Plant lactobacillus fermentation process

Abstract

The invention belongs to the technical field of microbial fermentation, and provides a plant lactobacillus fermentation process. The fermentation process provided by the invention comprises the preparation processes of strain preparation, primary seed tank culture, fermentation tank culture and the like. According to the fermentation process, low-cost raw materials such as corn steep liquor and molasses are used as a culture medium, a trace amount of inorganic salt is added into the culture medium, the ratio of all the raw materials is adjusted, and a material supplementing process is combined, so that the cost is reduced, the growth of thalli and stable fermentation of the thalli are ensured, and the zymophyte quantity of the plant lactic acid bacteria is increased to 2,59 billion from original 10,000,000,000,000,000,000,000,000,000,000,000,000,000.

Description

Technical Field

[0001] The invention belongs to the technical field of microbial fermentation, and particularly relates to a plant lactic acid bacteria fermentation process. Background Art

[0002] Plant lactic acid bacteria are a type of bacteria that can ferment sugars to produce lactic acid. They are widely found in nature, especially in vegetable and fruit foods. Through fermentation, plant lactic acid bacteria can give food a unique flavor and taste, while improving the nutritional value and biological activity of food. In the food industry, plant lactic acid bacteria fermentation technology is widely used in the production of dairy substitutes, fermented vegetables, functional foods and other products.

[0003] The traditional plant lactic acid bacteria fermentation process usually has the following problems: first, the fermentation bacteria amount is low. In the traditional plant lactic acid bacteria fermentation process, the fermentation bacteria amount is usually 80-100×10 8 CFU / mL is relatively low. Low fermentation bacteria amount will affect fermentation efficiency, prolong fermentation time, and also affect the flavor and nutritional value of the product. Secondly, the raw material cost is high. The raw material cost of the plant lactic acid bacteria fermentation process is relatively high, mainly due to the purchase of high-quality plant raw materials and the cultivation of lactic acid bacteria strains. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a plant lactic acid bacteria fermentation process. The fermentation process uses relatively cheap raw materials (corn syrup, molasses, etc.) instead of peptone, yeast extract powder, glucose and other high-priced raw materials as culture medium, adds trace inorganic salts to the culture medium, and combines the feeding process, which not only reduces the cost of raw materials and increases the amount of fermented bacteria, but also ensures the growth of bacteria and its stable fermentation, so that the amount of fermented bacteria is increased from the original 10.1 billion to 25.9 billion.

[0005] A plant lactic acid bacteria fermentation process mainly comprises the following steps:

[0006] (1) Preparation of bacterial strains: Activate the glycerol tube bacterial strains onto a first-generation plate and culture at 32-37°C for 2-3 days until colonies grow;

[0007] Pick 3-5 grown single colonies and activate them on the second generation plate, and culture them at 32-37℃ for 2-3 days until the colonies grow;

[0008] Pick the bacterial moss from the plate and inoculate it into a liquid shake bottle, culture it for 10 hours, pH is 4.5, OD≥3, and obtain the strain for tank application;

[0009] (2) Seed tank culture: The upper tank strain obtained in (1) is inoculated into a primary seed tank, with the inoculation amount being 0.3-1% of the seed tank culture medium, and the bacteria are fermented in the seed tank at 32-37° C. and 100 rpm to obtain a seed solution;

[0010] (3) Fermentation tank culture: The seeds in (2) were pressed into the fermentation tank by pressure difference, inoculated into the fermentation tank culture medium, and sterile air was introduced. The fermentation was cultured at 100 rpm and 32-37° C. for 2 h, and the feed was supplemented for 10-12 h. After the feed was stopped, the OD value was stopped when it was not too high.

[0011] Preferably, in (1), the preparation process of the solid culture medium used in the first-generation plate and the second-generation plate is as follows: by mass fraction, take 2% glucose, 1% peptone, 0.8% beef extract powder, 0.5% yeast extract powder, 0.3% sodium acetate, 0.1% dipotassium hydrogen phosphate, 0.05% magnesium sulfate, 0.04% manganese sulfate, 0.1% Tween 80, and the balance is purified water, stir and dissolve, adjust the pH to 6.4-6.6, and finally add agar powder with a mass fraction of 1.5-2%, sterilize at 121°C for 30 minutes, cool to 50-55°C after sterilization, pour into a plate with a diameter of 90 mm under sterile conditions, and the liquid volume of each plate is 20-25 mL. After solidification, incubate at 37°C for 24-36 hours.

