CN115572753A

CN115572753A - Abamectin fermentation production process and abamectin

Info

Publication number: CN115572753A
Application number: CN202211403412.0A
Authority: CN
Inventors: 赵瑞祥; 白晓光
Original assignee: Hebei Wanbo Biotechnology Co ltd
Current assignee: Hebei Wanbo Biotechnology Co ltd
Priority date: 2022-11-10
Filing date: 2022-11-10
Publication date: 2023-01-06

Abstract

The application relates to the technical field of production of pesticide products, and particularly discloses an abamectin fermentation production process and abamectin. A fermentation production process of avermectin comprises the steps of inoculating streptomyces avermitilis into a culture medium for fermentation, wherein the fermentation process is divided into five stages: 0-20 hours is adaptation period, 21-80 hours is growth period, 81-250 hours is stabilization period, 251-300 hours is aging period; the ventilation capacity in adaptation period is 2000-2500L/h, the ventilation capacity in growth period is 3000-3200L/h, the ventilation capacity in stationary period is 2200-2500L/h, and the ventilation capacity in aging period is 1900-2100L/h. According to the fermentation process for producing the abamectin, the yield of the abamectin can reach 6.89-7.11g/L, the yield of the abamectin is effectively improved, the ventilation volume is flexibly adjusted, the waste of air volume can be effectively reduced, resources are saved, and the overall economic benefit is improved.

Description

Abamectin fermentation production process and abamectin

Technical Field

The application relates to the technical field of production of pesticide products, in particular to an abamectin fermentation production process and abamectin.

Background

The abamectin is a novel biopesticide, is favored in the current biopesticide market, and has the characteristics of high efficiency, broad spectrum and low toxicity. The avermectin is used for preventing and controlling diamondback moth of cruciferae, scale louse of citrus leaf miner, cotton red spider, tetranychus urticae and cabbage caterpillar, etc., has unique insecticidal mechanism, can block nerve conduction of invertebrates, and has long duration. Meanwhile, the pesticide is easy to decompose in water and soil, and does not pollute the environment, so that the pesticide is a biological pesticide with great development potential.

The abamectin is produced by deep fermentation of streptomyces avermitilis, and in the existing abamectin fermentation process, streptomyces vermitilis is fermented and cultured in a culture medium containing starch, soybean cake powder, yeast powder and the like, the common period is about 300 hours, the intermediate temperature is controlled to be 27-28 ℃, the ventilation quantity is 2800-3000L/h, and the stirring is 130r/min.

Aiming at the related technologies, the applicant considers that the consumption cost is high, the yield of the abamectin is low, and the overall economic value is low.

Disclosure of Invention

In order to reduce cost consumption and improve the yield of abamectin so as to improve the overall economic value, the application provides an abamectin fermentation production process and abamectin.

In a first aspect, the application provides an avermectin fermentation production process, which adopts the following technical scheme:

a fermentation production process of avermectin is characterized in that streptomyces avermitilis is inoculated in a culture medium for fermentation, and the fermentation process is divided into five stages: 0-20 hours as adaptation period, 21-80 hours as growth period, 81-250 hours as stabilization period, 251-300 hours as aging period;

the ventilation capacity in adaptation period is 2000-2500L/h, in growth period is 3000-3200L/h, in stationary period is 2200-2500L/h, and in aging period is 1900-2100L/h.

By adopting the technical scheme, the fermentation liquor for producing the abamectin is totally non-Newtonian fluid, the shear thinning characteristic is met, the fermentation process is divided into different periods according to the growth characteristic of the abamectin produced by fermenting the streptomyces avermitilis, the ventilation volume is adjusted according to the growth characteristic of the different periods, the strain can be metabolized secondarily as soon as possible and continuously to achieve a better effect, and the yield of the abamectin is increased.

