Bacillus sp.50-2 with salt-tolerant and growth-promoting functions and application of bacillus sp.50-2 in degradation of antibiotics

Abstract

The invention discloses bacillus sp.50-2 with salt-tolerant and growth-promoting functions and an application of the bacillus sp.50-2 in the aspect of degrading antibiotics. The Bacillus sp.50-2 provided by the invention is separated from an experimental field in which penicillin mushroom dreg organic fertilizer is applied in a pharmaceutical factory, the strain has the characteristics of high temperature resistance and saline-alkaline tolerance, has the capability of generating various growth promoting factors, and has the degradation rate of 99.80% for high-concentration (1000mg / L) penicillin within 48 hours, and a microbial agent prepared from the strain can significantly improve the growth of cotton, so that the cotton quality is improved, and the cotton quality is improved. The plant height of the cotton is increased by 32.31%, the root length is increased by 41%, the emergence rate is increased by 100%, and the fresh weight is increased by 74.5%; the microbial agent can improve the salinity resistance of cotton, the germination rate of the cotton is increased by 50% under salt stress, the salt-tolerant growth-promoting bacillus strain provides an excellent strain resource for saline-alkali farmland soil antibiotic pollution remediation, and the microbial agent has high agricultural application prospects and economic value.

Description

Technical Field

[0001] The present invention relates to the technical field of microorganisms and biodegradation, and particularly to a strain with salt tolerance and growth promotion functions and its application in degrading antibiotics. Background Art

[0002] As a highly effective broad-spectrum antibiotic, penicillin has played a huge role in the treatment of bacterial infections and has been widely used in medical treatment, animal husbandry, aquaculture, and agricultural production. Currently, the global consumption of penicillin is huge and shows an increasing trend year by year. However, due to the widespread use of penicillin and the lack of effective supervision and disposal measures, a large amount of penicillin enters the environment through medical wastewater, emissions from livestock and poultry farms, and production wastewater from antibiotic pharmaceutical companies, causing serious environmental pollution. Penicillin pollution has obvious ecological toxic and side effects. It not only inhibits the growth of beneficial microorganisms in the soil, slows down the decomposition of organic matter and the nutrient cycling process, reduces soil fertility, and destroys the ecological balance of the soil, but also restricts plant growth, reduces yields, and degrades quality. Penicillin pollution not only harms the environment but also affects the health of animals and humans through the food chain. Long-term exposure to an environment with penicillin residues may lead to the generation of drug-resistant bacteria in the human body, reduce the therapeutic effect of antibiotics, and even trigger the emergence of "super bacteria", seriously threatening public health safety. Therefore, the development of efficient and environmentally friendly antibiotic degradation technologies has become one of the important research directions in current environmental governance.

[0003] The natural attenuation of toxic and harmful organic pollutants in the environment mainly depends on the metabolic actions of related microorganisms. Microbial degradation technology is considered the most effective means for treating antibiotic pollution due to its advantages such as low cost, environmental friendliness, and strong sustainability. Currently, domestic and foreign scholars have made certain progress in the isolation and screening of penicillin-degrading bacteria, and have reported various bacteria with the ability to degrade penicillin, such as Pseudomonas spp., Bacillus spp., Streptomyces spp., etc. These microorganisms can decompose penicillin antibiotics through mechanisms such as secreting penicillinase and show a certain degradation efficiency under laboratory conditions. However, existing strains still face many challenges in practical applications, such as poor adaptability to environmental conditions, limited degradation efficiency, and reduced activity in salinized or extreme environments, which severely limit their engineering applications in fields such as the remediation of antibiotic-polluted soils and water purification.

