Paenibacillus vaidmannii SXZY-01 and application thereof
By screening and optimizing Bacillus videmannii SXZY-01 and its culture medium, the problem of excessive tannins in tobacco was solved, achieving efficient, safe, and environmentally friendly tannin degradation, thereby improving the sensory quality and market competitiveness of tobacco.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA TOBACCO SHAANXI IND
- Filing Date
- 2026-02-12
- Publication Date
- 2026-06-23
AI Technical Summary
Existing tobacco products have excessively high tannin content, resulting in poor quality. Current degradation methods are inefficient, costly, and prone to damaging natural flavor. Furthermore, there is a lack of strain resources, low enzyme activity, immature fermentation processes, and a lack of safety assessments.
We screened out Bacillus videmannii SXZY-01 and optimized its culture medium. We utilized its secreted tannin enzymes to degrade tannins in tobacco and applied it in tobacco processing through an optimized fermentation process. We selected corn flour, soybean meal, and CuSO4 as the culture medium components to improve enzyme activity and stability.
It significantly degrades tannins in tobacco, improves the sensory quality of tobacco, enhances aroma harmony and smoothness, reduces bitterness, with a degradation rate of 17.26%, and increases the overall sensory quality score by 9.2%. It is low-cost and environmentally friendly.
Smart Images
Figure CN122256171A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of bio-fermentation technology and relates to a strain of Bacillus videmannii SXZY-01 and its applications. Background Technology
[0002] Tannins, as important polyphenols in tobacco, have a dual impact on tobacco quality. In appropriate amounts, tannins can be converted into aroma components such as aldehydes, ketones, and acids during tobacco fermentation and combustion, giving tobacco its unique aroma and smooth taste. However, when tannin content exceeds a certain threshold, it leads to increased bitterness and off-flavors, resulting in a noticeable astringent and harsh throat sensation. This problem is particularly prominent in certain tobacco types, such as cigar tobacco and sun-cured tobacco, severely affecting the smoking quality and market acceptance of the tobacco.
[0003] Studies have shown that moderately reducing the tannin content in tobacco can significantly improve its quality. When the tannin degradation rate of cigar tobacco leaves reaches 39.69%, the bitterness and off-flavors of the tobacco leaves are significantly reduced, and the smoke becomes smoother and more delicate. The tannin degradation process also releases phenolic substances such as gallic acid, which have pleasant flavors, forming a richer aroma profile and comprehensively enhancing the commercial value and market competitiveness of tobacco.
[0004] Currently, methods for degrading tannins in tobacco mainly include physical, chemical, and biological methods. Physical methods suffer from low efficiency and high cost; chemical methods have limitations such as harsh reaction conditions, complex byproducts, and environmental pollution. Biodegradation methods, especially microbial degradation technology, show great promise due to their mild conditions, high specificity, and environmental friendliness. Existing research has found that certain bacteria and fungi have the ability to degrade tannins, such as Pantotheca agglutinosa (…). pantoea agglomerans ) and Bacillus splendidus ( Paenibacillus lautus strains such as )
[0005] However, current research on tannin-degrading bacteria still has significant limitations: a scarcity of highly efficient strains, and the tanninase activity of existing strains is generally low; substrate inhibition exists; fermentation processes are immature; degradation efficiency and stability are insufficient; and safety assessments are lacking. These limitations severely restrict the widespread application of tannin degradation technology in the tobacco industry. Summary of the Invention
[0006] The technical solution of this invention is: a strain of Bacillus videmannii ( Bacillus wiedmannii SXZY-01, with accession number CCTCC NO: M 2025151, was deposited at the China Center for Type Culture Collection on January 15, 2025.
[0007] The present invention also provides the application of the above-mentioned Bacillus videmannii or its fermentation products in tobacco processing.
[0008] Preferably, the fermentation product includes tanninase.
[0009] This invention also provides a biological agent prepared from Bacillus videmannii or its fermentation products, which is used to: degrade tannins in tobacco; improve the sensory quality of tobacco, characterized by at least one of aroma quality, aroma intensity, woody off-flavors, irritation, aftertaste, strength, concentration, and smoothness; enhance aroma harmony, reduce the harshness of smoke, and improve the bitterness of the aftertaste; and secrete or prepare tannin enzymes. This biological agent is an enzyme preparation for tobacco processing.
