high adaptability of Sphingopyxis bacteria to adverse environments gives them a significant advantage in environmental remediation, and they are widely used to degrade organic compounds. Previous studies have shown that strains of this genus can degrade chlorpyrifos, polyethylene glycol, microcystin, 1,2,3-trichloropropane, etc. However, there are few studies on the degradation of plant autotoxins by this bacterium. In the growth of Panax notoginseng, autotoxins include saponins and phenolic acids. This example tests the degradation effect of Sphingopyxis SPX122 on phenolic acids.

[0057] Soil was treated with *Sphingosine mononitrate bacteria* SPX122 for two consecutive months, with sterile water treatment serving as the control group (CK). The bacteria were irrigated weekly, with an OD value of 0.6 and a volume of 50 ml per treatment. The initial and final concentrations of four phenolic acids in the soil were determined using absolute quantitative methods. The degradation effects of the bacteria on the four main phenolic acids in the soil are summarized below. Figure 11 In p-hydroxybenzoic acid, the average degradation rate of the control group (CK) was 5.03%, while the average degradation rate after treatment with *Sphingosine Boxerella salina* SPX122 was 25.62%. In ferulic acid, the average degradation rate of CK during natural degradation was 13.50%, while the average degradation rate after treatment with *Sphingosine Boxerella salina* SPX122 was 12.67%, but there was no significant difference between the two treatments. In p-coumaric acid, the average degradation rate of CK was 2.40%, while the average degradation rate after treatment with *Sphingosine Boxerella salina* SPX122 was 4.76%. In cinnamic acid, the average degradation rate of CK was 1.44%, while the average degradation rate after treatment with *Sphingosine Boxerella salina* SPX122 was 0.99%. Therefore, among the four phenolic acid treatments, the total degradation rate of the four phenolic acids in the soil by CK was 5.02%, while the total degradation rate by *Sphingosine Boxerella salina* SPX122 was 15.04%. Comprehensive analysis showed that Sphingosine Box Bacterium SPX122 can significantly degrade phenolic acids in soil, but the degradation ability varies for different phenolic acids. Sphingosine Box Bacterium SPX122 has a stronger degradation ability for total phenolic acids.

[0058] Example 8: Effects of Sphingosine Box Bacterium SPX122 on Plant Growth 1. Effects of Sphingosine Trichophyton Species SPX122 on Lettuce Growth To explore the effects of Sphingosine Box Bacterium SPX122 treatment on plant growth, lettuce, which is relatively sensitive to phenolic acids, was selected for growth measurement. Lettuce seeds were planted in soil that had been treated with Sphingosine Box Bacterium SPX122 (treatment method as in Example 7) for two months. The survival rate, fresh weight per plant, dry weight per plant and root growth of lettuce were recorded.

[0059] The results show that ( Figure 12 The treatment with *Sphingosine Trichophyton* SPX122 did not significantly affect the survival rate of lettuce seedlings. However, SPX122 treatment significantly increased the fresh weight and dry weight per lettuce plant. SPX122 treatment also increased root length, root surface area, and root volume, but there was no significant difference compared to the control (sterile water treatment group). Therefore, soil treatment with *Sphingosine Trichophyton* SPX122 promoted lettuce growth and dry matter accumulation.

[0060] 2. Effects of Sphingosine Trichophyton spp. SPX122 on tomato growth Studies have shown that phenolic acids affect the growth of tomato seedlings. Therefore, tomatoes were selected for growth measurement. Tomato seeds were planted in soil that had been treated with Sphingomyelin-Styrax sp. SPX122 (treatment method as in Example 7) for two months. The survival rate of tomato seedlings, fresh weight of single plants, dry weight of single plants and root growth were recorded.

[0061] The results show that ( Figure 13 Sphingosine trichophyton (SPX122) significantly increased the seedling survival rate of tomatoes. The fresh and dry weight of individual plants treated with SPX122 were slightly higher than the control (CK), but the difference was not statistically significant. SPX122 treatment increased the root length, root diameter, root surface area, and root volume of lettuce, but there were no significant differences compared to the CK. Therefore, soil treatment with SPX122 promoted the growth and dry matter accumulation of tomatoes.

[0062] 3. Effects of Sphingosine Trichophyton spp. SPX122 on strawberry growth Studies have shown that the accumulation of phenolic acids in the soil is an important cause of continuous cropping obstacles in strawberries. In order to study the degradation of phenolic acids by Sphingosine Box Bacterium SPX122, strawberries were selected for pot experimentation. Strawberry seedlings were transplanted into the soil treated (treatment method is the same as in Example 7) for two months. After the growth differences were observed, the survival rate, fresh weight of single plants, dry weight of single plants and growth of new roots were counted.

[0063] The results show that ( Figure 14 Sphingosine-containing fungi SPX122 significantly increased the survival rate of strawberry seedlings; Sphingosine-containing fungi SPX122 significantly increased the fresh weight and dry weight of individual strawberry plants; however, there were no significant differences in root indicators. Therefore, Sphingosine-containing fungi SPX122 promoted the survival rate of strawberry seedlings and the growth of the aboveground parts.

[0064] 4. Effects of Sphingosine Trichophyton Species SPX122 on Soybean Growth Studies have shown that the accumulation of phenolic acids in the soil affects the growth of soybean seedlings. Therefore, soybeans were selected for pot culture verification. Soybean seeds were planted in soil treated (treatment method as in Example 7) for two months. After differences in growth were observed, the survival rate, fresh weight per plant, dry weight per plant, and new root growth were statistically analyzed. The results showed ( Figure 15 The survival rate of soybeans treated with *Sphingosine Boxerella salina* SPX122 was not significantly different from that of the control (CK). SPX122 treatment significantly increased the aboveground fresh weight, dry weight, and underground fresh and dry weight of individual soybean plants. SPX122 treatment also significantly increased the growth of root surface area, root diameter, and root volume. Therefore, *Sphingosine Boxerella salina* SPX122 promotes soybean growth.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A strain of Sphingosine Box Bacteria ( Sphingopyxis sp. ), characterized in that, It is sphingosine mononitrate fungus SPX122, with accession number CGMCC No.31092.

2. A microbial inoculant, characterized in that, It contains the Sphingosine Box Bacterium SPX122 as described in claim 1.

3. The microbial agent according to claim 2, characterized in that, The microbial agent is a freeze-dried fermentation broth of Sphingosine Trichophyton spp. SPX122.

4. The microbial agent according to claim 3, characterized in that, The freeze-dried fermentation broth also includes a freeze-drying protectant.

5. The use of the sphingosine box bacteria of claim 1 or the microbial agent of any one of claims 2 to 4 in the degradation of Re, Rc, Rg1, Rf, Rh1, Rd, Rb1, R1 or Rb2 saponins.

6. The application of the Sphingosine Box Bacterium as described in claim 1 or the microbial agent as described in any one of claims 2 to 4 in improving the survival rate of Panax notoginseng seedlings or the dry weight of Panax notoginseng.

7. The application of the sphingosine-containing bacteria of claim 1 or the microbial agent of any one of claims 2 to 4 in the degradation of phenolic acids; wherein the phenolic acid is p-hydroxybenzoic acid or coumaric acid.

8. The application of the Sphingosine Box Bacterium of claim 1 or the microbial agent of any one of claims 2 to 4 in promoting plant growth or dry matter accumulation; wherein the plant is lettuce, tomato, strawberry or soybean.

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