[0012] Preferably, the preparation method of the liquid culture medium in the liquid shake flask in (1) is:

[0013] Calculated by mass fraction, take 2% glucose, 1% peptone, 0.8% beef extract powder, 0.5% yeast extract powder, 0.3% sodium acetate, 0.1% dipotassium hydrogen phosphate, 0.05% magnesium sulfate, 0.04% manganese sulfate, and 0.1% Tween 80, add purified water, adjust the pH to 6.4-6.6, and sterilize at 121°C for 30 minutes.

[0014] Preferably, the raw materials and formula of the seed tank culture medium in (2) are: by mass fraction, 1-2% peptone, 1-3% yeast extract, 1-3% glucose, 0.5-1% beef extract powder, 0.1-0.8% potassium dihydrogen phosphate, 0.1-0.8% magnesium sulfate, 0.2-0.5% sodium acetate, and 0.05-0.15% manganese sulfate.

[0015] Preferably, the fermentation culture conditions in the seed tank in (2) are as follows: closed and non-ventilated, pH 6.5-7.0 before disinfection, pH 6.2-6.4 after disinfection, water added to 600L before disinfection, volume 800-900L after disinfection, sterilization at 121-125°C for 30-40min, no control of dissolved oxygen, defoaming agent dosage of 0.1%, and culture at 32-37°C for 6-10h.

[0016] Preferably, in (3), the conditions for fermentation in the fermenter are:

[0017] The pH before disinfection is 6.5-7.5, the pH after disinfection is 6.0-7.0, the volume before disinfection is added with water to 8T, the volume after disinfection is added with water to 10T, sterilize at 121-125°C for 30-40min, adjust the pH to 6.5, use 0.1% defoaming agent, and culture at 32-37°C, 0.03-0.05MPa, 100rpm for 20-24h.

[0018] Preferably, the raw materials and proportions of the fermentation tank culture medium in (3) are as follows: by mass fraction, 2-3% molasses, 2-4% corn steep liquor, 0.5-1.5% glucose, 0.2-0.5% sodium acetate, 0.05-0.2% ammonium citrate, 0.5-1% ammonium sulfate, 0.1-0.8% potassium dihydrogen phosphate, 0.1-0.8% magnesium sulfate, and 0.05-0.15% manganese sulfate.

[0019] Preferably, (3) the medium supplement formula: by mass fraction, corn syrup 15%, molasses 10%, trace inorganic salt 0.5%;

[0020] The composition of trace inorganic salts is: by mass fraction, ferrous sulfate 0.5%, zinc sulfate 0.08%, cobalt sulfate 0.1%, copper sulfate 0.3%, biotin 0.1%;

[0021] The feed volume is 30% of the raw volume of the fermenter medium in (3);

[0022] The feeding flow rate is 30L / h / T; during the feeding process, the reducing sugar content is ≤2mg / mL, and the amino nitrogen content is ≤3mg / mL.

[0023] Compared with the prior art, the present invention has the following advantages and effects:

[0024] (1) After adopting the fermentation process provided by the present invention, the fermentation cycle is not much different from the original process, but the amount of fermented bacteria is significantly increased from 10.1 billion in the traditional process to 25.9 billion;

[0025] (2) The yeast extract powder and peptone used in the original formula are replaced with corn syrup and molasses, and combined with the feeding process, so that the fermentation process cost of the present invention is reduced by about 80%. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a microscopic picture of the strain in Example 2;

[0027] Figure 2 This is a picture of the colony morphology of the strain in Example 2 on a solid plate. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in conjunction with specific implementation methods.

[0029] Example 1 Preparation of strains

[0030] 1.1 Culture medium configuration

[0031] (1) Raw materials and proportions of solid culture medium: by mass fraction, glucose 2%, peptone 1%, beef extract powder 0.8%, yeast extract powder 0.5%, sodium acetate 0.3%, dipotassium hydrogen phosphate 0.1%, magnesium sulfate 0.05%, manganese sulfate 0.04%, Tween 80 0.1%.

[0032] Take the above raw materials, add the remaining amount of pure water, stir evenly, dissolve, adjust pH 6.6, and finally add 2% agar powder by mass, sterilize at 121℃ for 30min; after sterilization, take the culture medium out of the sterilizer, wait for the temperature to drop to 55℃, pour it into a plate (diameter 90mm) under sterile conditions, and the liquid volume of each plate is about 25mL. After solidification, place it in a 37℃ incubator for 36h without bacteria before use.