[0010] Preferably, the method for preparing the biological agent includes the following steps: Step 1: Activate the bacterial strain: Inoculate Bacillus videmannii SXZY-01 into NA solid medium and incubate at 25-35℃ for 36-72 hours; Step 2, Preparation of seed culture: Take the bacterial cells cultured in Step 1, inoculate them into liquid culture medium, and culture them in a shaker at 30-35℃ and 180-200 r / min for 12-16 h to obtain seed culture; Step 3, scale-up culture: Inoculate the seed culture obtained in step 2 into NA liquid medium at 2% to 4% of the culture medium weight, and culture at 30℃ to 35℃ and shaking speed of 180 to 200 r / min for 24 to 48 hours to obtain fermentation broth; Step 4: Preparation of crude enzyme solution: Centrifuge the fermentation broth obtained in Step 3 at 3-5℃ and 8000-10000 rpm for 9-11 minutes, and collect the supernatant, which is the biological agent. The fermentation product is the supernatant obtained after centrifugation of its fermentation broth.
[0011] More preferably, in step 1, the composition of the NA solid culture medium includes: 2-4 g / L beef extract, 8-12 g / L peptone, 4-6 g / L sodium chloride, and 18-22 g / L agar powder; in step 3, the composition of the NA liquid culture medium includes: 5-25 g / L corn flour, 5-25 g / L soybean meal, and 1-9 g / L CuSO4.
[0012] More preferably, in step 3, the NA liquid culture medium comprises: 15 g / L corn flour, 15 g / L soybean meal, and 7 g / L CuSO4.
[0013] Preferably, the biological agent is used to process tobacco shreds, comprising the following steps: Step A: Spray the biological agent onto the tobacco shreds at 0.5% to 5% of the mass of the tobacco leaves to be treated, adjust the moisture content of the tobacco shreds to 18% to 22%, seal, and ferment at 40 to 50°C and 70% to 80% humidity for 20 to 30 hours. Step B: Dry the tobacco shreds at 80℃ for 10-15 minutes to balance the moisture content.
[0014] The beneficial effects of this invention are: 1. The *Bacillus videmannii* SXZY-01 strain screened in this invention is a tannin-producing strain with high tannin activity. After optimizing the enzyme-producing culture medium for this strain, its enzyme production capacity was significantly improved, with tannin activity increasing from an initial 5.82 U / mL to 40.98 U / mL, a relative increase of 604.12%. This indicates that a culture medium composed of specific concentrations of corn flour, soybean meal, and CuSO4 can efficiently activate the enzymatic reaction. Furthermore, the carbon and nitrogen sources used in the culture medium are corn flour and soybean meal, respectively, both commonly used raw materials in agricultural production. These are widely available and inexpensive, significantly reducing the overall preparation cost of this invention and demonstrating good economic viability and industrial application potential.
[0015] 2. This invention applies an optimized culture medium of Bacillus videmannii SXZY-01 enzyme solution to tobacco leaf processing, precisely controlling the concentration of the fermentation enzyme solution to degrade tannins in tobacco leaves, thereby significantly improving the sensory quality of tobacco. Results of tannin content changes and sensory evaluation show that, when the enzyme solution concentration is 2.5%, the tannin degradation rate in tobacco leaves treated with this strain reaches 17.26%. Key indicators such as aroma, irritation, aftertaste, and smoothness are significantly improved, with a total score of 47.5 points, a 9.2% increase compared to the T1 control group (43.5 points). Specifically, the aroma is significantly improved, with increased aroma volume, improved smoke smoothness, reduced irritation, and significantly improved bitterness and lingering sensation in the aftertaste, while smoothness is increased. This effectively overcomes the shortcomings of existing physicochemical methods that easily destroy natural flavor components.
