Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be described in further detail with reference to the following examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.
Screening and identification of bacillus subtilis natto subspecies R3
1. Screening for sample sources
Taking 500g of fresh soybeans, wrapping the fresh soybeans with fresh sun-dried lotus leaves, and fermenting the fresh soybeans in a ventilation place for 15 days in summer to obtain the natto. 0.34-1 g of prepared natto is ground and dissolved in 20ml of L0.75% physiological saline solution, and then the mixture is oscillated for 1h and kept stand, and the supernatant is used as the original bacterial suspension to be screened.
2. Primary screen
Taking original bacteria suspension original times of solution, respectively coating 10 -1~10-8 dilution solutions on beef extract protein vein culture medium plates, arranging 3 parallel plates for each treatment, and uniformly coating dilution solutions; culturing in a constant temperature incubator at 37 ℃ for 24 hours in an inversion way, observing the growth condition of colonies, selecting a flat plate with uniform colony distribution and colony numbers between 30 and 80, picking single colonies with different colony morphologies for gram staining, and observing under a microscope: the bacillus is repeatedly purified until pure seeds are obtained. 41 single colonies, designated as R1 to R41 in sequence, were obtained by separating and purifying from 7 natto seeds, respectively, according to the above-described method.
3. Double screen
The R1 to R41 obtained by separation are inoculated on a skim milk solid culture medium, and are inversely cultured at 37 ℃ until the colony number is not less than 200, and then the following treatment is carried out:
The plate was put into a pulsed strong light sterilization apparatus FD2000 (Shanghai rayleigh intelligent science and technology limited) to perform pulsed light irradiation treatment, and the conditions of each treatment were: pulse voltage 2220V, pulse number 65 times, and irradiation distance 5cm. The total treatment is 10 times, 1 time is carried out at intervals of 1-2 hours, colonies surviving on the plates after 10 times of treatment are transferred to fresh plates, 3 generations are transferred together, and the strains which can still survive through 3 generations transfer are R2, R3, R9, R15 and R22 finally.
4. Final screen
And respectively inoculating R2, R3, R9, R15 and R22 obtained by re-screening to respective dibbling on an anticoagulant plate, culturing for 24 hours at 37 ℃, observing whether a lysosome ring is generated, and detecting thrombin activity.
Wherein the anticoagulant plate comprises: 3.0g/L beef extract, 10.0g/L peptone, 5.0g/L NaCL, 20g/L agar and 10v/v%20NIH/mL thrombin standard solution; wherein, 20NIH/mL thrombin standard solution was prepared with physiological saline at pH5.0, thrombin formulation was purchased from Sigma-Aldrich under accession number P00734, 150UNITS. The thrombin standard solution should be poured into the plate evenly when the plate is cooled to below 45 ℃ until the plate is completely solidified.
Inoculating R2, R3, R9, R15 and R22 obtained by re-screening into a final-screen liquid culture medium according to an inoculum size of 5wt%, transferring to a 37% shaking table at 120rpm, culturing for 30-35 h, and taking the fermentation broth to perform ACE inhibition as an index for screening. Among them, ACE inhibition activity is referred to below.
Wherein the final screening culture solution comprises 8wt% of leech low-temperature dried product, 2g/L natto, 3g/L skimmed milk powder, 0.5g/L beef extract, 5g/L peptone and 5g/L NaCL, and the pH value is 7.0-7.2.
As a result, as shown in FIG. 1, the plate on which the lysosome ring was produced had only R3, and the strains having ACE inhibition ratios had R2, R3, R9, R15 and R22.
5. ACE inhibition activity assay
The improved Cushman ultraviolet colorimetry is adopted to measure the ACE inhibition rate of the fermentation broth.
Preparation of HIL substrate solution: the ACE substrate Hip-His-Leu (HHT, sigma) was dissolved in borate buffer solution at pH8.3 containing 0.lmol/L NaCL to give a concentration of 5 mmol/L.
Mixing 100 μL of 5.0mmol/L HHT solution and 40 μL of centrifuged scallop skirt fermentation broth, keeping the mixture in a water bath at 37 ℃ for 10min, adding 20 μL of 0.l U/mL ACE enzyme solution, uniformly mixing, and reacting in a constant-temperature water bath at 37 ℃ for 35min.
