CN115948622A - Microbial fermentation control method, device, system, equipment and medium - Google Patents

Abstract

The present invention relates to the field of microbial fermentation control, and specifically provides a microbial fermentation control method, device, system, equipment, and medium. The microbial fermentation control method includes: collecting tail gas monitoring data during the microbial fermentation process; inputting the tail gas monitoring data Carry out data analysis to the quantitative relationship model, and output the substrate consumption rate by the quantitative relationship model; determine the feeding speed command according to the substrate consumption rate; feed. The invention realizes real-time monitoring and precise control of the entire fermentation process of the polyhydroxyalkanoate through precise quantitative control of feeding, and effectively improves the production intensity and fermentation stability of PHA.

Description

Microbial fermentation control method, device, system, equipment and medium

Technical Field

The present invention relates to the field of microbial fermentation, and in particular to a microbial fermentation control method, device, system, equipment and medium.

Background Art

Polyhydroxyalkanoates (PHA) are mainly produced by fermentation using sugars or lipids as carbon sources. In order to ensure a high PHA yield, the entire fermentation process usually needs to be regulated. Commonly used fermentation process control techniques mostly use parameters such as pH, dissolved oxygen, temperature, and pressure as the basis or means of control strategies. However, most of these parameters can only reflect the physicochemical properties of the reaction system. When the fermentation process is controlled by these parameters, the instability of the control process will reduce the fermentation production capacity, ultimately affecting the fermentation yield and fermentation quality.

Summary of the invention

The present invention provides a microbial fermentation control method, device, system, equipment and medium to solve the technical defect of low fermentation production capacity in the existing microbial fermentation technology. The present invention can adjust the feeding rate based on the tail gas monitoring data, and then quantitatively control the fermentation process to improve the stability of the fermentation process.

In a first aspect, the present invention provides a method for controlling microbial fermentation, comprising:

Collect tail gas monitoring data of microbial fermentation process;

Inputting the tail gas monitoring data into a quantitative relationship model for data analysis, and outputting a substrate consumption rate from the quantitative relationship model;

a feed rate instruction determined according to the substrate consumption rate;

The feed rate instruction is used to instruct to add feed to the fermentation process according to the feed rate.

According to the microbial fermentation control method provided by the present invention, the tail gas monitoring data includes oxygen consumption rate, carbon dioxide generation rate, PHA synthesis oxygen consumption rate, PHA synthesis _CO2 release rate, cellular respiration oxygen consumption rate, and cellular respiration _CO2 release rate.

According to the microbial fermentation control method provided by the present invention, the quantitative relationship model is used to calculate the substrate consumption rate based on the quantitative relationship established between the oxygen consumption rate, the carbon dioxide generation rate and the substrate conversion rate;

The quantitative relationship model specifically performs the following steps:

Determining a carbon dioxide generation component according to the carbon dioxide generation rate and a first coefficient;

Determining a consumption difference based on the oxygen consumption rate and the carbon dioxide generation component;

Determining the consumption component according to the consumption difference and a second coefficient;

Determining a substrate consumption rate according to the consumption component and the substrate conversion rate;

The first coefficient is calculated from the cellular respiration oxygen consumption rate and the cellular respiration _CO2 release rate; the second coefficient is calculated from the first coefficient, the PHA synthesis oxygen consumption rate, the PHA synthesis oxygen consumption, and the PHA synthesis _CO2 release rate.

The microbial fermentation control method provided by the present invention further comprises:

Inputting the oxygen consumption rate into a fermentation stage confirmation model, confirming the current target fermentation stage by the fermentation stage confirmation model, and confirming the start and end of the feeding program based on the current target fermentation stage;

And based on the current target fermentation stage, confirming the feeding control interval corresponding to the target fermentation stage; and regulating the feeding speed based on the value of the feeding control interval combined with the substrate consumption rate.

According to the microbial fermentation control method provided by the present invention, the target fermentation stage includes the fermentation initial stage, the fermentation growth stage, the fermentation stable stage and the fermentation decay stage, and the corresponding feeding control intervals are: the preset feeding speed, the first feeding control interval, the second feeding control interval, and the third feeding control interval;

The values of the preset feeding speed, the first feeding control interval, the second feeding control interval, and the third feeding control interval are preset feeding speeds.

According to the microbial fermentation control method provided by the present invention, the microorganism is a microorganism capable of accumulating polyhydroxyalkanoates in the cell, including microorganisms of the following genera: Aeromonas, Alcaligenes, Azotobacter, Bacillus, Clostridium, Halobacterium, Nocardia, Rhodospirilla, Pseudomonas, Ralstonia, and Zoogloea.

In a second aspect, a microbial fermentation control device is also provided, comprising:

Collection unit: used to collect tail gas monitoring data of the fermentation process of microorganisms;

Analysis unit: used for inputting the exhaust gas monitoring data into the quantitative relationship model for data analysis; outputting the substrate consumption rate from the quantitative relationship model;

A determination unit: used for determining a feeding speed instruction according to the substrate consumption rate;

The feed rate instruction is used to instruct to add feed to the fermentation process according to the feed rate.

According to the microbial fermentation control device of the present invention, the analysis unit also includes: a unit for inputting the oxygen consumption rate into a fermentation stage confirmation model, confirming the current target fermentation stage by the fermentation stage confirmation model, and confirming the start and end of the feeding program based on the current target fermentation stage; and a unit for confirming the feeding control interval corresponding to the target fermentation stage based on the current target fermentation stage; and regulating the feeding speed based on the value of the feeding control interval combined with the substrate consumption rate.

In a third aspect, a microbial fermentation control system is also provided, comprising the microbial fermentation control device, for controlling the fermentation process of microorganisms according to the tail gas monitoring data;

Also includes:

Fermentation tank, used to provide a fermentation environment for microorganisms;

An exhaust gas sampling pipeline, used for collecting exhaust gas from the fermentation tank;

Flow distributor, used for flow regulation;

Exhaust gas mass spectrometry analyzer, used to analyze exhaust gas component information;

An exhaust gas status monitoring unit, used to obtain exhaust gas monitoring data;

The microorganism is a microorganism capable of accumulating polyhydroxyalkanoate in cells.

In a fourth aspect, an electronic device is also provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the microbial fermentation control method is implemented when the processor executes the program.

In a fifth aspect, a non-transitory computer-readable storage medium is also provided, on which a computer program is stored, and when the computer program is executed by a processor, the microbial fermentation control method is implemented.

The present invention provides a microbial fermentation control method, device, system, equipment and medium. In the fermentation process of polyhydroxyalkanoate, input tail gas monitoring data is obtained in real time, and the substrate consumption rate is determined after the tail gas monitoring data is input into a quantitative relationship model in real time, and the current required feeding rate is obtained by real-time and accurate analysis; in addition, the feeding rate instruction can be further adjusted according to the substrate consumption rate in combination with the feeding control interval corresponding to the real-time fermentation stage of polyhydroxyalkanoate, so as to realize feeding control for all stages of the process including the new process of polyhydroxyalkanoate fermentation. The present invention realizes real-time monitoring and precise control of the entire fermentation process of polyhydroxyalkanoate by using the tail gas data collected in real time and the accurate and controllable quantitative control model for feeding, thereby effectively improving the production intensity and fermentation stability of PHA.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic diagram of a process for controlling microbial fermentation provided by the present invention;

FIG2 is a schematic diagram of a fermentation stage confirmation model provided by the present invention;

FIG3 is a schematic diagram of a process for calculating a substrate consumption rate based on a quantitative relationship provided by the present invention;

FIG4 is a schematic diagram of the structure of a microbial fermentation control system provided by the present invention;

FIG5 is a diagram showing the effect of using the microbial fermentation control method provided by the present invention;

FIG6 is a schematic diagram of the structure of a microbial fermentation control device provided by the present invention;

FIG. 7 is a schematic diagram of the structure of an electronic device provided by the present invention.

