Bioreactor and its method for cultivating microorganisms
The bioreactor design with optimized pipe configurations and temperature control addresses uneven distribution and efficiency issues, achieving uniform gas saturation and mass transfer for efficient microorganism cultivation.
Patent Information
- Authority / Receiving Office
- RU · RU
- Patent Type
- Patents
- Current Assignee / Owner
- OBSHCHESTVO S OGRANICHENNOJ OTVETSTVENNOSTYU INVESTITSIONNAYA KOMPANIYA VERKHNYAYA ANGARA
- Filing Date
- 2025-06-11
- Publication Date
- 2026-06-30
AI Technical Summary
Existing bioreactors face challenges such as complex design and maintenance, uneven distribution of nutrients, oxygen, and temperature, and low efficiency at low gas feed rates, leading to potential cell damage and suboptimal growth conditions for microorganisms.
A bioreactor design featuring an upper and lower chamber connected by bubble and circulation pipes, with a thermostatic casing and degassing channel, ensuring controlled gas supply and temperature regulation, and optimized pipe diameters and lengths for effective mass transfer and gas saturation.
Ensures uniform distribution of the gas phase, effective mass transfer, and controlled temperature conditions, supporting efficient cultivation of microorganisms across a wide range of gas flow rates without cell damage.
Smart Images
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Abstract
Description
[0001] Technical field.
[0002] The invention relates to the microbiological industry, to methods and apparatus for cultivating unicellular microorganisms.
[0003] Technique level.
[0004] Bioreactors are specialized devices used to cultivate microorganisms such as bacteria, fungi, and yeast under controlled conditions. They play a key role in the biotechnology and food industries, as well as in pharmaceutical production.
[0005] Loop-type fermenters (U-loop) are widely used. They are a vertical or horizontal tubular system in the form of a closed loop with a pump through which the culture medium circulates.
[0006] Loop reactors are known from the prior art and are described in patents, for example, RU 2747305 C2 “System and method (variants) for intensifying biomass production” (priority date 16.06.2017), RU 2824554 C1 “Fermentation reactor and fermentation process” (priority date 28.02.2018), RU 2771462 C2 “Fermentation reactor and fermentation process”.
[0007] Reactors of this type provide good mixing without the use of mechanical stirrers, which reduces the risk of cell damage, efficient gas exchange due to the large contact surface of the liquid with the gas, and the ability to operate in continuous mode.
[0008] The disadvantages of such reactors include the complexity of design and maintenance compared to classic stirred tank fermenters, problems with temperature uniformity throughout the volume with a long loop, uneven distribution of the gas phase throughout the reactor volume, and low efficiency at low gas feed rates.
[0009] Bioreactors in the form of cultivation tanks equipped with a stirrer are also widely used. An example of such a bioreactor is the bioreactor according to the patent for utility RU 153682 U1 "Bioreactor" (priority date 11 / 26 / 2014). Bioreactors in the form of cultivation tanks in which a gas lift is used for mixing are also known from the prior art. They also have partitions for separating flows. An example of such a bioreactor is the bioreactor according to the patent RU 122088 U1 "Anaerobic bioreactor" (priority date 05 / 14 / 2012).
[0010] The disadvantages of reactors of this design are the uneven distribution of nutrients, oxygen and temperature, which can negatively affect cell growth, the use of stirrers can also lead to cell damage.
[0011] The most versatile design for ensuring high mass transfer rates, uniform distribution of the gas phase and controlled temperature conditions is the shell-and-tube gas-lift bioreactor. They are equipped with upper and lower tanks containing culture fluid, which are connected by vertical tubes that ensure the circulation of the culture fluid between the tanks. Some of the tubes are gas-lift tubes, i.e. they ensure the rise of the culture fluid from the lower tank to the upper tank by supplying gas from below. The tubes pass through an insulated tank into which the heat exchange medium is supplied.
[0012] This design ensures effective mixing of the culture liquid without the use of mechanical stirrers, high mass transfer rates, effective and uniform saturation of the liquid with gas, high energy efficiency, and effective heat exchange to maintain the required cultivation temperature.
[0013] Examples of such reactors are disclosed in patents SU 199087 A1 “Shell-and-tube gas lift apparatus” (priority date 09 / 20 / 1965), SU 1212550 A1 “Gas lift apparatus” (priority date 06 / 05 / 1984), SU 1632490 A1 “Gas lift apparatus” (priority date 03 / 30 / 1989).
[0014] The technical solution described in patent SU 1632490 A1 is the closest to the claimed technical solution.
[0015] The said patents do not disclose the specifics of the placement of bubble and circulation pipes, as well as the requirements for their sizes, to ensure the cultivation of microorganisms.
[0016] The essence of the invention.
[0017] The aim of the present invention is to efficiently cultivate microorganisms in a gas lift reactor.
[0018] The technical result to which the invention is directed is to ensure effective mass transfer in a bioreactor for cultivating microorganisms.
