Method for comprehensively utilizing various nutrient substances of soy sauce and bean dreg powder

Abstract

The invention discloses a method for comprehensively utilizing various nutrient substances of soy sauce and bean dreg powder, which mainly comprises the following steps of: firstly, extracting soluble protein and most salt in the soy sauce and bean dreg powder into supernate by a water washing method, and directly applying the supernate to fermentation of microorganisms, which is an extraction process as well as an effective desalting process; if the soy sauce and bean dreg powder washing liquid is prepared into a nutrient mixture in a drying manner, the nutrient mixture is a yeast powder nutrient analogue with the same function as yeast powder. And secondly, after the washed precipitate is dried, more than 65% of salt is removed compared with soy sauce bean dreg powder, the grease content can reach more than 20%, the protein in-vitro digestibility can reach about 65%, and the precipitate can be directly used as a feed raw material of livestock and poultry. The method is simple and convenient in process, high in operability and low in treatment cost.

Description

Technical Field

[0001] The invention belongs to the field of resource utilization of soy sauce residues, relates to a method for comprehensively utilizing various nutrients in soy sauce bean dregs powder, and in particular to overall simple and high-value application of nutrients in soy sauce bean dregs powder. Background Art

[0002] Soy sauce is a condiment made from soybeans and / or defatted soybeans (soybean meal or soybean cake), wheat and / or bran through microbial fermentation. In 2021, China's annual soy sauce production exceeded 7.5 million tons, and the production and consumption of soy sauce have been increasing year by year in the past four years. However, for every 1 kg of soy sauce produced, about 0.67 kg of soy sauce dregs powder will be produced.

[0003] Soy sauce dregs powder contains 20% to 30% crude protein, more than 10% carbohydrates, and the crude fat content of the soy sauce dregs powder remaining after producing high-end soy sauce with soybeans as raw materials is more than 20%. It can be seen that soy sauce dregs powder not only has a large yield, but also contains a large amount of nutrients and has a great recycling value.

[0004] However, the undried soy sauce dregs powder has a high moisture content, which can easily breed microorganisms and cause environmental pollution. At the same time, the soy sauce dregs powder contains a large amount of salt, which can cause animal poisoning if used directly as feed, and can cause soil salinization if used as fertilizer or directly landfilled.

[0005] At present, the following methods are mainly used to reuse soy sauce dregs powder: 1) Directly develop it as feed and feed additives: add wheat bran, rice bran and other auxiliary materials to soy sauce dregs powder, and then use it as feed after proper fermentation. However, the high salt content limits the amount of soy sauce dregs powder used, and the cost of the desalination process is relatively high; or use soy sauce dregs powder as a substrate for the production of feed additive enzyme preparations, but the addition of auxiliary materials before fermentation also limits its usage. 2) Develop it as a fertilizer: treat soy sauce dregs powder by fermentation or other treatments, and use it as fertilizer for agricultural planting. However, the commercial value of using soy sauce dregs powder as fertilizer after treatment is not high. 3) Develop and extract other nutrients: extract oil, soluble dietary fiber, soy isoflavones, protein, etc. from soy sauce dregs powder, but the extraction process is mostly complicated.

[0006] Most current research focuses on the utilization of a specific component of soy sauce dregs powder or its application in a certain direction. Only a small amount of nutrients in soy sauce dregs powder can be utilized, which will cause a large amount of nutrients to be wasted and lacks an overall simple application solution.

[0007] The water washing and desalination of soy sauce dregs powder has been reported in a large number of literatures (e.g., CN 101385532B), but no literature focuses on the nutritional value of the desalted solution, and more research focuses on how to prevent the loss of nutritional components during the desalting process; water extraction as a method for extracting protein components from soy sauce dregs powder has also been reported in the literature (e.g., Study on Extraction Method and Process Optimization of Soy Sauce Dregs Protein, Shu Dongmei et al., China Brewing, Vol. 34, No. 6, pp. 67-71), but its protein extraction rate is lower than that of the alkaline method or the enzyme method and has not been studied in detail. Summary of the invention