[0033] (2) Raw materials and proportions of liquid culture medium: by mass fraction, glucose 2%, peptone 1%, beef extract powder 0.8%, yeast extract powder 0.5%, sodium acetate 0.3%, dipotassium hydrogen phosphate 0.1%, magnesium sulfate 0.05%, manganese sulfate 0.04%, Tween 80 0.1%.

[0034] Take the above raw materials, add the remaining amount of purified water, stir and dissolve, adjust the pH to 6.6, sterilize at 121°C for 30 minutes, and inoculate after cooling.

[0035] 1.2 The steps for preparing the canning strain are as follows:

[0036] (1) Activate the glycerol tube bacteria on a sterile clean bench and culture them on a first-generation plate at 37°C for 3 days until colonies grow that are milky white, have neat edges, are uniform in size, and are free of foreign bacteria;

[0037] (2) Pick 5 single colonies from the first-generation plate and activate the second-generation plate in a sterile clean bench. Incubate at 37°C for 3 days until the colonies grow out, are milky white, have neat edges, are uniform in size, and are free of foreign bacteria;

[0038] (3) Pick the bacterial moss from the plate and inoculate it into a liquid shake flask. Cultivate it for 10 hours. When the pH drops to 4.5 and the OD is ≥3, and there are no foreign bacteria under microscopic examination, it can be used as the strain for tanking.

[0039] Example 2 Preparation of strains

[0040] 2.1 Culture medium configuration:

[0041] (1) Raw materials and proportions of solid culture medium: by mass fraction, glucose 2%, peptone 1%, beef extract powder 0.8%, yeast extract powder 0.5%, sodium acetate 0.3%, dipotassium hydrogen phosphate 0.1%, magnesium sulfate 0.05%, manganese sulfate 0.04%, Tween 80 0.1%.

[0042] Take the above raw materials, add purified water, stir, dissolve, and adjust the pH to 6.4, and finally add 1.5% agar powder by mass, sterilize at 121℃ for 30min; after sterilization, take the culture medium out of the sterilizer, wait for the temperature to drop to 50℃, and pour it into a plate (90mm in diameter) under sterile conditions, with each plate containing about 20mL of liquid. After solidification, place it in a 37℃ incubator for 24h without bacteria before use.

[0043] (2) Raw materials and proportions of liquid culture medium: by mass fraction, glucose 2%, peptone 1%, beef extract powder 0.8%, yeast extract powder 0.5%, sodium acetate 0.3%, dipotassium hydrogen phosphate 0.1%, magnesium sulfate 0.05%, manganese sulfate 0.04%, Tween 80 0.1%.

[0044] Take the above raw materials, add the remaining amount of purified water, stir and dissolve, adjust the pH to 6.4, sterilize at 121°C for 30 minutes, and inoculate after cooling.

[0045] 2.2 The steps for preparing the canning strain are as follows:

[0046] (1) Activate the glycerol tube bacteria on a sterile clean bench and culture them on a first-generation plate at 37°C for 2 days until colonies grow that are milky white, have neat edges, are uniform in size, and are free of foreign bacteria;

[0047] (2) Pick 4 single colonies from the first-generation plate and activate the second-generation plate in a sterile clean bench. Incubate at 37°C for 2 days until the colonies grow out, are milky white, have neat edges, are uniform in size, and are free of foreign bacteria;

[0048] (3) Pick the bacterial moss from the plate and inoculate it into a liquid shake flask. Cultivate it for 10 hours. When the pH drops to 4.5 and the OD is ≥3, and there are no foreign bacteria under microscopic examination, it can be used as the strain for tanking.

[0049] Example 3-4 Fermentation process

[0050] 1. First-level seed tank cultivation

[0051] 1.1 Formulation

[0052] Table 1 1.5m 3 Tank culture medium formula table (mass percentage %)

[0053] Serial number raw material Example 3 Example 4 1 Peptone 1 2 2 Yeast extract 1 3 3 glucose 1 3 4 Beef dip powder 0.5 1 5 Potassium dihydrogen phosphate 0.1 0.8 6 Magnesium sulfate 0.1 0.8 7 Sodium acetate 0.2 0.5 8 Manganese sulfate 0.05 0.15