DETAILED DESCRIPTION

In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

The microorganisms referred to in the present invention include microorganisms that can accumulate polyhydroxyalkanoates in cells, specifically including microorganisms of the following genera: Aeromonas, Alcaligenes, Azotobacter, Bacillus, Clostridium, Halobacterium, Nocardia, Rhodospirilla, Pseudomonas, Ralstonia, and Zoogloea. In order to more accurately describe the specific implementation scheme of the present invention, the present invention takes microorganisms that produce polyhydroxyalkanoates (PHA) as an example. All fermentation control methods in the following embodiments are based on microorganisms that produce polyhydroxyalkanoates (PHA) as the description object, but this should not be interpreted as the present invention can only perform fermentation control on polyhydroxyalkanoates (PHA), which will not be described in detail here.

Polyhydroxyalkanoate (PHA) is a biopolymer polyester compound synthesized by microorganisms. It exists in the form of granular inclusions in microbial cells and has good biocompatibility, degradability, and plasticity. As an excellent biodegradable material, PHA has shown great potential in the fields of textile, agriculture, food, medical and health. At present, the fermentation process using lipid substances as carbon sources will have problems such as difficult substrate monitoring, excessive foam, and unstable process. For example, in the process of fermenting PHA using oil as substrate, too much substrate oil will cause too much foam in the fermentation process, affecting the stability of the fermentation process. Too little substrate oil will lead to insufficient production intensity and reduce the production capacity of the fermentation. Therefore, in order to solve the above technical problems and effectively improve the production intensity and fermentation stability of PHA, the present invention provides a fermentation control method for preparing polyhydroxyalkanoate, which uses an efficient, accurate and timely method to monitor and accurately control the entire fermentation process in real time. FIG1 is a flow diagram of the microbial fermentation control method provided by the present invention, including:

Collect tail gas monitoring data of microbial fermentation process;

Inputting the tail gas monitoring data into the quantitative relationship model for data analysis; outputting the substrate consumption rate from the quantitative relationship model;

determining a feed rate instruction according to the substrate consumption rate;

The feed rate instruction is used to instruct to add feed to the fermentation process according to the feed rate.

In step 101, the tail gas monitoring data of the fermentation process for preparing polyhydroxyalkanoates is collected, and the PHA production strain is used as the starting strain, and a high-activity seed liquid is obtained through slant screening, strain activation, primary seed culture, secondary seed culture and other processes, and the high-activity seed liquid is transferred to a fermentation tank filled with PHA fermentation medium, and the fermentation culture conditions are controlled, and the multi-dimensional parameters in the fermentation process are monitored in real time to obtain real-time tail gas monitoring data in the process of monitoring the fermentation of polyhydroxyalkanoates. The tail gas monitoring data includes but is not limited to: oxygen consumption rate, carbon dioxide generation rate, PHA synthesis oxygen consumption rate, PHA synthesis _CO2 release rate, cellular respiration oxygen consumption rate, and cellular respiration _CO2 release rate.

Optionally, the PHA production strain is a microorganism capable of accumulating PHA intracellularly, including but not limited to Aeromonas, Alcaligenes, Azotobacter, Bacillus, Clostridium, Halobacterium, Nocardia, Rhodospirilla, Pseudomonas, Ralstonia, Zoogloea, etc. Optionally, the microorganism may be Alcaligenes lipolytica, Alcaligenes latus, Ralstonia eutropha, Pseudomonas aeruginosa, Rhodococcus opacus, Bacillus subtilis, etc.

Optionally, in the process of obtaining the highly active seed solution, the secondary seed culture time is 8 to 14 hours, the dissolved oxygen 600 is 3 to 7 before transferring to the fermentation medium, and the inoculation amount is 1-10%.

Optionally, the polyhydroxyalkanoate PHA described in the present invention includes but is not limited to poly-β-hydroxybutyrate PHB, copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate PHBV, copolyester of 3-hydroxybutyric acid and 3-hydroxyhexanoic acid PHBHHx, and poly-3-hydroxybutyrate-4-hydroxybutyrate P34HB.

Optionally, the fermentation medium is composed of: 10-20 g/L oil, 1-5 g/L disodium hydrogen phosphate, 0.5-2 g/L potassium dihydrogen phosphate, 3-5 g/L ammonium sulfate, and 0.1-0.5 g/L magnesium sulfate heptahydrate.

Optionally, the fermentation culture conditions at least include controlling the temperature between 28°C and 34°C, the pH between 6.3 and 7.2, the rotation speed between 200rpm and 1200rpm, and the pressure between 0.02MPa and 0.1MPa.

Optionally, the tail gas monitoring data includes oxygen consumption rate and carbon dioxide generation rate. Those skilled in the art understand that in real-time monitoring of multi-dimensional parameters in the fermentation process, parameters such as the volume percentage of oxygen in the air, the volume percentage of carbon dioxide in the air, the volume percentage of nitrogen in the air, the volume percentage of oxygen in the tail gas, the volume percentage of carbon dioxide in the tail gas, the volume percentage of nitrogen in the tail gas, the air flow rate, the gas molar volume and the fermentation liquid volume will be obtained, and the oxygen consumption rate and carbon dioxide generation rate are calculated and determined based on the above-mentioned specific parameters. Specifically, the oxygen consumption rate is determined by the following formula:

In formula (1), OUR is the oxygen consumption rate, O ₂ (Reference) is the volume percentage of oxygen in the air, O ₂ is the volume percentage of oxygen in the tail gas, N ₂ (Reference) is the volume percentage of nitrogen in the air, N ₂ is the volume percentage of nitrogen in the tail gas, F _m is the air flow rate, V _m is the gas molar volume, and V is the fermentation liquid volume.

Accordingly, the carbon dioxide generation rate is determined by the following formula:

In formula (2), CER is the carbon dioxide generation rate, CO ₂ (Reference) is the volume percentage of carbon dioxide in the air, CO ₂ is the volume percentage of carbon dioxide in the tail gas, N ₂ (Reference) is the volume percentage of nitrogen in the air, N ₂ is the volume percentage of nitrogen in the tail gas, F _m is the air flow rate, V _m is the gas molar volume, and V is the fermentation liquid volume.

In step 102, the exhaust gas monitoring data is input into a quantitative relationship model to obtain a substrate consumption rate output by the quantitative relationship model.

The quantitative relationship model can reflect the quantitative relationship between the input tail gas monitoring data and the substrate consumption rate, that is, according to the oxygen consumption rate and the carbon dioxide generation rate, the corresponding substrate consumption rate can be determined.

The specific substrate consumption rate can be determined according to the above formula (1) and formula (2), and can refer to the following formula:

In formula (3), _Vs is the substrate consumption rate, α is the second coefficient, OUR is the oxygen consumption rate, β is the first coefficient, CER is the carbon dioxide generation rate, and Yiild is the conversion rate of substrate to product. The first coefficient β is calculated from the cellular respiration oxygen consumption rate and the cellular respiration _CO2 release rate; the second coefficient α is calculated from the first coefficient β, the PHA synthesis oxygen consumption rate, the PHA synthesis oxygen consumption, and the PHA synthesis _CO2 release rate.