[0004] Soil salinization widely exists in the northwest region. Coupled with the current serious problem of antibiotic residues in surrounding farmland caused by the application of livestock and poultry manure and mushroom residue organic fertilizers in large numbers of farms, these pose higher requirements for the survival and functions of microorganisms. Therefore, screening out penicillin-degrading strains with salt tolerance, strong environmental adaptability, and good growth-promoting functions in such special ecological environments can not only effectively improve the efficiency of antibiotic pollution treatment but also play a positive role in the sustainable development of agriculture. Therefore, exploring strains with high-efficiency penicillin degradation and salt tolerance and growth-promoting functions is of great significance for improving the microecology of saline-alkali soil, enhancing the stress resistance of crops, and for ecological restoration and the development of green agriculture. Summary of the Invention

[0005] Regarding the problems that the growth of beneficial microorganisms in the soil is inhibited due to penicillin pollution, the soil fertility is reduced, the ecological balance of the soil is damaged, and it leads to restricted plant growth, decreased yield, and deteriorated quality. And microbial degradation is the most effective way to solve penicillin pollution, but there are still few strains with high-efficiency penicillin degradation ability, strong environmental adaptability, and good salt tolerance and growth-promoting functions. The present invention provides a Bacillus strain with high-efficiency penicillin degradation ability and salt tolerance and growth-promoting functions. A Bacillus sp. 50-2 strain was isolated from the experimental field where the pharmaceutical factory applied penicillin residue organic fertilizer. This strain has the characteristics of high temperature and salt-alkali tolerance and the ability to produce various growth-promoting factors. The degradation rate of high-concentration (1000 mg / L) penicillin within 48 hours is as high as 99.80%. The microbial inoculant prepared using the Bacillus sp. 50-2 strain can significantly improve the growth of cotton. The plant height of cotton increased by 32.31%, the root length increased by 41%, the emergence rate increased by 100%, and the fresh weight increased by 74.5% (relative to CK); this microbial inoculant can improve the salinity resistance of cotton. Under salt stress, the germination rate of cotton increased by 50% (relative to CK). The above results all show that the microbial inoculant prepared from the salt-tolerant and growth-promoting Bacillus sp. 50-2 strain provided by the present invention has a significant promoting effect on plant growth and at the same time has strong stress resistance. This salt-tolerant and growth-promoting strain provides excellent bacterial resources for the remediation of antibiotic pollution in saline-alkali farmland soil and has high agricultural application prospects and economic value.

[0006] To achieve the above technical effects, the present invention is realized through the following technical solutions.

[0007] The Bacillus sp. strain 50-2 provided by the present invention was isolated from a soil sample in an experimental field where penicillin bacterial residue organic fertilizer was applied in a pharmaceutical factory. Through phylogenetic analysis of the 16S rRNA sequence, the strain Bacillus sp. 50-2 belongs to the genus Bacillus. After gene sequencing of this strain, the obtained sequence was trimmed and spliced by Seqman software and then uploaded to the NCBI website for BLAST alignment analysis. The similarity between the 16S rRNA sequence of Bacillus sp. 50-2 and Bacillus albus (NR_157729) is up to 98.20%. Sequences with higher homology were selected to construct a 16S rRNA phylogenetic tree, and it can be seen that the strain Bacillus sp. 50-2 is most closely related to Bacillus albus (NR_157729) and is in the same branch. Through a series of polyphasic taxonomic identifications, it can be determined that the strain Bacillus sp. 50-2 is a species of the genus Bacillus. This strain has been deposited in the China Center for Type Culture Collection (CCTCC), address: Wuhan University, Wuhan, China, postal code: 430072, deposit date: November 18, 2024, deposit number: CCTCC No: M20242591.

[0008] In the present invention, the gene sequence of the Bacillus sp. strain 50-2 is shown in SEQ ID NO:1.

[0009] Preferably, the culture conditions of the Bacillus sp. strain 50-2 are: the growth temperature range is 20 - 50 °C, and the optimum growth temperature is 30 °C; the growth pH range is pH 5 - 10, the optimal pH is 7.0, and it can tolerate 1 - 8% NaCl.

