Corn steep liquor for fermentation and its preparation method and application

Abstract

The application provides corn steep liquor for fermentation and a preparation method and application thereof, and belongs to the technical field of biology.The preparation of the corn steep liquor for fermentation comprises the following steps: hydrolyzing corn steep liquor, homogenizing the hydrolyzed corn steep liquor, and then heating and filtering the homogenized corn steep liquor to obtain the corn steep liquor for fermentation.The hydrolysis and high-pressure homogenization process are combined, microorganisms remaining in the corn steep liquor can be effectively cracked, macromolecular proteins and other substances can be decomposed into nutrients which are easy to utilize, the risk of contamination of a fermentation tank due to incomplete sterilization of the corn steep liquor is reduced, and the conversion rate of a fermentation product is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of biotechnology, and particularly relates to a corn steep liquor for fermentation, a preparation method and application thereof. BACKGROUND

[0002] Corn steep liquor is a byproduct of corn starch production, containing a large amount of amino acids, vitamins and growth factors, and is a cheap organic nitrogen source. Its rich nutritional ingredients can promote cell growth and improve fermentation acid production and sugar acid conversion rate. In the fermentation production of amino acids, corn steep liquor as an organic nitrogen source and growth factor supplier plays an important role in amino acid fermentation. It contains rich biotin and limiting amino acids, which can significantly affect the fermentation process of amino acids. By increasing the amount of corn steep liquor, part of the organic nitrogen source such as soybean meal hydrolysate, yeast powder and hair powder can be reduced or replaced, thereby reducing the cost of amino acid production. Corn steep liquor can also be used as a high-quality feed additive and raw material to provide the necessary nutrients for animals. It contains rich protein, amino acids, vitamins and minerals, which can improve the nutritional ingredients of feed, increase the palatability and nutritional value of feed.

[0003] The traditional corn steep liquor treatment method is hydrolysis method, which can better treat corn steep liquor, but there are still a large amount of microorganisms such as bacillus in the treated corn steep liquor. The inactivation temperature of bacillus is high, and at the same time, there are many impurities in the corn steep liquor, which wrap the miscellaneous bacteria. Incomplete sterilization during fermentation use can easily lead to contamination and affect the fermentation level. Therefore, it is necessary to propose a new corn steep liquor treatment method for fermentation to solve the problem of high microbial content in corn steep liquor, reduce the risk of contamination in fermentation production, and improve the utilization rate of corn steep liquor. SUMMARY

[0004] Therefore, the present application aims to provide a corn steep liquor for fermentation, a preparation method and application thereof. The present application can effectively crack the residual microorganisms in the corn steep liquor, and at the same time, decompose macromolecular proteins and other substances into easily utilized nutrients, reduce the risk of contamination caused by incomplete sterilization of corn steep liquor in the fermentation tank, and improve the conversion rate of fermentation products.

[0005] To solve the above technical problems, the present application provides the following technical solutions:

[0006] The present application provides a preparation method of corn steep liquor for fermentation, comprising the following steps: hydrolyzing corn steep liquor, homogenizing the hydrolyzed corn steep liquor, then heating and filtering the homogenized corn steep liquor to obtain corn steep liquor for fermentation.

[0007] Preferably, the step of hydrolyzing corn steep liquor comprises: heating corn steep liquor, holding after heating is completed, then cooling the corn steep liquor, adding concentrated sulfuric acid, adjusting the pH to below 2.5, and stirring to obtain corn steep liquor hydrolysate.

[0008] Preferably, the corn steep liquor is heated to 100-130℃, and the holding time is 10-30 min.

[0009] Preferably, the corn steep liquor is cooled to 70-90℃.

[0010] Preferably, the volume ratio of the concentrated sulfuric acid to the corn steep liquor is 1:1-4.

[0011] Preferably, the homogenization is carried out under the conditions of temperature 15-30℃, pressure 60-100 Mpa, and feeding amount 10-30 L / min.

[0012] Preferably, the homogenized corn steep liquor is heated to 70-90℃.

[0013] Preferably, the filter pore size is 30-50 mesh.

[0014] The present application provides the corn steep liquor for fermentation prepared by the preparation method.