In step 103, a feeding speed instruction is determined according to the substrate consumption rate; wherein the feeding speed instruction is used to instruct to feed the fermentation process according to the feeding speed. The present invention takes tail gas monitoring data as the main basis, establishes a quantitative relationship model between tail gas monitoring data and substrate consumption rate, and accurately controls the feed flow acceleration according to the model feedback result, realizes accurate monitoring and control of the fermentation process state, and ensures efficient and stable operation of fermentation.

Optionally, the microbial fermentation control method provided by the present invention further includes: inputting the oxygen consumption rate into a fermentation stage confirmation model, confirming the current target fermentation stage by the fermentation stage confirmation model, and confirming the start and end of the feeding program based on the current target fermentation stage. And based on the current target fermentation stage, confirming the feeding control interval corresponding to the target fermentation stage; and regulating the feeding speed based on the value of the feeding control interval combined with the substrate consumption rate.

Optionally, the fermentation stage confirmation model is used to determine the target fermentation stage from the correspondence between all fermentation stages and the oxygen consumption rate according to the oxygen consumption rate. The target fermentation stage is determined from the correspondence between all fermentation stages and the oxygen consumption rate according to the oxygen consumption rate. The all fermentation stages are different fermentation stages according to the change of polyhydroxyalkanoate PHA over time. Optionally, all fermentation stages include the initial fermentation stage, the fermentation growth stage, the fermentation stabilization stage and the fermentation decay stage. The oxygen consumption rate in different fermentation stages will be significantly different. Therefore, the present invention can determine the different fermentation stages of polyhydroxyalkanoate PHA according to the oxygen consumption rate. When it is determined to be the initial fermentation stage, no feeding speed instruction is issued, that is, no feeding is required, and the feeding program is not started; when it is determined to be the fermentation growth stage, the feeding instruction is issued, that is, the feeding program starts to execute; when it is at the end of the fermentation decay period, the fermentation process ends, and it is confirmed that no feeding speed instruction is issued, that is, the feeding program ends.

In step 103, the feeding instruction is controlled and adjusted according to the target fermentation stage, and the feeding speed in the feeding instruction is determined according to the substrate consumption rate. Each fermentation stage has a corresponding feeding control interval, and the feeding control interval is used to control the feeding speed. The present invention takes tail gas monitoring data as the main basis, establishes a quantitative relationship model between tail gas monitoring data and substrate consumption rate, and accurately adjusts the acceleration of the feeding flow according to the feedback results of the model, thereby realizing accurate monitoring and control of the fermentation process state and ensuring efficient and stable operation of the fermentation.

Optionally, the target fermentation stage includes the fermentation initial stage, the fermentation growth stage, the fermentation stable stage and the fermentation decay stage, and the corresponding feeding control intervals are: the preset feeding speed, the first feeding control interval, the second feeding control interval and the third feeding control interval.

The supplemented material in the present invention is oil, which includes but is not limited to edible vegetable oil and animal oil, wherein the edible vegetable oil includes but is not limited to soybean oil, palm oil, peanut oil, corn oil, rapeseed oil, peanut oil, sesame oil, canola seed finished oil, refined coconut oil, rice bran crude oil, cottonseed crude oil, rice finished oil, refined safflower oil, linseed finished oil, pepper finished oil; the animal oil includes but is not limited to fish oil, chicken oil, beef tallow, sheep oil and lard.

The values of the preset feeding speed, the first feeding control interval, the second feeding control interval, and the third feeding control interval determined by the present invention are preset feeding speeds.

Optionally, the preset feed rate used in the present invention includes a feed rate within the feed control interval determined based on the substrate consumption rate in the historical data and the target fermentation stage corresponding to the substrate consumption rate. Through such historical sample data, the real-time substrate consumption rate is used as a parameter indicator to adjust the rate of flow addition oil replenishment during the fermentation process. For example, for a newly developed or new fermentation process, fermentation is carried out according to the preset value of the feed control interval during the fermentation process, and the real-time substrate consumption rate is obtained by using the present invention to make adjustments. Therefore, during the entire fermentation process, the production intensity of PHA can be maximized, the fermentation efficiency of PHA can be improved, and the technical problems of excessive oil accumulation in the fermentation matrix due to excessive oil replenishment speed and excessive foam in the fermentation liquid due to too small an oil replenishment number are solved.

Those skilled in the art understand that PHA fermentation is an oxygen-consuming process, and changes in the respiration of microbial cells indirectly reflect the metabolic state of the cells. Therefore, combining the oxygen consumption rate and the carbon dioxide generation rate to achieve real-time monitoring of the fermentation process is of great significance for achieving precise control of the fermentation process, improving production efficiency and stability, etc. The present invention is a method that can effectively improve the stability and production intensity of the PHA fermentation process. According to the differences in growth characteristics at different fermentation stages, by real-time monitoring of changes in tail gas detection parameters during the fermentation process, a quantitative relationship model between the tail gas detection parameters and the substrate consumption rate is established, thereby real-time monitoring of the substrate consumption rate, and precise control of the feed addition rate, thereby achieving real-time monitoring and precise control of the fermentation process, and being suitable for large-scale industrial production.

The present invention provides a microbial fermentation control method, device, system, equipment and medium. In the fermentation process of polyhydroxyalkanoate, input tail gas monitoring data is obtained in real time, and the substrate consumption rate is determined after the tail gas monitoring data is input into a quantitative relationship model in real time. The feeding speed instruction is adjusted in a feeding control interval corresponding to the real-time fermentation stage of the polyhydroxyalkanoate according to the substrate consumption rate, thereby realizing feeding control of all stages of the fermentation of the polyhydroxyalkanoate. The present invention realizes real-time monitoring and precise control of the entire fermentation process of the polyhydroxyalkanoate by quantitatively controlling feeding in stages, thereby effectively improving the production intensity and fermentation stability of PHA.

Optionally, before determining the target fermentation stage from the corresponding relationship between all fermentation stages and oxygen consumption rates according to the oxygen consumption rate, the method further comprises:

When the oxygen consumption rate is 0 or less than the first preset threshold, determining that the polyhydroxyalkanoate at the time corresponding to the oxygen consumption rate is in the initial fermentation stage;

When the oxygen consumption rate is greater than or equal to the first preset threshold value and less than the second preset threshold value, it is determined that the polyhydroxyalkanoate at the time corresponding to the oxygen consumption rate is in the fermentation growth stage;

When the oxygen consumption rate is greater than or equal to the second preset threshold value and less than the third preset threshold value, it is determined that the polyhydroxyalkanoate at the moment corresponding to the oxygen consumption rate is in the fermentation stable stage;

When the oxygen consumption rate shows signs of starting to decrease and is less than a third preset threshold, it is determined that the polyhydroxyalkanoate at the time corresponding to the oxygen consumption rate is in the fermentation decay stage;

The corresponding relationship between all fermentation stages and the oxygen consumption rate is constructed according to the corresponding relationship between each fermentation stage and the oxygen consumption rate in the fermentation initial stage, the fermentation growth stage, the fermentation stabilization stage and the fermentation decay stage.

