Method for preparing abamectin fermentation liquor by biologically fermenting contaminated material

Abstract

The invention relates to a method for preparing abamectin fermentation liquor by biologically fermenting a contaminated material. The method comprises the following steps: three-stage fermentation culture which is divided into first-stage seed culture, second-stage seed culture and fermentation tank culture, preparing abamectin fermentation liquor by utilizing a fermented bacterial material, mixing rape seed cake powder and wheat germ powder according to a certain proportion, and fermenting by combining a precursor fed-batch feeding method, so that the effect of recycling energy is achieved; the environmental protection pressure is relieved, the fermentation titer is promoted to be improved, the fermentation period is shortened, and the drinking water consumption is reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of fermentation, and particularly relates to a method for preparing avermectin fermentation liquor from biological fermentation dyeing material. BACKGROUND

[0002] Avermectin is a kind of penicillin antibiotic with wide sources, small toxicity and strong antibiotic effect, and is widely used in medical science, agriculture and other fields. The production of avermectin is mainly carried out through microbial fermentation. At present, the fermentation process of avermectin has been relatively mature, but there are still problems such as low yield, long fermentation period, unstable quality, and low peak ratio.

[0003] Biological fermentation dyeing has a great influence on fermentation productivity, extraction rate, yield, product quality and three waste treatment. The dyeing material in the late fermentation period has no extraction value and can only be discharged to wastewater treatment after inactivation by heating, which causes great waste of raw material cost and increases the pressure and cost of wastewater treatment. SUMMARY

[0004] The present application aims to overcome the above-mentioned defects of the prior art, and provides a method for preparing avermectin fermentation liquor from biological fermentation dyeing material, which can save the cost of avermectin fermentation raw materials and maximize the economic value of biological fermentation dyeing material.

[0005] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: Streptomyces avermitilis is used as a strain for three-stage fermentation, including primary seed culture, secondary seed culture and fermentation tank culture, to prepare avermectin fermentation liquor, and a preparation method thereof is provided.

[0006] The specific scheme is as follows:

[0007] The primary seed culture medium is composed of 20-80 kg of corn starch, 5-40 kg of soybean meal, 2-20 kg of yeast powder, 3-35 kg of rapeseed cake powder:wheat germ powder (1.5:1), 1-20 kg of yeast paste, and the rest is drinking water, and the culture period is 30-60 h;

[0008] The secondary seed culture medium is composed of 300-1500 kg of corn starch, 80-500 kg of soybean meal, 50-200 kg of yeast powder, 50-210 kg of rapeseed cake powder:wheat germ powder (1.5:1), 40-200 kg of yeast paste, and the rest is drinking water, and the culture period is 13-40 h;

[0009] The fermentation medium consists of the following raw materials: 23,500-52,000 kg of corn starch, 3,100-9,700 kg of soybean meal, 1,400-4,900 kg of yeast powder, 100-500 kg of defoamer, 100-700 kg of calcium carbonate, 2.0-11.0 kg of amylase, 5,000 kg of sterilized inoculum, and a culture cycle of 310-390 hours. The remainder is drinking water.

[0010] A method for preparing avermectin fermentation broth from bio-fermented bacterial material, comprising the following steps:

[0011] (1) Primary seed culture:

[0012] The bacterial suspension was inoculated into a primary seed tank using a flame inoculation method. The tank temperature was maintained at 25.0-31.0℃ throughout the inoculation; the air flow rate was 100-350 m³ / h for 0-18 hours. 3 / h; 18h - Transplanting: 150-500m 3 / h; the tank pressure is maintained at 0.020-0.070MPa, the pH value is 6.20-8.10, the mycelial concentration reaches 10-25%, and the mycelium forms a network. Then it is transferred to the secondary seed tank for seed expansion culture. The culture cycle is 30-60h.