[0054] 1.2 Fermentation process

[0055] Table 2 1.5m 3 Tank fermentation process control parameters

[0056]

[0057]

[0058] 1.3 Inoculation

[0059] In Example 3, the cultured upper tank strain in Example 1 is inoculated into a primary seed tank by flame inoculation, and the inoculation amount is 0.3% of the seed tank culture medium (the formula is shown in Table 1). After that, the seed tank fermentation culture process in Table 2 is used for culture, and the temperature in the seed tank is controlled at 32° C. and the rotation speed is 100 rpm. When the bacteria grow up, samples are taken regularly during the above process to detect pH, OD, and microscopic examination; OD ≥ 3, when the bacteria grow up to meet the standard and there are no foreign bacteria under microscopic examination, all the seed liquid is transferred to the fermentation tank for fermentation tank culture (the transfer pipeline needs to be steam sterilized for 1 hour, and the pipeline is cooled with sterile air before transferring).

[0060] Alternatively, in Example 4, the cultured upper tank strain in Example 2 is inoculated into a primary seed tank by flame inoculation, and the inoculation amount is 1% of the seed tank culture medium (the formula is shown in Table 1). After completion, the seed tank is cultured according to the seed tank fermentation culture process in Table 2, and the temperature in the seed tank is controlled at 37° C. and the rotation speed is 100 rpm. When the bacteria grow up, samples are taken regularly during the above process to detect pH, OD, and microscopic examination; OD ≥ 3, when the bacteria grow up to meet the standard and there are no foreign bacteria under microscopic examination, all the seed liquid is transferred to the fermentation tank for fermentation tank culture (the transfer pipeline needs to be steam sterilized for 1 hour, and the pipeline is cooled with sterile air before transferring).

[0061] 2. Fermentation tank culture

[0062] 2.1 Formula (basic material)

[0063] Table 3 15m 3 Tank culture medium formula table (mass percentage %)

[0064]

[0065]

[0066] Feed formula (%, mass percentage): corn syrup 15%, molasses 10%, trace inorganic salt 0.5%, and the balance is water.

[0067] Supplement volume: about 30% of the base material volume (about 2.4m 3 ).

[0068] Trace salts (%, mass percentage): ferrous sulfate 0.5%, zinc sulfate 0.08%, cobalt sulfate 0.1%, copper sulfate 0.3%, biotin 0.1%.

[0069] 2.2 Fermentation process

[0070] Table 4 15m 3 Tank fermentation process

[0071]

[0072] In Example 3, after the seed tank is grown, according to the operation, the seed is pressed into the fermentation tank by pressure difference (the medium formula in the fermentation tank is shown in Table 3). During the pressing process, the pressure of the seed tank is controlled at 0.15MPa, and the pressure of the fermentation tank is controlled at 0.02MPa. After all the transfers, the valve is closed, sterile air is introduced, the stirring is turned on at 100rpm, no ventilation, the temperature is set at 30°C, and the fermentation is started according to the process in Table 4;

[0073] Initial pH is 6.5. When pH drops to 6.0, click on pH auto-control and control it at 6.5. After 2 hours of cultivation, the bacteria grow up, OD>2.5, and start feeding at a flow rate of 30L / h / T. During the feeding process, the reducing sugar content is controlled to be ≤2mg / mL and the amino nitrogen content is ≤3mg / mL. The feeding flow rate is adjusted according to the above indicators. Feed for about 10 hours. After stopping feeding, the tank can be stopped when the OD value is not long. The entire culture cycle is 20 hours.

[0074] Alternatively, in Example 4, after the seed tank is grown, according to the operation, the seed is hydraulically pressed into the fermentation tank by pressure difference (the medium formula in the fermentation tank is shown in Table 3). The pressure of the seed tank is controlled at 0.2MPa, and the pressure of the fermentation tank is controlled at 0.03MPa. After all are transferred, the valve is closed, sterile air is introduced, the stirring is turned on at 100rpm, no ventilation, the temperature is set at 40°C, and fermentation is started according to the process in Table 4;

[0075] The initial pH is 7.5. When the pH drops to 7.0, click on the pH automatic control and control it at 6.5. Cultivate for 2 hours. When the bacteria grow up and OD>2.5, start feeding with a flow rate of 30L / h / T. During the feeding process, control the reducing sugar content to ≤2mg / mL and the amino nitrogen content to ≤5mg / mL. Adjust the feeding flow rate according to the above indicators. Feed for about 12 hours. After stopping feeding, wait until the OD value is not too long and then stop the tank. The whole culture cycle is 24 hours.

