Automatic continuous strain culture system based on intelligent temperature control and precise sensing

Abstract

The invention discloses an automatic strain continuous culture system based on intelligent temperature control and precise sensing, the system comprises an upper cover, an outer frame, a bearing table and a base, a plurality of incubators are arranged in the outer frame, the center temperature of the incubators can be obtained through a temperature measuring head at the bottom, and a temperature sensor of a sealing cover of the upper cover obtains the internal air temperature; a constant-temperature water source connected with circulating water of the outer frame provides environment temperature; based on the three temperatures, the strain temperature and the variation trend of the strain temperature are predicted through a thermal inertia differential equation, and the heater power and the constant-temperature water source temperature are adjusted according to the temperature variation trend. According to the invention, accurate monitoring and intelligent regulation and control of multi-zone temperature are realized, the problems of poor temperature control and single monitoring of a traditional culture device are solved, and the stability and the automation degree of strain culture are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a strain automated continuous culture system based on intelligent temperature control and precise sensing. BACKGROUND

[0002] In the fields of microbial breeding, fermentation engineering and biopharmaceuticals, the growth state regulation of strains and the efficient synthesis of metabolic products are highly dependent on stable and precise culture environment. Temperature, as a core control parameter, its slight fluctuation can significantly affect the proliferation rate of strains, enzyme activity expression and target product yield. However, the current mainstream strain culture device still has three major bottlenecks in practical application, which seriously restricts the culture efficiency and result reliability:

[0003] Firstly, the temperature control system lacks systematic design and has poor stability. The existing equipment mostly relies on traditional culture dishes combined with single-zone heating chips, or only uses water baths for rough temperature control. It cannot offset the interference of environmental temperature fluctuations, and it is also difficult to balance the local temperature rise caused by strain metabolic heat, resulting in temperature fluctuations of the culture system often exceeding ±2℃, which cannot meet the high-precision culture needs.

[0004] Secondly, the temperature monitoring dimension is single and the data representativeness is insufficient. Traditional devices generally use single-point temperature measurement mode. The sensor is either attached to the outer wall of the culture device or suspended in the top air layer, which can only reflect the local environmental temperature and cannot capture the real temperature of the strain growth microenvironment. This "point-to-area" monitoring method leads to the lack of accurate data support for actual temperature control decision-making, and the phenomenon of "normal sensor display but strain has been stressed by temperature" often occurs.

[0005] Thirdly, the degree of automation is low and the operation risk is prominent. The key links such as temperature regulation, nutrient supply and sampling detection still rely on manual intervention: when the sensor prompts that the temperature deviates, manual adjustment of heating power or water change is needed; opening the culture device cover is needed when adding carbon source and nitrogen source, which not only has a lag response, but also destroys the sterile environment, with a contamination risk of more than 30%. At the same time, the randomness of manual operation also leads to poor reproducibility of culture results between batches, which is difficult to meet the stringent requirements of industrial production on stability.

[0006] Therefore, it is a key requirement to develop an automated continuous culture system that can realize multi-region precise temperature measurement, dynamic prediction and intelligent control, in order to break through the current technical bottlenecks and promote the development of microbial culture towards high precision, low intervention and standardization. SUMMARY

[0007] The present application aims to overcome the defects of low temperature control precision, one-sided monitoring and insufficient automation of existing strain culture devices, and provides a strain automated continuous culture system based on intelligent temperature control and precise sensing, and a control method, which realizes multi-dimensional temperature monitoring, dynamic prediction and precise regulation during strain culture process.

[0008] The application discloses a strain automatic continuous culture system based on intelligent temperature control and precise sensing, which comprises an upper cover, an outer frame, a bearing table and a base.

[0009] The inner part of the outer frame is provided with a semi-closed chamber, and a plurality of culture devices are arranged in the chamber; the culture devices are in a whole conical shape, the bottom of each culture device is provided with a semicircular groove protruding inward, the center of the semicircular groove is provided with a temperature measuring groove protruding inward, the upper surface of the bearing table is provided with a semicircular heater matched with the semicircular groove, the middle part of the semicircular heater is provided with a temperature measuring head, and the temperature measuring head is used for measuring the temperature at the center of the culture device, i.e. T1.

[0010] The lower surface of the upper cover is provided with a plurality of sealing covers, the sealing covers are matched with the top shape of the culture devices, the lower surface of each sealing cover is attached with a temperature sensor, and the temperature sensor is used for measuring the temperature of the air in the culture device, i.e. T2.