[0013] (2) Secondary seed culture:

[0014] The primary seed culture that meets the quality requirements is transferred to the secondary seed culture medium, with the tank temperature maintained at 25.0-31.0℃ throughout the process; the air flow rate is 1000-3500 m³ / h for 0-18 hours. 3 / h, 18h - transplanting 1800-4000m 3 / h; maintain tank pressure at 0.03-0.07 MPa; stir without turning on for 0-8 hours, and after 8 hours, transfer at 80-200 r / min. When the pH is 6.00-7.30, the mycelial concentration reaches 18-45%, the mycelia form clumps and are free of contaminants, it can be transferred to a fermenter for fermentation. The cultivation cycle is 12-43 hours.

[0015] (3) Fermentation culture:

[0016] The qualified secondary seed culture was transferred to the fermenter culture medium. The fermenter temperature was maintained at 25.0-31.0℃ throughout the process; the fermenter pressure was 0.012-0.047MPa; and the air flow rate was 2000-10000 m³ / h for 0-9 hours. 3 / h, 9-200h 5000-11000m 3 / h, 200h - tank discharge 5500-10000m 3 / h; the entire process is controlled within 200r / min, and the fermentation cycle is 280-450h. The pH is controlled at 5.70-7.50.

[0017] During the fermentation process, the fermenter culture adopts the fed-batch method for feeding, which includes feeding water, sugar, precursors, pH control, and defoamer.

[0018] The specific control of feed replenishment in the fermentation tank is as follows:

[0019] (1) Water replenishment: After 60 hours of growth in the fermenter, replenish water daily with 0-40 ml. 3 ;

[0020] (2)(2) Sugar supplementation: After 60 hours of growth in the fermenter, supplement sugar with 0-10 mg daily. 3 The starch sugar solution concentration is 20%-40%.

[0021] (3) Precursor replenishment: After 60 hours of growth in the fermenter, add 0.2-1.1% sodium propionate solution every 4 hours for 1 hour each time, for a total of 120 hours;

[0022] (4) pH control: After fermentation for 80 hours, the pH is controlled at 5.50-7.50.

[0023] (5) Add defoamer: Observe with the naked eye and check the computer data. When the volume of foam exceeds 2% of the normal fermentation liquid volume, add 20-100L of 20-50% GP type polyether defoamer solution.

[0024] The technical solution of the present invention has the following beneficial technical effects:

[0025] 1. Using fermented substrate to prepare avermectin fermentation broth saves raw material costs and reduces wastewater and waste discharge. Furthermore, the substrate contains unutilized proteins, macro-elements, and trace elements and enzymes required for microbial growth. The resulting avermectin fermentation broth achieves energy recycling and reduces environmental pressure. The residual avermectin in the substrate can also play a role in biological regulation in the fermentation broth, promoting improved fermentation efficiency, reducing the fermentation cycle, and saving drinking water consumption, among other unexpected technical effects.

[0026] 2. Since avermectin fermentation is a typical non-growth-coupled fermentation, rapeseed meal contains 35-45% crude protein and is rich in trace elements, vitamins, and amino acids. It is not only of excellent quality but also inexpensive. The polysaccharides it contains further promote the balling stage of avermectin during secondary metabolism. Because the mycelium has a vigorous metabolism and consumes nutrients quickly in the early stage of fermentation, the crude protein and polysaccharides in rapeseed meal can effectively promote the nutrients and trace elements required for mycelial growth. The isoleucine contained in wheat germ can significantly promote the synthesis of avermectin and glucose metabolism, improve the efficiency of acyl-CoA synthase, and accelerate the rate of mycelial synthesis of lactone rings.

[0027] 3. Since the mycelium of the strain is more sensitive in the early stage of fermentation, a 0.05-0.12% sodium propionate solution is added after 60-120 hours of fermentation. By directly adding the sodium propionate precursor, the potency is increased and the tank discharge cycle is shortened, thereby reducing energy consumption.

[0028] 4. During the fermentation process, a fast and efficient GP-type polyether defoamer is used, which does not affect the subsequent separation and purification process, and ultimately increases the tank volume to achieve the effect of increasing production.