[0008] In order to improve the deficiencies of the prior art, the present invention provides a method for extracting nutrients from soy sauce bean dregs powder and its application. The present invention provides a method for extracting nutrients from soy sauce bean dregs powder and its application. The specific features include: first, the present invention extracts soluble nutrients from soy sauce bean dregs powder into a supernatant (referred to as "soy sauce bean dregs powder aqueous phase extract" in the present invention) by a water washing method and directly uses it for microbial fermentation. This is both an extraction process and an effective desalination process. If the soy sauce bean dregs powder water washing liquid is made into a nutrient mixture by drying, it is a yeast powder nutrient analog with the same function as yeast powder. Secondly, the oil content of the precipitate after water washing can reach more than 20% after drying, and the in vitro digestibility of protein can reach about 65%, which can be directly used as a feed raw material for livestock and poultry. The method is simple in process, highly operable, and has low processing cost.

[0009] A first aspect of the present invention provides a method for comprehensively utilizing various nutrients in soy sauce dregs powder, the method comprising:

[0010] 1) adding water to the soy sauce dregs powder, mixing, and solid-liquid separation to obtain a soy sauce dregs powder aqueous extract;

[0011] 2) optionally drying the obtained soy sauce dregs extract to obtain a nutrient mixture;

[0012] 3) using the aqueous extract obtained in step 1) or the nutrient mixture obtained in step 2) as a microbial fermentation medium, a feed solution, or a microbial nutrient such as a raw material for a microbial nutrient for sewage treatment, a food additive, or a feed raw material;

[0013] 4) Optionally drying the remaining precipitate to obtain a feed material.

[0014] In a specific embodiment of the present invention, the method of adding water and mixing can be steam washing, soaking and stirring with water, or repeated washing with water.

[0015] In a specific embodiment of the present invention, the mass ratio of water to soy sauce residue is 3:1 to 20:1, for example, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1 or 20:1; preferably, it is 10:1.

[0016] In a preferred embodiment of the present invention, water extraction is carried out at a temperature less than 40°C, preferably less than 30°C, preferably at room temperature, at which temperature a yeast powder nutritional analog having the same functions as yeast powder can be obtained without losing the protein content of the precipitate, and the operation is simple.

[0017] In a specific embodiment of the present invention, in step 3), the extract obtained in step 1) or the nutrient mixture obtained in step 2) is used as a yeast powder substitute or as a nitrogen source.

[0018] In a specific embodiment of the present invention, in step 3), the aqueous extract obtained in step 1) or the nutrient mixture obtained in step 2) is prepared into a microbial fermentation medium, a feed solution or a microbial nutrient such as a microbial nutrient for sewage treatment, or is prepared as food or feed.

[0019] In a specific embodiment of the present invention, the remaining precipitate is dried to obtain a product that is used as a raw material for livestock or aquatic feed.

[0020] In the first aspect of the present invention, after the soy sauce dregs powder is washed, the water-soluble nutrients are extracted into the solution, and the remaining precipitate is dried. The dried precipitate has a fat content of more than 20% and a protein content of about 16%. The protein digestibility of the precipitate is about 65%, so it can be directly used as a feed raw material to provide nutrients such as fat and protein for livestock and poultry, and it will not cause animal poisoning due to high salt and will not affect animal growth due to digestibility.

[0021] In a second aspect, the present invention also provides a nutritional mixture which is a nutritional analog of yeast powder having the same functions as yeast powder.

[0022] In a specific embodiment of the present invention, the nutrient mixture is prepared by a soy sauce dregs extract through a drying process.

[0023] The nutrient mixture of the present invention is a nutrient analog of yeast powder, and the two have similar functions, such as: being an excellent food additive, which can be used in seasoning and beverages, etc.; being a feed raw material with high nutritional value, which can be used in livestock and poultry aquaculture; and more importantly, being a new type of organic nitrogen source for microbial fermentation.

[0024] The method for microbial fermentation includes culture medium or feed solution for microbial fermentation, and also includes other types of microbial nutrients, such as microbial nutrients for sewage treatment. Those skilled in the art can prepare corresponding microbial nutrients under the guidance of the present invention in combination with the prior art. For example, CN110510752A discloses a microbial growth-promoting and synergistic nutrient containing yeast extract. Those skilled in the art can replace the yeast extract based on the composition of the soy sauce dregs powder aqueous phase extract or nutrient mixture disclosed in the present application to obtain a microbial nutrient with similar composition and function.