[0011] The side surface of the outer frame is provided with a circulating water outlet and a circulating water inlet, the circulating water outlet and the circulating water inlet are connected with a constant-temperature water source, and the temperature of the constant-temperature water source is the environmental temperature of the culture device, i.e. T3.

[0012] The system is internally provided with a calculation module, and the calculation module adjusts the working conditions of the semicircular heater or the constant-temperature water source according to the numerical difference of T1, T2 and T3.

[0013] In order to further improve the automatic operation level of the system and meet the dynamic demand of the strain on nutrient substances and gas environment in different growth stages, the sealing cover is designed as an integrated functional module, and a supply pipe and an exhaust pipe are arranged through the surface of the sealing cover to form a complete gas-liquid circulation channel. The supply pipe is connected with an external storage unit and a gas cylinder through a sterile pipeline, can accurately and quantitatively inject liquid nutrient substances such as carbon source, nitrogen source and growth factor into the culture device according to a preset program or real-time monitoring of the strain density, and can supplement oxygen or carbon dioxide according to needs, so that the carbon-nitrogen ratio and the dissolved oxygen content of the culture system are always in the optimal range.

[0014] The exhaust pipe cooperated with the supply pipe is responsible for the efficient discharge of metabolic waste gas, and the carbon dioxide and volatile metabolites generated in the growth process of the strain are discharged through the pipeline in time, so that the local microenvironment is prevented from being acidified or the gas partial pressure is prevented from being imbalanced due to the accumulation of the metabolic waste gas in the culture device, and the strain activity is affected.

[0015] To match the continuous culture process and reduce manual intervention, the culture device is further provided with a liquid outlet communicating with the inner cavity, the liquid outlet is connected to a liquid taking port of the base through a pipeline, and an electromagnetic valve is connected in series in the middle section of the pipeline.

[0016] Further, the number of the culture devices is 6.

[0017] Further, the surfaces of the bearing table, the upper cover and the outer frame are provided with heat preservation materials.

[0018] The application further provides a temperature control method based on the system, which acquires the temperatures of different regions, predicts the instantaneous temperature change trend of the bacteria by using a thermal inertia differential equation, dynamically adjusts the power of the semicircular heater and the temperature of the constant temperature water source according to the deviation of Tc from the set temperature, and forms a closed loop control.

[0019] An instantaneous temperature change prediction method for an automatic continuous culture system acquires the temperatures of different regions in a bacteria culture system: measures the temperature at the center of the culture device, i.e., T1, measures the temperature of the air inside the culture device, i.e., T2, and measures the ambient temperature of the culture device, i.e., T3.

[0020] The instantaneous temperature change trend of the bacteria is calculated as follows:

[0021]

[0022] wherein, is the predicted temperature of the bacteria; C is the thermal inertia parameter of the system, which is obtained by measurement; , , are the heat transfer coefficients of the culture liquid, the air and the water, respectively;

[0023] The temperature of the constant temperature water source or the power of the semicircular heater is adjusted according to the instantaneous temperature change trend, so that the actual temperature of the bacteria is controlled to be within the set range.

[0024] The control of the temperature adjusts the power of the semicircular heater and the temperature of the constant temperature water source according to the deviation and change trend of Tc from the set temperature, and specifically includes the following steps:

[0025] S1, when the predicted instantaneous temperature change is a decrease, and the minimum value of the set temperature, at which time the power of the semicircular heater is increased, and the temperature of the constant-temperature water source is raised to the maximum value of the set temperature for the strain culture;

[0026] S2, when the predicted instantaneous temperature change is a decrease, but is still within the set temperature, at which time the power of the semicircular heater is not changed, only the temperature of the constant-temperature water source is raised, and the temperature of the constant-temperature water source must not exceed the maximum value of the set temperature for the strain culture;

[0027] S3, when the predicted instantaneous temperature change is an increase, but is still within the set temperature, at which time the power of the semicircular heater is not changed, only the temperature of the constant-temperature water source is reduced, and the temperature of the constant-temperature water source must not be lower than the minimum value of the set temperature for the strain culture;

[0028] S4, when the predicted instantaneous temperature change is an increase, and is higher than the maximum value of the set temperature, at which time the power of the semicircular heater is reduced, and the temperature of the constant-temperature water source is reduced to the minimum value of the set temperature for the strain culture.