[0029] This method utilizes fermented substrate to prepare avermectin fermentation broth, which saves raw material costs and reduces wastewater and waste discharge, truly achieving resource recycling. The optimal ratio of rapeseed meal and wheat germ further promotes avermectin aggregation during secondary metabolism and enhances the synthesis and conversion of avermectin B1a, reducing impurities. Furthermore, the direct addition of sodium propionate precursor increases potency, reduces tanking cycle time, and lowers energy consumption. The use of a fast and efficient GP-type polyether defoamer increases tanking volume, thereby increasing production. Detailed Implementation

[0030] All other embodiments obtained are within the scope of protection of this invention. The embodiments of the present invention will be clearly and completely described below in conjunction with the examples. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, those skilled in the art can readily see the obvious gains compared with conventional processes in the following embodiments without any inventive effort.

[0031] The Streptomyces avermitilis described in this invention can be any existing avermectin-producing Streptomyces avermitilis, preferably Streptomyces avermitilis, with the strain preservation number CGMCC4.5508.

[0032] All reagents and raw materials used in this invention are commercially available. Unless otherwise specified, the experimental materials and reagents used in the following examples are commercially available.

[0033] Avermectin is produced using *Streptomyces avermectin* as the inoculum through a three-stage fermentation process. The fermentation equipment has the following volume: Stage 1 tank: 6m³. 3 Secondary tank 70m 3 398m fermentation tank 3 .

[0034] Example 1

[0035] (1) Primary seed culture: 35 kg corn starch, 17 kg soybean meal, 13 kg yeast powder, 18 kg rapeseed meal: wheat germ powder (1.5:1), 10 kg yeast extract, and the remainder was drinking water; the tank temperature was 27.5℃ throughout; the air flow rate was 150 m³ / h from 0 to 18 h. 3 / h; 18h - Transplanting: 350m 3 / h; the tank pressure is maintained at 0.038MPa, the pH is set at 6.70, the mycelial concentration is 25%, the mycelium forms a network, and the culture cycle is 40h.

[0036] (2) Secondary seed culture: 1000 kg corn starch, 205 kg soybean meal, 80 kg yeast powder, 120 kg rapeseed meal: wheat germ powder (1.5:1), 78 kg yeast extract, and the remainder is drinking water; the tank temperature is controlled at 28.5℃ throughout the process; the air flow rate is 2800 m³ / h for 0-18 hours. 3 / h, 18h - transplanting 3200m 3 / h; tank pressure maintained at 0.41MPa; stirring not turned on for 0-8h, 130r / min from 8h to transplanting. pH set at 6.80, culture period 33h.

[0037] (3) Fermentation culture: 37,000 kg corn starch, 4,600 kg soybean meal, 2,370 kg yeast powder, 350 kg defoamer, 360 kg calcium carbonate, 8.5 kg amylase, 5,000 kg sterilized inoculum, and the remainder is drinking water. The tank temperature was controlled at 29.0℃ throughout the process; tank pressure: 0.038 MPa; air flow rate: 5300 m³ / h (0-9 hours). 3 / h, 9-200h 7200m 3 / h, 200h - 7000m tank discharge 3 / h; Stirring: 120r / min.

[0038] Fermentation tank feeding control:

[0039] ①Replenish drinking water: Based on the bacterial concentration, replenish a total of 8ml of drinking water daily. 3 ;

[0040] ② Acid-base balance adjustment: pH set at 6.68;

[0041] ③Supplement sugar: Based on the total sugar and reducing sugar levels, supplement a total daily sugar intake of 3mg. 3 ;

[0042] ④ Add defoamer: Depending on the foam situation, add 20-50% of GP type polyether defoamer solution, with a total volume of 75L;

[0043] ⑤ Precursor addition: After 60-120 hours of growth in the fermenter, add a total of 80L of 0.55% sodium propionate solution.

[0044] The fermentation cycle was 312 hours, the avermectin potency was measured to be 8363 μ / mL, and the fermentation tank volume was 320 m³. 3 .

[0045] Example 2

[0046] (1) Primary seed culture: 47 kg corn starch, 20 kg soybean meal, 8 kg yeast powder, 25 kg rapeseed meal: wheat germ powder (1.5:1), 9 kg yeast extract, and the remainder was drinking water; the tank temperature was 28.0℃ throughout; the air flow rate was 170 m³ / h from 0 to 18 hours. 3 / h; 18h - Transplanting: 400m 3 / h; the tank pressure is maintained at 0.042MPa, the pH is set at 6.68, the mycelial concentration is 24%, the mycelium forms a network, and the culture cycle is 38h.