[0015] The present application provides the use of the corn steep liquor for fermentation prepared by the preparation method in the preparation of fermentation medium.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] The present application combines the hydrolysis and homogenization processes, which can effectively crack the residual microorganisms in the corn steep liquor, and can also decompose macromolecular proteins and other substances into easily utilized nutrients, thereby reducing the risk of contamination of the fermentation tank due to incomplete sterilization of the corn steep liquor, and improving the conversion rate of the fermentation product. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The left picture is the corn steep liquor hydrolysate prepared by Example 1, and the right picture is the corn steep liquor for fermentation prepared by Example 1 of the present application.

[0019] Figure 2 The left bottle is the corn steep liquor for fermentation prepared by Example 1 of the present application, and the right bottle is the corn steep liquor hydrolysate prepared by Example 1. DETAILED DESCRIPTION

[0020] The application provides a preparation method of corn steep liquor for fermentation, which comprises the following steps: hydrolyzing corn steep liquor, homogenizing the hydrolyzed corn steep liquor, and then heating and filtering the homogenized corn steep liquor to obtain the corn steep liquor for fermentation.

[0021] In the application, the step of hydrolyzing the corn steep liquor comprises the following steps: heating the corn steep liquor, keeping the temperature after heating, cooling the corn steep liquor after keeping the temperature, adding concentrated sulfuric acid to the corn steep liquor, adjusting the pH to below 2.5, and stirring to obtain the corn steep liquor hydrolysate.

[0022] In the application, the corn steep liquor is heated to 100-130 DEG C, preferably 110-125 DEG C, and further preferably 120 DEG C; and the keeping temperature is kept for 10-30 min, preferably 18-28 min, and further preferably 20 min.

[0023] In the application, the corn steep liquor is cooled to 70-90 DEG C, preferably 78-88 DEG C, and further preferably 80 DEG C during the hydrolysis of the corn steep liquor.

[0024] In the application, the volume ratio of sulfuric acid to corn steep liquor is 1:1-4, preferably 1:1.5-3.5, and further preferably 1:2.5. The application increases the proportion of sulfuric acid during hydrolysis and reduces the pH, which is not conducive to the growth of bacteria.

[0025] In the application, the homogenization is carried out under the following conditions: temperature 15-30 DEG C, pressure 60-90 Mpa, and feeding amount 10-30 L / min. The liquid material is forced to pass through a micro gap under high pressure, so that the material becomes fine and uniform under the action of high pressure and shearing force. When the material passes through the homogenization valve under high pressure, shearing, impact and cavitation effects are generated, so that the particles in the material are broken and the homogenization effect is achieved. The high-pressure homogenization method can effectively crack the residual microorganisms in the corn steep liquor and decompose macromolecular proteins and other substances into easily utilized nutrients.

[0026] In the application, the homogenized corn steep liquor is heated to 70-90 DEG C, preferably 78-88 DEG C, and further preferably 80 DEG C.

[0027] In the application, the pore size of the filter is 30-50 mesh, preferably 35-45 mesh, and further preferably 40 mesh. The filtration in the application is preferably carried out by using a filter bag.

[0028] The application also provides the corn steep liquor for fermentation prepared by the preparation method.

[0029] The application also provides the use of the corn steep liquor prepared by the preparation method in the preparation of a fermentation medium.

[0030] In the present application, all components or reagents or culture media are commercially available unless otherwise specified.

[0031] The technical solutions in the present application will be described clearly and completely in combination with the embodiments in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present application.

[0032] Embodiment 1

[0033] (1) The corn steep liquor was heated to 120℃, and after the heating was completed, the corn steep liquor was kept at 120℃ for 20 min. After the keeping was completed, the corn steep liquor was cooled to 75℃. Then, 98% concentrated sulfuric acid was added to the corn steep liquor at a volume ratio of 1:2.5, the pH was adjusted to below 2.5, and the mixture was stirred at 100 rpm for 30 min to obtain a corn steep liquor hydrolysate.

[0034] (2) The corn steep liquor hydrolysate was subjected to homogenization treatment by a high-pressure homogenizer, the temperature of the homogenizer was set to 20℃, the pressure was set to 80 Mpa, and the feeding amount of the corn steep liquor hydrolysate was set to 20 L / min to obtain a homogenized corn steep liquor.

[0035] (3) The homogenized corn steep liquor was heated to 85℃, and after the heating was completed, the homogenized corn steep liquor was filtered through a 40-mesh filter bag to obtain a fermentation corn steep liquor.