[0016] 3. This invention achieves precise regulation of tannins in tobacco by screening the highly efficient tannin-producing strain SXZY-01 and optimizing the culture medium. This effectively solves the problem of heavy bitter aftertaste in existing tobacco leaves and provides an innovative technical path for the green improvement of tobacco quality. Attached Figure Description
[0017] Figure 1 This is a streak plate diagram of Bacillus videmannii SXZY-01 strain and its application examples according to the present invention. Figure 2 This is a graph showing the enzyme activity determination results of Bacillus videmannii SXZY-01 in different liquid culture media in this embodiment of the invention; Figure A is a bar chart showing the effect of carbon source type on tanninase activity; Figure B is a line graph showing the effect of optimal carbon source concentration on tanninase activity; Figure C is a bar chart showing the effect of nitrogen source type on tanninase activity; Figure D is a line graph showing the effect of optimal nitrogen source concentration on tanninase activity; Figure E is a bar chart showing the effect of inorganic salt type on tanninase activity; and Figure F is a line graph showing the effect of optimal inorganic salt concentration on tanninase activity. Figure 3 This is a standard curve based on tannin content at 275 nm in an embodiment of the present invention. Detailed Implementation
[0018] The related technologies of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0019] like Figures 1-3 As shown, this invention addresses the shortcomings of existing tobacco processing methods, such as poor sensory quality due to excessive tannin content, and the low efficiency and potential damage to the original flavor of tobacco caused by traditional physicochemical methods for reducing tannin. It provides a highly efficient, safe, and specific tannin-degrading strain and develops a corresponding application process for it in tobacco fermentation. By screening highly active microbial strains from specific habitats, combined with strain modification and fermentation process optimization, particularly in the optimization of the enzyme-producing culture medium, this invention innovatively selects soybean meal, wheat bran, and other grain-based materials as the main culture medium components. This not only ensures wide availability and low cost of raw materials but also high safety, effectively improving the enzyme production efficiency and stability of tannin-degrading enzymes, ensuring that tannins are effectively degraded without affecting other quality characteristics of tobacco. The application of this technology will effectively solve the long-standing problem of excessive tannin in the tobacco industry, improve the quality and added value of tobacco products, and offer environmental and sustainability advantages, providing a new technological path for the high-quality development of the tobacco industry.
[0020] According to one aspect of this disclosure, a strain of Bacillus videmannii ( ) was isolated through screening. Bacillus wiedmannii SXZY-01 was deposited on January 15, 2025 at the China Center for Type Culture Collection (Wuhan University, Wuhan, China, 430072, China) with accession number CCTCC NO: M 2025151.
[0021] According to one aspect of this disclosure, a biological agent is provided containing the Bacillus videmannii SXZY-01 and / or its fermentation products, the fermentation products including tanninases.
[0022] According to one aspect of this disclosure, the use of Bacillus videmannii SXZY-01 or the biological agent in at least one of the following or in the preparation of a product having at least one of the following functions: (1) Degrading tannins in tobacco; (2) Improve the sensory quality of tobacco, wherein the sensory quality is characterized by at least one of aroma quality, aroma quantity, woody off-flavor, irritation, aftertaste, strength, concentration, and smoothness; (3) Enhance aroma harmony, reduce the harshness of smoke, and improve the bitterness of aftertaste; (4) Secretion or preparation of tannins.
[0023] According to another aspect of this disclosure, a method for preparing the biological agent is provided, characterized by comprising the following steps: (1) Activation of bacterial strain: The Bacillus videmannii SXZY-01 was inoculated into NA solid medium and cultured at 25-35℃ for 36-72h; (2) Preparation of seed culture: Pick the bacterial cells cultured in step (1), inoculate them into liquid culture medium, and culture them in a shaker at 30-35℃ and 180-200 r / min for 12-16 h to obtain seed culture; (3) Expanded culture: The seed culture obtained in step (2) is inoculated into NA liquid culture medium at 2% to 4% of the weight of the culture medium, and cultured at 30℃ to 35℃ and shaking speed of 180 to 200 r / min for 24 to 48 hours to obtain fermentation broth; (4) Preparation of crude enzyme solution: Centrifuge the obtained fermentation broth at 3-5℃ and 8000-10000rpm for 9-11min, and take the supernatant, which is the biological agent.
[0024] In some of the disclosed embodiments, the NA solid culture medium composition is as follows: beef extract 3.0 g / L, peptone 10.0 g / L, sodium chloride 5.0 g / L, and agar powder 20.0 g / L.
[0025] In some of the disclosed embodiments, the liquid culture medium composition is: corn flour 5.0-25.0, soybean meal 5.0-25.0, CuSO4 1.0-9.0 in g / L. Preferably, the liquid culture medium composition is: corn flour 15.0, soybean meal 15.0, CuSO4 7.0 in g / L.
[0026] According to another aspect of this disclosure, a method for processing tobacco shreds is provided, characterized by comprising the following steps: (1) Spray the biological agent onto the tobacco shreds at 0.5% to 5% of the mass of the tobacco leaves to be treated, and adjust the moisture content of the tobacco shreds to 18% to 22% and then seal it. Ferment at 40 to 50°C and 70% to 80% humidity for 20 to 30 hours. (2) Dry the tobacco at 80°C for 10-15 minutes to balance the moisture content.