[0047] (2) Secondary seed culture: 800 kg corn starch, 135 kg soybean meal, 100 kg yeast powder, 120 kg rapeseed meal: wheat germ powder (1.5:1), 83 kg yeast extract, and the remainder is drinking water; the tank temperature is controlled at 28.2℃ throughout the process; the air flow rate is 2500 m³ / h for 0-18 hours. 3 / h, 18h - transplanting 3000m 3 / h; tank pressure maintained at 0.43MPa; stirring not turned on for 0-8h, 120r / min from 8h onwards for transplanting. pH set at 6.73, culture period 35h.

[0048] (3) Fermentation culture: 32,600 kg corn starch, 5,100 kg soybean meal, 2,860 kg yeast powder, 200 kg defoamer, 430 kg calcium carbonate, 7.6 kg amylase, 5,000 kg sterilized inoculum, and the remainder is drinking water. The tank temperature was maintained at 28.8℃ throughout the process; tank pressure: 0.040 MPa; air flow rate: 4200 m³ / h (0-9 hours). 3 / h, 9-200h 6800m 3 / h, 200h - tank discharge 5900m 3 / h; Stirring: 125r / min.

[0049] Fermentation tank feeding control:

[0050] ① Hydration: Based on the bacterial concentration, replenish a total of 9.5 ml of water daily. 3 ;

[0051] ② Acid and alkali replenishment: After 80 hours of fermentation, remove from the tank and set the pH value to 6.70;

[0052] ③Supplement sugar: Based on the total sugar and reducing sugar levels, supplement a total daily sugar intake of 3mg. 3 ;

[0053] ④ Add defoamer: Depending on the foam situation, add 20-50% of GP type polyether defoamer solution, with a total volume of 75L;

[0054] ⑤ Precursor addition: After 60-120 hours of growth in the fermenter, add a total of 80L of 0.55% sodium propionate solution.

[0055] The fermentation cycle was 317 hours, and the avermectin potency was measured to be 8450 μ / mL. The tank volume was 318 m³. 3 .

[0056] Example 3

[0057] (1) Primary seed culture: 50 kg corn starch, 25 kg soybean meal, 16 kg yeast powder, 22 kg rapeseed meal: wheat germ powder (1.5:1), 14 kg yeast extract, and the remainder was drinking water; the tank temperature was 28.0℃ throughout; the air flow rate was 170 m³ / h from 0 to 18 h. 3 / h; 18h - Transplanting: 400m 3 / h; the tank pressure is maintained at 0.042MPa, the pH value is 6.68, the mycelial concentration is 23%, the mycelium forms a network, and the culture cycle is 39h.

[0058] (2) Secondary seed culture: 800 kg corn starch, 135 kg soybean meal, 100 kg yeast powder, 120 kg rapeseed meal: wheat germ powder (1.5:1), 83 kg yeast extract, and the remainder is drinking water; the tank temperature is controlled at 28.1℃ throughout the process; the air flow rate is 2000 m³ / h for 0-18 hours. 3 / h, 18h - transplanting 3500m 3 / h; maintain tank pressure at 0.40MPa; do not turn on the stirrer for 0-8h, and from 8h onwards, stir at 150r / min. Set the pH to 6.72 and the culture period to 34h.

[0059] (3) Fermentation culture: 41320 kg corn starch, 3300 kg soybean meal, 1900 kg yeast powder, 210 kg defoamer, 370 kg calcium carbonate, 5.9 kg amylase, 5000 kg sterilized inoculum, and the remainder is drinking water. The tank temperature was controlled at 28.0℃ throughout the process; tank pressure: 0.041 MPa; air flow rate: 5800 m³ / h (0-9 hours). 3 / h, 9-200h 6300m 3 / h, 200h - 7500m tank discharge 3 / h; Stirring: 120r / min.