[0036] Embodiment 2

[0037] (1) The corn steep liquor was heated to 100℃, and after the heating was completed, the corn steep liquor was kept at 100℃ for 15 min. After the keeping was completed, the corn steep liquor was cooled to 70℃. Then, 98% concentrated sulfuric acid was added to the corn steep liquor at a volume ratio of 1:1, the pH was adjusted to below 2.5, and the mixture was stirred at 120 rpm for 20 min to obtain a corn steep liquor hydrolysate.

[0038] (2) The corn steep liquor hydrolysate was subjected to homogenization treatment by a high-pressure homogenizer, the temperature of the homogenizer was set to 15℃, the pressure was set to 60 Mpa, and the feeding amount of the corn steep liquor hydrolysate was set to 10 L / min to obtain a homogenized corn steep liquor.

[0039] (3) The homogenized corn steep liquor was heated to 70℃, and after the heating was completed, the homogenized corn steep liquor was filtered through a 60-mesh filter bag to obtain a fermentation corn steep liquor.

[0040] Embodiment 3

[0041] (1) The corn steep liquor was heated to 130°C, and after the heating was completed, the corn steep liquor was maintained at 130°C for 20 min. After the maintaining was completed, the corn steep liquor was cooled to 90°C. Then, 98% concentrated sulfuric acid was added to the corn steep liquor at a volume ratio of 1:4, and the pH was adjusted to 2.5 or less. The mixture was stirred at 150 rpm for 40 min to obtain a corn steep liquor hydrolysate.

[0042] (2) The corn steep liquor hydrolysate was subjected to homogenization treatment by a high-pressure homogenizer. The temperature of the homogenizer was set to 30°C, the pressure was set to 90 MPa, and the feeding amount of the corn steep liquor hydrolysate was set to 30 L / min to obtain a homogenized corn steep liquor.

[0043] (3) The homogenized corn steep liquor was heated to 90°C, and after the heating was completed, the homogenized corn steep liquor was filtered through a 100-mesh filter bag to obtain a fermentation corn steep liquor.

[0044] Comparative Example 1

[0045] Compared with Example 1, no homogenization treatment was performed, and the other steps were the same as those in Example 1.

[0046] Comparative Example 2

[0047] Compared with Example 1, the feeding amount in step (2) was changed to 40 L / min, and the other steps were the same as those in Example 1.

[0048] Comparative Example 3

[0049] Compared with Example 1, the homogenization pressure in step (2) was reduced to 40 MPa, and the other steps were the same as those in Example 1.

[0050] Comparative Example 4

[0051] Compared with Example 1, the homogenization temperature in step (2) was reduced to 10°C, and the other steps were the same as those in Example 1.

[0052] Comparative Example 5

[0053] Compared with Example 1, the homogenization pressure in step (2) was increased to 100 MPa, and the other steps were the same as those in Example 1.

[0054] Experimental Example 1

[0055] The corn steep liquor hydrolysate and the fermentation corn steep liquor in Example 1 were subjected to microscopic examination. The steps of the microscopic examination were as follows: The corn steep liquor hydrolysate and the fermentation corn steep liquor were respectively coated on a glass slide and heated to fix, 1 min of crystal violet was dropped for dyeing, and deionized water was used for washing to remove the floating color. The water flow during the washing process should not be too fast to avoid damaging the smear. Filter paper was used to absorb the excess water, and a drop of camphor oil was dropped. The microscopic examination was observed by a microscope with a 10-fold objective lens and a 100-fold objective lens. Figure 1As shown in the figure, the homogeneous corn syrup contains a large number of broken wall bacteria, and it is difficult to find the complete bacteria morphology. Thus, the method of the present application destroys the microorganism bacteria in the corn syrup for fermentation, and the obtained corn syrup for fermentation is free of bacteria pollution.

[0056] The state of the corn syrup hydrolysate in Example 1 and the corn syrup for fermentation is compared. As shown in the figure, the corn syrup before homogenization contains a large number of insoluble impurities, and the impurities are broken and dissolved after homogenization, and the corn syrup is mixed uniformly. Thus, the present application can better treat the corn syrup, which is beneficial to the utilization of the corn syrup in fermentation. Figure 2

[0057] Experimental Example 2

[0058] The corn syrup for fermentation prepared in Example 1 is used to ferment and produce lysine, and the steps are as follows:

[0059] (1) Preparation of primary seed tank medium: 450 g of beet molasses, 2 g of ferrous sulfate, 2 g of manganese sulfate, 40 g of potassium dihydrogen phosphate, 200 g of corn syrup for fermentation, 350 g of ammonium sulfate, 15 mg of copper sulfate, 15 mg of zinc sulfate, 50 mg of biotin and 2 ml of defoaming agent are dissolved in water, and the volume is made to be 10.5 L in a 30 L fermentation tank. Sterilization is carried out at 121℃ for 20 min. 1 kg of glucose powder and 20 g of magnesium sulfate are weighed and dissolved in water, and the volume is made to be 1.5 L in a feeding tank. The plug is wrapped with gauze and cowhide paper, and sterilized in a sterilization pot at 121℃ for 20 min.