Taking out from the water bath, adding 200 mu L lmol/L HCL into the reaction system to terminate the reaction, adding 1.2mL of hippuric acid generated by frozen acetic acid and acetic acid extraction, centrifuging at 3500rpm for 5min after vortex shaking and mixing uniformly, sucking 1.0mL of acetic acid and acetic acid layer, drying and cooling in a 90 ℃ oven for 1 hour, adding 4mL of distilled water for full dissolution, and measuring the absorbance at 228nm after vortex mixing. Parallel control except that 200. Mu.L mol/L HCl was added before the reaction to terminate the reaction, the remaining components, the operation steps and the reaction tube were repeated 3 times to average the absorbance values, and then the ACE inhibition ratios of the above-mentioned fermentation broths of R2, R3, R9, R15 and R22 were calculated according to the formula, resulting in fermentation broths of 48h, and ACE inhibition ratios of the fermentation broths of R2, R3, R9, R15 and R22 were 67.5%, 73.2%, 73.1%, 71.9% and 68.3%, respectively.
6. Identification of R3 Strain
Through the steps of primary screening, secondary screening and final screening, only the R3 strain can generate a thrombin ring for thrombin and can also generate an ACE inhibition effect through fermentation, so that the R3 strain obtained through screening is identified.
Extracting genome of strain R3 as template, performing PCR amplification with universal primer (27F: agagttgatctggcgcctcag, shown as SEQ ID NO. 1; 1499 2R: ggttacttgtacgactt, shown as SEQ ID NO. 2), detecting by agarose electrophoresis of 1%, and displaying at 900%
A distinct band is about bp, as shown in FIG. 2, which shows that the 16SrDNA fragment of the genome of the strain has been amplified, and the fragment length obtained by sequencing is 867bp, as shown in SEQ ID NO. 3.
The sequences of strain BN-3 were aligned in NCBI using Blast, and the strains with higher homology all belonged to Bacillus, indicating that the strain R3 selected was Bacillus subtilis, bacillus natto subsp. Bacillus subtilis natto. The strain R3 is named Bacillus subtilis subsp.natto R3 and is preserved in China general microbiological culture Collection center with the preservation number of CGMCC No.21709, the strain is named as Bacillus subtilis subsp.natto R3, the preservation date is 2021, 01 month 25, and the preservation address is North Star Xiyu No. 1, no. 3 in the Korean region of Beijing city.
Low-temperature dried product of bacillus subtilis natto subspecies R3 fermented leech
The embodiment of the application also discloses a method for fermenting the leech low-temperature dried product by utilizing the bacillus subtilis subsp natto R3 disclosed in the embodiment. The method specifically comprises the following steps:
1) Preparing a seed culture solution and a fermentation culture solution, wherein the seed culture solution comprises 1-8wt% of leech low-temperature dried product, and the fermentation culture solution comprises 1-5wt% of leech low-temperature dried product;
2) Preparing a seed suspension, wherein the seed suspension is obtained by inoculating the preserved bacillus subtilis natto subspecies into the seed culture solution for culture after strain activation;
3) Obtaining a fermentation liquor, wherein the fermentation liquor is obtained by transferring the seed suspension into the fermentation culture liquor, and carrying out ventilation fermentation under the stirring condition of 150-180 rpm at the temperature of 34-45 ℃, wherein the ratio of air quantity to tank volume is 1: 0.5-1 (v/v.m) for 36-72 h;
4) And (3) obtaining a dry product, wherein the dry product is obtained by purifying the fermentation broth.
According to the embodiment of the application, the low-temperature dried leech product is fermented by utilizing the bacillus subtilis natto subspecies R3, so that hirudin contained in the low-temperature dried leech product is fully utilized, and the polypeptide with anticoagulation effect is synthesized through biodegradation. In addition, since R3 strain was modified by pulsed light treatment, ACE-inhibiting polypeptides were synthesized. Thus, a dry product is obtained by the fermentation process.
In specific example 1, the preserved strain R3 was transferred to a slant medium, cultured at 37℃for 24 hours, transferred to a seed culture medium, and shake-flask cultured at 150rpm at 37℃for 24 hours. Wherein the seed culture solution comprises 6.5wt% of leech low-temperature dried product, 1.5g/L natto, 2.6g/L skimmed milk powder, 0.5g/L beef extract, 15g/L peptone and 5g/L NaCL, and the pH of the seed culture solution is 7.0-7.2. And (3) measuring the absorbance OD660 of the seed cell suspension to be not lower than 0.8, and detecting living bacteria by adopting a living bacteria counting method, wherein the number of the living bacteria is not lower than 10 8 cfu/mL.