When the oxygen consumption rate is greater than or equal to the first preset threshold and less than the second preset threshold, it is determined that the polyhydroxyalkanoate at the moment corresponding to the oxygen consumption rate is in the initial stage of fermentation. The oxygen consumption rate may optionally be 0 mmol/L/h, and the first preset threshold may optionally be 60 mmol/L/h, that is, when the oxygen consumption rate is greater than or equal to 0 mmol/L/h and less than 60 mmol/L/h, it is determined that the polyhydroxyalkanoate at the moment corresponding to the oxygen consumption rate is in the initial stage of fermentation.

When the oxygen consumption rate is greater than or equal to a first preset threshold and less than a second preset threshold, it is determined that the polyhydroxyalkanoate at the moment corresponding to the oxygen consumption rate is in the fermentation growth stage. The second preset threshold may optionally be 120mmol/L/h, that is, when the oxygen consumption rate is greater than or equal to 60mmol/L/h and less than 120mmol/L/h, it is determined that the polyhydroxyalkanoate at the moment corresponding to the oxygen consumption rate is in the fermentation growth stage.

When the oxygen consumption rate is greater than or equal to the second preset threshold and less than the third preset threshold, it is determined that the polyhydroxyalkanoate at the moment corresponding to the oxygen consumption rate is in the stable fermentation stage, and the third preset threshold can optionally be 160mmol/L/h, that is, when the oxygen consumption rate is greater than or equal to 120mmol/L/h and less than 160mmol/L/h, it is determined that the polyhydroxyalkanoate at the moment corresponding to the oxygen consumption rate is in the stable fermentation stage.

When the oxygen consumption rate begins to show a decreasing trend and is less than the third preset threshold, it is determined that the polyhydroxyalkanoates at the moment corresponding to the oxygen consumption rate are in the fermentation decay stage, that is, when the oxygen consumption rate begins to be less than 160mmol/L/h, optionally, such as in the range of 120mmol/L/h to 140mmol/L/h, it is determined that the polyhydroxyalkanoates at the moment corresponding to the oxygen consumption rate are in the fermentation decay stage.

In such an embodiment, the oxygen consumption rate is monitored in real time, and the fermentation stage of the polyhydroxyalkanoate is determined according to the oxygen consumption rate. Specifically, the cells grow under the initial base oil conditions, i.e., the initial fermentation stage, and the feeding rate is 0; after the cells enter the exponential growth period, i.e., the fermentation growth stage, OUR is between 60-120 mmol/L/h, and the feeding rate is adjusted according to the substrate consumption rate; the cells enter the growth stability period, i.e., the fermentation stability stage, OUR is between 120-160 mmol/L/h, and the feeding rate is adjusted according to the substrate consumption rate; the cells gradually enter the decay period, i.e., the fermentation decay stage, OUR is between 120-140 mmol/L/h, and the feeding rate is adjusted according to the substrate consumption rate.

According to the correspondence between each fermentation stage and the oxygen consumption rate in the fermentation initial stage, the fermentation growth stage, the fermentation stabilization stage and the fermentation decay stage, the correspondence between all the fermentation stages and the oxygen consumption rate is constructed. In the implementation scheme given in the present invention, there are four stages in total, while in other fermentation controls, there may be three stages, five stages or even more. The correspondence set composed of the correspondence between each fermentation stage and the oxygen consumption rate is the correspondence between all the fermentation stages and the oxygen consumption rate.

FIG2 is a schematic flow diagram of a fermentation stage confirmation model provided by the present invention, wherein the fermentation stage confirmation model is also used for:

Based on the current oxygen consumption rate, confirm the initial stage of fermentation and its correspondence with the preset feeding rate;

Based on the current oxygen consumption rate, confirm the fermentation growth stage and the corresponding relationship with the first feeding control interval;

Based on the current oxygen consumption rate, confirm the fermentation stable stage and the corresponding relationship with the second feeding control interval;

Based on the current oxygen consumption rate, confirm the fermentation decay stage and its corresponding relationship with the third feeding control interval;

The values of the preset feeding speed, the first feeding control interval, the second feeding control interval, and the third feeding control interval are preset feeding speeds.

Optionally, based on the current target fermentation stage, determining a feeding control interval corresponding to the target fermentation stage; and regulating the feeding speed instruction based on a value of the feeding control interval combined with the substrate consumption rate, comprises:

In the case where the target fermentation stage is the initial stage of fermentation, no feeding is required. In an optional embodiment, the preset feeding rate is 0, that is, there is no need to feed the polyhydroxyalkanoates being fermented, and a small amount of oil can be added according to the preset feeding rate, that is, the feeding rate instruction is generated according to the preset feeding rate. Those skilled in the art understand that the oil replenishment time point is when the oil added to the culture medium is consumed for a period of time and then the feeding begins. The OD value is mainly used to determine whether to start feeding. OD is a comprehensive indicator of the concentration, chromaticity, bacterial mass and bacterial elongation and expansion of the fermentation medium. In general, feeding can be started when OD is greater than or equal to 30.

When the target fermentation stage is the fermentation growth stage, the fermentation stabilization stage or the fermentation decay stage, oil is replenished according to the preset feeding rate, and then the oil replenishment rate is adjusted based on the real-time substrate consumption rate _Vs as the oil replenishment rate required at the current moment.

In step 201, the correspondence between the initial stage of fermentation and the preset feeding rate is confirmed. When the fermentation of polyhydroxyalkanoic acid ester is in the initial stage of fermentation, the preset feeding rate is determined. The preset feeding rate can be 0, that is, during the entire initial stage of fermentation of polyhydroxyalkanoic acid ester, there is no need to feed the polyhydroxyalkanoic acid ester being fermented.

In step 202, the correspondence between the fermentation growth stage and the first feeding control interval is confirmed. When the fermentation of polyhydroxyalkanoic acid ester is in the fermentation growth stage, the value of the first feeding control interval includes the substrate consumption rate at the beginning of feeding in the fermentation growth stage to the substrate consumption rate before the beginning of the fermentation stabilization stage. The first feeding control interval can optionally be 3g/L/h to 5g/L/h, that is, in the fermentation growth stage, the feeding speed is controlled according to a rate of 3g/L/h to 5g/L/h.

In step 203, the correspondence between the fermentation stabilization stage and the second feeding control interval is confirmed. When the fermentation of polyhydroxyalkanoic acid ester is in the fermentation stabilization stage, the value of the second feeding control interval includes the substrate consumption rate at the beginning of feeding in the fermentation stabilization stage to the substrate consumption rate before the beginning of the fermentation decay stage. The second feeding control interval can be optionally 5g/L/h to 10g/L/h, that is, in the fermentation stabilization stage, the feeding speed is controlled according to a rate of 5g/L/h to 10g/L/h.

In step 204, the correspondence between the fermentation death stage and the third feeding control interval is confirmed. When the fermentation of polyhydroxyalkanoic acid ester is in the fermentation death stage, the value of the third feeding control interval includes the substrate consumption rate from the start of feeding in the fermentation death stage to the substrate consumption rate at the end of fermentation. The third feeding control interval can be optionally 3g/L/h to 6g/L/h, that is, in the fermentation death stage, the feeding speed is controlled according to a rate of 3g/L/h to 6g/L/h.

In another optional embodiment, a linear fitting relationship can be established according to the substrate consumption rate and the feeding rate in each feeding control interval, or an exponential function fitting relationship can be constructed to determine different feeding rates in each feeding control interval according to different substrate consumption rates.