[0027] Example Example 1: Screening and identification of Bacillus videmannii SXZY-01 In 2020, Bacillus videmannii was isolated from the surface of tobacco leaves in Ankang, Shaanxi Province, and named SXZY-01.
[0028] The isolation and screening process of strain SXZY-01 is as follows: 2g of Ankang tobacco from Shaanxi Province was placed in 30mL of sterile water and cultured in a shaker at 30℃ and 180r / min for 36h to prepare a bacterial suspension. Subsequently, a screening medium was prepared using tannic acid as the sole nutrient source. After inoculating the bacterial suspension, strains that could grow normally in this medium were determined to have tannin degradation ability. Finally, the target strain was selected and streaked onto NA solid medium for isolation. After multiple purifications, pure strain SXZY-01 was obtained (see streak plate results for details). Figure 1 It was identified as Bacillus videmannii ( ). Bacillus wiedmannii It is currently deposited at the China Center for Type Culture Collection, accession number CCTCC NO:M 2025151.
[0029] Example 2: Optimization of biological agent preparation and culture conditions (1) Activation of bacterial strain: The Bacillus videmannii SXZY-01 was inoculated into NA solid medium and cultured at 30°C for 48 h; (2) Preparation of seed culture: Pick the bacterial cells cultured in step (1), inoculate them into NA liquid culture medium, and culture them in a shaker at 30℃ and 200 r / min for 16 h to obtain seed culture; (3) Expanded culture: The seed culture obtained in step (2) was inoculated into NA liquid medium (calculated as g / L, beef extract 3.0, peptone 10.0, sodium chloride 5.0, natural pH) at 30℃ and shaken at 200 r / min for 24 h to obtain fermentation broth; (4) Preparation of crude enzyme solution: Centrifuge the obtained fermentation broth at 4℃ and 10000rpm for 10min, and take the supernatant, which is the biological agent.
[0030] The tanninase activity of this biological agent was measured and the result was 5.82 U / mL.
[0031] Under the premise of keeping other parameters constant, the effects of different types of carbon sources, nitrogen sources, inorganic salts, and the optimal concentration of the culture medium on tanninase activity were investigated. The results are as follows: Figure 2 As shown.
[0032] Among the six carbon sources tested (culture medium: 3.0 g / L carbon source, 10 g / L peptone, 5 g / L NaCl), sucrose, starch, wheat bran, and corn flour all showed positive effects on tanninase activity. Corn flour exhibited the best performance, with an enzyme activity of 18.32 U / mL, significantly higher than the other carbon sources (see [link to test results]). Figure 2 A). From the perspective of concentration effect, the enzyme activity was highest at a corn flour concentration of 15 g / L, reaching 26.38 U / mL (see...). Figure 2 B). This indicates that corn flour, as a carbon source, can provide more suitable nutritional conditions for microbial growth and enzyme synthesis.
[0033] In the nitrogen source experiment (the culture medium consisted of 3.0 g / L beef extract, 10 g / L nitrogen source, and 5 g / L NaCl), such as Figure 2 As shown in Figure C, all five nitrogen sources (yeast extract, soybean peptone, soybean meal, tryptone, and ammonium nitrate) exhibited a promoting effect on tanninase activity. Soybean meal showed the highest enzyme activity (16.48 U / mL), and the highest enzyme activity of 25.25 U / mL was obtained at a soybean meal concentration of 20 g / L (see Figure C). Figure 2 D). Soybean meal, as a natural organic nitrogen source, may contain richer amino acids and growth factors, which are beneficial for enzyme synthesis.
[0034] In addition, the results of the inorganic salt experiment (culture medium: beef extract 3.0 g / L, peptone 10 g / L, inorganic salts 5 g / L) (see...) Figure 2 All six inorganic salts (E, F) can enhance tanninase activity, with CuSO4 being the most effective (13.58 U / mL), and the optimal concentration being 5 g / L (19.42 U / mL). Copper ions, as cofactors of many enzymes, play an important role in the catalytic activity of enzymes.
