Devodia sp. And method for fermenting corn steep liquor by using devodia sp.

Abstract

The invention relates to the technical field of microorganisms, in particular to Devodia sp. And a method for fermenting corn steep liquor by using the Devodia sp. The invention provides the Deworth's bacteria capable of efficiently degrading vomitoxin in the corn steep liquor, the Candida krusei and the Candida krusei are used for cooperatively fermenting the corn steep liquor, the pH of the corn steep liquor can be increased, the content of vomitoxin and antinutritional factors in the corn steep liquor can be reduced, the content of choline in the corn steep liquor is remarkably increased, the quality of the corn steep liquor is obviously improved, and the yield of the corn steep liquor is increased. The corn steep liquor subjected to synergistic fermentation can be better applied to the field of animal feed and has a wide application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of microorganisms, in particular to a strain of Devoschia and a method for fermenting corn steep liquor by using the strain. Background Art

[0002] Feed and its feed ingredients are very susceptible to mycotoxin contamination during growth and storage. Mycotoxin then enters the food chain, threatening the healthy breeding of animals and seriously restricting the development of animal husbandry. Deoxynivalenol (DON) is one of the most widespread mycotoxins. It is mainly a type of mycotoxin produced by Fusarium and is widely found in grains such as corn, wheat and barley. Deoxynivalenol mainly affects protein synthesis by affecting the synthesis of DNA and RNA and blocking the initiation of translation. The toxin can cause reproductive performance disorders such as loss of appetite, developmental stunting, metabolic disorders, immune disorders, infertility in female animals, miscarriage in pregnant animals, and fetal abnormalities in livestock and poultry, causing serious damage to the livestock industry.

[0003] Corn slurry is the concentrate of corn soaking water during the wet extraction of corn starch. Corn slurry is rich in protein, soluble sugars, short-chain starch, amino acids, minerals and trace elements, and is a high-quality animal feed raw material. However, corn slurry contains a certain amount of sulfites, and long-term feeding will lead to sulfite residues in livestock and poultry; and the pH of corn slurry is relatively low, and long-term feeding of corn slurry will also affect the animal's digestive system, affecting its health and production performance; in addition, there are problems such as vomitoxin contamination in corn slurry, which seriously restricts its application.

[0004] In the prior art, CN103387950 discloses a strain of Devosulina, which can degrade vomitoxin in grains. CN118406618A also discloses a strain of Devosulina and its application, which still has the ability to degrade vomitoxin after being cultured in a low pH environment and has good tolerance to low pH environments. However, these prior arts do not focus on the problem of increasing the pH of corn steep liquor and degrading sulfites.

[0005] Therefore, how to increase the pH of corn steep liquor and reduce the content of vomitoxin and sulfite in corn steep liquor has become a technical problem that urgently needs to be solved in this field. Summary of the invention

[0006] First, the present invention provides a strain of Devoshigena ( Devosia sp. ), which is Devosia C2-8, and its preservation number is CGMCC No.32030.

[0007] The strain can efficiently degrade vomitoxin in corn steep liquor and can completely degrade 100 µg / mL of DON within 10 minutes, thereby solving some of the problems existing in the above-mentioned prior art.

[0008] Furthermore, the present invention provides a microbial agent containing the Devospasella C2-8.

[0009] In some embodiments, the microbial agent is a lyophilized powder of fermentation broth of Devospasella C2-8.

[0010] In some embodiments, the fermentation broth freeze-dried powder also includes a freeze-drying protectant.

[0011] Furthermore, the present invention provides a product containing the Devospasella C2-8 or the microbial agent.

[0012] Furthermore, the present invention provides the use of the Devospasella C2-8 or the microbial agent in preparing a product.

[0013] In some embodiments, the product is a feed or a feed additive.

[0014] Furthermore, the present invention also provides the use of the Devospasella C2-8, the microbial agent or the product in degrading vomitoxin.

[0015] In some embodiments, the present invention provides the use of the Devospasella C2-8, the microbial agent or the product in degrading vomitoxin in neutral corn steep liquor.

[0016] In addition, the present invention also provides a method for fermenting corn steep liquor, comprising: Candida krusei ) 109 is inoculated into corn steep liquor for fermentation until the pH reaches above 6.5 and then sterilized, and then inoculated with Devosia C2-8 for secondary fermentation; the Candida krusei ( Candida krusei ) The accession number of 109 is CGMCC No.32031.

[0017] By using Candida krusei 109 and Devosia solani C2-8 to synergistically ferment corn steep liquor, the pH value of corn steep liquor can be increased, the contents of vomitoxin and anti-nutritional factors in corn steep liquor can be reduced, and the content of choline in corn steep liquor can be increased.

[0018] Preferably, the anti-nutritional factors are phytic acid and sulfite ions.

[0019] The Candida krusei 109 in the present invention is isolated and screened from fermented food. The strain was deposited in the General Microbiological Center of the China Microbiological Culture Collection Administration on September 20, 2024. The address of the depository unit is: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing; Postal Code: 100101, Classification Name: Candida krusei Candida krusei , the deposit number is CGMCC No.32031.