In the adaptation period, the strain grows slowly, and the ventilation capacity is relatively low, so that the strain adapts to the growth environment in the culture medium; during the growth period, the apparent viscosity of the fermentation liquor is rapidly increased due to rapid growth of strains, the oxygen consumption rate is rapidly increased due to rapid increase of the amount of the strains, the oxygen supply capacity of the fermentation liquor is reduced due to the increase of the apparent viscosity of the fermentation liquor, and the ventilation capacity is increased to provide enough dissolved oxygen for the fermentation liquor so as to ensure rapid growth of hyphae; after the stable period, the shape of the thalli changes, the thalli starts to form balls, the interior of the thalli is limited by oxygen transfer, the respiration is limited, the oxygen consumption rate does not rise any more, the apparent viscosity of the fermentation liquor is gradually reduced, the ventilation capacity does not need to rise continuously, the ventilation capacity is properly adjusted down, the dissolved oxygen amount in the fermentation liquor is reduced, and the respiratory action of the thalli is prevented from being influenced by overhigh concentration of the dissolved oxygen; after the aging period, the growth of the bacteria balls is basically finished, and the ventilation capacity is reduced, so that the dissolved oxygen concentration in the fermentation liquor is reduced, the autolysis speed of hyphae can be slowed down, the yield time can be prolonged as much as possible, and the yield of the abamectin is further improved.

Regulating ventilation quantity according to different growth characteristics of the strains in the fermentation period, thereby controlling the concentration of dissolved oxygen in the fermentation liquid, providing an environment which is more beneficial to growth for the strains in each period, and being beneficial to improving the yield of the abamectin; in addition, the ventilation amount is adjusted along with the growth period, the waste of the air amount can be reduced, the ventilation amount is controlled to be 2800-3000L/h relative to the whole growth period by calculating 70 cubic meters of air supply per hour by a 240 kilowatt motor, about 15% of air amount can be saved, the waste of the air amount is reduced, and the economic benefit is improved.

Preferably, the stirring speed in the adaptation period is 0, the stirring speed in the growth period is 125-135r/min, the stirring speed in the stabilization period is 80-105r/min, and the stirring speed in the aging period is 0.

By adopting the technical scheme, the shear force is provided for the fermentation liquor by stirring, so that the mixing effect of the fermentation liquor is improved, the mass transfer and the heat transfer in the fermentation liquor are ensured, and the yield of the abamectin is favorably improved. In the adaptation period and the aging period, the apparent viscosity of the fermentation liquor is low, the aeration has certain mixing and transferring functions, stirring is not carried out at the moment, energy transfer in the fermentation liquor cannot be influenced, and the Wu Jiaoban state can also avoid the strain in the adaptation period from being damaged, reduce autolysis of the bacteria balls in the aging period and be beneficial to improving the yield of the abamectin. In the growth period and the stabilization period, the surface viscosity of the fermentation liquor is relatively high, and the fermentation liquor can be mixed by stirring to carry out capacity transfer, so that the growth of hyphae is ensured.

In addition, the stirring speed is controlled according to different growth characteristics of the strains during fermentation, and compared with the whole growth period, the stirring speed of 130r/min is used for operation, and the motor of the stirrer is 130 kilowatts, so that about 40% of electricity consumption can be saved, the resource waste is reduced, and the economic benefit is improved.

Preferably, the temperature in the adaptation phase is 27-28 ℃, the temperature in the growth phase is 29-30 ℃, the temperature in the stationary phase is 26-27 ℃ and the temperature in the aging phase is 25-26 ℃.

By adopting the technical scheme, the environmental temperature is controlled according to different growth characteristics of the strains during fermentation, so that an environment which is more beneficial to growth is provided for the strains in each period, and the yield of the abamectin is improved; compared with the method that the water is used for heating in the whole growth period, the method is operated at the temperature of 27-28 ℃, and the sectional heating mode can save about 20% of water consumption, reduce water resource waste and improve economic benefits.

Preferably, part of the fermentation broth is discharged at the later stage of the stationary phase, i.e., 200-250 hours, and the same volume of fermentation broth cultured for 40-60 hours is supplemented.

Preferably, the discharged fermentation liquor accounts for 2-3% of the total volume of the fermentation liquor.

The avermectin fermentation liquor has non-Newtonian fluid property. In the fermentation process of the streptomyces avermitilis, the hypha form is changed, the non-Newtonian fluid property of the fermentation liquid is gradually weakened, the fermentation liquid is diluted, the foam is gradually increased, the liquid level of the fermentation liquid is increased, and the escape liquid is generated in severe cases. By adopting the technical scheme, a part of fermentation liquor is discharged at the later stage of the stabilization period, new fermentation liquor is supplemented, the supplemented new fermentation liquor strain enters the growth period, and the mycelium supplemented in the fermentation liquor has secondary metabolic capability and can immediately carry out the biosynthesis of the abamectin; in addition, the fermentation liquor is supplemented, so that the inhibition of metabolites is relieved, the activity of bacteria is kept, and the nutrient contents such as carbon, nitrogen and the like in the fermentation liquor are higher than those in the fermentation liquor in the later period of the stabilization period, so that more energy support is provided for the biosynthesis of abamectin in the later period, the continuous and rapid improvement of titer is facilitated, and the yield of abamectin is improved.