[0010] Furthermore, the present application also provides the fermentation broth of the Bacillus sp. strain 50-2.

[0011] Furthermore, the present application also provides the application of the Bacillus sp. strain 50-2 or the fermentation broth in degrading penicillin.

[0012] Furthermore, the present application also provides the application of the Bacillus sp. strain 50-2 or the fermentation broth in preparing a penicillin-degrading preparation.

[0013] Furthermore, the present application also provides the application of the Bacillus sp. strain 50-2 or the fermentation broth in promoting salt tolerance and growth of cotton.

[0014] Furthermore, the present application also provides a method for degrading penicillin, which uses the Bacillus sp. 50-2 or the bacterial solution described above to treat penicillin.

[0015] The fermentation of the Bacillus sp. 50-2 uses NB medium.

[0016] The fermentation treatment conditions of the Bacillus sp. 50-2 are 30°C.

[0017] Through the above technical solutions, the present invention obtains the following technical effects:

[0018] (1) The Bacillus sp. 50-2 strain provided by the present invention has a certain ability to degrade penicillin. By using a high-performance liquid chromatograph (Agilent 1260) to explore the penicillin degradation ability of the Bacillus sp. 50-2 strain, it can be known that the Bacillus sp. 50-2 strain has a degradation rate of up to 99.80% for 1000 mg / L penicillin within 48 hours. This shows that the Bacillus sp. 50-2 strain has a significant degradation effect on high-concentration penicillin.

[0019] (2) The Bacillus sp. 50-2 strain provided by the present invention has the ability to promote plant growth. Using the microbial inoculant prepared from the Bacillus sp. 50-2 strain to treat cotton seeds, the plant height of cotton increased by 32.31%, the root length increased by 41%, the emergence rate increased by 100%, and the fresh weight increased by 74.5% (relative to CK). This microbial inoculant can improve the salinity resistance of plants. Under salt stress, the germination rate of cotton increased by 50% (relative to CK), indicating that the Bacillus sp. 50-2 strain inoculant can significantly improve the salinity resistance of plants while promoting plant growth, and has broad development and application prospects in plant salt tolerance and growth promotion, and can be widely used in the agricultural industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Shown is the phylogenetic evolution tree of the Bacillus sp. 50-2 strain based on the 16S rRNA gene sequence.

[0021] Figure 2 Shown are the colony morphology and Gram staining micrograph of the Bacillus sp. 50-2 strain.

[0022] Among them, Figure a shows the colony morphology on the medium; Figure b shows the Gram staining micrograph of the strain.

[0023] Figure 3It shows a schematic diagram of the IAA production ability of Bacillus sp. strain 50-2.

[0024] Figure 4 It shows a schematic diagram of the penicillin degradation ability test results of Bacillus sp. strain 50-2.

[0025] Figure 5 It shows a comparative photo of the state of the salt tolerance germination experiment of cotton seeds soaked with the microbial inoculum of Bacillus sp. strain 50-2.

[0026] Figure 6 It shows a comparative photo of the growth of cotton in saline-alkali soil with the microbial inoculum of Bacillus sp. strain 50-2.

[0027] Figure 7 It shows the effect of the microbial inoculum of Bacillus sp. strain 50-2 on the growth of cotton in saline-alkali soil. Detailed implementation mode

[0028] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0029] Nutrient agar (NA) medium: peptone 10 g, beef extract powder 3 g, NaCl 5 g, agar powder 15 g, distilled water 1 L, pH value 7.3 ± 0.2.

[0030] Penicillin-degrading bacteria screening medium: Add penicillin stock solution to the sterilized nutrient agar (NA) medium to make the antibiotic concentration 10, 100, 1000 μg·mL -1 .

[0031] Nutrient broth (NB) medium: peptone 10.0 g, beef powder 3.0 g, sodium chloride 5.0 g, distilled water 1 L, pH value 7.3 ± 0.2.