[0025] The third aspect of the present invention provides the use of the aqueous phase extraction of soy sauce dregs powder or the nutrient mixture in microbial fermentation, food or feed.

[0026] In a specific embodiment of the present invention, the application is to add the soy sauce dregs extract or the nutrient mixture to the fermentation medium, feed solution or nutrient agent, preferably as a yeast powder substitute or as a nitrogen source.

[0027] In a specific embodiment of the present invention, the added amount of the soy sauce dregs extract is 50-250 ml / L, preferably 100 ml / L.

[0028] In a specific embodiment of the present invention, the microorganism comprises bacteria or fungi, and the bacteria or fungi include but are not limited to wild or genetically engineered Escherichia coli, Bacillus, Corynebacterium, lactic acid bacteria, yeast and Streptomyces. For example, Escherichia coli, Bacillus subtilis, Bacillus megaterium, Bacillus amyloliquefaciens, Bacillus licheniformis, Corynebacterium glutamicum, Brevibacterium flavum, Saccharomyces cerevisiae, Candida utilis, Pichia pastoris, Lactobacillus acidophilus, Lactobacillus plantarum.

[0029] In the fourth aspect of the present invention, a culture medium, feed solution or microbial nutrient for microbial fermentation is provided, which comprises the aqueous extract or nutrient mixture of the soy sauce dregs powder of the present invention, and nutrients such as suitable carbon sources and growth factors.

[0030] Beneficial Effects

[0031] The present invention is characterized in that:

[0032] 1) The present invention extracts soluble nutrients from soy sauce okara powder into a supernatant (referred to as "soy sauce okara powder extract" in the present invention) by a water washing method and directly uses it for microbial fermentation.

[0033] 2) After washing, the precipitate is dried, and more than 65% of the salt is removed compared with the soy sauce dregs powder, and the fat content can reach more than 20%, and the in vitro digestibility of protein can reach about 65%, and it can be directly used as a feed raw material for livestock and poultry.

[0034] 3) The present invention prepares a nutrient mixture from the soy sauce dregs powder water washing liquid in a dry manner, which is a nutrient analogue of yeast powder having the same function as yeast powder.

[0035] Compared with the existing methods and technologies, the method of the present invention is a comprehensive utilization of soy sauce dregs powder, but the process operation is very simple. The soy sauce dregs powder extract obtained by washing can be used as an organic nitrogen source for microbial fermentation, providing organic nitrogen sources, vitamins and growth factors for microbial growth metabolism; it can also be used as an excellent food additive for seasoning and beverages; it is also a feed raw material with high nutritional value, which can be used in livestock and poultry aquaculture. The precipitate after washing has the characteristics of low salt and high digestibility, and can be used directly as a feed raw material. The whole scheme not only simply and efficiently handles the soy sauce dregs waste, but also clarifies the product application scenarios, realizes the resource utilization of soy sauce dregs, and has very huge economic value and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a flow chart of the soy sauce dregs powder extraction method mentioned in the present invention;

[0037] Figure 2 This is a flow chart of repeatedly washing soy sauce dregs mentioned in the present invention; DETAILED DESCRIPTION

[0038] The method and application of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0039] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0040] The raw materials and reagents added, the instruments used, and the operating steps used in the following examples are all contents that can be routinely determined by a person of ordinary skill in the art.

[0041] The specific components and / or preparation methods of the culture medium used in the following examples are as follows:

[0042] Soy sauce dregs powder

[0043] In the present invention, soy sauce dregs powder, soy sauce dregs or soy sauce dregs have the same meaning, and refer to the solid residue produced after the fermentation and oil extraction or oil pouring of the raw materials for brewing soy sauce.

[0044] microorganism

[0045] Escherichia coli: Escherichia coli BW25113.

[0046] Corynebacterium glutamicum: Corynebacterium glutamicum CICC 23655.

[0047] Bacillus subtilis: Bacillus subtilis CGMCC1.1087.