[0060] Fermentation tank feeding control:

[0061] ① Hydration: Based on the bacterial concentration, replenish a total of 10ml of water daily. 3 ;

[0062] ②Acid and alkali replenishment: After 80 hours of fermentation, remove from the tank and set the pH value to 6.72;

[0063] ③Supplement sugar: Based on the total sugar and reducing sugar levels, supplement a total of 5mg of sugar daily. 3 ;

[0064] ④ Add defoamer: Depending on the foam situation, add 20-50% of GP type polyether defoamer solution, with a total volume of 95L;

[0065] ⑤ Precursor addition: After 60-120 hours of growth in the fermenter, add a total of 72 L of 0.55% sodium propionate solution.

[0066] The fermentation cycle was 300 hours, the abamectin potency was measured to be 8425 μ / mL, and the fermentation tank volume was 319 m³. 3 .

[0067] Comparative Example 1 (Disclosed Formula)

[0068] (1) Primary seed culture: 75 kg corn starch, 20 kg soybean meal, 12 kg yeast powder, 85 kg corn gluten meal, 12 kg yeast extract, and the remainder was drinking water. The tank temperature was 28.1℃ throughout the process; the air flow rate was 170 m³ / h from 0 to 18 h. 3 / h; 18h - Transplanting: 400m 3 / h; the tank pressure is maintained at 0.042MPa, the pH is set at 6.70, the mycelial concentration is 21%, the mycelium forms a network, and the culture cycle is 43h.

[0069] (2) Secondary seed culture: 940 kg corn starch, 271 kg soybean meal, 82 kg yeast powder, 243 kg corn gluten meal, 114 kg yeast extract, and the remainder was drinking water; the tank temperature was controlled at 28.5℃ throughout the process; the air flow rate was 0-18 h / 2230 m³ / h. 3 / h, 18h - transplanting 3650m 3 / h; tank pressure maintained at 0.41MPa; stirring not turned on for 0-8h, 160r / min from 8h to transplanting. pH set at 6.72, culture period 40h.

[0070] (3) Fermentation culture: 31200 kg corn starch, 4650 kg soybean meal, 2700 kg yeast powder, 210 kg defoamer, 370 kg calcium carbonate, 5.9 kg amylase, and the remainder is drinking water. The tank temperature was controlled at 28.0℃ throughout the process; tank pressure: 0.041 MPa; air flow rate: 4700 m³ / h (0-9 hours). 3 / h, 9-200h 5500m 3 / h, 200h - tank discharge 6900m 3 / h; Stirring: 123r / min.

[0071] Fermentation tank feeding control:

[0072] ① Hydration: Based on the bacterial concentration, replenish a total of 9.4m of water daily. 3 ;

[0073] ② Acid and alkali replenishment: After 80 hours of fermentation, remove from the tank and set the pH value to 6.70;

[0074] ③ Sugar supplementation: Based on the total sugar and reducing sugar levels, supplement a total of 6.3 mg of sugar daily. 3 ;

[0075] ④ Add defoamer: Depending on the foam situation, add a total of 95L of silicone defoamer solution.

[0076] The fermentation cycle was 345 hours, the abamectin potency was measured to be 7180 μ / mL, and the fermentation tank volume was 301 m³. 3 .

[0077] Comparative Example 2 (Comparative Example 1 replaces corn gluten powder with rapeseed meal: wheat germ powder (1.5:1))

[0078] (1) Primary seed culture: 75 kg corn starch, 20 kg soybean meal, 12 kg yeast powder, 20 kg rapeseed meal: wheat germ powder (1.5:1), 12 kg yeast extract, the remainder being drinking water; tank temperature maintained at 28.1℃ throughout; air flow rate 0-18h: 170 m³ / h. 3 / h; 18h - Transplanting: 400m 3 / h; the tank pressure is maintained at 0.042MPa, the pH is set at 6.70, the mycelial concentration is 24%, the mycelium forms a network, and the culture cycle is 39h.

[0079] (2) Secondary seed culture: 940 kg corn starch, 271 kg soybean meal, 82 kg yeast powder, 160 kg rapeseed meal: wheat germ powder (1.5:1), 114 kg yeast extract, and the remainder was drinking water; the tank temperature was controlled at 28.5℃ throughout the process; the air flow rate was 0-18 h 2230 m³ / h 3 / h, 18h - transplanting 3650m 3 / h; tank pressure maintained at 0.41MPa; stirring not turned on for 0-8h, 160r / min from 8h onwards for transplanting. pH set at 6.72, culture period 37h.