[0019] The technical result to which the invention is directed is the efficient distribution of the gas phase in the bioreactor for cultivating microorganisms.
[0020] The technical result to which the invention is directed is the effective thermostatting of the culture liquid in the process of cultivating microorganisms.
[0021] The technical result is achieved in that the bioreactor for cultivating microorganisms includes an upper chamber for cultivating, a lower chamber for cultivating, circulation pipes, bubble pipes, a thermostatic casing, a degassing channel and a gas supply device, wherein the degassing channel is located in the upper chamber, the upper and lower chambers are connected to each other through bubble pipes for lifting the culture liquid from the lower chamber to the upper chamber and through circulation pipes for flowing the culture liquid from the upper chamber to the lower chamber, the lower ends of the circulation pipes in the lower chamber are below the lower ends of the bubble pipes, at least part of the bubble or circulation pipes pass through the thermostatic casing, which provides for regulation of the temperature of the culture liquid, the gas supply device provides for the supply of gas to the area above the lower ends of the circulation pipes, but below the lower ends of the bubble pipes,the internal diameter of the bubble and circulation pipes is from 50 to 400 mm, the length of the bubble and circulation pipes is from 30 to 100 of their internal diameters, the lower ends of the circulation pipes in the lower chamber are below the lower ends of the bubble pipes at a distance of 1 to 10 internal diameters of the bubble pipes, while the lower part of the bubble pipes may have an extension.
[0022] The technical result is achieved by cultivating microorganisms using the above-described bioreactor for cultivating microorganisms, wherein at least one gas selected from methane, oxygen, nitrogen, synthesis gas, hydrogen, carbon monoxide, carbon dioxide, or a mixture thereof is used as the gas for supply through the gas supply device.
[0023] The technical result is achieved in that the bioreactor for cultivating microorganisms includes an upper chamber for cultivating, a lower chamber for cultivating, circulation pipes, bubble pipes and a gas supply device, wherein the upper and lower chambers are connected to each other through bubble pipes for lifting the culture liquid from the lower chamber to the upper chamber and through circulation pipes for flowing the culture liquid from the upper chamber to the lower chamber, and the gas supply device ensures the supply of gas to the region below the lower ends of the bubble pipes, which ensures the circulation of the culture liquid in the reactor by creating ascending gas-liquid flows in the bubble pipes and descending liquid flows in the circulation pipes, wherein the ascending liquid flow is actively saturated with gas, which ensures effective mass transfer and saturation of the culture liquid with the gas phase in the reactor.
[0024] The technical result is achieved in that in the bioreactor, the gas supply device ensures the supply of gas to the area above the lower ends of the circulation pipes, while the lower ends of the circulation pipes in the lower chamber are located below the lower ends of the bubble pipes at a distance of 1 to 10 internal diameters of the bubble pipes, which allows the gas phase to enter the bubble pipes, but eliminates the leakage of the gas phase from the gas supply device into the circulation pipes, which maintains continuous and uniform circulation of the culture liquid, effective mass transfer and saturation of the culture liquid with the gas phase.
[0025] The technical result is achieved by the fact that the upper chamber of the bioreactor has a channel for degassing, which ensures the removal of excess gas, maintaining circulation and removing metabolic products.
[0026] The technical result is achieved by the fact that at least part of the bubbling or circulation pipes pass through the thermostatic casing, which ensures the regulation of the temperature of the culture liquid, which makes it possible to maintain an optimal temperature in the reactor due to heat exchange between the circulation pipes and the environment inside the cavity of the thermostatic casing.
[0027] The technical result is achieved by the fact that the internal diameter of the bubbling and circulation pipes is from 50 to 400 mm, which ensures effective mass transfer and saturation of the culture liquid with the gas phase, the use of pipes with an internal diameter of less than 50 mm leads to a slowdown in the circulation rate and a decrease in mass transfer due to hydraulic resistance, and the use of pipes with an internal diameter of more than 400 mm reduces the quality of saturation of the culture liquid with the gas phase, since the mixing of the gas-liquid flow and the distribution of gas bubbles in the ascending flow are deteriorated.
[0028] The technical result is achieved by the fact that the length of the bubbling and circulation pipes is from 30 to 100 of their internal diameters, which ensures effective mass transfer and saturation of the culture liquid with the gas phase, the use of pipes with a length of less than 30 of their internal diameters reduces the quality of saturation of the culture liquid with the gas phase due to a relative increase in the mixing zone of the gas and liquid phases and a decrease in the contact time of gas bubbles with the culture liquid in the ascending flow, the use of pipes with a length of more than 100 of their internal diameters leads to a slowdown in the circulation rate and a decrease in mass transfer due to hydraulic resistance.
[0029] The technical result can be additionally ensured by the fact that the lower part of the bubble tubes can have an expansion, which simplifies the entry of the gas phase into the circulation tubes, which has a positive effect on the mass transfer and saturation of the culture liquid with the gas phase.