[0032] Antibiotic enrichment medium: Add penicillin to the sterilized nutrient broth (NB) liquid medium to make the antibiotic concentration 50 μg·mL -1 .

[0033] LB nutrient agar medium, used for the isolation and purification of penicillin-degrading bacteria. Main components (g / L): tryptone 10g, yeast extract 5g, NaCl 10g, agar 15g, distilled water 1L, pH value 7.0 ± 0.2. The corresponding volume of antibiotic stock solution should be added to the LB medium containing antibiotics when it is cooled to about 60 °C.

[0034] Tween-20 medium, used for screening bacterial lipase. Ingredients: peptone 10g, NaCl 5g, CaCl2·H2O 0.1g, Tween-20 10g, agar 15g, distilled water 1L, pH value 7.2 ± 0.2.

[0035] Amylase screening medium, ingredients: beef extract 5g, NaCl 5g, soluble starch 5g, agar 20g, distilled water 1000mL, pH 7.2.

[0036] Protease screening medium, ingredients: skim milk powder 50g, agar 12g, distilled water 1000mL, pH 7.2 ± 0.2.

[0037] PKO medium, organic phosphorus medium, Ashby medium, potassium-solubilizing bacteria medium, CAS medium, King's B medium, etc. were all purchased from Haibo Biotechnology Co., Ltd., Qingdao High-Tech Industrial Park.

[0038] The stock solutions used in the present invention are as follows:

[0039] Penicillin stock solution: Weigh 1g of penicillin drug, dissolve it in 100mL of sterile water to prepare a penicillin stock solution of 10000 μg·mL -1 , and dispense it into brown reagent bottles, and store it in the dark at below -20 °C (avoid repeated freezing and thawing, validity period 1 month).

[0040] In the following examples of this application, "Bacillus sp.50-2" is abbreviated as "Bacillus sp.50-2" or "strain 50-2" in the following example part.

[0041] The following examples use conventional instrument equipment in the art. The experimental methods without specific conditions indicated in the following examples usually follow conventional conditions or the conditions recommended by the manufacturer. Various raw materials used in the following examples are all conventional commercially available products with conventional specifications in the art unless otherwise stated.

[0042] Example 1: Isolation, screening and identification of Bacillus sp.50-2 strain

[0043] (1) Isolation and screening

[0044] Soil samples were collected from an experimental field where penicillin residue organic fertilizer was applied in a pharmaceutical factory. 10 g of soil was placed in a 250 mL conical flask, and 90 mL of sterile normal saline was added. The mixture was cultured in a constant temperature shaker (30 °C, 150 rpm) for 2 h to obtain mixture A. 1 mL of supernatant A was transferred to a test tube containing 9 mL of sterile water. After shaking and mixing evenly, 1 mL of the supernatant was taken from the test tube and added to another test tube containing 9 mL of sterile water. This dilution was repeated until the dilution reached 10 -5 、10 -6 times. 100 μL was taken and spread on the penicillin-degrading bacteria screening medium containing penicillin concentrations of 10, 100, and 1000 μg·mL -1 . Three parallel samples were prepared for each dilution factor and placed in a constant temperature incubator at 30 °C for 96 h. During this period, the colony growth on each screening medium was observed.

[0045] Colonies with different colors and morphologies were picked from the penicillin-degrading bacteria screening medium and repeatedly streaked for isolation until colonies with a single morphology were obtained under a microscope. The corresponding single colonies were picked and inoculated into a penicillin enrichment medium containing 50 μg·mL -1 penicillin (the penicillin enrichment medium was prepared by adding a penicillin stock solution to a sterilized nutrient broth (NB) liquid medium to make the antibiotic concentration 50 μg·mL -1 . After culturing at 30 °C and 150 rpm for 2 d, it was inoculated into an NB medium containing 250 g·mL -1 penicillin at an inoculation amount of 1%. It was continuously transferred 4 times, and the concentration of penicillin was gradually increased to domesticate the strain. Finally, the concentration was increased to 1000 μg·mL -1 (50, 250, 500, 1000 μg·mL -1 ). Then, 100 μL of the fermentation broth was evenly spread on the MSM agar medium containing 1000 μg·mL -1 penicillin and cultured at 30 °C for 3 - 5 d. Single colonies were picked for isolation and purification, and the purified strains were transferred to the slant of the NA medium for storage for later use.