[0080] (3) Fermentation culture: 31200 kg corn starch, 4650 kg soybean meal, 2700 kg yeast powder, 210 kg defoamer, 370 kg calcium carbonate, 5.9 kg amylase, and the remainder is drinking water. The tank temperature was controlled at 28.0℃ throughout the process; tank pressure: 0.041 MPa; air flow rate: 4700 m³ / h (0-9 hours). 3 / h, 9-200h 5500m 3 / h, 200h - tank discharge 6900m 3 / h; Stirring: 123r / min.

[0081] Fermentation tank feeding control:

[0082] ① Hydration: Based on the bacterial concentration, replenish a total of 9.5 ml of water daily. 3 ;

[0083] ②Acid and alkali replenishment: After 80 hours of fermentation, remove from the tank and set the pH value to 6.68;

[0084] ③ Sugar supplementation: Based on the total sugar and reducing sugar levels, supplement a total of 6.2 mg of sugar daily. 3 ;

[0085] ④ Add defoamer: Depending on the foam situation, add a total of 90L of silicone defoamer solution.

[0086] The fermentation cycle was 337 hours, the abamectin potency was measured to be 7240 μ / mL, and the fermentation tank volume was 293 m³. 3 .

[0087] Comparative Example 3 (Comparative Example 1 with added fermented inoculum)

[0088] (1) Primary seed culture: 75 kg corn starch, 20 kg soybean meal, 12 kg yeast powder, 85 kg corn gluten meal, 12 kg yeast extract, and the remainder was drinking water. The tank temperature was 28.1℃ throughout the process; the air flow rate was 170 m³ / h from 0 to 18 h. 3 / h; 18h - Transplanting: 400m 3 / h; the tank pressure is maintained at 0.042MPa, the pH is set at 6.70, the mycelial concentration is 21%, the mycelium forms a network, and the culture cycle is 42h.

[0089] (2) Secondary seed culture: 940 kg corn starch, 271 kg soybean meal, 82 kg yeast powder, 243 kg corn gluten meal, 114 kg yeast extract, and the remainder was drinking water; the tank temperature was controlled at 28.5℃ throughout the process; the air flow rate was 0-18 h / 2230 m³ / h. 3 / h, 18h - transplanting 3650m 3 / h; tank pressure maintained at 0.41MPa; stirring not turned on for 0-8h, 160r / min from 8h to transplanting. pH set at 6.72, culture period 41h.

[0090] (3) Fermentation culture: 31200 kg corn starch, 4650 kg soybean meal, 2700 kg yeast powder, 210 kg defoamer, 370 kg calcium carbonate, 5.9 kg amylase, 5000 kg fermentation substrate, and the remainder is drinking water. The tank temperature was controlled at 28.0℃ throughout the process; tank pressure: 0.041 MPa; air flow rate: 4700 m³ / h (0-9 hours).3 / h, 9-200h 5500m 3 / h, 200h - tank discharge 6900m 3 / h; Stirring: 123r / min.

[0091] Fermentation tank feeding control:

[0092] ① Hydration: Based on the bacterial concentration, replenish a total of 9.2m of water daily. 3 ;

[0093] ② Acid and alkali replenishment: After 80 hours of fermentation, remove from the tank and set the pH value to 6.71;

[0094] ③ Sugar supplementation: Based on the total sugar and reducing sugar levels, supplement a total of 6.5 mg of sugar daily. 3 ;

[0095] ④ Add defoamer: Based on the foam situation, add a total of 96L of silicone defoamer solution.

[0096] The fermentation cycle was 336 hours, the avermectin potency was measured to be 7125 μ / mL, and the fermentation tank volume was 296 m³. 3 .

