阅读说明：本技术 一种醋酸泼尼松的发酵方法 (Prednisone acetate fermentation method ) 是由 谭志云 卢绍波 谭建权 王钱钢 杨宗禄 于 2021-09-28 设计创作，主要内容包括：本发明公开了一种醋酸泼尼松的发酵方法,该发酵方法包括以下步骤：一级发酵：将成熟的菌体悬浮液分别接种于一号种子罐和二号种子罐中培养形成一号菌丝体和二号菌丝体；将一号菌丝体接种于发酵罐中培养15-20h后,加入二号菌丝体继续培养16-22h,再补入种子液继续培养4h；向发酵罐中加入溶剂、醋酸可的松微粉搅拌后进行转化,转化完成后,升温采用乙酸乙酯提取浓缩液得到醋酸泼尼松；本发明中通过分期加入菌丝体,并在二级发酵后期补入种子液,使得整个发酵过程中菌种都保持足够的营养,满足转化要求,获得更高的转化率；同时选用简单节杆菌对醋酸可的松进行转化,转化率更高。(The invention discloses a fermentation method of prednisone acetate, which comprises the following steps: primary fermentation: respectively inoculating mature thallus suspension into a first seed tank and a second seed tank to culture to form a first mycelium and a second mycelium; inoculating the first mycelium into a fermentation tank for culturing for 15-20h, adding the second mycelium for continuously culturing for 16-22h, and supplementing seed liquid for continuously culturing for 4 h; adding a solvent and cortisone acetate micro powder into a fermentation tank, stirring, converting, heating, and extracting a concentrated solution by using ethyl acetate to obtain prednisone acetate; in the invention, the mycelium is added stage by stage, and the seed liquid is supplemented in the later stage of secondary fermentation, so that the strains can maintain enough nutrition in the whole fermentation process, the conversion requirement is met, and higher conversion rate is obtained; meanwhile, the simple arthrobacterium is selected to convert the cortisone acetate, so that the conversion rate is higher.)

1. A fermentation method of prednisone acetate is characterized in that,

the fermentation method comprises the following steps:

primary fermentation: respectively inoculating the thallus suspension into a first seed tank and a second seed tank to culture to form a first mycelium and a second mycelium;

secondary fermentation: inoculating the first mycelium into a fermentation tank for culturing for 15-20h, adding the second mycelium for continuously culturing for 16-22h, and supplementing seed liquid for continuously culturing for 4 h;

and (3) transformation: adding a solvent and cortisone acetate micro powder into a fermentation tank, stirring, converting, heating, and extracting a concentrated solution by using ethyl acetate to obtain prednisone acetate.

2. The method of fermenting prednisone acetate according to claim 1,

the spore liquid is obtained by the following method:

transplanting Arthrobacter simplex to a slant culture medium, culturing for 5-7 days at 28-30 ℃, and maturing spores;

the mature Arthrobacter simplex is prepared into a thallus suspension by using sterile normal saline.

3. The method of fermenting prednisone acetate according to claim 2,

the slant culture medium comprises glucose 1.6-1.8%, yeast extract 1.5-1.8%, agar 1-1.5% and water in balance.

4. The method of fermenting prednisone acetate according to claim 1,

the culture conditions in the first seeding tank are as follows: culturing at 27 ℃ for 40h, wherein the tank pressure is 0.01-0.02MPa, and the stirring speed is 320-;

the culture conditions in the second seed tank are as follows: culturing at 25 deg.C for 40-50h in the second seed tank under 0.01-0.02MPa and stirring at 320-.

5. The method of fermenting prednisone acetate according to claim 4,

the seed liquid in the first seed tank and the second seed tank has the same components, and comprises: 2.0-2.2% of glucose, 0.8-1% of cottonseed powder, 0.8-1% of prinsepia utilis royle powder, 0.8-1.2% of yeast extract, 0.1% of sodium dihydrogen phosphate and the balance of water.

6. The method of fermenting prednisone acetate according to claim 1,

the components of the fermentation liquor in the secondary fermentation are the same as those of the seed liquor.

7. The method of claim 5 or 6, wherein the seed solution and the fermentation broth are sterilized at a temperature of 118 ℃ to 123 ℃.

8. The method of fermenting prednisone acetate according to claim 1,

the solvent is one or a mixture of methanol, acetonitrile, ethanol and acetone.