[0035] Example 3: Orthogonal Experiment of Culture Medium for Bacillus videlmani SXZY-01 Strain The shaking speed was fixed at 200 r / min, the temperature at 30℃, and the inoculum amount was 3% of the weight of the culture medium. An orthogonal combination experiment was set up, as shown in Table 1 (Experimental Design and Enzyme Activity Results), specifically: corn flour (10, 15, 20 g / L), soybean meal (15, 20, 25 g / L), CuSO4 (3, 5, 7 g / L).
[0036]
[0037] As shown in Table 1, the tanninase activity reached its highest level (40.98 U / mL) when the culture medium composition was 15 g / L corn flour, 20 g / L soybean meal, and 7 g / L CuSO4. This represents an increase of 35.16 U / mL compared to the enzyme activity in NA medium (5.82 U / mL), and an increase of 14.6 U / mL compared to the maximum enzyme activity after single-factor optimization (26.38 U / mL). This indicates that culture medium optimization can effectively improve the tanninase activity of strain SXZY-01.
[0038] Example 4: Tannin Degradation Rate and Sensory Evaluation of Tobacco Fermented with Enzyme Solutions of Different Concentrations A fixed mass ratio of material solution (distilled water + enzyme solution): tobacco shreds = 1.5:10 was used. Enzyme solution concentration gradients were set according to 0%, 0.5%, 1.5%, 2.5%, 3.5%, and 4.5% of the mass of the tobacco leaves to be treated, denoted as T1, T2, T3, T4, T5, and T6, respectively. The optimal biological agent from Example 3 (culture medium conditions: corn flour 15 g / L, soybean meal 20 g / L, CuSO4 7 g / L) was sprayed onto the tobacco shreds and then sealed for fermentation at 40℃ and 70% humidity for 24 h. After fermentation, the tobacco shreds were dried at 80℃ for 15 min to balance the moisture content, then rolled into cigarettes. The remaining portion was further dried in a 50℃ oven for 2 h.
[0039] The dried tobacco shreds were ground into powder, passed through a 40-mesh sieve, and the tannin content in the tobacco leaves was determined using a plant tannin detection kit (manufactured by Beijing Solarbio Technology Co., Ltd., model BC1395). The sensory quality of the tobacco shreds was evaluated in accordance with YC / T 138-1998 Tobacco Sensory Evaluation Method.
[0040] The results are as follows: Table 2 (Tannin Content in Tobacco under Different Treatments) shows that the tannin content of tobacco treated with different concentrations of enzyme solution all showed a decreasing trend. Under treatment T4, the tannin content decreased by 1040 nmol / g compared to treatment T1, with a degradation rate of 17.26%. When the enzyme solution concentration exceeded the T4 level (i.e., groups T5 and T6), the tannin degradation effect no longer improved, indicating the existence of an optimal concentration range. The data in Table 2 comprehensively show that adding the optimized Bacillus videmannii SXZY-01 inoculant can effectively increase the degradation of tannins in tobacco.
[0041]
[0042] Table 3 (Sensory Quality Evaluation Table for Treated Tobacco) shows that spraying different concentrations of enzyme solution with optimized culture medium onto tobacco leaves for fermentation significantly improved the overall quality compared to the control group (T1) sprayed with distilled water. The improvement was most pronounced at an enzyme solution concentration of 2.5% (T4 treatment). Specifically, the aroma was significantly improved, with increased aroma intensity, smoother smoke, reduced astringency, and noticeable improvement in bitterness and lingering aftertaste, along with increased smoothness. It should be noted that further increasing the enzyme concentration may lead to excessively high fermentation intensity, resulting in a decrease in tobacco quality compared to the T4 treatment. This indicates that the *Bacillus viride* SXZY-01 strain enzyme solution obtained through culture medium optimization can effectively improve the fermentation quality of tobacco leaves at suitable concentrations (especially 2.5%), demonstrating significant advantages in key indicators such as aroma, smoke, and aftertaste. This provides reliable data support for the industrial application of this technology.
[0043]
[0044] In summary, this invention successfully screened and isolated Bacillus videmannii SXZY-01 and its biological agents, which showed significant effects in degrading tannins in tobacco and improving the sensory quality of tobacco. Through a series of experiments, including orthogonal experiments on culture media and studies on the fermentation of tobacco shreds with different concentrations of enzyme solutions, the optimal culture medium composition and enzyme solution concentration were determined.