3 is a schematic diagram of a process for calculating a substrate consumption rate based on a quantitative relationship provided by the present invention, wherein the quantitative relationship model is used to calculate the substrate consumption rate based on a quantitative relationship established between an oxygen consumption rate, a carbon dioxide generation rate, and a substrate conversion rate;

The quantitative relationship model specifically includes the following execution steps:

Determining a carbon dioxide generation component according to the carbon dioxide generation rate and a first coefficient;

Determining a consumption difference based on the oxygen consumption rate and the carbon dioxide generation component;

Determining the consumption component according to the consumption difference and a second coefficient;

The substrate consumption rate is determined based on the consumption fraction and the substrate conversion rate.

Specifically, the process of establishing the quantitative relationship model between tail gas monitoring data and substrate consumption rate is as follows:

OUR＝OUR1+OUR2 (4)

CER＝CER1+CER2 (5)

In formula (4) and formula (5), OUR is the oxygen consumption rate, CER is the carbon dioxide generation rate, OUR1 is the oxygen consumption rate of PHA synthesis, OUR2 is the oxygen consumption rate of cellular respiration, CER1 is the _CO2 release rate of PHA synthesis, and CER2 is the _CO2 release rate of cellular respiration.

Furthermore, the ratio of PHA synthesis oxygen consumption rate to CO ₂ release rate k ₁ is:

Furthermore, the ratio of the cellular respiration oxygen consumption rate to the CO ₂ release rate β is:

Furthermore, there are

According to the fact that k ₂ grams of oxygen are needed to synthesize 1 gram of PHA, the PHA synthesis rate V _p is:

Assuming that the conversion rate of lipid to PHA is Yield, the substrate consumption rate _Vs is:

则得到

即式(3)。make

Then we get

That is formula (3).

In step 301, the carbon dioxide generation component is determined according to the product of the carbon dioxide generation rate and a first coefficient β, wherein the value range of the first coefficient may be between 1 and 3.

In step 302, a consumption difference is determined according to a difference between the oxygen consumption rate and the carbon dioxide generation component. Specifically, the consumption difference is determined by subtracting the carbon dioxide generation component from the oxygen consumption rate.

In step 303, the consumption component is determined according to the product of the consumption difference and a second coefficient, and the value range of the second coefficient α can be selected between 0.5 and 0.8.

In step 304, the substrate consumption rate is determined according to the quotient of the consumption component and the conversion rate of the substrate to the product. Specifically, reference may be made to the above formula (3), which will not be repeated here. Optionally, the conversion rate of the substrate to the product ranges from 0.65 to 0.9.

FIG4 is a schematic diagram of the structure of a microbial fermentation control system provided by the present invention. The present invention discloses a microbial fermentation control system, including a microbial fermentation control device 6, which is used to control the fermentation process of the microorganism according to the tail gas monitoring data;

It also includes: a fermentation tank 1, used to provide a fermentation environment for microorganisms;

An exhaust gas sampling pipeline 2 is used to collect exhaust gas from the fermentation tank;

Flow distributor 3, used for flow regulation;

An exhaust gas mass spectrometer 4 is used to analyze the component information of the exhaust gas;

An exhaust gas status monitoring unit 5, used to obtain exhaust gas monitoring data;

The microorganism is a microorganism capable of accumulating polyhydroxyalkanoate in cells.

In the present invention, the multi-dimensional parameters in the fermentation process will be realized through the exhaust gas mass spectrometry analysis device 4, and the exhaust gas state monitoring unit 5 is used to obtain the exhaust gas monitoring data. The fermentation exhaust gas passes through the exhaust gas sampling pipeline 2 from the fermentation tank 1 through the flow distributor 3 for flow regulation, and then enters the exhaust gas mass spectrometry analysis device 4. The volume flow rate entering the exhaust gas mass spectrometry analysis device 4 is 0-2L/min. The exhaust gas mass spectrometry analysis device 4 can effectively detect the changes in the concentrations of a series of components such as oxygen concentration, carbon dioxide concentration, and nitrogen concentration in the exhaust gas. After that, the exhaust gas mass spectrometry analysis device 4 transmits the detected result information to the exhaust gas state monitoring unit 5, which can monitor the concentration content information of each component in the exhaust gas in real time. Finally, based on the quantitative relationship model between the exhaust gas monitoring parameters and the substrate consumption rate, the microbial fermentation control device 6 is adjusted in real time to adjust the feeding rate. Specifically, the establishment process of the quantitative relationship model between the exhaust gas monitoring data and the substrate consumption rate refers to the above process and will not be repeated here.

The present invention also includes a memory and a program or instruction stored in the memory and executable on the microbial fermentation control device 6. When the program or instruction is executed by the microbial fermentation control device 6, the fermentation control method for preparing polyhydroxyalkanoates is executed. The method includes: collecting tail gas monitoring data of the microbial fermentation process; inputting the tail gas monitoring data into a quantitative relationship model for data analysis; outputting a substrate consumption rate from the quantitative relationship model; determining a feed rate instruction according to the substrate consumption rate; and the feed rate instruction is used to indicate feeding into the fermentation process according to the feed rate.

In order to verify that the present invention can play a role in real-time monitoring and precise control of the entire fermentation process, and verify that the present invention can increase PHA yield, increase PHA production intensity, and increase the conversion rate of substrate to product, the present invention will be described in conjunction with the following experimental examples:

As comparative experimental example 1 of the present invention, the control method of the present invention is not adopted, and the existing program feeding form is adopted, that is, the fermentation process of PHA production is fed according to the numerical range set by experience:

Seed culture: PHBHHx was fermented using Eutropha rosea as the base strain. First, a primary activation culture was carried out at 30°C and 200rpm for about 10 seconds. Then, 1% (v/v) was inoculated into the seed culture medium and cultured at 30°C and 200rpm for 10 hours. The seed culture medium contained 10 g/L peptone, 3 g/L yeast powder, and 3 g/L ammonium sulfate.

Fermentation culture: 10% inoculum was inoculated into 35 L of sterilized fermentation medium. The fermentation conditions were as follows: temperature controlled at 30°C, pH controlled at 6.5, ventilation volume controlled at 1 vvm, rotation speed controlled at 200 rpm, pressure controlled at 0.04 MPa, and fermentation medium composed of 10 g/L palm oil, 1 g/L disodium hydrogen phosphate, 2 g/L potassium dihydrogen phosphate, 3 g/L ammonium sulfate, and 0.2 g/L magnesium sulfate heptahydrate.

The process of setting according to experience:

During fermentation for 0 to 10 h, the stirring speed and dissolved oxygen coupling were controlled at 30%, and the maximum speed was 300 rpm;

During the fermentation period of 10 to 30 h, oil was added at a constant rate of 3 g/L/h.

After 30-50h of fermentation, adjust the oil replenishment rate to 6g/L/h;

After 50-56h of fermentation, the oil replenishment rate was adjusted to 4g/L/h and maintained until the tank was lowered. When the tank was finally lowered, the PHA yield was 8.40kg, the PHA production intensity was 3g/L/h, and the conversion rate from substrate to product was 80%.

Experimental Example 1: Compared with Comparative Experimental Example 1, the control method of the present invention is used to feed the process of fermentation production of PHA:

Seed culture: Same as comparative experimental example 1, no further details are given here.