[0060] (2) After sterilization, the liquid in the feeding tank is added into the tank through a peristaltic pump. The temperature is set to 32℃, the pH is set to 7.0, the stirring speed is set to 600 r, the tank pressure is set to 0.1 Mpa, and the air volume is set to 7.5 L / min. After maintaining stability for 10 min, the dissolved oxygen is calibrated to 100%. Under the protection of a flame ring, 500 mL of lysine corynebacterium seed is poured into the fermentation tank through the inoculation port. The stirring speed is set to 300 r, the air volume is set to 7.5 L / min, and the tank pressure is set to 0.05 Mpa. During the fermentation process, the stirring speed and air volume are increased when the dissolved oxygen decreases, and the dissolved oxygen is maintained at 30-40%.

[0061] (3) Preparation of large tank medium: 2.5 g of ferrous sulfate, 2.5 g of manganese sulfate, 15 g of potassium dihydrogen phosphate, 300 g of ammonium sulfate, 15 mg of copper sulfate, 15 mg of zinc sulfate, 40 mg of biotin, 200 g of corn syrup for fermentation, 300 g of beet molasses, 10 g of betaine, 15 g of magnesium sulfate and 2 ml of defoaming agent are dissolved in water, and the volume is made to be 11 L in a 50 L fermentation tank. Sterilization is carried out at 121℃ for 20 min.

[0062] ​(4) Preparation of the flow addition of small materials: ferrous sulfate 2 g, manganese sulfate 2 g, phosphoric acid 45 g, magnesium sulfate 55 g, copper sulfate 100 mg, zinc sulfate 100 mg, biotin 40 mg, corn syrup for fermentation 400 g, sugar beet molasses 450 g, betaine 60 g, and antifoaming agent 2 ml were dissolved in water, and the volume was made up to 6 L in a flow addition tank. The tank was sterilized at 121°C for 20 min. The sugar solution and ammonium sulfate for production were taken from the workshop and sterilized at 121°C for 20 min.

[0063] (5) After sterilization, 300 g of the sugar solution was added to the fermentation tank by peristaltic pump. The bacteria in the primary seed tank were transferred to the large tank by a transfer pipe, and the transfer volume was 2.5 L. The temperature was set to 37°C, the pH was set to 6.9, the stirring speed was set to 300 r, the tank pressure was set to 0.05 MPa, the air volume was set to 0.5 m 3 / h, and the dissolved oxygen was calibrated to 100%. The tank was controlled to start fermentation.

[0064] After the pH rose again, the sugar solution, small materials, and ammonium sulfate were added for 24 h. The flow addition ratio of the sugar solution to the small materials was 8:1 (v / v) before 24 h, and 9:1 (v / v) after 24 h. The residual sugar was controlled to 0.5-1.0%, the ammonia nitrogen was controlled to 0.3-0.4%, and the dissolved oxygen was controlled to more than 30% during fermentation. As the fermentation proceeded, the stirring speed, air volume, and tank pressure were gradually increased when the dissolved oxygen was less than 30% to maintain the dissolved oxygen at more than 30% until the highest conditions. When the dissolved oxygen was too high in the late fermentation, the stirring speed and air volume were gradually reduced until the end of fermentation. The tank was discharged after 48 h of fermentation, and the lysine content and conversion rate were determined.

[0065] Experimental Example 3

[0066] The difference from Experimental Example 2 is that the fermentation corn syrup prepared in Example 1 is replaced with the fermentation corn syrup prepared in Comparative Example 1.

[0067] Experimental Example 4

[0068] The difference from Experimental Example 2 is that the fermentation corn syrup prepared in Example 1 is replaced with the fermentation corn syrup prepared in Comparative Example 2.

[0069] Experimental Example 5

[0070] The difference from Experimental Example 2 is that the fermentation corn syrup prepared in Example 1 is replaced with the fermentation corn syrup prepared in Comparative Example 3.