Specifically, the seed cell suspension meeting the requirement is transferred into fermentation culture solution, and is aerated and fermented under the stirring condition of 150-180 rpm at 34-45 ℃, the ratio of air quantity to tank volume is 1:0.5-1 (v/v.m), and the fermentation is carried out for 36-72 h. Wherein the fermentation culture solution comprises 3.4wt% of leech low-temperature dried product, 1.5g/L natto, 10g/L glucose, 3g/L skimmed milk powder, 0.5g/L beef extract, 15g/L peptone and 5g/L NaCL, and the pH of the fermentation culture solution is 7.0-7.2.
Detecting the absorbance OD660 of the fermentation liquid to be not lower than 0.8, and purifying. The purification treatment steps of specific example 1 include:
Leaching: adding water with the volume of 5 times into the fermentation liquor, fully leaching for 6-8 hours at the temperature of more than 85 ℃, and centrifuging to obtain supernatant;
Ultrafiltration: firstly, treating with a 5KD hollow fiber column, collecting concentrated solution, drying (or freeze-drying) at low temperature to obtain a dried product, and preserving at-20 ℃.
Comparative example 1: for this reason, the present application also provides a method for fermenting leech low-temperature dried product using existing bacillus subtilis subsp. The procedure was the same as in example 1 above, except that the strain used for fermentation was Bacillus subtilis subsp.subtilis CICC23916, purchased from China industry microbiological culture Collection center. And leaching and ultrafiltering the fermentation broth to obtain a dry product.
Detection of dried articles
The product was dissolved in water and treated with a 1KD hollow fiber column, and the filtrate and concentrate were collected, respectively. The concentrated solution is dried (or freeze-dried) at low temperature to obtain the component 1. Concentrating the filtrate with hollow fiber column of 3KD, and drying (or lyophilizing) at low temperature to obtain component 2.
The component 1 and the component 2 are respectively purified by Sephadex-G25, and the main component with high absorbance at 215nm is collected, concentrated and frozen so as to carry out Nano-upgrading liquid chromatography-mass spectrometry (Nano-UPLC-MS) identification.
The Nano-UPLC-MS identification method comprises the following steps:
Chromatographic conditions: c18 chromatographic column, sample injection volume of 10 μL, column temperature of 30deg.C, flow rate of 300nL/min, and detection wavelength of 215nm. Mobile phase a: containing 100% acetonitrile, mobile phase B: ultrapure water containing 0.1% (V/V) formic acid.
Gradient separation conditions: the mobile phase solution B is increased from 5% to 45% in 0-40 min, increased from 45% to 80% linearly in 40-50min, maintained at 80% for 5min, and finally reduced to 5% equilibrium for 15min.
Mass spectrometry conditions: nano-scale electrospray ionization ((nano-ESI), positive ion mode scanning, scanning range m/z 350-1800. Primary spectrogram scanning resolution is 120K, secondary spectrogram scanning resolution is 7.5K, cascade fragmentation energy is 30%, and fragmentation mode is high-energy collision fragmentation cleavage HCD.
The mass spectrum is shown in figures 3-4, the molecular weight of Nano-UPLC-MS is obtained from component 1 and component 2, and the polypeptide with IPRPQSHNDFDFEEIPEEYLQ, 2637.8 and KKKPE and 700.83Da is found from the amino acid sequence obtained from component 1 by analysis and identification and comparison with BIOPEP database.
It can be seen that the fermented product provided by the embodiment of the application comprises the two dry products. Activity detection of component 1 and component 2 polypeptides
Test solution: a20 mg/mL 10mL solution of component 1 was prepared as described above, and a 20mg/mL 10mL solution of component 2 was prepared as described above.
In addition, a dried leech product (available from Siam Ralin Biotechnology Co., ltd.) was prepared as a 20mg/mL 10mL solution as a control.
Fibrinogen 10mg (purchased from Sigma) was weighed and dissolved to 2mL with Tris-HCl; the packed thrombin (Sigma-Aldrich, accession number P007434, 150 UNITS) was diluted with pure water to 1mL and shaken well to give a thrombin solution with a concentration of 40U/mL; precisely sucking 50 mu L of sample solution, placing into a test tube, adding 100 mu L of fibrinogen solution, shaking uniformly, placing into a 37 ℃ water bath, slowly adding thrombin solution, 5 mu L per minute, shaking while adding, observing coagulation condition until coagulation, recording the volume of consumed thrombin solution, and calculating the activity of a sample according to the following formula, wherein the activity U=C1×vl/C2×V2; wherein U represents U/mg per 1g of thrombin-containing activity unit; c1 represents the active concentration U/mL of thrombin; c2 represents the concentration of the sample solution of 20mg/mL; v1 represents the volume of thrombin consumed, μL; v2 represents the amount of the sample solution added in. Mu.L.