[0020] The Devosella C2-8 in the present invention was isolated and screened from wheat. The strain was deposited in the General Microbiological Center of the China Microbiological Culture Collection Administration on September 20, 2024. The depository address is: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing; Postal Code: 100101, Classification Name: Devosella Devosia sp. , the deposit number is CGMCC No.32030.

[0021] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a strain of Devosia that can efficiently degrade vomitoxin in corn steep liquor. By using the strain with Candida krusei to synergistically ferment corn steep liquor, the pH value of corn steep liquor can be increased, the contents of vomitoxin and anti-nutritional factors in corn steep liquor can be reduced, the content of choline in corn steep liquor can be significantly increased, and the quality of corn steep liquor can be significantly improved. The corn steep liquor after synergistic fermentation can be better applied in the field of animal feed, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the growth curve of Devosia C2-8.

[0023] Figure 2 This is the result graph of the degradation of DON standard by Devosia C2-8.

[0024] Figure 3 This is the result of Devosia C2-8 degrading DON in neutral corn steep liquor medium.

[0025] Figure 4 This is a graph showing the results of Candida krusei working together with Devosia to degrade DON in corn steep liquor culture medium.

[0026] Figure 5 This is a graph showing the effect of fermentation of Candida krusei and Devosia on the anti-nutritional factors of corn steep liquor culture medium.

[0027] Figure 6 This is a graph showing the effects of fermentation of Candida krusei and Devosia on the nutritional factors of corn steep liquor culture medium. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In the examples provided in this specification, if no specific techniques or conditions are specified, the techniques or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased through regular channels.

[0030] Example 1 Growth curve of Devosia C2-8 A single clone of Devosella C2-8 was selected and transferred to LB medium. The culture was carried out at 180 rpm and 37 °C for 24 h to obtain the seed solution of Devosella C2-8. Devosella C2-8 was inoculated into LB medium at a 0.1% inoculation rate and cultured at 180 rpm and 37 °C. Samples were taken at 0, 6, 12, 24, 30, 36, and 42 h, respectively. The absorbance of Devosella was detected at 600 nm, and the growth curve was finally drawn.

[0031] like Figure 1 As shown, the logarithmic phase of Devosia is 6-24h, and the stable phase is reached after 24h.

[0032] Example 2 Degradation of DON Standard by Devoshigena C2-8 A single clone of Devosella C2-8 was selected and transferred to LB medium. The culture was carried out at 180 rpm and 37 °C for 24 h to obtain the Devosella C2-8 seed solution. Devosella C2-8 was inoculated into LB medium at a 1% inoculation rate. The culture was carried out at 180 rpm and 37 °C. Samples were taken at 18, 20, 22, 24, 26, 28, 42 and 48 h, respectively. DON standards with a final concentration of 100 µg / mL were added, respectively. The culture was carried out at 180 rpm and 37 °C, and samples were taken at 1, 3, 5, 10 and 60 min, respectively, to detect the DON content.

[0033] like Figure 2 As shown, Devosella cultured for 24 h can completely degrade 100 µg / mL DON standard within 10 min.

[0034] Example 3 Degradation of DON in Neutral pH Corn Stew by Devosia C2-8 A single clone of Devosella C2-8 was selected and transferred to LB medium. The culture was carried out at 180 rpm and 37 °C for 24 h to obtain the Devosella C2-8 seed solution. Devosella C2-8 was inoculated at 1% and 5% in corn slurry medium with different concentrations (the pH of corn slurry was adjusted to 7.0, and the corn slurry medium was prepared at concentrations of 4%, 8%, 12%, 16%, 20% and 24%, and sterilized at 121 °C for 15 min). The culture was carried out at 180 rpm and 37 °C, and samples were taken after 24 h to detect the DON content in the corn slurry.

[0035] like Figure 3As shown, at a 1% inoculation amount, Devosella C2-8 can completely degrade DON in 8% corn steep liquor within 24 hours; at a 5% inoculation amount, Devosella C2-8 can completely degrade DON in 12% corn steep liquor within 24 hours.

[0036] Example 4: Candida krusei 109 increases the pH of corn steep liquor and then Devosia spp. C2-8 degrades DON in corn steep liquor A single clone of Candida krusei was selected and placed in YPD medium, and cultured at 180 rpm and 28°C for 24 h to obtain a Candida krusei seed solution, which was inoculated with 5% of the Candida krusei into a 4%-32% corn steep liquor medium, and the medium was sterilized when the pH of the medium reached above 6.5. Then, Devospasella C2-8 was inoculated at 1% of the inoculation amount and cultured at 180 rpm and 37°C until DON in the corn steep liquor was completely degraded.

[0037] like Figure 4 As shown in the data, when Candida krusei raised the pH of 4%-24% corn steep liquor culture medium to neutral, the inoculated Devospastoles could completely degrade DON in corn steep liquor, but as the corn steep liquor concentration increased, the time for Devospastoles to degrade DON in corn steep liquor increased; when the concentration of corn steep liquor culture medium was increased to 28%, the ability of Devospastoles to degrade DON in its culture medium was significantly reduced. After incubation for 3 days, the degradation rate of DON in 28% corn steep liquor culture medium was only 22%.