Preferably, the culture medium comprises the following raw materials in parts by weight: 120-140 parts of starch, 15-18 parts of soybean cake powder, 3-5 parts of yeast powder, 0.1-0.3 part of ammonium sulfate, 0.01-0.03 part of cobalt chloride, 0.01-003 part of sodium molybdate, 1-3 parts of sodium lactate, 2-4 parts of polyethylene glycol and 8-12 parts of sawdust.

By adopting the technical scheme, starch is used as a carbon source and the soybean cake is used as a nitrogen source in the culture medium, so that basic nutrition is provided for the growth of the strain; and the sodium lactate can be used as a secondary metabolic precursor substance to be directly converted into propionyl CoA and methylmalonyl CoA and enter avermectin molecules, so that more pyruvic acid and lactic acid are converted into acetyl CoA in the strain fermentation process, and the acetyl CoA is the most direct precursor for synthesizing the avermectin, thereby being beneficial to improving the yield of the avermectin.

Preferably, the molecular weight of the polyethylene glycol is 6000.

Preferably, the preparation method of the culture medium comprises the following steps:

1) Dissolving sodium lactate and polyethylene glycol in water, adding wood chips for absorption, and drying to obtain a mixture A;

2) And mixing the mixture A with the rest raw materials to obtain a culture medium.

By adopting the technical scheme, the sodium lactate and the polyethylene glycol are mixed with the saw dust, and the saw dust adsorbs the sodium lactate and the polyethylene glycol, so that the sodium lactate can be slowly released, the stable concentration of the sodium lactate in the fermentation liquid is kept, the situation that the yield of the abamectin is sharply reduced due to the fact that the acidity is enhanced because of overhigh concentration, the growth of thalli is inhibited, the in vivo synthesis is also inhibited is avoided, and the yield of the abamectin is favorably improved.

In a second aspect, the application provides an avermectin obtained by any one of the avermectin fermentation production processes.

In summary, the present application has the following beneficial effects:

1. according to the method, the ventilation volume in the fermentation liquor is adjusted according to the characteristics of the strains in different growth periods, the dissolved oxygen level in the fermentation liquor is controlled, the strains can be metabolized as early as possible and continuously for a second time to achieve a better effect, the yield of the abamectin can reach 6.89-7.11g/L, the yield of the abamectin is effectively improved, the ventilation volume is adjusted flexibly, the waste of the ventilation volume can be effectively reduced, resources are saved, and the overall economic benefit is improved.

2. In the application, partial fermentation liquor is preferably discharged at the later stage of the stabilization period, new fermentation liquor with the same volume is supplemented, the supplemented new fermentation liquor strain enters the growth period, and the mycelium supplemented in the fermentation liquor has secondary metabolism capability and can immediately carry out biosynthesis of abamectin; the supplemented fermentation liquor reduces the inhibition of metabolites, keeps the vitality of the thalli, supplements nutrient components, provides more energy support for later-stage abamectin biosynthesis, is favorable for continuously and quickly improving the titer, and improves the yield of abamectin.

Detailed Description

The present application will be described in further detail with reference to examples.

Preparation examples of starting materials and intermediates

Raw materials

The raw materials of the embodiments of the present application can be obtained through commercial sale:

ammonium sulfate, cobalt chloride, sodium molybdate, sodium lactate and polyethylene glycol-6000 are all chemically pure;

the fineness of the wood chips is 100-160 meshes.

Preparation example

Preparation examples 1 to 5

1) Dissolving sodium lactate and polyethylene glycol in water according to the raw material ratio in Table 1, adding sawdust to absorb for 30min, and drying at 55 ℃ to obtain a mixture A;

2) And mixing the mixture A with the rest raw materials to obtain the culture medium.

TABLE 1 preparative examples 1-5 raw material compounding Table (100 g)

Preparation example 6

The preparation example 6 is the same as the preparation example 1 in raw material ratio, and the preparation method comprises the following steps:

the culture medium was obtained by mixing the raw materials except water in the ratios of the raw materials shown in Table 1.