[0046] The penicillin degradation ability of the selected strains was investigated using a high-performance liquid chromatograph (Agilent 1260) to select the best highly efficient degradation strains for subsequent research. The selected strains were inoculated into an NB medium containing 1000 μg·mL -1 penicillin at an inoculation amount of 2% and cultured in an oscillator at 30 °C and 170 r / min for 48 h. The degradation rate was determined by high-performance liquid chromatography (HPLC), and the highly efficient penicillin-degrading bacterium Bacillus sp. 50-2 was obtained.

[0047] (II) Molecular identification of Bacillus sp. 50-2 strain

[0048] Using colony PCR technology, the penicillin highly degrading strains screened were identified. The PCR reaction conditions were as follows: 95°C for 5 min, 94°C for 30 s, 54°C for 30 s, 72°C for 30 s (cycle 30x), 72°C for 7 min, and stored at 4°C. After detection by agarose gel electrophoresis, it was sent to Sangon Biotech (Shanghai) for sequencing. The returned sequences were trimmed and spliced using Seqman software, and the processed sequences were uploaded to the NCBI database for sequence alignment. After identification, the sequenced length of the strain Bacillus sp. 50-2 was 1455 bp, and the sequencing result was shown in SEQ ID No: 1. It belongs to the genus Bacillus and has the highest similarity of 98.20% with Bacillus albus (NR_157729). A phylogenetic tree was constructed using the Neighbor-joining method with MEGA 11.0 software (bootstrap 1000 times), and the results were shown in the appendix Figure 1 as shown.

[0049] Example 2: Polyphasic taxonomic identification of Bacillus sp. 50-2 strain

[0050] (I) Colony morphology and physiological and biochemical determination

[0051] It was experimentally confirmed that the strain Bacillus sp. 50-2 was a Gram-positive bacterium, motile, short rod-shaped, capable of forming spores, light yellow. The colony morphology was shown in the appendix Figure 2 . The growth temperature range of the strain was 20-50°C, and the optimum growth temperature was 30°C; the growth pH range was pH 5-10, and the optimal pH was 7.0. It could tolerate 1-8% NaCl.

[0052] (II) Functional characteristics of Bacillus sp. 50-2 strain

[0053] 1. Enzyme production characteristics of Bacillus sp. 50-2 strain

[0054] Tween-20, amylase, and protease screening media were used to identify the lipase, amylase, and protease production of the strain Bacillus sp. 50-2. Bacillus sp. 50-2 was inoculated into the corresponding media and cultured at 30°C for 3-7 d. For the lipase and protease screening media, observe whether a clear zone appears on the media. If a clear zone appears, it is positive. After culturing on the amylase screening medium, directly drop iodine solution on the surface of the culture and immediately visually inspect the results. The positive reaction is that the surface of the medium is dark blue and a colorless clear zone appears around the colony. The results were determined according to the above method, and it was found that the amylase of the strain Bacillus sp. 50-2 was positive, while the lipase and protease were negative. The detection results were shown in Table 1.