9. The method of fermenting prednisone acetate according to claim 1,

the fermentation process in the secondary fermentation process is preferably as follows: culturing No. one mycelium at 26 deg.C for 15 hr, supplementing No. two mycelium, culturing for 16 hr, adding seed solution without spore inoculation, and culturing for 4 hr while stirring at 280 r/min.

Technical Field

The invention belongs to the field of medical biology, and particularly relates to a fermentation method of prednisone acetate.

Background

With the large-scale production of antibiotics and the establishment of a submerged fermentation technology, modern fermentation engineering pharmacy rises rapidly, and various primary metabolites are produced by utilizing metabolism regulation and fermentation from the beginning and are gradually converted into a cell continuous fermentation technology. In recent years, with the development of bioengineering, the microbial strains used for fermentation pharmacy are not limited to natural microorganisms.

Prednisone acetate is white or almost white crystalline powder; is insoluble in water, slightly soluble in ethanol and ethyl acetate, slightly soluble in acetone, and easily soluble in chloroform, is a corticoid drug, and has effects of influencing glycometabolism, resisting inflammation, resisting allergy, resisting toxicity, and resisting malignant lymphoid tissue diseases. Prednisone acetate is generally prepared by converting cortisone acetate into prednisone acetate, for example, patent with publication number CN101760495B proposes that arthrobacterium AS 1.94 is used AS a transformation strain to convert cortisone acetate into prednisone acetate, but the conversion rate in the method is low and is only 77.3%; also, patent publication No. CN 106893754A discloses Arthrobacter AS 1.754 AS the transformed strain, which produces prednisone impurity 8.2%. The method has the advantages that the conversion rate is not high when the prednisone acetate is prepared, and impurities are generated.

Disclosure of Invention

Aiming at the problems, the invention discloses a prednisone acetate fermentation method, which comprises the following steps:

primary fermentation: respectively inoculating the thallus suspension into a first seed tank and a second seed tank to culture to form a first mycelium and a second mycelium;

secondary fermentation: inoculating the first mycelium into a fermentation tank for culturing for 15-20h, adding the second mycelium for continuously culturing for 16-22h, and supplementing seed liquid for continuously culturing for 4 h;

and (3) transformation: adding a solvent and cortisone acetate micro powder into a fermentation tank, stirring, converting, heating, and extracting a concentrated solution by using ethyl acetate to obtain prednisone acetate.

The spore liquid is obtained by the following method:

transplanting Arthrobacter simplex to a slant culture medium, culturing for 5-7 days at 28-30 ℃, and maturing a thallus suspension;

the mature cells were suspended in sterile physiological saline.

Further, the components of the slant culture medium are 1.6-1.8% of glucose, 1.5-1.8% of yeast extract, 1-1.5% of agar and the balance of water.

Further, the culture conditions in the first seeding tank are as follows: culturing at 27 ℃ for 40h, wherein the tank pressure is 0.01-0.02MPa, and the stirring speed is 320-;

the culture conditions in the second seed tank are as follows: culturing at 25 deg.C for 40-50h in the second seed tank under 0.01-0.02MPa and stirring at 320-.

Further, the seed liquid in the first seed tank and the second seed tank has the same components, and the method comprises the following steps: 2.0-2.2% of glucose, 0.8-1% of cottonseed powder, 0.8-1% of prinsepia utilis royle powder, 0.8-1.2% of yeast extract, 0.1% of sodium dihydrogen phosphate and the balance of water.

Further, the components of the fermentation liquor in the secondary fermentation are the same as the components of the seed liquor.

Further, the sterilization temperature of the seed liquid and the fermentation liquid is 118-123 ℃.

Further, the solvent is one or a mixture of methanol, acetonitrile, ethanol and acetone.

Further, the fermentation process in the secondary fermentation process is preferably as follows: culturing No. one mycelium at 26 deg.C for 15 hr, supplementing No. two mycelium, culturing for 16 hr, adding non-inoculated seed liquid, and culturing for 4 hr while stirring at 280 r/min.

The invention has the beneficial effects that:

in the invention, the suspension is divided into two parts to be separately cultured to form a first mycelium and a second mycelium, the first mycelium and the second mycelium are added in batches in the secondary fermentation process, and the seed liquid is supplemented in the later stage of the secondary fermentation, so that the strains can maintain enough nutrition in the whole fermentation process, the conversion requirement is met, and higher conversion rate is obtained;

according to the invention, the simple arthrobacter is selected to convert the cortisone acetate, so that the conversion rate is higher; the raw materials used in the invention are common raw materials, and are cheap and suitable for large-scale production.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a fermentation method of prednisone acetate, which adopts Arthrobacter simplex as a transformation strain to transform cortisone acetate into prednisone acetate.