[0048] Saccharomyces cerevisiae ATCC9763

[0049] Activation medium

[0050] The activation medium for Escherichia coli, Corynebacterium glutamicum and Bacillus subtilis is LB medium: 10 g / L tryptone, 5 g / L yeast powder and 10 g / L sodium chloride.

[0051] The activation medium for Saccharomyces cerevisiae is YPD medium: 20 g / L peptone, 10 g / L yeast extract, and 20 g / L glucose.

[0052] Activation and shake flask fermentation conditions

[0053] Activation and shake flask fermentation conditions of Escherichia coli and Bacillus subtilis: shaking culture at 37°C and a rotation speed of 220 rpm.

[0054] Activation and shake flask fermentation conditions of Corynebacterium glutamicum and Saccharomyces cerevisiae: shaking culture at 30°C and a rotation speed of 220 rpm.

[0055] Shake flask fermentation medium

[0056] Shake flask culture medium for the negative control group: KH2PO4 3.0g / L, Na2HPO4 12.8g / L, NaCl 0.5g / L, NH4Cl3.2g / L, FeSO4·7H2O 0.1g / L, MgSO4·7H2O 2.46g / L, CaCl2 0.2g / L, and glucose 10g / L.

[0057] Shake flask culture medium for the soy sauce dregs powder extract experimental group: add 200 mL / L of soy sauce dregs powder extract to the above-mentioned negative control group culture medium composition.

[0058] Positive control group shake flask culture medium: add 5g / L yeast powder to the above negative control group culture medium composition.

[0059] After adding all the components to the above culture medium, it was sterilized at 121° C. for 20 min to obtain the corresponding culture medium.

[0060] The above-mentioned additive liquid (substance) is adjusted to neutrality before use.

[0061] In the following Example 1, soy sauce dregs powder was treated by water washing to extract and desalt, and the soy sauce dregs powder extract was obtained by filtration, and the desalting treatment of the dregs powder was completed at the same time.

[0062] The following Example 2 is a feasible application of making feed products from soy sauce dregs powder.

[0063] The following examples 3-5 used a shake flask system and a fermentation tank system to ferment wild-type and genetically engineered bacteria Escherichia coli, Corynebacterium glutamicum, Bacillus subtilis, and Saccharomyces cerevisiae, and added the soy sauce dregs powder extract obtained by filtering in step 1 of Example 1. After 24 hours of shake flask fermentation, the biomass (OD 600 ), with a synthetic culture medium without organic nitrogen source as the negative control group, a composite culture medium containing common organic nitrogen source as the positive control group, and a composite culture medium containing soy sauce dregs powder extract as the experimental group, to confirm the growth-promoting effect of soy sauce dregs powder extract on bacteria and fungi.

[0064] Example 1: Soy sauce bean dregs powder washing separation washing supernatant

[0065] Method 1: Add 1000 mL of water to 100 g of soy sauce dregs powder, soak and stir for 2 hours, filter and collect the washing supernatant and filter cake. The washing supernatant is the soy sauce dregs powder extract, and its component test results are shown in Table 1; the filter cake is dried in an oven at 105°C to constant weight, and the ash content of the sample is 1.96%, that is, the desalination rate is above 80%;

[0066] Table 1: Test results of water wash supernatant in method 1

[0067]

[0068] Method 2: Take 100g of soy sauce dregs (water content about 25%), add 300mL of water at a solid-liquid ratio of 1:3, stir for 10min until mixed evenly, filter, collect the filtrate (Ⅰ water washing liquid), and use the filtrate to rinse the next portion of soy sauce dregs (water content about 25%) again, and filter and collect the filtrate (Ⅱ washing liquid) and filter cake in the same way. Repeat the washing of three portions of soy sauce dregs. See the process for details. Figure 2 ; The second filter cake was washed with 300 mL of fresh water again, and the washing liquid (Ⅱ washing liquid) was collected by filtration; each filtrate was sampled, and glycine (Gly) was used as the target content measurement item, representing the degree of extraction of nutrients in the washing liquid, and sent for HPLC inspection, and the ash content was measured at the same time, which synchronously represented the salt content in the washing liquid after washing the soy sauce dregs powder, and the desalination rate of each washing liquid was calculated to reflect the washing effect and estimate the number of washing times. The results are shown in Table 2;