[0055] Table 1: Enzyme-producing characteristics of Bacillus sp. 50-2

[0056] Enzyme classification Whether positive Lipase - Amylase + Protease -

[0057] 2. Growth-promoting characteristics of Bacillus sp. 50-2

[0058] Spot inoculate Bacillus sp. 50-2 into the media of PKO, organic phosphorus, Ashby, potassium-solubilizing bacteria medium and CAS medium, and incubate at a constant temperature of 30 °C for 3-7 d. Observe whether a hydrolysis zone appears around the colony, and judge the results according to the above method. It is found that Bacillus sp. 50-2 produces clear zones on PKO, organic phosphorus, Ashby, potassium-solubilizing bacteria medium and CAS medium, proving that Bacillus sp. 50-2 can dissolve inorganic phosphorus and organic phosphorus and has the abilities of nitrogen fixation, potassium solubilization and siderophore production. The test results are shown in Table 2.

[0059] Explore the IAA production of Bacillus sp. 50-2 by colorimetry: Inoculate 200 μL of the Bacillus sp. 50-2 bacterial suspension into 2 tubes containing 5 mL of King's B liquid medium respectively. Add 200 mg / L L-tryptophan to one tube of King's B liquid medium and do not add tryptophan to the other tube. Incubate on a shaker at 30 °C and 150 r / min for 3 d, then centrifuge at 4 °C and 5000 r / min for 10 min. Pipette 100 μL of the centrifuged bacterial liquid into a white porcelain plate, and at the same time add an equal volume of Salkowski colorimetric solution (50 mL of 35% HClO4 + 1 mL of 0.5 mol / L FeCl3), mix well, and use the culture solution without inoculated strain as a blank control. Observe the color change after standing at room temperature in the dark for 30 min. The redder the color, the stronger the IAA production ability of the strain. It is found that the Bacillus sp. 50-2 bacterial liquid with tryptophan added is significantly pinker than the Bacillus sp. 50-2 bacterial liquid without tryptophan added. The results show that Bacillus sp. 50-2 has the ability to produce IAA. The results are shown in Figure 2 。

[0060] Table 2: Growth-promoting characteristics of Bacillus sp. 50-2

[0061]

[0062]

[0063] Example 3: Determination of the Penicillin Degrading Ability of Bacillus sp. 50-2 Strain

[0064] Add 5 mL of the prepared penicillin stock solution of 10,000 μg·mL -1 to a conical flask containing 50 mL of NB medium, so that the final concentration of penicillin is 1,000 μg·mL -1 . Inoculate the selected strain into the NB medium containing 1,000 μg / mL penicillin at an inoculation amount of 2%, with 3 replicates for each treatment. In addition, set up an NB medium solution without inoculation as a control (CK) for each group of experiments. Cultivate in a sealed manner with a sealing film at 30 °C and 170 rpm for 2 days. Determine the penicillin concentration in the solution by HPLC, and calculate the degradation efficiency of Bacillus sp. 50-2 on penicillin. The calculation of the degradation rate uses the following calculation formula:

[0065] Degradation rate = (Initial penicillin concentration - Penicillin concentration after degradation) / Initial penicillin concentration × 100%

[0066] For the determination results of the degradation efficiency of Bacillus sp. 50-2 on penicillin, see Appendix Figure 4 . The results show that the strain Bacillus sp. 50-2 has a significant degradation effect on penicillin, and the degradation rate of 1,000 mg / L penicillin is as high as 99.80% within 48 h.

[0067] Example 4: Application of the Microbial Inoculum of Bacillus sp. 50-2 Strain

[0068] (I) Preparation of the Bacillus sp. 50-2 Inoculum

[0069] Inoculate a single colony of Bacillus sp. 50-2 into NB liquid medium and culture at 30 °C for 16 h to obtain the Bacillus sp. 50-2 seed liquid. Inoculate it into NB liquid medium at an inoculation amount of 2% and ferment for 2 d to prepare the Bacillus sp. 50-2 microbial inoculum.