[0038] Example 5 Effect of synergistic fermentation of Candida krusei 109 and Devosia solani C2-8 on anti-nutritional factors in corn steep liquor Pick a single clone of Candida krusei into YPD medium, culture at 180rpm, 28℃ for 24h, obtain Candida krusei seed liquid, inoculate Candida krusei into 16% corn steep medium at 5% inoculation, sterilize when the pH of the medium reaches above 6.5, then inoculate Devospasmus C2-8 at 1% inoculation, culture at 180rpm, 37℃ for 24h, and detect the concentration of phytic acid and sulfite in corn steep medium. The determination of sulfite in corn steep liquor refers to GB 5009.34-2022 Determination of sulfur dioxide in food. Determination of phytic acid: weigh 10g of sample and place it in a conical flask, add 40mL sodium sulfate-hydrochloric acid extraction solution (sodium sulfate concentration is 10%, hydrochloric acid concentration is 1.2%), shake and extract for 2h, centrifuge the extract at 5000rpm for 5min, collect the supernatant, and make up to 50mL with sodium sulfate-hydrochloric acid extraction solution, filter through rapid filter paper for use. Take 0.5g of anion exchange resin (AG1-X4106µm-250µm, ion exchange capacity 3.5mmol / g) and wet load it into an empty column tube, wash the ion exchange column with 15mL of 0.7mol / L sodium chloride solution and 20mL of water respectively. Take 5mL of filtrate, add 1mL of 30g / L sodium hydroxide solution, dilute to 30mL with water, mix well and transfer to the activated ion exchange column, then elute the exchange column with 15mL of water and 15mL of 0.05mol / L sodium chloride solution at a flow rate of 1mL / min, and discard the effluent. Finally, elute with 25mL of 0.7mol / L sodium chloride solution, collect the eluate, and dilute to 25mL. Accurately pipette 5 mL of the eluate obtained in the previous section into a 10 mL colorimetric tube, add 4 mL of ferric chloride-sulfosalicylic acid reaction solution, mix well, let stand for 20 min, pipette part of the mixture into a 1 mL colorimetric dish, measure the absorbance at 500 nm, and determine the phytic acid content according to the standard curve.

[0039] like Figure 5 As shown, after fermentation with Candida krusei and Devosia solani, the contents of phytic acid and sulfite were significantly reduced, with the phytic acid concentration decreasing from 1.81 mg / mL to 0.98 mg / mL and the sulfite concentration decreasing from 0.37 mg / mL to 0.28 mg / mL.

[0040] Example 6 Effect of synergistic fermentation of Candida krusei 109 and Devosia solani C2-8 on nutritional factors in corn steep liquor Pick a single clone of Candida krusei into YPD medium, culture at 180rpm, 28℃ for 24h, obtain Candida krusei seed solution, inoculate Candida krusei into 16% corn steep liquor medium at 5% inoculation, sterilize when pH of medium reaches above 6.5, then inoculate Devosella C2-8 at 1% inoculation, culture at 180rpm, 37℃ for 24h, and detect the changes of crude protein, inositol and choline content in corn steep liquor medium. The determination of crude protein content refers to GB / T 6432-2018, the determination of inositol content refers to NY / T 1345-2007, and the determination of choline content refers to NY / T 1819-2009.

[0041] The results are as follows Figure 6 As shown in the figure, after fermentation by Candida krusei and Devosia solani, the contents of crude protein and inositol in corn steep liquor decreased, but the differences in content changes were not significant; while the content of choline increased to a certain extent, from 2.35 g / L to 3.33 g / L.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A strain of Devoshigena ( Devosia sp. ), characterized in that, It is Devosia sp. C2-8, and its deposit number is CGMCC No.32030.

2. A microbial agent containing the Devospasella C2-8 according to claim 1.

3. The microbial agent according to claim 2, characterized in that: The microbial agent is freeze-dried powder of fermentation broth of Devospasella C2-8.

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

5. A product containing the Devospasella C2-8 according to claim 1 or the microbial agent according to any one of claims 2 to 4.

6. Use of the Devospasella C2-8 described in claim 1 or the microbial agent described in any one of claims 2 to 4 in the preparation of a product.

7. Use of the Devoserella C2-8 described in claim 1, the microbial agent described in any one of claims 2 to 4, or the product described in claim 5 in degrading vomitoxin.

8. Use of the Devoserella C2-8 described in claim 1, the microbial agent described in any one of claims 2 to 4, or the product described in claim 5 in degrading vomitoxin in neutral corn steep liquor.

9. A method for fermenting corn steep liquor, characterized in that: include: Candida krusei ( Candida krusei ) 109 is inoculated into corn steep liquor for fermentation until the pH reaches above 6.5 and then sterilized, and then inoculated with the Devosia C2-8 described in claim 1 for secondary fermentation; the Candida krusei ( Candida krusei ) The accession number of 109 is CGMCC No.32031.

10. The method according to claim 9, characterized in that The processing method can increase the pH value of corn steep liquor, reduce the contents of vomitoxin and anti-nutritional factors in corn steep liquor, and increase the content of choline in corn steep liquor.

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