[0069] Table 2: Results of washing soy sauce dregs in method 2

[0070]

[0071] The results showed that when the solid-liquid ratio of soy sauce dregs was 1:10, rich soluble nutrients were extracted into the aqueous solution, and the desalination rate was above 80%. The washing method could be immersion stirring (see method 1, the solid-liquid ratio could be adjusted according to the specific situation), or the residue could be repeatedly washed with less water for multiple times (see method 2, the solid-liquid ratio was 1:3, which could be adjusted according to the specific situation). The washing liquid could repeatedly wash multiple batches of residue, and the desalination rate of a batch of residue was above 70% after the second washing. The two methods had comparable effects, and most of the soluble nutrients in the soy sauce dregs could be extracted. The scale-up production could be selected according to the actual situation, and the treatment method was simple and effective.

[0072] Example 2 Feasibility of preparing feed products from the precipitate after washing soy sauce dregs powder

[0073] Step 1: add 20L of water to 2kg of soy sauce dregs powder, stir for 2 hours, filter to obtain the washed supernatant and filter cake, dry the filter cake in an oven at 70-75°C for 48 hours, take a sample to test the moisture content, if the moisture content is greater than 10%, continue drying until the moisture content is qualified, and after drying, crush and mix to obtain feed product A.

[0074] Step 2: Take 100g of feed product A, add 300mL of tap water, add caustic soda flakes to adjust the pH to about 7.5 while stirring, then add 2g of alkaline protease, continue stirring for 4 hours, adjust the pH to neutral with phosphoric acid after the end, release the feed liquid, transfer to a 70-75℃ oven and dry for 72 hours, take samples to test the moisture content, if the moisture content is greater than 10%, continue drying until the moisture content is qualified, and after drying, crush and mix to obtain feed product B.

[0075] Step 3: Take 100g of feed product A, add 300mL of tap water, add caustic soda flakes while stirring to adjust the pH to about 10.0, then add 2g of alkaline protease, continue stirring for 4 hours, adjust the pH to neutral with phosphoric acid after the end, release the feed liquid, transfer it to a 70-75℃ oven and dry it for 72 hours, take samples to test the moisture content, if the moisture content is greater than 10%, continue drying until the moisture content is qualified, and after drying, crush and mix to obtain feed product C.

[0076] Step 4: Conduct in vitro digestion tests on feed products A, B and C to simulate the physiological digestion of pigs, using single enzyme method and double enzyme method respectively. The specific steps are as follows:

[0077] Gastric digestion: Accurately weigh 4.00 g of feed product and place it in a 100 mL Erlenmeyer flask. Add 20 mL of dilute hydrochloric acid solution with a pH of 2.7 and containing 2 mg / mL pepsin into the flask, and adjust the pH of the chyme to 3.18 with 1 M hydrochloric acid solution. Mix well and seal with sealing film. Place in a constant temperature horizontal shaking incubator at 39°C and digest at 120 rpm for 60 min.

[0078] Intestinal digestion: After gastric digestion, take out the flask, add 20mL of pH 6.80 phosphate buffer containing 4mg / mL trypsin, so that the final concentration of trypsin in the flask is 2mg / mL, and adjust the pH of the chyme to 6.8 with 2M sodium hydroxide solution. The final feed-water ratio is 1:10, and continue to place it in a constant temperature horizontal shaker at 39℃ and digest at 120rpm for 240min.

[0079] The above-mentioned pepsin uses biochemical grade pepsin which is easily available on the market, and its enzyme activity is ≧1200U / g, which is lower than the 10000 enzyme activity of pepsin stipulated in the national standard. The focus of this test is to compare the digestibility of product A and product B, and then accurately determine the digestibility after subsequent external inspection.

[0080] After the whole simulated digestion was completed, the digested chyme in the flask was inactivated, part of the supernatant was taken for later use, and the remaining chyme was used to determine the dry matter digestibility.

[0081] Dry matter digestibility: The feed residue after digestion and quiescence is vacuum filtered and completely transferred to filter paper with accurately weighed mass, and then dried in a 105°C oven to constant weight, and the mass of the reference after digestion is accurately measured; the moisture content of the blank feed product is measured according to GB / T6435 and the dry matter content is calculated, and finally the dry matter digestibility of the feed is calculated based on the mass of the residue after digestion and the mass before digestion.