Examples

Example 1

The fermentation production process of the abamectin comprises the following steps:

inoculating streptomyces avermitilis in the culture medium obtained in the preparation example 1 in an inoculation amount of 5%, and performing fermentation culture to obtain avermectin; the fermentation culture conditions are as follows:

the adaptation period is 0-20 hours: the ventilation amount is 2000L/h, the reaction temperature is 27 ℃, and the stirring speed is 0;

growth period 21-80 hours: the aeration rate is 3000L/h, the reaction temperature is 29 ℃, and the stirring speed is 130r/min;

the stable period is 81-250 hours: the ventilation amount is 2200L/h, the reaction temperature is 26 ℃, and the stirring speed is 90r/min;

aging period 251-300 hours: the aeration rate was 1900L/h, the reaction temperature was 25 ℃ and the stirring speed was 0.

Example 2

In contrast to example 1, the fermentation conditions in example 2 were:

the adaptation period is 0-20 hours: the ventilation amount is 2500L/h, the reaction temperature is 27 ℃, and the stirring speed is 0;

growth period 21-80 hours: the aeration rate is 3200L/h, the reaction temperature is 29 ℃, and the stirring speed is 130r/min;

the stable period is 81-250 hours: the aeration rate is 2500L/h, the reaction temperature is 26 ℃, and the stirring speed is 90r/min;

aging period 251-300 hours: the aeration rate was 2100L/h, the reaction temperature was 25 ℃ and the stirring rate was 0.

Example 3

Different from the example 1, the fermentation culture conditions in the example 3 are as follows:

the adaptation period is 0-20 hours: the ventilation amount is 2000L/h, the reaction temperature is 28 ℃, and the stirring speed is 0;

growth period 21-80 hours: the aeration rate is 3000L/h, the reaction temperature is 28 ℃, and the stirring speed is 130r/min;

the stable period is 81-250 hours: the ventilation amount is 2200L/h, the reaction temperature is 28 ℃, and the stirring speed is 90r/min;

aging period 251-300 hours: the aeration rate was 1900L/h, the reaction temperature was 28 ℃ and the stirring speed was 0.

Example 4

Different from the example 1, the fermentation culture conditions in the example 4 are as follows:

the adaptation period is 0-20 hours: the ventilation volume is 2000L/h, the reaction temperature is 28 ℃, and the stirring speed is 130r/min;

growth period 21-80 hours: the aeration rate is 3000L/h, the reaction temperature is 30 ℃, and the stirring speed is 130r/min;

the stable period is 81-250 hours: the aeration rate is 2200L/h, the reaction temperature is 27 ℃, and the stirring speed is 130r/min;

aging period 251-300 hours: the aeration rate is 1900L/h, the reaction temperature is 26 ℃, and the stirring speed is 130r/min.

Example 5

Unlike example 1, in example 5, when the reaction was carried out for 200 hours, 2% of the total volume of the fermentation broth was discharged and the same volume of fermentation broth cultured for 50 hours was supplemented.

Example 6

Unlike example 1, in example 6, when the reaction was carried out for 250 hours, 2% of the total volume of the fermentation broth was discharged and the same volume of fermentation broth cultured for 50 hours was supplemented.

Example 7

Unlike example 1, in example 7, when the reaction proceeded to 275 hours, 3% of the total volume of the fermentation broth was discharged and the same volume of fermentation broth cultured for 50 hours was supplemented.

Example 8

Unlike example 1, in example 8, when the reaction was carried out for 200 hours, 2% of the total volume of the fermentation broth was discharged and the same volume of fermentation broth cultured for 60 hours was supplemented.

Example 9

Unlike example 1, in example 9, when the reaction was carried out for 200 hours, 2% of the total volume of the fermentation broth was discharged and the same volume of fermentation broth cultured for 30 hours was supplemented.

Example 10

Unlike example 1, in example 10, when the reaction was carried out for 200 hours, 2% of the total volume of the fermentation broth was discharged and the same volume of fermentation broth cultured for 80 hours was supplemented.

Examples 11 to 15

In contrast to example 5, the media in examples 11-15 were obtained from preparation examples 2-6, respectively.