Meanwhile, the test sample is tested for ACE inhibition activity by adopting the ACE inhibition activity test method provided by the embodiment, and the test result is shown in table 1.
TABLE 1
Determination of IC 50 value for purified fraction 2: freeze-dried samples (0.1-2.0 mg/mL) with different concentrations are prepared, the ACE inhibition rate of the samples is measured according to the method provided by the embodiment, a correlation curve is made on the ACE inhibition rate by the logarithmic value of the concentration of the samples, and the IC 50 value of the samples is calculated.
As shown in table 1, component 1 contains a polypeptide component with high anticoagulant activity and a molecular weight of 2637.8, and component 2 contains a polypeptide component with high ACE inhibition rate and a molecular weight of 700.83Da, so that it is proved that the dried product provided in example 1 of the present application contains both polypeptide components, and has high anticoagulant activity (far higher than that of leech low-temperature dried product) and high ACE inhibition rate. The dried product obtained by fermenting the leech low-temperature dried product with Bacillus subtilis subsp.sub.CICC 23916 of comparative example 1 has only anticoagulation activity, but does not have ACE inhibition, and the influence on anticoagulation activity and ACE inhibition is eliminated by detecting other natto powder, glucose and skimmed milk powder in the fermentation culture solution.
Animal experiment
To further verify the effect of the dried product obtained by fermentation with R3 bacteria in the examples of the present application, the following will be described in connection with animal experiments.
1. Materials and methods
1.1, Laboratory animals and test drugs
120 Wistar rats, each half of which has a weight of 250-280g, were provided by the laboratory animal center at the university of eastern Shandong, and were assigned a certification number of SCXK (lu) -2003004a.
Test drugs 100mg of example 1, comparative example 1 and dried leech at low temperature were dissolved in 2mL of 0.75% physiological saline, respectively, to give test samples, and Xuesaitong injection (100 mg,2mL, kunqiao group Co., ltd.) was used as positive control 1.
1.2, Establishing MCAO model rats
Rat surgical modeling: rats were anesthetized by intraperitoneal injection of 10% chloral hydrate (350 mg/kg body weight), fixed supine, incision in the middle of the neck, incised the skin, blunt-separated layers of tissue, separated right Common Carotid Artery (CCA), internal Carotid Artery (ICA) and External Carotid Artery (ECA), ligated ECA and CCA, and after occlusion of the ICA distal end with a venous clip, an incision was made rapidly at the common carotid artery approximately 0.5cm from the ECA and ICA bifurcation, and a nylon wire (0.32 mm) coated with paraffin at one end was inserted to an insertion depth of 1.85±0.5mm, achieving middle cerebral artery occlusion leading to cerebral ischemia. Ligating the entrance, suturing the incision, and retaining the nylon thread head and tail outside the body. After 1h of ischemia, the rats were again anesthetized, pulling the nylon wire extra-retaining ends to slightly resistance to achieve middle cerebral artery reperfusion. The artificial operation is similar to other model mice in separating common carotid artery, internal carotid artery and external jugular vein, but ligating right common carotid artery CCA, preserving heat of the operated rat, and completing the establishment of MCAO model rat. The established MCAO model rats were scored for neurological examination with reference to a score Zea Longa score of 3or4, indicating successful modeling.
1.3 Effects on MCAO rats
And (3) observing neurological symptoms and tissue biochemical index measurement tests: wistar rats were divided into a blank group, a model group and a dosing group. The established MCAO model mice are subjected to intraperitoneal injection, and the test products are prepared by the low-temperature dried products of the example 1, the comparative example 1 and the leech and the positive control product 1. The injection accumulation was 20mg/kg body weight. The blank and model groups were given equal amounts of saline, and the blank group machine was used for normal healthy Wistar rats not subjected to the above-described surgery.