[0082] Protein digestibility: The protein content of the digested residue (fixed mass) used for dry matter digestibility determination is determined by Kjeldahl nitrogen analyzer, and the protein content of the total amount of digested residue is calculated; the total protein content of the absolute dry feed is determined at the same time; the amount of digested protein is calculated based on the total amount of feed protein and the total amount of protein in the digested residue to obtain the protein digestibility.

[0083] The results of feed product digestibility are shown in Table 3;

[0084] Table 3: Results of in vitro digestibility tests of feed products simulating pig digestion

[0085]

[0086] In addition, feed product A was sent externally for relevant physical and chemical tests according to the requirements for pig feed, and the results are shown in Table 4;

[0087] Table 4: Test results of feed product A

[0088]

[0089]

[0090] The results showed that the nutritional components (mainly fat and protein) of the feed products made from soy sauce dregs powder can meet the requirements of pig feeding conditions. The enzyme-treated feed products B and C significantly improved the gastric digestibility compared with the original feed product A.

[0091] Step 5: In addition, the feed product A prepared in step 1 was taken for routine testing. The relative percentage of each fatty acid in the oil was determined according to the national standard GB 5009.168-2016, and the degradation rate of product A in the rumen of cattle was determined. The results are shown in Tables 5 and 6

[0092] Table 5: Relevant tests for the application of product A in cattle feed

[0093]

[0094]

[0095] Table 6: Degradation parameters of dry matter of Product A in cattle rumen

[0096]

[0097] The results showed that Product A was almost completely degraded in the rumen, indicating that Product A could meet the requirements as cattle feed.

[0098] Feed products made from soy sauce dregs powder can replace products such as soybean meal and corn. They have high nutritional value and the processing method is simple and efficient. This realizes the resource utilization of soy sauce dregs powder and provides data support for its feasibility application in feed.

[0099] Example 3 Growth experiment of microorganisms using soy sauce dregs powder extract in a shake flask system

[0100] Shake flask fermentation method: Take 200ul of the glycerol tube strains of the above-mentioned Escherichia coli, Corynebacterium glutamicum, Bacillus subtilis, and Saccharomyces cerevisiae and inoculate them into LB or YPD activation medium, place them in a suitable temperature and rotation speed for 10 hours to obtain an activated seed solution. Inoculate the activated seed solution into the fermentation medium at an inoculation rate of 1%, and shake and culture it at a suitable temperature and rotation speed for 24 hours. The OD 600 The increase is shown in Table 7.

[0101] Table 7: Results of shake flask fermentation experiment in Example 3

[0102]

[0103]

[0104] The results of shake flask fermentation showed that the effect of soy sauce dregs powder extract was better than yeast powder in culturing Escherichia coli and Bacillus subtilis. The effect of soy sauce dregs powder extract was slightly worse than yeast powder in culturing Corynebacterium glutamicum and Saccharomyces cerevisiae. This showed that soy sauce dregs powder extract could replace yeast powder as an organic nitrogen source for the growth of Escherichia coli, Bacillus subtilis, Corynebacterium glutamicum and Saccharomyces cerevisiae.

[0105] Example 4 Growth experiment of Escherichia coli BW25113 using soy sauce dregs powder extract in a fermentation tank system