[0070] (II) Application of the Bacillus sp. 50-2 Microbial Inoculum in Cotton Salt Tolerance

[0071] Measure the absorbance value of the Bacillus sp. 50-2 microbial inoculum at 600 nm and dilute it with sterile water to OD 600= 0.05. Select cotton seeds that are plump and have no obvious damage. After disinfecting them with sodium hypochlorite and 75% alcohol and then cleaning the surface with water, add 50 mL of sterile water and place them in a water bath at 55 °C. After incubating for 30 min, soak them overnight at room temperature for 12 h. After discarding the soaking sterile water, add them to the prepared microbial agent and soak the seeds for 4 h. The control group is an equal amount of sterile water (CK H2O). Spread the cotton seeds on a petri dish containing 10 mL of 1.5% NaCl (the petri dish contains double-layer filter paper) and grow them at 25 °C. Count the number of germinated seeds every day. After growing for 4 days, calculate the germination rate. The results show that after growing for 4 days, there are significant differences in the germination rates of cotton among different treatments, with the germination rates of cotton in each treatment group increasing by 50% compared to the blank control group. It can be seen that Bacillus sp. 50-2 has a significant effect on plant growth under salt stress. The results are shown in Figure 5 .

[0072] (III) Application of Bacillus sp. 50-2 microbial agent in promoting cotton growth

[0073] Measure the absorbance value of Bacillus sp. 50-2 microbial agent at OD 600nm and dilute it to OD 600 = 0.05. Select cotton seeds that are plump and have no obvious damage. After disinfecting them with sodium hypochlorite and 75% alcohol and then cleaning the surface with water, add sterile water to the cotton seeds and place them in a water bath at 55 °C. After incubating for 30 min, soak them overnight at room temperature for 12 h. After discarding the soaking sterile water, add them to the prepared microbial agent and soak the seeds for 4 h. The control group is soaked with an equal amount of sterile water (CK H2O) for 4 h. Using the potting method, sow 20 seeds treated with Bacillus sp. 50-2 microbial agent and the control treatment into a 20 cm × 10 cm pot containing 2.5 kg of soil, with a sowing depth of 3 cm, and grow them to maturity in the natural environment. Measure various morphological parameters of the cotton plants in the experimental group and the control group, including germination rate, plant height, root length, fresh weight of the above-ground part, etc. The results show that the above indicators in the experimental group are significantly higher than those in the control group. The plant height of cotton increases by 32.31%, the root length increases by 41%, the emergence rate increases by 100%, and the fresh weight increases by 74.5% (relative to CK). It shows that the Bacillus sp. 50-2 microbial agent has a significant promoting effect on cotton growth. The specific test results are shown in Appendix Figure 6 and Appendix Figure 7 as shown.

[0074] The above embodiments are only used to illustrate the technical concept and characteristics of the present invention in a specific scenario. The purpose is to enable those who need this technology to understand the content of the present invention and implement it, and does not limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A strain of Bacillus sp. 50-2, characterized in that, The Bacillus sp. 50-2 strain was deposited at the China Center for Type Culture Collection (CCTCC) on November 18, 2024, with the deposit number CCTCC No: M20242591, and its gene sequence is shown as SEQ ID NO:

1.

2. A fermented broth of the Bacillus sp. 50-2 strain according to claim 1.

3. Use of the Bacillus sp. 50-2 strain according to claim 1 or the fermented broth according to claim 2 in degrading penicillin.

4. Use of the Bacillus sp. 50-2 strain according to claim 1 or the fermented broth according to claim 2 in preparing a penicillin-degrading preparation.

5. Use of the Bacillus sp. 50-2 strain according to claim 1 or the fermented broth according to claim 2 in promoting salt tolerance and growth of cotton.

6. A method for degrading penicillin, characterized in that, Treat penicillin with the Bacillus sp. 50-2 strain according to claim 1 or the fermented broth according to claim 2.

7. The method according to claim 6, wherein The fermentation of the Bacillus sp. 50-2 strain uses NB medium.

8. The method according to claim 6, wherein The fermentation treatment conditions of the Bacillus sp. 50-2 strain are 30 °C.

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