1.4, Determination of cerebral infarction scope:
The animals are subjected to head breaking after 1 hour of ischemia reperfusion for 23 hours, are rapidly placed on an ice tray for taking brains, the olfactory bulb, the cerebellum and the low-level brains are removed, are frozen at the temperature of minus 20 ℃ for 20 minutes, are taken out, are uniformly cut into 6 pieces, are placed in a bottle containing TTC, are closed, are incubated in a 37C incubator for 30 minutes, and are transferred into a 4% paraformaldehyde solution for fixation. The non-ischemic portion was stained rose-red, and the ischemic portion was white. After fixing the brain tissue, the ischemic portion was carefully separated and weighed, and the cerebral infarction range (%) =infarct area weight/whole brain weight×100% was determined as follows.
1.5, Determination of Biochemical index of brain tissue
The index includes superoxide dismutase (SOD), malondialdehyde (MDA), lactate Dehydrogenase (LDH), glutathione (GSH), glutathione peroxidase (GSH-PX), nitric Oxide (NO), na +-K+ -ATPase, and Ca +-Mg+ -ATPase.
The detection method comprises the following steps: 10% brain homogenate obtained according to the method is centrifuged at 4000rpm for 10min, 20 mu L of supernatant is taken, and the LDH content is measured according to the instructions of an LDH measuring kit (Abcam China); respectively taking 30 mu L, and measuring SOD and GSH content according to the specification of SOD and GSH measuring kit (Abcam China); taking 100 mu L of supernatant, and determining MDA content according to the specification of an MDA determination kit (Beijing Box manufacturing technology Co., ltd.); 200 mu L of supernatant is taken and GSH-PX content is measured according to the specification of GSH-PX measuring kit (Shanghai Shangzun biotechnology Co., ltd.); 500. Mu.L of the supernatant was used to determine the NO content according to the instructions of the NO determination kit (Shanghai Redsi Biotech Co., ltd.).
1.6 Establishment of animal model of stress hypertension rat (SIHI)
And molding by adopting a high-salt diet composite cold stress method. The Wistar rats were fed with a high-salt rat feed (synergistic) containing 10% sodium chloride and a 0.85% sodium chloride solution every day, and the rats were placed in an exposure box containing water at 5±2 ℃ with a glass plate as the face wall and a certain amount of water every day for 4 hours, and after continuous treatment for 2 weeks, blood pressure of the rats was measured with a BP-6 type animal noninvasive blood pressure test system and continuously measured 3 times, and the average value was taken until the blood pressure reached the highest (compared with normal Wistar rats), and experiments were started after the blood pressure was maintained relatively stable at a high level, and the criterion was that the blood pressure after stress should have a significant difference from the blood pressure before stress (P < 0.01).
1.7 Action of rats greater than SIHI
SIHR rats were randomly divided into dosing, positive control and model groups. The administration group administers SIHR the test pieces provided in example 1, comparative example 1 and leech low-temperature dried product, respectively, to rats, and the administration dose was 20mg/kg body weight. The positive control group was administered SIHR rats with gavage irbesartan (sonofil, france) at a dose of 16.5mg/kg. The model group is SIHR rats, and no test sample is given. Normal Wistar rats were also established as a blank. The administration was stopped for 4 consecutive weeks, and after the rat blood pressure was stabilized, the rat tail artery blood pressure was measured by indirect pressure measurement and the measurement result was recorded.
1.8 Data processing
The experimental data are subjected to data analysis by Excel 2013 and SPSS 22.0 statistical software for statistical arrangement, each data is measured for a plurality of times and represented by an average value and a standard deviation thereof, and single-factor analysis of variance (One-way ANOVA) and DunCan's multiple comparison are respectively carried out by SPSS 22.0, and a significant difference mark is carried out.
2. Results
TABLE 2
As shown in Table 2, the brain tissue of the rats in the blank group is normal, and the rats in the model group and the administration group have different degrees of infarct, the cerebral infarction range of the rats in the administration group is obviously reduced relative to that of the model group after the administration of the test sample, wherein the test sample provided in example 1, namely the dried product obtained by fermenting the leech low-temperature dried product by adopting the R3 strain disclosed in the embodiment of the application, has the most obvious effect of reducing the infarct degree of the rats.