[0076] 3. Fermentation results

[0077] As shown in Examples 3-4, the fermentation cycle of the plant lactic acid bacteria fermentation process provided by the present invention is 20h (Example 3) and 24h (Example 4), the OD value is 30 (Example 3) and 40 (Example 4), and the total number of viable bacteria is detected according to the national standard for lactic acid bacteria detection;

[0078] Detection of fermentation bacteria can yield 15m 3 Total bacterial count in the fermentation tank: 240×10 8 CFU / mL, 243×10 in Example 4 8 CFU / mL.

[0079] Example 5

[0080] The difference from Example 3 is that this example uses 60m 3 The concentration of each raw material in each formula remains unchanged, and the added volume is increased in proportion to the volume of the fermenter. Other experimental conditions and steps are the same as those in Example 3;

[0081] The total number of bacteria obtained by fermentation was 259×10 8 CFU / mL.

[0082] Example 6

[0083] The difference from Example 4 is that this example uses 60m 3 The concentration of each raw material in each formula remains unchanged, and the added volume is increased in proportion to the volume of the fermenter. Other experimental conditions and steps are the same as those in Example 4;

[0084] The total number of bacteria obtained by fermentation was 248×10 8 CFU / mL.

[0085] In summary, the plant lactic acid bacteria fermentation process provided by the present invention reduces the cost of raw materials by about 80%, and the amount of fermented bacteria is reduced from 101×10 8 CFU / mL increased to 200~300×10 8 CFU / mL, which has been significantly improved.

[0086] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent changes and modifications made within the scope of the present invention should still fall within the scope of the present invention.

[0087] Comparative Example

[0088] Fermentation process of the original formula:

[0089] 1. The fermentation tank culture medium in the original formula (by mass fraction) is: 2.6% glucose, 1.4% peptone, 1.2% yeast extract powder, 0.35% sodium acetate, 0.1% potassium dihydrogen phosphate, and 0.05% magnesium sulfate.

[0090] 2. Inoculate the prepared liquid bacteria into the primary seed tank at a rate of 3% and culture for 8 hours.

[0091] The process of the first-level seed tank: culture temperature 37°C, no ventilation, tank pressure 0.05MPa, rotation speed 100rpm, culture to OD ≥ 3, culture for 8h, and then transfer to the fermentation tank for fermentation culture.

[0092] 3. Fermentation tank process parameters: culture temperature 37°C, no ventilation, tank pressure 0.05MPa, rotation speed 100rpm, and culture time of about 24h.

[0093] The results of fermentation using the original formula and fermentation process are shown in Table 5:

[0094] Table 5 Comparison of workshop production data

[0095] batch content <![CDATA[Fermenter volume (m 3 )]]> Plant lactic acid bacteria viable count (CFU / mL) 1 Original recipe 15 <![CDATA[101×10 8 ]]> 2 Example 3 15 <![CDATA[240×10 8 ]]> 3 Example 4 15 <![CDATA[243×10 8 <!-- 6 -->]]> 4 Example 5 60 <![CDATA[259×10 8 ]]> 5 Example 6 60 <![CDATA[248×10 8 ]]>

[0096] It can be seen from the data in Table 5 that the number of live bacteria of plant lactic acid bacteria obtained by the fermentation process of the present invention (Examples 3 to 6) is significantly higher than that obtained by the original formula process, increasing by nearly 2.6 times.

Claims

1. A plant lactic acid bacteria fermentation process, characterized in that: The main steps include: (1) Prepare bacterial strains: activate the glycerol tube bacterial strains onto the first-generation plate and culture at 32-37°C for 2-3 days until colonies grow; Pick 3-5 grown single colonies and activate them on the second generation plate, and culture them at 32-37℃ for 2-3 days until the colonies grow; Pick the bacterial moss from the plate and inoculate it into a liquid shake bottle, culture it for 10 hours, pH is 4.5, OD≥3, and obtain the strain for tank application; (2) Seed tank culture: The upper tank strain obtained in (1) is inoculated into the primary seed tank, with the inoculation amount being 0.3-1% of the seed tank culture medium, and the bacteria are cultured in the seed tank at 32-37°C and 100 rpm to obtain a seed solution; (3) Fermentation tank culture: Use pressure difference to press the seeds in (2) into the fermentation tank and inoculate them into the fermentation tank culture medium. Pass sterile air and ferment at 100 rpm and 32-37°C for 2 h. Feed for 10-12 h. After stopping the feeding, stop the tank culture when the OD value does not increase.