The culture medium is a mixture of multiple nutrients which are required by the growth and reproduction of microorganisms and the biosynthesis of various metabolites and are prepared according to a certain proportion. The composition of the culture medium has important influence on the growth and reproduction of thalli, the biosynthesis of products, the separation and refining of the products and the quality and yield of the products. The nutrition activity of the microorganism is realized by secreting a large amount of enzyme to the outside, decomposing nutrients such as macromolecular protein, sugar, fat and the like in the surrounding environment into micromolecular compounds and absorbing the micromolecular nutrients by means of the osmosis of cell membranes. All fermentation media must provide the carbon, nitrogen, inorganic elements, growth factors, water and oxygen necessary for microbial growth and product synthesis. For large-scale fermentation production, in addition to considering the requirements of the microorganisms, the price and the source of the culture medium raw materials must be considered, the culture medium raw materials selected in the invention are all simply available on the market, the price is proper, and the price is only an exemplary exhibition of the raw material components related to the invention.

The fermentation method comprises the following steps:

preparing a seed solution: transplanting Arthrobacter simplex to a slant culture medium, culturing for 5-7 days at 28-30 ℃, preparing the mature thalli into suspension by using sterile normal saline after seeds are mature, and performing vacuum drying and low-temperature storage; the slant culture medium comprises glucose 1.6-1.8%, yeast extract 1.5-1.8%, agar 1-1.5% and water in balance.

Primary fermentation: respectively inoculating the stored seed liquid into a first seed tank and a second seed tank, culturing the first seed tank for 40h at 27 ℃ to obtain a first mycelium, culturing the second seed tank for 40-50h at 25 ℃ to obtain a second mycelium, wherein the tank pressure is 0.01-0.02MPa, and the stirring speed is 320-360r/min to ensure that the seed liquid is in a uniform state; the components of the seed liquid in the two seed tanks are 2.0-2.2 percent of glucose, 0.8-1 percent of cotton seed powder, 0.8-1 percent of prinsepia utilis royle powder, 0.8-1.2 percent of yeast extract, 0.1 percent of sodium dihydrogen phosphate and the balance of water, and the seed liquid is prepared by more than the normal using amount.

Secondary fermentation: inoculating the first mycelium into a fermentation tank, culturing for 15-20h at 24-26 ℃, calculating the specific growth rate, oxygen specific consumption rate, product specific generation rate and the like of the mycelium at the moment by using a sensor or sampling, supplementing the second mycelium, continuing fermentation and culture for 16-22h, supplementing the missed seed solution, and continuing culture at the stirring rotation speed of 260 plus 280r/min until the sampled mycelium is free of mixed bacteria in microscopic examination, the mycelium is thick and dense, the protoplasm is full, and the mycelium buoyancy is large, so that the next step can be carried out. The fermentation liquid in the fermentation tank has the same components as the seed liquid, and comprises 2.0-2.2% of glucose, 0.8-1% of cottonseed powder, 0.8-1% of prinsepia utilis royle powder, 0.8-1.2% of yeast extract, 0.1% of sodium dihydrogen phosphate and the balance of water.

And (3) transformation: adding an organic solvent and cortisone acetate micro powder (substrate) into the cultured fermentation liquor, stirring, converting at 30-36 ℃ for 30-35h at the rotation speed of 400-500r/min, heating to 68 ℃ after the reaction is finished, stopping the reaction, extracting the fermentation liquor by using ethyl acetate, concentrating the organic phase, and measuring the substrate conversion rate. Wherein, the solvent comprises one or more of methanol, acetonitrile, ethanol and acetone, preferably methanol, the methanol can increase the solubility of the cortisone acetate and the decomposition rate of the cortisone acetate, the concentration of the solvent is lower than 2%, the solvent does not generate toxicity to microorganisms, the cortisone acetate is firstly dissolved in the organic solvent, the adding speed of the cortisone acetate is determined according to the conversion rate of the strains, and the concentration is generally 300-700 mg/L.

Part of the raw materials selected in the examples of the present invention are shown in the following table:

example 1

The fermentation method of prednisone acetate comprises the following steps:

preparing a seed solution: transplanting Arthrobacter simplex to a slant culture medium, culturing for 7 days at 28 ℃, and preparing a seed solution from mature Arthrobacter strains by using sterile normal saline after seeds are mature; the slant culture medium comprises glucose 1.6%, yeast extract 1.5%, agar 1% and water in balance.