[0097] Comparative Example 4 (Comparative Example 1 with added sodium propionate solution)

[0098] (1) Primary seed culture: 75 kg corn starch, 20 kg soybean meal, 12 kg yeast powder, 85 kg corn gluten meal, 12 kg yeast extract, and the remainder was drinking water. The tank temperature was 28.1℃ throughout the process; the air flow rate was 170 m³ / h from 0 to 18 h. 3 / h; 18h - Transplanting: 400m 3 / h; the tank pressure is maintained at 0.042MPa, the pH is set at 6.70, the mycelial concentration is 22%, the mycelium forms a network, and the culture cycle is 42h.

[0099] (2) Secondary seed culture: 940 kg corn starch, 271 kg soybean meal, 82 kg yeast powder, 243 kg corn gluten meal, 114 kg yeast extract, and the remainder was drinking water; the tank temperature was controlled at 28.5℃ throughout the process; the air flow rate was 0-18 h / 2230 m³ / h. 3 / h, 18h - transplanting 3650m 3 / h; tank pressure maintained at 0.41MPa; stirring not turned on for 0-8h, 160r / min from 8h to transplanting. pH set at 6.72, culture period 40h.

[0100] (3) Fermentation culture: 31200 kg corn starch, 4650 kg soybean meal, 2700 kg yeast powder, 210 kg defoamer, 370 kg calcium carbonate, 5.9 kg amylase, and the remainder is drinking water. The tank temperature was controlled at 28.0℃ throughout the process; tank pressure: 0.041 MPa; air flow rate: 4700 m³ / h (0-9 hours). 3 / h, 9-200h 5500m 3 / h, 200h - tank discharge 6900m 3 / h; Stirring: 123r / min.

[0101] Fermentation tank feeding control:

[0102] ① Hydration: Based on the bacterial concentration, replenish a total of 9.4m of water daily. 3 ;

[0103] ② Acid and alkali replenishment: After 80 hours of fermentation, remove from the tank and set the pH value to 6.70;

[0104] ③ Sugar supplementation: Based on the total sugar and reducing sugar levels, supplement a total of 6.3 mg of sugar daily. 3 ;

[0105] ④ Add defoamer: Depending on the foam situation, add a total of 95L of silicone defoamer solution.

[0106] ⑤ Precursor addition: After 60-120 hours of growth in the fermenter, add a total of 83 L of 0.55% sodium propionate solution.

[0107] The fermentation cycle was 329 hours, the abamectin potency was measured to be 7038 μ / mL, and the fermentation tank volume was 298 m³. 3 .

[0108] Comparative Example 5 (Comparative Example 1 uses a different GP-type polyether defoamer)

[0109] (1) Primary seed culture: 75 kg corn starch, 20 kg soybean meal, 12 kg yeast powder, 20 kg rapeseed meal: wheat germ powder (1.5:1), 12 kg yeast extract, the remainder being drinking water; tank temperature maintained at 28.1℃ throughout; air flow rate 0-18h: 170 m³ / h. 3 / h; 18h - Transplanting: 400m 3 / h; the tank pressure is maintained at 0.042MPa, the pH is set at 6.70, the mycelial concentration is 24%, the mycelium forms a network, and the culture cycle is 41h.

[0110] (2) Secondary seed culture: 940 kg corn starch, 271 kg soybean meal, 82 kg yeast powder, 160 kg rapeseed meal: wheat germ powder (1.5:1), 114 kg yeast extract, and the remainder was drinking water; the tank temperature was controlled at 28.5℃ throughout the process; the air flow rate was 0-18 h 2230 m³ / h3 / h, 18h - transplanting 3650m 3 / h; tank pressure maintained at 0.41MPa; stirring not turned on for 0-8h, 160r / min from 8h to transplanting. pH set at 6.72, culture period 38h.

[0111] (3) Fermentation culture: 31200 kg corn starch, 4650 kg soybean meal, 2700 kg yeast powder, 210 kg defoamer, 370 kg calcium carbonate, 5.9 kg amylase, and the remainder is drinking water. The tank temperature was controlled at 28.0℃ throughout the process; tank pressure: 0.041 MPa; air flow rate: 4700 m³ / h (0-9 hours). 3 / h, 9-200h 5500m 3 / h, 200h - tank discharge 6900m 3 / h; Stirring: 123r / min.