Fermentation culture: Same as comparative experimental example 1, no further details are given here.

Construction of tail gas quantitative relationship model: According to the fermentation control conditions, the tail gas monitoring parameters are established to monitor the tail gas parameter indicators OUR and CER in the tail gas status monitoring software, and at the same time, a quantitative relationship between the tail gas monitoring data and the substrate consumption rate is established.

The following process is obtained based on the fermentation control of the present invention:

During fermentation for 0 to 10 hours, the stirring speed is coupled with dissolved oxygen and controlled at 30%, with a maximum speed of 300 rpm;

After 10-30h of fermentation, feed addition was started. Based on the real-time substrate consumption rate V _s , the oil addition rate was adjusted in real time and controlled between 3.3 and 4.3 g/L/h.

After 30 to 50 hours of fermentation, the oil replenishment rate was adjusted in real time based on the real-time substrate consumption rate V _s to 4.3 to 6.4 g/L/h.

After 50 to 56 hours of fermentation, the oil replenishment rate was adjusted in real time based on the real-time substrate consumption rate _Vs , and the oil replenishment rate was 4.6 to 5.0 g/L/h. When the fermentation was finally put into the tank, compared with the programmed fed-batch fermentation of the first comparative example, the PHA yield in the quantitative model feeding mode was increased by 23.3% to 10.36 kg, the PHA production intensity was increased by 16.3% to 3.49 g/L/h, and the conversion rate of substrate to product was increased from 80% to 85%.

As comparative experiment example 2 of the present invention, the control method of the present invention is not adopted, and the existing program feeding form is adopted, that is, the process of fermentation production of PHA is fed according to the numerical range set by experience:

Seed culture: Same as comparative experimental example 1, no further details are given here.

Fermentation culture: The fermentation medium is 10 g/L soybean oil, and the rest is the same as that of comparative experiment 1, which will not be described here.

The process of setting according to experience:

During fermentation for 0 to 10 h, the stirring speed and dissolved oxygen coupling were controlled at 30%, and the maximum speed was 300 rpm;

During the fermentation period of 10 to 30 h, oil was added at a constant rate of 3 g/L/h.

After 30-50h of fermentation, adjust the oil replenishment rate to 5g/L/h;

After 50-56 h of fermentation, the oil replenishment rate was adjusted to 3 g/L/h and maintained until the tank was lowered. When the tank was finally lowered, the fermentation results were shown in Table 1. The PHA yield was 6.75 kg, the PHA production intensity was 2.41 g/L/h, and the conversion rate from substrate to product was 75%.

Experimental Example 2: Compared with Comparative Experimental Example 2, the control method of the present invention is used to feed the process of fermentation production of PHA:

Seed culture: Same as comparative experimental example 1, no further details are given here.

Fermentation culture: The fermentation medium is 10 g/L soybean oil, and the rest is the same as that of Comparative Experiment 1, which will not be described here.

Construction of tail gas quantitative relationship model: According to the fermentation control conditions, the tail gas monitoring parameters are established to monitor the tail gas parameter indicators OUR and CER in the tail gas status monitoring software, and at the same time, a quantitative relationship between the tail gas monitoring parameters and the substrate consumption rate is established.

The following process is obtained based on the fermentation control of the present invention:

During fermentation for 0 to 10 hours, the stirring speed is coupled with dissolved oxygen and controlled at 30%, with a maximum speed of 300 rpm;

After 10-30h of fermentation, feed addition was started. Based on the real-time substrate consumption rate _Vs , the oil addition rate was adjusted in real time and controlled between 3-4g/L/h.

After 30 to 50 hours of fermentation, the oil replenishment rate was adjusted in real time based on the real-time substrate consumption rate V _s to 3.5 to 5.5 g/L/h.

During the fermentation period of 50 to 56 h, the oil replenishment rate was adjusted in real time based on the real-time substrate consumption rate _Vs , and the oil replenishment rate reached 4.0 to 5.0 g/L/h. When the fermentation was finally put into the tank, compared with the programmed fed-batch fermentation, the PHA yield under the quantitative model feeding mode increased by 15.6% to 7.8 kg, the PHA production intensity increased by 15.8% to 2.79 g/L/h, and the conversion rate of substrate to product increased from 75% to 78%.

As comparative experiment example 3 of the present invention, the control method of the present invention is not adopted, and the existing program feeding form is adopted, that is, the process of fermentation production of PHA is fed according to the numerical range set by experience:

Seed culture: Eutropha rosea was used as the base strain for PHB fermentation. Other details were the same as those in Comparative Experiment 1 and will not be described in detail here.

Fermentation culture: Same as comparative experimental example 1, no further details are given here.

The process of setting according to experience:

During fermentation for 0 to 10 h, the stirring speed and dissolved oxygen coupling were controlled at 30%, and the maximum speed was 300 rpm;

During the fermentation period of 10 to 30 h, oil was added at a constant rate of 3 g/L/h.

After 30-50h of fermentation, adjust the oil replenishment rate to 4.5g/L/h;

After 50-56 h of fermentation, the oil replenishment rate was adjusted to 3.5 g/L/h and maintained until the tank was lowered. When the tank was finally lowered, the PHA yield was 6.65 kg, the PHA production intensity was 2.38 g/L/h, and the conversion rate from substrate to product was 76%.

Experimental Example 3: Compared with Comparative Experimental Example 3, the control method of the present invention is used to feed the process of fermentation production of PHA:

Seed culture: Eutropha rosea was used as the base strain for PHB fermentation. Other details were the same as those in Comparative Experiment 1 and will not be described in detail here.

Fermentation culture: Same as comparative experimental example 1, no further details are given here.

Construction of tail gas quantitative relationship model: According to the fermentation control conditions, the tail gas monitoring parameters are established to monitor the tail gas parameter indicators OUR and CER in the tail gas status monitoring software, and at the same time, a quantitative relationship between the tail gas monitoring parameters and the substrate consumption rate is established.

The following process is obtained based on the fermentation control of the present invention:

During the fermentation period of 0 to 10 hours, the stirring speed is coupled with the dissolved oxygen and controlled at 30%, with a maximum speed of 300 rpm;

After 10-30h of fermentation, feed addition was started. Based on the real-time substrate consumption rate _Vs , the oil addition rate was adjusted in real time and controlled between 3-4g/L/h.

After 30 to 50 hours of fermentation, the oil replenishment rate was adjusted in real time based on the real-time substrate consumption rate V _s to 3 to 4.5 g/L/h.

After 50 to 56 hours of fermentation, the oil replenishment rate was adjusted in real time based on the real-time substrate consumption rate _Vs , and the oil replenishment rate was 3 to 3.5 g/L/h. When the fermentation was finally carried out, compared with the third comparative example, the PHA yield in the third example under the quantitative model feeding mode was increased by 5.6% to 7.02 kg, the PHA production intensity was increased by 5.5% to 2.51 g/L/h, and the conversion rate of substrate to product was increased from 76% to 78%.

In order to further verify whether the fermentation control process of the present invention is applicable to different fermentation conditions, the present invention also conducted experimental examples under conditions of different active strains, different culture media, different rotation speeds, etc.:

Experimental Example 4: Using high-activity seeds and the control method of the present invention to feed the fermentation process of PHA production:

Seed culture: 3% (v/v) was inoculated into the seed culture medium. Other steps were the same as those in comparative experiment 1 and will not be described again.