[0106] Fermentation tank fermentation method: Take 200ul of the glycerol tube of Escherichia coli BW25113 (Escherichia coli) and inoculate it into LB activation medium, shake and culture at 37°C for 10 hours, and rotate at 220rpm to obtain activated seed liquid. The activated seed liquid is inoculated into three fermentation mediums at an inoculation rate of 1%: ① Negative control group: ammonium sulfate 8g / L, potassium dihydrogen phosphate 2g / L, magnesium sulfate 1g / L, betaine 2g / L, nicotinic acid 0.2g / L, vitamin B1 0.02g / L, adjust pH to 6.8-7.2, sterilize at 121°C for 20 minutes, place at 30-40°C, add sterile glucose in a clean bench, and the final concentration of glucose is 20g / L, and standby. ② Positive control group: the above negative control group culture medium + yeast powder 3g / L, adjust pH to 6.8-7.2 and sterilize at 121℃ for 20 minutes, place at 30-40℃, add sterile glucose in the clean bench, the final concentration of glucose is 20g / L, and set aside. ③ Experimental group: the above negative control group culture medium + soy sauce dregs powder extract 100ml / L, adjust pH to 6.8-7.2 and sterilize at 121℃ for 20 minutes, place at 30-40℃, add sterile glucose in the clean bench, the final concentration of glucose is 20g / L, and set aside. In a 1L fermentation tank containing 500mL fermentation medium, the fermentation temperature is 37°C, the rotation speed is 500-1500rpm, the ventilation volume is 0.6-1.7v / v / m, the dissolved oxygen is controlled at 15-30%, and 500g / L of glucose feed solution is added to maintain the glucose concentration in the fermentation liquid at 5-10g / L; 50% (v / v) concentration of ammonia water is added to maintain the pH of the fermentation liquid at 6.5-7.5. Fermentation is stopped after 16h. Among them, OD 600 The increase is shown in Table 8.

[0107] Table 8: Results of the fermentation experiment of the supernatant of Escherichia coli BW25113 in Example 4

[0108]

[0109] The fermentation results in the fermenter showed that the soy sauce dregs powder extract had the same effect as yeast powder in culturing wild-type Escherichia coli in the fermenter system, indicating that it can replace yeast powder in the fermentation production of wild-type Escherichia coli.

[0110] Example 5 Growth experiment of genetically engineered Escherichia coli using soy sauce dregs powder in a fermentation tank system

[0111] The genetically engineered bacteria Escherichia coli used in this example are: Escherichia coli genetically engineered bacteria M (Escherichia coli) is a patent (CN114410701A) published by the applicant. Strain: The plasmid combination pZA-ilvAIH and pZE-ilvCmD-ilvE-ygaZH was transformed into the Escherichia coli recipient bacteria DV10 (ΔldhAΔptaΔpoxBΔadhEΔpflBΔmgsAΔfrdAΔdadAΔavtAΔilvE) to obtain the strain (temporarily named strain M, the same below)

[0112] Fermentation tank fermentation method: Take 200ul of the glycerol tube strain of the above-mentioned Escherichia coli engineering bacteria M (Escherichia coli) and inoculate it into LB activation medium, shake and culture at 37°C for 10 hours, and the rotation speed is 220rpm to obtain the activated seed liquid. The activated seed liquid is inoculated into three fermentation mediums at an inoculation rate of 1%: ① Negative control group: ammonium sulfate 8g / L, potassium dihydrogen phosphate 2g / L, magnesium sulfate 1g / L, betaine 2g / L, nicotinic acid 0.2g / L, vitamin B1 0.02g / L, adjust the pH to 6.8-7.2, sterilize at 121°C for 20 minutes, place at 30-40°C, add sterile glucose in the clean bench, and the final concentration of glucose is 20g / L, and standby. ② Positive control group: the above negative control group culture medium + yeast powder 3g / L, adjust pH to 6.8-7.2 and sterilize at 121℃ for 20 minutes, place at 30-40℃, add sterile glucose in the clean bench, the final concentration of glucose is 20g / L, and set aside. ③ Experimental group: the above negative control group culture medium + soy sauce dregs powder extract 100ml / L, adjust pH to 6.8-7.2 and sterilize at 121℃ for 20 minutes, place at 30-40℃, add sterile glucose in the clean bench, the final concentration of glucose is 20g / L, and set aside. In a 1L fermentation tank containing 500mL fermentation medium, the fermentation temperature is 37°C, the rotation speed is 500-1500rpm, the ventilation volume is 0.6-1.7v / v / m, the dissolved oxygen is controlled at 15-30%, and 500g / L of glucose feed solution is added to maintain the glucose concentration in the fermentation liquid at 5-10g / L; 50% (v / v) concentration of ammonia water is added to maintain the pH of the fermentation liquid at 6.5-7.5. Fermentation is stopped after 16h. Among them, OD 600 The increase is shown in Table 4.