Primary fermentation: respectively inoculating the seed liquid into a first seed tank and a second seed tank, culturing the first seed tank for 40h at 27 ℃, culturing the second seed tank for 40h at 25 ℃, and respectively obtaining a first mycelium and a second mycelium, wherein the tank pressure is 0.01MPa, and the stirring speed is 320 r/min; the seed liquid in the two seed tanks comprises 2.0% of glucose, 0.8% of cottonseed powder, 0.8% of prinsepia utilis royle powder, 0.8% of yeast extract, 0.1% of sodium dihydrogen phosphate and the balance of water.

Secondary fermentation: inoculating the first mycelium into a fermentation tank, culturing at 26 ℃ for 15h, supplementing the second mycelium, continuously fermenting and culturing for 16h, adding seed liquid without inoculated spores, and stirring at the rotating speed of 260r/min, wherein the components of fermentation liquid in the fermentation tank are the same as those of the seed liquid.

And (3) transformation: adding ethanol and cortisone acetate into the cultured fermentation broth, stirring, and converting at 36 deg.C for 30h at 400 r/min. After the reaction is finished, heating to 68 ℃ to terminate the reaction, extracting fermentation liquor by adopting ethyl acetate, concentrating an organic phase, and measuring the substrate conversion rate.

Example 2

The fermentation method of prednisone acetate comprises the following steps:

preparing a seed solution: transplanting Arthrobacter simplex to a slant culture medium, culturing for 6 days at 29 ℃, and preparing a seed solution from mature Arthrobacter strains by using sterile normal saline after seeds are mature; the slant culture medium comprises glucose 1.7%, yeast extract 1.65%, agar 1.25% and water in balance.

Primary fermentation: respectively inoculating the seed liquid into a first seed tank and a second seed tank, culturing the first seed tank for 40h at 27 ℃, culturing the second seed tank for 45h at 25 ℃, and respectively obtaining a first mycelium and a second mycelium, wherein the tank pressure is 0.15MPa, and the stirring speed is 340 r/min; the seed liquid in the two seed tanks comprises 2.1% of glucose, 0.9% of cottonseed powder, 0.9% of prinsepia utilis royle powder, 1% of yeast extract, 0.1% of sodium dihydrogen phosphate and the balance of water.

Secondary fermentation: inoculating the first mycelium into a fermentation tank, culturing at 26 deg.C for 15h, supplementing the second mycelium, continuously fermenting for 16h, adding non-inoculated seed liquid, stirring at 270r/min, and fermenting with the same fermentation liquid components as the seed liquid.

And (3) transformation: adding ethanol and cortisone acetate into the cultured fermentation broth, stirring, and converting at 33 deg.C for 32h at 450 r/min. After the reaction is finished, heating to 68 ℃ to terminate the reaction, extracting fermentation liquor by adopting ethyl acetate, concentrating an organic phase, and measuring the substrate conversion rate.

Example 3

The fermentation method of prednisone acetate comprises the following steps:

preparing a seed solution: transplanting Arthrobacter simplex to a slant culture medium, culturing for 5 days at 30 ℃, and preparing a spore solution from a mature Arthrobacter strain by using sterile normal saline after seeds are mature; the slant culture medium comprises glucose 1.8%, yeast extract 1.8%, agar 1.5% and water in balance.

Primary fermentation: respectively inoculating the seed solution into a first seed tank and a second seed tank, culturing the first seed tank for 40h at 27 ℃, culturing the second seed tank for 50h at 25 ℃, and respectively obtaining a first mycelium and a second mycelium at the tank pressure of 0.02MPa and the stirring speed of 360 r/min; the seed liquid in the two seed tanks comprises 2.2% of glucose, 1% of cottonseed powder, 1% of prinsepia utilis royle powder, 1% of yeast extract, 0.1% of sodium dihydrogen phosphate and the balance of water.

Secondary fermentation: inoculating the first mycelium into a fermentation tank, culturing at 26 deg.C for 15h, supplementing the second mycelium, continuously fermenting for 16h, adding seed solution without inoculated spore, culturing for 4h, and stirring at 280 r/min. The fermentation liquid in the fermentation tank has the same components as the seed liquid.