[0029] Compared with the prior art, the present application has the following beneficial effects:

[0030] 1. Comprehensive and accurate temperature measurement: By measuring the temperature in three dimensions of T1 (culture medium center), T2 (internal air), and T3 (environment), a three-dimensional temperature measurement network is constructed from the core area of the culture medium to the air layer and then to the external environment, which completely captures the temperature gradient of the strain growth microenvironment, and completely overcomes the one-sidedness problem of traditional devices caused by single temperature measurement, laying a data foundation for accurate temperature control.

[0031] 2. Intelligent and efficient temperature control: The temperature prediction model established based on the heat inertia differential equation can calculate the actual temperature of the strain and the instantaneous change trend in real time, and through the advance adjustment of the power of the bottom semicircular heater and the temperature of the constant-temperature water source, a dynamic response closed-loop control is formed.

[0032] 3. High degree of automation: The integrated automatic feeding, sterile sampling, and exhaust functions realize a few intervention operations in the whole process of strain culture, which not only reduces the pollution risk caused by human contact, but also guarantees the stability of continuous culture; through the array layout design, the experimental scale can be flexibly adjusted to meet the high-throughput screening demand, especially suitable for multi-group comparison experiments in the strain selection and breeding stage. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a general structure schematic diagram of a strain automatic continuous culture system based on intelligent temperature control and accurate sensing;

[0034] Figure 2 is an exploded view of the culture system;

[0035] Figure 3 is a structural schematic view of the upper cover in the culture system;

[0036] Figure 4 is a structural schematic view of the incubator in the culture system;

[0037] Figure 5 is a structural sectional view of the incubator;

[0038] Figure 6 is a structural schematic view of the bottom of the culture system;

[0039] Figure 7 is an installation schematic view of the incubator;

[0040] 1. upper cover, 2. outer frame, 3. bearing table, 4. base, 5. incubator, 6. circulating water outlet, 7. liquid taking port, 8. temperature measuring head, 9. circulating water inlet, 10. water bath cavity, 101. supply pipe, 102. exhaust pipe. DETAILED DESCRIPTION

[0041] In order to deepen the understanding of the present application, the present application will be further described in conjunction with the embodiments and the accompanying drawings, which are only used to explain the present application and do not constitute a limitation on the protection scope of the present application.

[0042] Example 1:

[0043] As shown in Figures 1-7 , a strain automatic continuous culture system based on intelligent temperature control and precise sensing includes an upper cover 1, an outer frame 2, a bearing table 3, and a base 4. The outer frame 2 is a cuboid structure, and the internal chamber size is 50 cm x 30 cm x 20 cm. Six conical incubators 5 are arranged in the chamber, arranged in a 2 x 3 array. The radius of the semicircular groove at the bottom of the incubator 5 is 3 cm, and the depth of the temperature measuring groove is 2 cm.

[0044] The bearing table 3 is made of 316L stainless steel, and a semicircular heater is arranged on the upper surface corresponding to each incubator. The power is adjustable from 0 to 50 W. The Pt1000 temperature measuring head 8 in the middle of the heater has an accuracy of ±0.05℃, and extends into the temperature measuring groove of the incubator to collect T1.

[0045] The upper cover 1 is made of polytetrafluoroethylene, and the lower surface of the sealing cover is sealed with the top of the incubator. The temperature sensor (accuracy ±0.1℃) on the lower surface of the sealing cover collects T2. The supply pipe 101 on the sealing cover is connected to a sterile liquid storage tank, and the flow rate is controlled by a plunger pump with an accuracy of ±0.5%. The exhaust pipe 102 is connected to a sterilization filter.

[0046] The circulating water outlet 6 and the circulating water inlet 9 on the side of the outer frame 2 are connected to a constant temperature water tank through silica gel pipes, the temperature range is 5-60℃, the precision is ±0.1℃, a water bath circulation is formed, and T3 is the set temperature of the constant temperature water tank. The liquid outlet at the bottom of the incubator 5 is connected to the liquid taking port 7 of the base 4 through a rubber pipe, and an electromagnetic valve on the pipe controls the liquid outlet. The surface of the bearing table 3, the upper cover 1 and the outer frame 2 are all coated with a heat preservation layer, so as to reduce heat loss.

[0047] S1. Start the system, and set the target temperature range to 30±0.5℃;

[0048] S2. The temperature measuring head 8 collects T1=30.2℃, the sealing cover sensor collects T2=29.8℃, and the constant temperature water tank feedbacks T3=29.5℃;

[0049] S3. Substitute the differential equation

[0050]

[0051] It is calculated that =0.02℃ / s, the system is in a temperature rising trend, Tc=30.1℃, and is in the set range;

[0052] S4. Keep the heater power unchanged, reduce the constant temperature water source temperature from 29.5℃ to 29.0℃, and inhibit the temperature rising trend; after 3 minutes, Tc is stabilized at 30.0℃.