Comparative example

Comparative example 1

Unlike example 1, the fermentation culture conditions in comparative example 1 were:

the adaptation period is 0-20 hours: the ventilation amount is 2800L/h, the reaction temperature is 27 ℃, and the stirring speed is 0;

growth period 21-80 hours: the aeration rate is 2800L/h, the reaction temperature is 29 ℃, and the stirring speed is 130r/min;

the stable period is 81-250 hours: the ventilation amount is 2800L/h, the reaction temperature is 26 ℃, and the stirring speed is 90r/min;

aging period 251-300 hours: the aeration rate was 2800L/h, the reaction temperature was 25 ℃ and the stirring rate was 0.

Comparative example 2

Unlike example 1, the fermentation culture conditions in comparative example 2 were:

growth period 21-80 hours: the ventilation volume is 3000L/h, the reaction temperature is 29 ℃, and the stirring speed is 130r/min;

Comparative example 3

Unlike example 1, the fermentation culture conditions in comparative example 3 were:

growth period 21-80 hours: the aeration rate is 2500L/h, the reaction temperature is 29 ℃, and the stirring speed is 130r/min;

Comparative example 4

Unlike example 1, the fermentation culture conditions in comparative example 4 were:

the adaptation period is 0-20 hours: the ventilation volume is 2000L/h, the reaction temperature is 27 ℃, and the stirring speed is 0;

Comparative example 5

Unlike example 1, the fermentation culture conditions in comparative example 5 were:

aging period 251-300 hours: the aeration rate was 2500L/h, the reaction temperature was 25 ℃ and the stirring speed was 0.

Performance test

Detection method/test method

The yield of avermectins in examples 1-15 and comparative examples 1-5 was determined by GC/M S:

the GC conditions were: agilentHP530 m.times.0.25 mm.times.0.25 μm capillary column; sample inlet temperature: 280 ℃, temperature rising program: maintaining the initial temperature at 70 deg.C for 2min, and heating to 290 deg.C at 5 deg.C/min for 5min; carrier gas: high-purity helium, 91kPa at a constant pressure mode, and the flow rate is 1mL/min; the sample volume is 1 mu L; the split ratio after the column is 10: 1;

the MS conditions are as follows: interface temperature: 280 ℃; an ionization mode: EI; an ionization mode: electron impact ionization (EI +); ion source temperature: 250 ℃; electron bombardment energy: 70eV; electron current: 40 muA; scanning mass range: 50-800m/z.

The results are shown in Table 2.

TABLE 2 Performance test results

	Abamectin yield (g/L)
		Example 1	6.86
Example 2	6.89
		Example 3	6.75
Example 4	6.79
		Example 5	7.02
Example 6	6.98
		Example 7	6.92
Example 8	7.11
		Example 9	6.93
Example 10	6.95
		Example 11	7.06
Example 12	7.03
		Example 13	6.98
Example 14	6.96
		Example 15	6.97
Comparative example 1	5.28
		Comparative example 2	5.35
Comparative example 3	5.19
		Comparative example 4	5.39
Comparative example 5	5.25

Combining examples 1-15 and comparative examples 1-5, and combining table 2, it can be seen that the yield of abamectin in examples 1-15 is higher than that in comparative examples 1-4, which indicates that the abamectin yield obtained by the fermentation production process of abamectin in the present application is higher.

Combining example 1 with comparative examples 1-5 and table 2, it can be seen that the yield of abamectin in comparative example 1 is significantly lower than that of example 1 by adopting uniform ventilation throughout the growth cycle in comparative example 1, which indicates that adjusting ventilation according to the characteristics of different growth cycles of the strain is beneficial to the improvement of abamectin yield, probably because the ventilation is adjusted such that the strain grows at more appropriate dissolved oxygen concentration in different growth periods of the strain, the strain can be metabolized secondarily as soon as possible and continuously to achieve better effect, and the yield of abamectin is increased; in comparative example 2, if the aeration amount in the adaptation period is out of the range defined in the present application, the production amount of abamectin is decreased, probably because the dissolved oxygen amount required for the undesirable strain in the initial adaptation period is low; in comparative example 3, if the aeration rate in the growth period is lower than the range defined in the application, the yield of the abamectin is reduced, which is probably because the apparent viscosity of the fermentation broth is rapidly increased due to the rapid growth of strains in the growth period, the oxygen consumption rate is rapidly increased due to the rapid increase of the amount of the strains, the oxygen supply capacity of the fermentation broth is reduced due to the increase of the apparent viscosity of the fermentation broth, and at the moment, the aeration rate is increased to provide enough dissolved oxygen for the fermentation broth, thereby ensuring the rapid growth of hyphae and improving the yield of the abamectin; in comparative example 4, if the ventilation amount in the stabilization period is higher than the range defined in the application, the yield of the abamectin is reduced, which is probably because the shape of the thalli changes after entering the stabilization period, the thalli starts to form balls, the respiration is limited, the oxygen consumption rate does not rise any more, the ventilation amount is properly adjusted to reduce the dissolved oxygen amount in the fermentation liquid, and the phenomenon that the respiration of the thalli is influenced by overhigh dissolved oxygen concentration is avoided; in comparative example 5, the aeration rate in the senescence stage is higher than the range defined in the present application, the yield of abamectin is reduced, probably because the growth of the mycelial pellets in the senescence stage is basically completed, the aeration rate is reduced, the autolysis speed of hyphae can be slowed down, the yield time of abamectin can be prolonged as much as possible, and the yield of abamectin is further improved.