And (3) transformation: adding ethanol and cortisone acetate into the cultured fermentation broth, stirring, and converting at 30 deg.C for 35h at 500 r/min. After the reaction is finished, heating to 68 ℃ to terminate the reaction, extracting fermentation liquor by adopting ethyl acetate, concentrating an organic phase, and measuring the substrate conversion rate.

Example 4

The fermentation method of prednisone acetate comprises the following steps:

preparing a seed solution: transplanting Arthrobacter simplex to a slant culture medium, culturing for 5 days at 30 ℃, and preparing a seed solution from mature Arthrobacter strains by using sterile normal saline after seeds are mature; the slant culture medium comprises glucose 1.8%, yeast extract 1.8%, agar 1.5% and water in balance.

Primary fermentation: respectively inoculating the seed solution into a first seed tank and a second seed tank, culturing the first seed tank for 40h at 27 ℃, culturing the second seed tank for 50h at 25 ℃, and respectively obtaining a first mycelium and a second mycelium at the tank pressure of 0.02MPa and the stirring speed of 360 r/min; the seed liquid in the two seed tanks comprises 2.2% of glucose, 1% of cottonseed powder, 1% of prinsepia utilis royle powder, 1% of yeast extract, 0.1% of sodium dihydrogen phosphate and the balance of water.

Secondary fermentation: inoculating the first mycelium into a fermentation tank, culturing at 26 deg.C for 17.5h, supplementing the second mycelium, continuously fermenting and culturing for 19h, adding the missed seed solution, culturing for 4h, and stirring at 280 r/min. The fermentation liquid in the fermentation tank comprises 2.0% of glucose, 1% of cottonseed powder, 1% of Prinsepia utilis Royle powder, 1.2% of yeast extract, 0.1% of sodium dihydrogen phosphate and the balance of water.

And (3) transformation: adding ethanol and cortisone acetate into the cultured fermentation broth, stirring, and converting at 30 deg.C for 35h at 500 r/min. After the reaction is finished, heating to 68 ℃ to terminate the reaction, extracting fermentation liquor by adopting ethyl acetate, concentrating an organic phase, and measuring the substrate conversion rate.

Example 5

The fermentation method of prednisone acetate comprises the following steps:

preparing a seed solution: transplanting Arthrobacter simplex to a slant culture medium, culturing for 5 days at 30 ℃, and preparing a seed solution from mature Arthrobacter strains by using sterile normal saline after seeds are mature; the slant culture medium comprises glucose 1.8%, yeast extract 1.8%, agar 1.5% and water in balance.

Primary fermentation: respectively inoculating the seed solution into a first seed tank and a second seed tank, culturing the first seed tank for 40h at 27 ℃, culturing the second seed tank for 50h at 25 ℃, and respectively obtaining a first mycelium and a second mycelium at the tank pressure of 0.02MPa and the stirring speed of 360 r/min; the seed liquid in the two seed tanks comprises 2.2% of glucose, 1% of cottonseed powder, 1% of prinsepia utilis royle powder, 1% of yeast extract, 0.1% of sodium dihydrogen phosphate and the balance of water.

Secondary fermentation: inoculating the first mycelium into a fermentation tank, culturing at 26 deg.C for 20h, supplementing the second mycelium, continuously fermenting for 22h, adding the seed solution, culturing for 4h, and stirring at 280 r/min. The fermentation liquid in the fermentation tank comprises 2.0% of glucose, 1% of cottonseed powder, 1% of Prinsepia utilis Royle powder, 1.2% of yeast extract, 0.1% of sodium dihydrogen phosphate and the balance of water.

And (3) transformation: adding ethanol and cortisone acetate into the cultured fermentation broth, stirring, and converting at 0 deg.C for 35h at 500 r/min. After the reaction is finished, heating to 68 ℃ to terminate the reaction, extracting fermentation liquor by adopting ethyl acetate, concentrating an organic phase, and measuring the substrate conversion rate.

Comparative example 1

The fermentation method of prednisone acetate comprises the following steps:

preparing a seed solution: transplanting Arthrobacter simplex to a slant culture medium, culturing for 5 days at 30 ℃, and preparing a spore solution from a mature Arthrobacter strain by using sterile normal saline after seeds are mature; the slant culture medium comprises glucose 1.8%, yeast extract 1.8%, agar 1.5% and water in balance.

Primary fermentation: inoculating the seed liquid into a seed tank, and culturing for 40h, wherein the tank pressure is 0.02MPa, and the stirring speed is 360 r/min; the seed liquid in the seed tank comprises 2.2% of glucose, 1% of cottonseed powder, 1% of prinsepia utilis royle powder, 1% of yeast extract, 0.1% of sodium dihydrogen phosphate and the balance of water.