[0045] In practical applications, tobacco companies can utilize this technology to apply Bacillus videmannii SXZY-01 or its biological agents to tobacco fermentation processes. During fermentation, conditions are strictly controlled, and the strain is cultured according to the optimal culture medium formula to obtain a highly active tannin enzyme fermentation broth. This broth is then sprayed onto tobacco shreds at a suitable concentration (e.g., 2.5%) and fermented under appropriate temperature and humidity conditions. This effectively reduces the tannin content in tobacco, thereby improving the quality and added value of tobacco products.
[0046] From an environmental and sustainability perspective, this technology uses soybean meal, wheat bran, and other grain-based materials as the main culture medium components. These raw materials are widely available, inexpensive, and highly safe, reducing the environmental pollution that may result from traditional physicochemical methods for reducing tannins. Furthermore, it effectively degrades tannins without affecting other quality characteristics of tobacco, meeting the requirements for high-quality development in the tobacco industry.
[0047] In the future, further in-depth research can be conducted on the mechanism of action of Bacillus videmannii SXZY-01 to explore its application potential in other fields. Genetic modification and optimization of this strain can also be performed to increase its tannin production and activity, providing more efficient and higher-quality solutions for the tobacco industry and related fields, and promoting the industry's green and sustainable development.
[0048] It should be emphasized that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.
Claims
1. A strain of Bacillus videmannii ( Bacillus wiedmannii SXZY-01, with accession number CCTCC NO: M2025151, was deposited at the China Center for Type Culture Collection on January 15, 2025.
2. The use of Bacillus videmannii or its fermentation product as described in claim 1 in tobacco processing.
3. The application of Bacillus videmannii or its fermentation product according to claim 2 in tobacco processing, characterized in that, The fermentation products include tanninase.
4. A biological agent prepared from Bacillus videmannii or its fermentation product as described in claim 1, wherein the biological agent is used for: Degrades tannins in tobacco; Improving the sensory quality of tobacco, wherein the sensory quality is characterized by at least one of aroma quality, aroma quantity, woody off-flavors, irritation, aftertaste, strength, concentration, and smoothness; It enhances aroma harmony, reduces the harshness of smoke, and improves the bitterness of the aftertaste; Secretion or preparation of tanninase.
5. The biological agent prepared from Bacillus videmannii or its fermentation product according to claim 4, characterized in that, The preparation method of the biological agent includes the following steps: Step 1, Activation of bacterial strain: The Bacillus videmannii SXZY-01 was inoculated into NA solid medium and cultured at 25-35℃ for 36-72 hours; Step 2, Preparation of seed culture: Take the bacterial cells cultured in Step 1, inoculate them into liquid culture medium, and culture them in a shaker at 30-35℃ and 180-200 r / min for 12-16 h to obtain seed culture; Step 3, scale-up culture: Inoculate the seed culture obtained in step 2 into NA liquid medium at 2% to 4% of the culture medium weight, and culture at 30℃ to 35℃ and shaking speed of 180 to 200 r / min for 24 to 48 hours to obtain fermentation broth; Step 4: Prepare crude enzyme solution: Centrifuge the fermentation broth obtained in step 3 at 3-5℃ and 8000-10000rpm for 9-11 minutes, and take the supernatant, which is the biological agent.
6. The biological agent prepared from Bacillus videmannii or its fermentation product according to claim 5, characterized in that, In step 1, the composition of the NA solid culture medium includes, in g / L: 2-4 g of beef extract, 8-12 g of peptone, 4-6 g of sodium chloride, and 18-22 g of agar powder. In step 3, the NA liquid culture medium consists of: corn flour 5-25 g / L, soybean meal 5-25 g / L, and CuSO4 1-9 g / L.
7. The biological agent prepared from Bacillus videmannii or its fermentation product according to claim 6, characterized in that, In step 3, the NA liquid culture medium consists of: 15 g / L corn flour, 15 g / L soybean meal, and 7 g / L CuSO4.
8. The biological agent prepared from Bacillus videmannii or its fermentation product according to claim 4, characterized in that, When the biological agent is used to process tobacco, the following steps are included: Step A: Spray the biological agent onto the tobacco shreds at 0.5% to 5% of the mass of the tobacco leaves to be treated, adjust the moisture content of the tobacco shreds to 18% to 22%, seal, and ferment at 40 to 50°C and 70% to 80% humidity for 20 to 30 hours. Step B: Dry the tobacco shreds at 80℃ for 10-15 minutes to balance the moisture content.