[0071] Experimental Example 6

[0072] The difference from Experimental Example 2 is that the fermentation corn syrup prepared in Example 1 is replaced with the fermentation corn syrup prepared in Comparative Example 4.

[0073] Experimental Example 7

[0074] The difference from Experimental Example 2 is that the fermentation corn steep liquor prepared in Example 1 is replaced by the fermentation corn steep liquor prepared in Comparative Example 5.

[0075] Experimental Example 8

[0076] The lysine content is determined by titration.

[0077] The conversion rate is calculated based on the following formula: sugar acid conversion rate = acid yield / total sugar consumption x 100%, acid yield = acid content x tank volume, and total sugar consumption is the actual consumption of glucose mass.

[0078] The results of the determined lysine content and conversion rate are shown in Table 1.

[0079] Table 1 Comparison results of lysine content and conversion rate of each group of fermentation

[0080]

[0081] Lysine fermentation has a relatively mature fermentation process, and it is found during the experiment that it is difficult to have a greater fermentation level improvement by making formula or process improvement. However, as can be seen from the results in Table 1, during the fermentation of lysine, the lysine content and conversion rate of lysine fermented by the fermentation corn steep liquor prepared in Example 1 are improved relative to the fermentation corn steep liquor prepared in Comparative Examples 1-5, indicating that the fermentation corn steep liquor prepared by the preparation process set by the present application has the effect of improving the yield of lysine.

[0082] Experimental Example 9

[0083] L-isoleucine is fermented and produced by using the fermentation corn steep liquor prepared in Example 1, and the steps are as follows:

[0084] (1) Prepare the first-stage seed tank medium: dissolve 0.8 g of ferrous sulfate, 0.5 g of manganese sulfate, 60 g of potassium dihydrogen phosphate, 600 g of fermentation corn steep liquor, 18 mg of copper sulfate, 12 mg of zinc sulfate, 0.16 g of biotin and 2 ml of defoaming agent in water, and make up to 10.5 L in a 30 L fermentation tank, and sterilize at 121°C for 20 min. Weigh 1 kg of glucose powder, 23 g of magnesium sulfate and 400 g of sugar beet molasses, dissolve in water, make up to 1.5 L in a flow tank, wrap the plug with gauze and cow leather, and sterilize in a sterilization pot at 121°C for 20 min.

[0085] (2) After sterilization, the feed liquid in the flow tank was added into the tank by peristaltic pump. The temperature was set at 30°C, pH 7.4, stirring 600 r, tank pressure 0.05 Mpa, air volume 12 L / min, and the stable state was maintained for 5 min before calibration of the dissolved oxygen 100%. Under the protection of the flame ring, 50 mL of Corynebacterium isolevi seed was poured into the fermenter through the inoculation port, and the stirring was set at 300 r, the air volume was 6 L / min, and the tank pressure was 0.05. During the fermentation process, the stirring speed and air volume were increased when the dissolved oxygen decreased, and the dissolved oxygen was maintained at 30-40%. OD detection was started at 8 h, and the detection was performed once every 2 h. After 22 h, the OD value was 0.653, and the pressure was maintained.

[0086] (3) Preparation of large tank medium: ferrous sulfate 50 mg, manganese sulfate 70 mg, potassium dihydrogen phosphate 20 g, ammonium sulfate 60 g, copper sulfate 12 mg, zinc sulfate 14 mg, biotin 0.15 g, and defoaming agent 2 ml were dissolved in water, and the volume was made up to 18 L in a 50 L fermenter. The medium was sterilized at 121°C for 20 min. 4 kg of glucose powder, 19 g of magnesium sulfate, and 430 g of sugar beet molasses were weighed and dissolved in water, and the volume was made up to 6 L in a flow tank. The plug was wrapped with gauze and cowhide paper, and sterilized in a sterilization pot at 121°C for 20 min.

[0087] (4) After sterilization, the feed liquid in the flow tank was added into the tank by peristaltic pump. The temperature was set at 32°C, pH 7.4, stirring 650 r, tank pressure 0.05 Mpa, air volume 1 m³ / h, and the stable state was maintained for 5 min before calibration of the dissolved oxygen 100%. The first stage seed tank liquid was transferred to the large tank by a transfer pipe, and the transfer volume was 4 L. The stirring was set at 300 r, the tank pressure was 0.05, and the ventilation ratio was 0.3, and the tank was controlled.