TABLE 3 Table 3
As shown in tables 2 and 3, after the rats are refilled by cerebral middle artery ischemia, MDA, GSH, SOD, GSH-PX, LDH and NO in brain tissues are obviously changed, the LDH, MDA and NO contents of the rats in the model group are obviously higher than those of the rats in the pseudo-blank group, and SOD, GSH and GSH-PX are obviously lower than those of the rats in the blank group. In the dosing group, the test article provided in example 1 significantly reduced LDH, MDA and NO levels in rat brain tissue, while SOD, GSH and GSH-PX levels were significantly increased after dosing the model rats, and wherein SOD and GSH-PX levels were nearly restored to be comparable to the blank group. In the administration group, after the test sample provided by the low-temperature dried leech products of comparative example 1 is administered to the model rat, the MDA, GSH, SOD, GSH-PX, LDH and NO contents in the brain tissue of the rat are partially changed, but the normal level is difficult to recover. Moreover, the test samples provided by the low-temperature dried leech products in comparative example 1 hardly significantly change the SOD, GSH-PX and LDH contents in brain tissues of the model rats. From this, it is shown that the sample provided in the embodiment 1 of the present application, that is, the dried product obtained by fermenting the leech low-temperature dried product with the R3 strain disclosed in the embodiment of the present application, has a protective effect against acidosis and free radical damage on brain tissue of model rats.
TABLE 4 Table 4
As can be seen from Table 4, the activities of Na +-K+ -ATPase and Ca 2+-Mg2 + -ATPase in brain tissues were evident in the blank groups after ischemia reperfusion of middle cerebral artery. In the administration group, after the test article provided in example 1 was administered to the model rats, the activity of Na +-K+ -ATPase and Ca 2+-Mg2+ -ATPase in brain tissues of the rats was significantly increased in the model group rats, and significantly higher than that in the positive control group. In the administration group, after the test sample provided by the low-temperature dried leech products of the comparative example 1 is administered to the model rats, the activities of Na +-K+ -ATPase and Ca 2+-Mg2+ -ATPase in brain tissues of the rats are not obviously changed relative to the model rats. From this, it is demonstrated that the test samples provided by comparative example 1 and the leech low temperature dried product have no significant effect on ischemia damage greater than Na +-K+ -ATPase and Ca 2+-Mg2+ -ATPase, whereas the dried product obtained by fermenting leech low temperature dried product with R3 strain disclosed in the example of the present application provided in example 1 of the present application can provide significant improvement.
TABLE 5
As can be seen from table 5, the steady systolic pressure and diastolic pressure of the established SIHR model rat are significantly higher than those of the blank group, which indicates that the model building was successful, and the diastolic pressure and systolic pressure of the positive control group are significantly reduced after the irbesartan is given to the SIHR model rat, which does play a role in reducing blood pressure, but the blood pressure of the rat is even lower than that of the normal Wistar rat, and the side effect of hypotension may be generated for the rat. In the administration group, the dry product obtained by fermenting the leech low-temperature dry product with the R3 strain disclosed in the embodiment 1 is administered to SIHR model rats, the diastolic pressure and the systolic pressure of the dry product are obviously reduced, and the blood pressure level of the dry product is equivalent to that of normal Wistar rats in a blank group, so that the dry product obtained by fermenting the leech low-temperature dry product with the R3 strain disclosed in the embodiment of the application has the effect of reducing blood pressure on rats, and has no obvious hypotensive side effect. In the administration group, the test sample provided by the low-temperature dried leech products of comparative example 1 does not have obvious blood pressure reducing effect after being administered to SIHR model rats.
In summary, the natto of example 1 of the present application is used as a screening source, and through a primary screening, a secondary screening and a final screening, and pulse light radiation treatment is used in the secondary screening, and through identification, a bacillus subtilis natto subspecies R3 is finally obtained through screening, and through a lysozyme experiment and ACE activity detection, it is found that the bacillus subtilis natto subspecies have anticoagulation and inhibition of ACE enzyme activity, while the conventional bacillus subtilis natto subspecies (comparative example 1) do not have both activities.
Furthermore, the application also ferments leech low-temperature dried product through R3 strain to obtain a dried product, and the dried product obtained by identifying that the dried product contains two active polypeptides, which respectively and correspondingly generate the effects of anticoagulation and inhibition of ACE enzyme activity, is proved by animal experiments to have the protection effect on ischemia reperfusion brain injury rats and reduce the blood pressure level of SIHR rats. Therefore, the embodiment of the application also provides an application prospect of applying the R3 strain to the preparation of anticoagulant products or the preparation of blood pressure reducing products.
While the application has been described with respect to the preferred embodiments, it is to be understood that the application is not limited thereto, and that those skilled in the art will appreciate that the application may be embodied with other forms and combinations of parts,
Modifications and substitutions that can be easily conceived are intended to be encompassed within the scope of the present application.