2. A plant lactic acid bacteria fermentation process as claimed in claim 1, characterized in that: (1) The preparation process of the solid culture medium used in the first-generation plate and the second-generation plate is as follows: by mass fraction, take 2% glucose, 1% peptone, 0.8% beef extract powder, 0.5% yeast extract powder, 0.3% sodium acetate, 0.1% dipotassium hydrogen phosphate, 0.05% magnesium sulfate, 0.04% manganese sulfate, 0.1% Tween 80, and the balance is purified water. Stir and dissolve, adjust the pH to 6.4-6.6, and finally add 1.5-2% agar powder by mass. Stir at 121°C for 30 min. After sterilization is completed, cool to 50-55°C and pour into a plate with a diameter of 90 mm under sterile conditions. The liquid volume of each plate is 20-25 mL. After solidification, incubate at 37°C for 24-36 h.

3. A plant lactic acid bacteria fermentation process according to claim 1, characterized in that: (1) The preparation method of liquid culture medium in liquid shake flask is as follows: Calculated by mass fraction, take 2% glucose, 1% peptone, 0.8% beef extract powder, 0.5% yeast extract powder, 0.3% sodium acetate, 0.1% dipotassium hydrogen phosphate, 0.05% magnesium sulfate, 0.04% manganese sulfate, and 0.1% Tween 80, add purified water, adjust the pH to 6.4-6.6, and sterilize at 121°C for 30 minutes.

4. A plant lactic acid bacteria fermentation process according to claim 1, characterized in that: (2) The raw materials and proportions of the medium for the seed tank are: Calculated by mass fraction: peptone 1-2%, yeast extract 1-3%, glucose 1-3%, beef extract powder 0.5-1%, potassium dihydrogen phosphate 0.1-0.8%, magnesium sulfate 0.1-0.8%, sodium acetate 0.2-0.5%, and manganese sulfate 0.05-0.15%.

5. A plant lactic acid bacteria fermentation process according to claim 1, characterized in that: The fermentation culture conditions of the seed tank described in (2) are: Sealed and not ventilated, pH 6.5-7.0 before disinfection, pH 6.2-6.4 after disinfection, add water to 600L before disinfection, volume 800-900L after disinfection, sterilize at 121-125℃ for 30-40min, do not control dissolved oxygen, use defoaming agent at 0.1%, and culture at 32-37℃ for 6-10h.

6. A plant lactic acid bacteria fermentation process according to claim 1, characterized in that: (3), the fermentation conditions of the fermentation tank are: The pH before disinfection is 6.5-7.5, the pH after disinfection is 6.0-7.0, the volume before disinfection is added with water to 8T, the volume after disinfection is added with water to 10T, sterilize at 121-125°C for 30-40min, adjust the pH to 6.5, the amount of defoaming agent is 0.1%, and culture is carried out at 32-37°C, 0.03-0.05MPa, and 100rpm for 20-24h.

7. A plant lactic acid bacteria fermentation process according to claim 1, characterized in that: (3) Raw materials and proportions of the medium for the fermentation tank: by mass fraction, molasses 2-3%, corn steep liquor 2-4%, glucose 0.5-1.5%, sodium acetate 0.2-0.5%, ammonium citrate 0.05-0.2%, ammonium sulfate 0.5-1%, potassium dihydrogen phosphate 0.1-0.8%, magnesium sulfate 0.1-0.8%, and manganese sulfate 0.05-0.15%.

8. A plant lactic acid bacteria fermentation process according to claim 1, characterized in that: (3) The formula of the medium supplement is: by mass fraction, corn syrup 15%, molasses 10%, trace inorganic salt 0.5%; The feed volume is 30% of the raw material volume of the fermenter medium in claim 7; The feeding flow rate was 30 L / h / T. During the feeding process, the reducing sugar content was ≤2 mg / mL and the amino nitrogen content was ≤3 mg / mL.

9. A plant lactic acid bacteria fermentation process as claimed in claim 8, characterized in that: The composition of trace inorganic salts is: by mass fraction, ferrous sulfate 0.5%, zinc sulfate 0.08%, cobalt sulfate 0.1%, copper sulfate 0.3%, and biotin 0.1%.

Images