[0088] (5) During the fermentation process, the initial sugar content was 12 g / dL. When the dissolved oxygen was lower than 20%, the stirring speed was gradually increased to maintain the dissolved oxygen at 20-30%. When the stirring speed was increased to 350 r, the ventilation ratio was increased by 0.1. Then the stirring speed was gradually increased to 400 r, and the ventilation ratio was increased to 0.4. In this way, the highest condition was achieved. In the later stage of fermentation, the stirring speed was gradually reduced when the dissolved oxygen was too high, and the ventilation ratio remained unchanged until the end of fermentation. After 21 h of fermentation, the pH increased, and after 10 min of pH increase, the L-isoleucine acid content and conversion rate were measured.

[0089] Experimental Example 10

[0090] The difference between Experimental Example 9 and Experimental Example 10 is that the fermentation corn syrup prepared in Example 1 is replaced with the fermentation corn syrup prepared in Comparative Example 1.

[0091] Experimental Example 11

[0092] The difference between Experimental Example 9 and Experimental Example 11 is that the fermentation corn syrup prepared in Example 1 is replaced with the fermentation corn syrup prepared in Comparative Example 2.

[0093] Experimental Example 12

[0094] The difference from Experimental Example 9 is that the fermentation corn steep liquor prepared in Example 1 is replaced with the fermentation corn steep liquor prepared in Comparative Example 3.

[0095] Experimental Example 13

[0096] The difference from Experimental Example 9 is that the fermentation corn steep liquor prepared in Example 1 is replaced with the fermentation corn steep liquor prepared in Comparative Example 4.

[0097] Experimental Example 14

[0098] The difference from Experimental Example 9 is that the fermentation corn steep liquor prepared in Example 1 is replaced with the fermentation corn steep liquor prepared in Comparative Example 5.

[0099] Experimental Example 15

[0100] The L-isoleucine content is determined by high performance liquid chromatography.

[0101] The conversion rate is calculated based on the following formula: sugar acid conversion rate = acid yield / total sugar consumption x 100%, acid yield = acid content x tank volume, and the total sugar consumption is the actual consumption of glucose mass.

[0102] The determined isoleucine content and conversion rate are shown in Table 2.

[0103] Table 2 Comparison of L-isoleucine content and conversion rate in each group

[0104]

[0105] Isoleucine fermentation itself produces low acid and belongs to low conversion rate fermentation. Compared with other amino acids, it is difficult to greatly improve the conversion rate, and a small increase in the conversion rate is a relatively large change in the experimental or production process. As can be seen from the results in Table 2, during the fermentation of isoleucine, the use of the fermentation corn steep liquor prepared in Example 1 to produce L-isoleucine has improved the L-isoleucine content and conversion rate relative to the fermentation corn steep liquor prepared in Comparative Examples 1-5, indicating that the fermentation corn steep liquor prepared by the preparation process of the present application has the effect of improving the yield of L-isoleucine.

[0106] The above only describes the preferred embodiments of the present application, and it should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered within the scope of protection of the present application.

Claims

1. A method for preparing a corn steep liquor for fermentation, characterized by, The method comprises the following steps: hydrolyzing corn steep liquor, homogenizing the hydrolyzed corn steep liquor, and then heating and filtering the homogenized corn steep liquor to obtain the corn steep liquor for fermentation. The step of hydrolyzing the corn steep liquor comprises the following steps: heating the corn steep liquor, keeping the temperature, cooling the corn steep liquor after the keeping, adding concentrated sulfuric acid to the corn steep liquor, stirring, and adjusting the pH to below 2.5 to obtain the corn steep liquor hydrolysate. The homogenization is performed under the following conditions: temperature 15-30 ℃, pressure 60-90 Mpa, and feeding amount 10-30 L / min. The corn steep liquor is heated to 100-130 ℃, and the keeping time is 10-30 min. The corn steep liquor is cooled to 70-90 ℃.

2. The production method according to claim 1, wherein The volume ratio of the concentrated sulfuric acid to the corn steep liquor is 1:1-4.

3. The production method according to claim 1, wherein The homogenized corn steep liquor is heated to 70-90 ℃.

4. The production method according to claim 1, wherein The pore size of the filter is 30-50 mesh.

5. The corn steep liquor for fermentation prepared by the preparation method of any one of claims 1-4.

6. The use of the corn steep liquor for fermentation prepared by the preparation method of any one of claims 1-4 in the preparation of a fermentation medium.

Images