[0053] Finally, it should be pointed out that the above examples are only used to illustrate the technical solutions of the present application and not to limit, although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the technical solutions of the present application, and they should all be covered in the claim range of the present application.

Claims

1. A strain automatic continuous culture system based on intelligent temperature control and precise sensing, characterized in that, It comprises an upper cover, an outer frame, a bearing table and a base; The inner part of the outer frame is provided with a semi-closed chamber, and a plurality of culture devices are arranged in the chamber. The culture devices are in a whole conical shape, and the bottom of each culture device is provided with a semi-circular groove protruding inward. A temperature measuring groove protrudes inward at the center of the semi-circular groove. The upper surface of the bearing table is provided with a semi-circular heater matched with the semi-circular groove. The middle part of the semi-circular heater is provided with a temperature measuring head. The temperature measuring head is used to measure the temperature at the center of the culture device, i.e. T1. The lower surface of the upper cover is provided with a plurality of sealing covers matched with the top shape of the culture device. Temperature sensors are attached to the lower surface of the sealing covers. The temperature sensors are used to measure the temperature of the air inside the culture device, i.e. T2. The side surface of the outer frame is provided with a circulating water outlet and a circulating water inlet. The circulating water outlet and the circulating water inlet are connected with a constant temperature water source. The temperature of the constant temperature water source is the environmental temperature of the culture device, i.e. T3. An internal calculation module is arranged. The calculation module adjusts the working condition of the semi-circular heater or the constant temperature water source according to the numerical difference of T1, T2 and T3.

2. The automatic continuous culture system of bacterial strains based on intelligent temperature control and precise sensing according to claim 1, characterized in that A supply pipe and an exhaust pipe are arranged on the sealing cover. The supply pipe is used to inject carbon source, nitrogen source, oxygen, carbon dioxide or other gas-liquid materials into the culture device. 3.The strain automatic continuous culture system based on intelligent temperature control and precision sensing according to claim 1 or 2, characterized in that The bottom of the culture device is provided with a liquid outlet connected with a liquid taking port on the base through a pipeline. An electromagnetic valve is arranged on the pipeline.

4. The automatic continuous culture system of bacterial strains based on intelligent temperature control and precise sensing according to claim 3, characterized in that The number of the culture devices is six.

5. The automatic continuous culture system of bacterial strains based on intelligent temperature control and precise sensing according to claim 3, characterized in that The surfaces of the bearing table, the upper cover and the outer frame are provided with heat preservation materials.

6. A transient temperature change prediction method for an automated continuous culture system, characterized by The temperatures of different areas in the bacterial culture system are obtained. The temperature at the center of the culture device is measured, i.e. T1. The temperature of the air inside the culture device is measured, i.e. T2. The environmental temperature of the culture device is measured, i.e. T3. The instantaneous temperature change trend of the bacterial culture is calculated. ; wherein, is the predicted temperature for the strain; C is a thermal inertia parameter for the system, which data is obtained by measurement; , , are the heat transfer coefficients for the culture broth, air, and water, respectively; The temperature of the constant temperature water source or the power of the semi-circular heater is adjusted according to the instantaneous temperature change trend, so as to control the actual temperature of the bacterial culture within the set range.

7. A transient temperature change prediction method for an automated continuous culture system according to claim 6, wherein, The temperature control comprises the following steps: S1, when the predicted instantaneous temperature change is a decrease, and when the minimum value of the set temperature is exceeded, the power of the semi-circular heater is increased and the temperature of the constant temperature water source is raised to the maximum value of the set temperature for the culture of the bacteria. S2, when the predicted instantaneous temperature change is a decrease, but is still within the set temperature, the power of the semi-circular heater is not changed, only the temperature of the constant temperature water source is raised, and the temperature of the constant temperature water source must not exceed the maximum value of the set temperature of the strain culture. S3, when the predicted instantaneous temperature change is a temperature increase, but the temperature of the constant temperature water source must not be lower than the minimum value of the set temperature of the bacterial culture; S4, when the predicted instantaneous temperature change is a temperature increase, and When the maximum value of the set temperature is exceeded, the power of the semi-circular heater is reduced and the temperature of the constant temperature water source is reduced to the minimum value of the set temperature for the culture of the bacterial strain.

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