Fermentation culture: Same as comparative experimental example 1, no further details are given here.

Construction of tail gas quantitative relationship model: According to the fermentation control conditions, the tail gas monitoring parameters are established to monitor the tail gas parameter indicators OUR and CER in the tail gas status monitoring software, and at the same time, a quantitative relationship between the tail gas monitoring parameters and the substrate consumption rate is established.

The following process is obtained based on the fermentation control of the present invention:

During the fermentation period of 0 to 10 hours, the stirring speed is coupled with the dissolved oxygen and controlled at 30%, with a maximum speed of 300 rpm;

After 10-30h of fermentation, feed addition was started. Based on the real-time substrate consumption rate _Vs , the oil addition rate was adjusted in real time and controlled between 4 and 5 g/L/h.

After 30 to 50 hours of fermentation, the oil replenishment rate was adjusted in real time based on the real-time substrate consumption rate V _s to 6 to 8 g/L/h.

During the fermentation period of 50-56 h, the oil replenishment rate was adjusted in real time based on the real-time substrate consumption rate _Vs to 4-5 g/L/h. When the fermentation was finally started, under the high-activity seeds and quantitative model feeding mode, the PHA yield was further increased to 12.18 kg, the PHA production intensity reached 3.95 g/L/h, and the conversion rate from substrate to product was 82%.

Experimental Example 5: Using different fermentation media and the control method of the present invention, the process of fermentation production of PHA was fed:

Seed culture: Same as comparative experimental example 1, no further details are given here.

Fermentation culture: The fermentation medium is 20 g/L palm oil, 1 g/L disodium hydrogen phosphate, 2 g/L potassium dihydrogen phosphate, 3 g/L ammonium sulfate, and 0.1 g/L magnesium sulfate heptahydrate. Other ingredients are the same as those in Comparative Experiment 1 and will not be described in detail here.

Construction of tail gas quantitative relationship model: According to the fermentation control conditions, the tail gas monitoring parameters are established to monitor the tail gas parameter indicators OUR and CER in the tail gas status monitoring software, and at the same time, a quantitative relationship between the tail gas monitoring parameters and the substrate consumption rate is established.

The following process is obtained based on the fermentation control of the present invention:

During fermentation for 0 to 10 hours, the stirring speed is coupled with dissolved oxygen and controlled at 30%, with a maximum speed of 300 rpm;

After 10-30h of fermentation, feed addition was started. Based on the real-time substrate consumption rate _Vs , the oil addition rate was adjusted in real time and controlled between 3.5 and 4.5 g/L/h.

After 30 to 50 hours of fermentation, the oil replenishment rate was adjusted in real time based on the real-time substrate consumption rate V _s to 5 to 7 g/L/h.

After 50-56 h of fermentation, the oil replenishment rate was adjusted in real time based on the real-time substrate consumption rate _Vs , and the oil replenishment rate reached 4.5-6.5 g/L/h. When the fermentation was finally started, under different culture media and quantitative model feeding modes, the PHA yield reached 10.61 kg, the PHA production intensity reached 3.64 g/L/h, and the conversion rate from substrate to product was 85%.

Experimental Example 6: Using different rotation speeds and the control method of the present invention to feed the process of fermentation production of PHA:

Seed culture: Same as comparative experimental example 1, no further details are given here.

Fermentation culture: The fermentation conditions are as follows: temperature controlled at 30°C, pH controlled at 6.5, ventilation volume controlled at 1 vvm, rotation speed controlled at 300 rpm, and pressure controlled at 0.04 MPa. Other conditions are the same as those in Comparative Experiment 1 and will not be described in detail here.

Construction of tail gas quantitative relationship model: According to the fermentation control conditions, the tail gas monitoring parameters are established to monitor the tail gas parameter indicators OUR and CER in the tail gas status monitoring software, and at the same time, a quantitative relationship between the tail gas monitoring parameters and the substrate consumption rate is established.

The following process is obtained based on the fermentation control of the present invention:

During fermentation for 0 to 10 hours, the stirring speed is coupled with dissolved oxygen and controlled at 30%, with a maximum speed of 300 rpm;

After 10-30h of fermentation, feed addition was started. Based on the real-time substrate consumption rate V _s , the oil addition rate was adjusted in real time and controlled between 3.3 and 4.3 g/L/h.

After 30 to 50 hours of fermentation, the oil replenishment rate was adjusted in real time based on the real-time substrate consumption rate V _s to 5.5 to 8.5 g/L/h;

During the fermentation period of 50-56 h, the oil replenishment rate was adjusted in real time based on the real-time substrate consumption rate _Vs , and the oil replenishment rate reached 6.5-4.5 g/L/h. When the fermentation was finally put into the tank, the PHA yield reached 10.79 kg, the PHA production intensity reached 3.71 g/L/h, and the conversion rate from substrate to product was 83% under the conditions of increasing the rotation speed and quantitative model feeding mode.

In order to facilitate viewing the corresponding relationship between different influencing factors and PHA yield, PHA production intensity and substrate to product conversion rate, the present invention summarizes the various parameters and test results of the above-mentioned comparative experimental examples 1-3 and experimental examples 1-6, as shown in Table 1 below.

Table 1

Among them, the oil supplementation amount represents the total oil added mass at the end of fermentation, the PHA yield represents the product of the PHA concentration and the fermentation volume at the end of fermentation, the PHA production intensity represents the average PHA synthesis rate during the fermentation process, and the substrate to product conversion rate represents the ratio of the product PHA mass to the substrate oil mass.

As shown in Figure 5, Figure 5 is a display diagram of the effect of the microbial fermentation control method provided by the present invention, in which the PHA production intensity and substrate to product conversion rate (substrate conversion rate) of comparative experimental examples 1-3 and experimental examples 1-6 are further compared. It can be intuitively seen that in terms of production intensity and substrate conversion efficiency, experimental examples 1-3 are better than the corresponding comparative experimental examples 1-3; and even under different fermentation conditions, such as experimental examples 4-6, the production intensity and substrate conversion rate are higher than comparative experimental example 1. At the same time, combined with experimental example 1, it can be verified that the stability of the control method provided by the present invention is relatively high.

The present invention provides a microbial fermentation control method, device, system, equipment and medium. Taking the fermentation process of polyhydroxyalkanoate as an example, in the fermentation process of polyhydroxyalkanoate, input tail gas monitoring data is obtained in real time, and the substrate consumption rate is determined after the tail gas monitoring data is input into a quantitative relationship model in real time. According to the substrate consumption rate, the feeding speed instruction is adjusted in the feeding control interval corresponding to the real-time fermentation stage of polyhydroxyalkanoate, so as to realize the feeding control of all stages of the fermentation of polyhydroxyalkanoate. The present invention realizes real-time monitoring and precise control of the entire fermentation process of polyhydroxyalkanoate by precise quantitative control of feeding, and effectively improves the production intensity and fermentation stability of PHA.

FIG6 is a schematic diagram of the structure of a microbial fermentation control device provided by the present invention. Taking the fermentation control process of polyhydroxyalkanoate as an example, the present invention provides a fermentation control device for preparing polyhydroxyalkanoate, comprising:

Collection unit 51: used to collect tail gas monitoring data of the fermentation process of microorganisms;

Analysis unit 52: used for inputting the exhaust gas monitoring data into the quantitative relationship model for data analysis; outputting the substrate consumption rate from the quantitative relationship model;

Determining unit 53: used to determine a feeding speed instruction according to the substrate consumption rate;

The feed rate instruction is used to instruct to feed the fermentation process according to the feed rate.