[0113] Table 9: Results of the fermentation experiment of the supernatant of the Escherichia coli in Example 5

[0114]

[0115] The fermentation results in the fermenter showed that the effect of soy sauce dregs powder extract and yeast powder was equivalent in culturing genetically engineered Escherichia coli in the fermenter system, indicating that it can replace yeast powder in the fermentation production of genetically engineered Escherichia coli.

[0116] Due to experimental material and space limitations, the present invention only uses the above five commonly used microorganisms for testing, and it can be reasonably inferred that it is also applicable to other microorganisms; at the same time, the purpose of the present invention is to test whether each component is usable, and its dosage is not systematically optimized. The optimal concentration optimization for specific goals should also be within the reasonable inference application range of this work.

[0117] The above examples are used to illustrate the specific implementation of the present invention. However, the protection scope of the present invention is not limited to the above exemplary implementation. Any modification, equivalent substitution, improvement, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A method for comprehensively utilizing various nutrients of soy sauce dregs powder, the method comprising: 1) adding water to the soy sauce dregs powder, mixing, and solid-liquid separation to obtain a soy sauce dregs powder aqueous extract; 2) optionally drying the obtained soy sauce and soybean dregs aqueous extract to obtain a nutrient mixture; 3) using the aqueous extract obtained in step 1) or the nutrient mixture obtained in step 2) as a microbial fermentation medium, a feed solution, or a microbial nutrient such as a raw material for a microbial nutrient for sewage treatment, a food additive, or a feed raw material; 4) Optionally drying the remaining precipitate to obtain a feed material.

2. The method according to claim 1, wherein in step 3), the extract obtained in step 1) or the nutrient mixture obtained in step 2) is used as a yeast powder substitute or as a nitrogen source.

3. The method according to claim 1, wherein the remaining precipitate is dried to obtain a product which is used as a raw material for livestock or aquatic feed.

4. A nutritional mixture obtained by steps 1) and 2) of the method according to any one of claims 1 to 2.

5. Use of the soy sauce dregs powder aqueous extract or nutrient mixture according to any one of claims 1 to 2 in microbial fermentation, food or feed.

6. Use of the soy sauce dregs powder aqueous extract or nutrient mixture described in any one of claims 1-2 in microbial fermentation.

7. The use according to claim 6, wherein the aqueous extract of soy sauce dregs powder or the nutrient mixture is added to a fermentation medium, a feed solution or a nutrient agent, preferably as a yeast powder substitute or as a nitrogen source; Preferably, the added amount of the soy sauce dregs powder extract is 50-250 ml / L, preferably 100 ml / L; Preferably, the microorganism comprises bacteria or fungi, and the bacteria or fungi include but are not limited to wild or genetically engineered Escherichia coli, Bacillus, Corynebacterium, lactic acid bacteria, yeast and Streptomyces. For example, Escherichia coli, Bacillus subtilis, Bacillus megaterium, Bacillus amyloliquefaciens, Bacillus licheniformis, Corynebacterium glutamicum, Brevibacterium flavum, Saccharomyces cerevisiae, Candida utilis, Pichia pastoris, Lactobacillus acidophilus, Lactobacillus plantarum.

8. A microbial fermentation medium, feed solution or microbial nutrient, comprising the soy sauce dregs powder aqueous extract or nutrient mixture according to the method of any one of claims 1 to 2; Preferably, the amount of the soy sauce dregs powder aqueous extract added is 50-250 ml / L, preferably 100 ml / L; Preferably, the microorganism comprises bacteria or fungi, and the bacteria or fungi include but are not limited to wild or genetically engineered Escherichia coli, Bacillus, Corynebacterium, lactic acid bacteria, yeast and Streptomyces. For example, Escherichia coli, Bacillus subtilis, Bacillus megaterium, Bacillus amyloliquefaciens, Bacillus licheniformis, Corynebacterium glutamicum, Brevibacterium flavum, Saccharomyces cerevisiae, Candida utilis, Pichia pastoris, Lactobacillus acidophilus, Lactobacillus plantarum.

9. The microbial fermentation medium, feed solution or microbial nutrient according to claim 8, further comprising a carbon source and a growth factor.

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