[0112] Fermentation tank feeding control:

[0113] ① Hydration: Based on the bacterial concentration, replenish a total of 9.2m of water daily. 3 ;

[0114] ②Acid and alkali replenishment: After 80 hours of fermentation, remove from the tank and set the pH value to 6.70;

[0115] ③ Sugar supplementation: Based on the total sugar and reducing sugar levels, supplement a total daily sugar intake of 6.4 mg / dL. 3 ;

[0116] ④ Add defoamer: Depending on the foam situation, add 20-50% GP type polyether defoamer solution to 73L.

[0117] The fermentation cycle was 342 hours, the avermectin potency was measured to be 7099 μ / mL, and the fermentation tank volume was 315 m³. 3 .

[0118]

Claims

1. A method for preparing avermectin fermentation broth by fermenting a fermentation medium with a strain of Streptomyces avermitilis, wherein the fermentation is carried out in three stages, i.e., primary seed culture, secondary seed culture and fermentation tank culture, and the fermentation is carried out for 310-390 hours, characterized in that: the primary seed culture medium comprises corn starch 20-80 kg, soybean meal 5-40 kg, yeast powder 2-20 kg, rapeseed meal: wheat germ meal (1.5:1) 3-35 kg, yeast paste 1-20 kg, and the rest is drinking water, and the culture period is 30-55 hours; the secondary seed culture medium comprises corn starch 300-1500 kg, soybean meal 80-500 kg, yeast powder 50-200 kg, rapeseed meal: wheat germ meal (1.5:1) 50-210 kg, yeast paste 40-200 kg, and the rest is drinking water, and the culture period is 13-40 hours; and the fermentation medium comprises corn starch 23500-52000 kg, soybean meal 3100-9700 kg, yeast powder 1400-4900 kg, antifoaming agent 100-500 kg, calcium carbonate 100-700 kg, amylase 2.0-11.0 kg, 5000 kg of the fermentation medium after sterilization, and the rest is drinking water, and the culture period is 310-390 hours. The ratio of rapeseed meal to wheat germ meal in the primary seed culture medium is 1.5:

1. The fermentation medium is a fermentation medium liquid after the seed tank or the fermentation tank is inoculated and then inactivated by heating during the fermentation of avermectin. The antifoaming agent in the fermentation medium is a GP type polyether antifoaming agent.

2. The method of claim 1, wherein the fermentation of the biological fermentation dyeing material to produce the abamectin fermentation broth is characterized by During the fermentation, the fermentation tank culture is carried out by using a feeding method, and the feeding includes feeding drinking water, feeding sugar, feeding a precursor, pH control and feeding an antifoaming agent.

3. The method of claim 1, wherein the fermentation of the biological fermentation dyeing material to produce the avermectin fermentation broth is characterized by The precursor in the feeding by using the feeding method during the fermentation is a sodium propionate solution.

4. The method of claim 1, wherein the fermentation of the biological fermentation dyeing material to produce the avermectin fermentation broth is characterized by The feeding of the fermentation tank is controlled as follows:

5. The method of claim 1, wherein the fermentation of the biological fermentation dye material to produce the avermectin fermentation broth is characterized by (3) Feeding the precursor: after the fermentation tank is cultured for 60 hours, 0.2-1.1% of a sodium propionate solution is fed, the feeding is carried out once every 4 hours, and each feeding is carried out for 1 hour, and the feeding is carried out until 120 hours; 6. The method of claim 5, wherein the fermentation of the biological fermentation dye material to produce the avermectin fermentation broth is characterized by (4) pH control: the pH is controlled at 5.50-7.50 when the fermentation is carried out for 80 hours and the fermentation tank is discharged; 7. The method of claim 5, wherein the fermentation of the biological fermentation dye material to produce the avermectin fermentation broth is characterized by (5) Feeding the antifoaming agent: when the volume of the foam exceeds 2% of the volume of the normal fermentation liquid in the tank, 20-50% of a GP type polyether antifoaming agent solution 20-100 L is fed. (1) Water replenishment: 0-40 ml of drinking water was replenished every day after 60 h of growth in the fermentor 3 ; (2) Sugar supplement: 0-10 m 3 ; starch sugar solution concentration is 20%-40%; ​ ​ ​

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