Combining example 1 with examples 5-10 and table 2, it can be seen that, in examples 5-10, part of the fermentation broth is discharged at the later stage of the stabilization period and the same volume of fermentation broth is supplemented, so that the yield of abamectin in examples 5-10 is higher than that in example 1, probably because the supplemented new fermentation broth strain enters the growth period, and the mycelium itself supplemented in the fermentation broth has secondary metabolic capability and can immediately perform biosynthesis of abamectin; the supplemented fermentation liquor reduces the inhibition of metabolites, keeps the activity of thalli, supplements nutrient components, provides more energy support for later-stage abamectin biosynthesis, is favorable for continuously and quickly improving the titer, and improves the yield of abamectin.

In combination with examples 5-7 and table 2, it can be seen that the yield of abamectin in examples 5-6 is higher than that in example 7, which is probably because the fermentation broth released in example 7 is too late, the biosynthesis of abamectin is already substantially completed, and the new fermentation broth has a low participation in abamectin biosynthesis.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.

Claims

1. A fermentation production process of abamectin is to inoculate streptomyces avermitilis in a culture medium for fermentation, and is characterized in that the fermentation process is divided into five stages: 0-20 hours is adaptation period, 21-80 hours is growth period, 81-250 hours is stabilization period, 251-300 hours is aging period;

the ventilation capacity in adaptation period is 2000-2500L/h, the ventilation capacity in growth period is 3000-3200L/h, the ventilation capacity in stationary period is 2200-2500L/h, and the ventilation capacity in aging period is 1900-2100L/h.

2. The fermentation production process of abamectin according to claim 1, characterized by comprising the following steps: the stirring speed in the adaptation period is 0, the stirring speed in the growth period is 125-135r/min, the stirring speed in the stabilization period is 80-105r/min, and the stirring speed in the aging period is 0.

3. The fermentation production process of abamectin according to claim 1, which is characterized by comprising the following steps: the temperature of the adaptation phase is 27-28 ℃, the temperature of the growth phase is 29-30 ℃, the temperature of the stabilization phase is 26-27 ℃ and the temperature of the aging phase is 25-26 ℃.

4. The fermentation production process of abamectin according to claim 1, characterized by comprising the following steps: discharging partial fermentation liquor at the later stage of the stabilization period, namely 200-250 hours, and supplementing the fermentation liquor with the same volume which is cultured for 40-60 hours.

5. The fermentation production process of abamectin according to claim 4, characterized by comprising the following steps: the discharged fermentation liquor accounts for 2-3% of the total volume of the fermentation liquor.

6. The fermentation production process of abamectin according to claim 1, which is characterized by comprising the following steps: the culture medium comprises the following raw materials in parts by weight: 120-140 parts of starch, 15-18 parts of soybean cake powder, 3-5 parts of yeast powder, 0.1-0.3 part of ammonium sulfate, 0.01-0.03 part of cobalt chloride, 0.01-003 part of sodium molybdate, 1-3 parts of sodium lactate, 2-4 parts of polyethylene glycol and 8-12 parts of sawdust.

7. The fermentation production process of abamectin according to claim 6, which is characterized in that: the molecular weight of the polyethylene glycol is 6000.

8. The fermentation production process of abamectin according to claim 6, which is characterized in that: the preparation method of the culture medium comprises the following steps:

1) Dissolving sodium lactate and polyethylene glycol in water, adding sawdust to absorb, and drying to obtain a mixture A;

9. An avermectin obtained by the avermectin fermentation production process of any one of claims 1 to 8.