In a microbial fermentation control device provided by the present invention, the analysis unit also includes: a unit for inputting the oxygen consumption rate into a fermentation stage confirmation model, confirming the current target fermentation stage by the fermentation stage confirmation model, and confirming the start and end of the feeding program based on the current target fermentation stage; and a unit for confirming the feeding control interval corresponding to the target fermentation stage based on the current target fermentation stage; and regulating the feeding speed based on the value of the feeding control interval combined with the substrate consumption rate.

FIG7 is a schematic diagram of the structure of an electronic device provided by the present invention. As shown in FIG7, the electronic device may include: a processor 610, a communication interface 620, a memory 630 and a communication bus 640, wherein the processor 610, the communication interface 620 and the memory 630 communicate with each other through the communication bus 640. The processor 610 may call the logic instructions in the memory 630 to execute the microbial fermentation control method, which includes: collecting tail gas monitoring data of the fermentation process of the microorganism; inputting the tail gas monitoring data into the fermentation stage confirmation model and the quantitative relationship model for data analysis; the fermentation stage confirmation model outputs the target fermentation stage, and the quantitative relationship model outputs the substrate consumption rate; the feeding speed instruction is adjusted according to the substrate consumption rate combined with the feeding control interval of the target fermentation stage; the feeding speed instruction is used to indicate feeding into the fermentation process according to the feeding speed.

In addition, the logic instructions in the above-mentioned memory 630 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute a microbial fermentation control method provided by the above-mentioned methods, which method includes: collecting exhaust gas monitoring data of the microbial fermentation process; inputting the exhaust gas monitoring data into a fermentation stage confirmation model and a quantitative relationship model for data analysis; the fermentation stage confirmation model outputs a target fermentation stage, and the quantitative relationship model outputs a substrate consumption rate; determining or regulating a feeding speed instruction based on the substrate consumption rate combined with a feeding control interval of the target fermentation stage; the feeding speed instruction is used to instruct the feeding of feed into the fermentation process according to the feeding speed.

On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the above-mentioned methods to provide a microbial fermentation control method, the method comprising: collecting exhaust gas monitoring data of the microbial fermentation process; inputting the exhaust gas monitoring data into a fermentation stage confirmation model and a quantitative relationship model for data analysis; outputting a target fermentation stage from the fermentation stage confirmation model, and outputting a substrate consumption rate from the quantitative relationship model; determining or regulating a feeding speed instruction based on the substrate consumption rate combined with a feeding control interval of the target fermentation stage; the feeding speed instruction is used to instruct feeding into the fermentation process according to the feeding speed.

The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Those of ordinary skill in the art may understand and implement it without creative effort.

Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM/RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. A method for controlling microbial fermentation, comprising: Collect tail gas monitoring data of microbial fermentation process; Inputting the tail gas monitoring data into a quantitative relationship model for data analysis, and outputting a substrate consumption rate from the quantitative relationship model; determining a feed rate instruction according to the substrate consumption rate; The feed rate instruction is used to instruct to feed the fermentation process according to the feed rate. 2. The microbial fermentation control method according to claim 1, characterized in that the tail gas monitoring data includes oxygen consumption rate, carbon dioxide generation rate, PHA synthesis oxygen consumption rate, PHA synthesis CO ₂ release rate, cellular respiration oxygen consumption rate, cellular respiration CO ₂ release rate; The quantitative relationship model is used to calculate the substrate consumption rate based on the quantitative relationship established among the oxygen consumption rate, the carbon dioxide generation rate and the substrate conversion rate; The quantitative relationship model specifically performs the following steps: Determining a carbon dioxide generation component according to the carbon dioxide generation rate and a first coefficient; Determining a consumption difference based on the oxygen consumption rate and the carbon dioxide generation component; Determining the consumption component according to the consumption difference and a second coefficient; Determining a substrate consumption rate according to the consumption component and the substrate conversion rate; The first coefficient is calculated from the cellular respiration oxygen consumption rate and the cellular respiration _CO2 release rate; the second coefficient is calculated from the first coefficient, the PHA synthesis oxygen consumption rate, the PHA synthesis oxygen consumption, and the PHA synthesis _CO2 release rate. 3. The microbial fermentation control method according to claim 2, characterized in that the microbial fermentation control method further comprises: Inputting the oxygen consumption rate into a fermentation stage confirmation model, confirming the current target fermentation stage by the fermentation stage confirmation model, and confirming the start and end of the feeding program based on the current target fermentation stage; And based on the current target fermentation stage, confirming the feeding control interval corresponding to the target fermentation stage; and regulating the feeding speed based on the value of the feeding control interval combined with the substrate consumption rate. 4. The microbial fermentation control method according to claim 3, characterized in that: The target fermentation stage includes the initial fermentation stage, the fermentation growth stage, the fermentation stabilization stage and the fermentation decay stage, and the corresponding feeding control intervals are: the preset feeding speed, the first feeding control interval, the second feeding control interval and the third feeding control interval; The values of the preset feeding speed, the first feeding control interval, the second feeding control interval, and the third feeding control interval are preset feeding speeds. 5. The microbial fermentation control method according to any one of claims 1 to 4, characterized in that the microorganism is a microorganism capable of accumulating polyhydroxyalkanoates in cells, including microorganisms of the following genera: Aeromonas, Alcaligenes, Azotobacter, Bacillus, Clostridium, Halobacterium, Nocardia, Rhodospirilla, Pseudomonas, Ralstonia, and Zoogloea. 6. A microbial fermentation control device, characterized in that it comprises: Collection unit: used to collect tail gas monitoring data of the fermentation process of microorganisms; Analysis unit: used for inputting the exhaust gas monitoring data into the quantitative relationship model for data analysis; outputting the substrate consumption rate from the quantitative relationship model; A determination unit: used for determining a feeding speed instruction according to the substrate consumption rate; The feed rate instruction is used to instruct to add feed to the fermentation process according to the feed rate. 7. The microbial fermentation control device according to claim 6, characterized in that it comprises: The analysis unit also includes: a unit for inputting an oxygen consumption rate into a fermentation stage confirmation model, confirming the current target fermentation stage by the fermentation stage confirmation model, and confirming the start and end of the feeding program based on the current target fermentation stage; and a unit for confirming a feeding control interval corresponding to the target fermentation stage based on the current target fermentation stage; and regulating the feeding speed based on the value of the feeding control interval combined with the substrate consumption rate. 8. A microbial fermentation control system, characterized in that it comprises the microbial fermentation control device according to claim 6 or 7, which is used to control the fermentation process of the microorganisms according to the exhaust gas monitoring data; Also includes: Fermentation tank, used to provide a fermentation environment for microorganisms; An exhaust gas sampling pipeline, used for collecting exhaust gas from the fermentation tank; Flow distributor, used for flow regulation; Exhaust gas mass spectrometry analyzer, used to analyze exhaust gas component information; An exhaust gas status monitoring unit, used to obtain exhaust gas monitoring data; The microorganism is a microorganism capable of accumulating polyhydroxyalkanoate in cells. 9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the microbial fermentation control method as described in any one of claims 1 to 5 when executing the computer program. 10. A non-transitory computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the microbial fermentation control method according to any one of claims 1 to 5 is implemented.

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