Secondary fermentation: inoculating the mycelium in the first seeding tank into a fermentation tank, culturing at 26 ℃ for 35h, and stirring at the rotating speed of 280r/min, wherein the components of fermentation liquor in the fermentation tank are the same as those of seed liquor.

And (3) transformation: adding ethanol and cortisone acetate into the cultured fermentation broth, stirring, and converting at 35 deg.C for 30h at 500 r/min. After the reaction is finished, heating to 75 ℃ to terminate the reaction, extracting fermentation liquor by adopting ethyl acetate, concentrating an organic phase, and measuring the substrate conversion rate.

Comparative example 2

The fermentation method of prednisone acetate comprises the following steps:

preparing a seed solution: transplanting Arthrobacter simplex to a slant culture medium, culturing for 5 days at 30 ℃, and preparing a seed solution from mature Arthrobacter strains by using sterile normal saline after seeds are mature; the slant culture medium comprises glucose 1.8%, yeast extract 1.8%, agar 1.5% and water in balance.

Primary fermentation: inoculating the seed liquid into a seed tank, culturing for 45h, wherein the tank pressure is 0.02MPa, and the stirring speed is 360 r/min; the seed liquid in the seed tank comprises 2.2% of glucose, 1% of cottonseed powder, 1% of prinsepia utilis royle powder, 1% of yeast extract, 0.1% of sodium dihydrogen phosphate and the balance of water.

Secondary fermentation: inoculating the mycelium in the first seeding tank into a fermentation tank, and culturing at 26 ℃ for 40.5h with the stirring speed of 280 r/min. The fermentation liquid in the fermentation tank has the same components as the seed liquid.

And (3) transformation: adding ethanol and cortisone acetate into the cultured fermentation broth, stirring, and converting at 35 deg.C for 30h at 500 r/min. After the reaction is finished, heating to 75 ℃ to terminate the reaction, extracting fermentation liquor by adopting ethyl acetate, concentrating an organic phase, and measuring the substrate conversion rate.

Comparative example 3

The fermentation method of prednisone acetate comprises the following steps:

preparing a seed solution: transplanting Arthrobacter simplex to a slant culture medium, culturing for 5 days at 30 ℃, and preparing a seed solution from mature Arthrobacter strains by using sterile normal saline after seeds are mature; the slant culture medium comprises glucose 1.8%, yeast extract 1.8%, agar 1.5%, and water in balance.

Primary fermentation: inoculating the seed liquid into a seed tank, and culturing for 50h, wherein the tank pressure is 0.02MPa, and the stirring speed is 360 r/min; the seed liquid in the seed tank comprises 2.2% of glucose, 1% of cottonseed powder, 1% of prinsepia utilis royle powder, 1% of yeast extract, 0.1% of sodium dihydrogen phosphate and the balance of water.

Secondary fermentation: inoculating the mycelium in the first seeding tank into a fermentation tank, and culturing at 26 ℃ for 48h with the stirring speed of 280 r/min. The fermentation liquid in the fermentation tank has the same components as the seed liquid.

And (3) transformation: adding ethanol and cortisone acetate into the cultured fermentation broth, stirring, and converting at 35 deg.C for 30h at 500 r/min. After the reaction is finished, heating to 75 ℃ to terminate the reaction, extracting fermentation liquor by adopting ethyl acetate, concentrating an organic phase, and measuring the substrate conversion rate.

The calculation was performed for the products in examples 1 to 5 and comparative examples 1 to 3 described above:

determination of substrate conversion: the conversion is expressed as the percentage of the mass of substrate converted to product during the reaction relative to the total mass of initial substrate. And (2) measuring by using HPLC, wherein the separation column is a C18 column, the detection wavelength is 240nm, and the mobile phase is acetonitrile: water (volume ratio) 50: the dissolution flow rate of 50 was 1.5 mL/min. The conversion rate of cortisone acetate is calculated by an area normalization method.

As can be seen from the above table, the conversion rate in the examples of the present invention is higher than that in the comparative example, and under the same conditions, when the mycelium culture condition in the first seed tank is 26 ℃ for 15h, the mycelium supplemented in the second seed tank is added for further fermentation culture for 16h, and then the culture is carried out for 4h, with the stirring speed of 280r/min, the conversion rate under the culture condition of this scheme is the highest (i.e. the scheme of example 3).

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.