[0030] The technical result is achieved by the fact that the use of the above-described bioreactor for cultivating microorganisms ensures effective mass transfer and saturation of the culture liquid in a wide range of gas flow rates.
[0031] The technical result is achieved by using at least one gas selected from methane, oxygen, nitrogen, synthesis gas, hydrogen, carbon monoxide, carbon dioxide, or a mixture thereof, supplied through the gas supply device, which enables the cultivation of various microbial strains. The gas mixture may be atmospheric air.
[0032] Brief description of drawings.
[0033] Fig. 1 - General view of the reactor.
[0034] In its most general form, a bioreactor for cultivating microorganisms is shown in Fig. 1, it includes an upper chamber (1) for culturing, a lower chamber (2) for culturing, circulation pipes (3), bubble pipes (4), a thermostatic casing (5), a degassing channel (6) and a gas supply device (7), wherein the degassing channel (6) is located in the upper chamber (1), the upper chamber (1) and the lower chamber (2) are connected to each other through bubble pipes (4) for lifting the culture liquid from the lower chamber to the upper chamber and through circulation pipes (3) for flowing the culture liquid from the upper chamber (1) to the lower chamber (2), the lower ends of the circulation pipes (3) in the lower chamber (1) are below the lower ends of the bubble pipes (4), the bubble pipes (4) and circulation pipes (3) pass through the thermostatic casing (5), which provides regulation of the temperature of the culture liquid,the gas supply device (7) ensures the supply of gas to the area above the lower ends of the circulation pipes (3), but below the lower ends of the bubble pipes (4), the internal diameter of the bubble pipes (4) and circulation pipes (3) is from 50 to 400 mm, the length of the bubble pipes (4) and circulation pipes (3) is from 30 to 100 of their internal diameters, the lower ends of the circulation pipes (3) in the lower chamber (2) are located below the lower ends of the bubble pipes (4) at a distance of from 1 to 10 internal diameters of the bubble pipes (4).,
[0035] In particular embodiments of the invention, the lower part of the bubble tubes (4) may have an extension to simplify the entry of the gas phase into the circulation tubes.
[0036] To implement the invention, a different number of circulation and bubble pipes can be selected, the internal diameters of the bubble and circulation pipes can also differ.
[0037] It is preferable to use pipes of the same diameter to ensure the manufacturability of the design.
[0038] The upper ends of the bubble and circulation pipes can be located at different or the same level relative to each other.
[0039] The lower ends of the bubble tubes can be located inside the lower chamber or attached to its body.
[0040] The thermostatic housing is generally a container through which bubble or circulation pipes pass, and a heat exchange medium is placed in the internal volume of the container, which ensures heat exchange between the heat exchange medium and the culture liquid through the walls of the pipes.
[0041] The preferred option is for all the bubbling and circulation pipes of the reactor to pass through the casing, but if necessary, heat exchange can also be achieved using a limited number of pipes.
[0042] The thermostatic housing may occupy all of the free space between the upper and lower cultivation chamber, or only part of this space, as shown in Fig. 1.
[0043] The gas supply device may be designed as a single channel or a set of channels for supplying gas, it may include devices for uniformly distributing gas in the volume of the lower chamber, for example, guide ribs, directional nozzles or injectors.
[0044] The bioreactor can be additionally equipped with channels for supplying and unloading culture liquid, loading minerals and microorganisms.
[0045] In its most general form, the cultivation of microorganisms in a bioreactor is carried out by placing microorganisms with a nutrient medium corresponding to their type in the volume of the reactor described above, after which feed gas is supplied to the gas supply device (7), also corresponding to the type of microorganisms, which ensures saturation of the medium with gas and circulation between the upper (1) and lower chambers (2), excess gas is removed from the upper chamber (1) through the degassing channel (6).
[0046] During the operation of the bioreactor, the temperature is monitored; for thermostatting, a medium with a set temperature is supplied to the thermostatting casing (5).
[0047] Increasing the distance from the lower ends of the circulation pipes to the lower ends of the bubble pipes by more than 10 internal diameters of the bubble pipes is not advisable, since it leads to an increase in the dimensions of the pipes and the reactor, while the risk of gas leakage from the gas supply device into the circulation pipes is practically eliminated.
[0048] Microorganisms consume nutrients and gas to form target products.
[0049] The feed gas can be methane, oxygen, nitrogen, synthesis gas, hydrogen, carbon monoxide, carbon dioxide, or a mixture of them.
[0050] Methanotrophs, methylotrophs, acetogens, heterotrophs, chemoorganotrophs, chemolithotrophs and others can be used as microorganisms.
[0051] The implementation of the invention is confirmed by the examples given below, but is not limited to them.
[0052] Example #1
[0053] For cultivating microorganisms, a bioreactor was used, assembled similarly to the diagram shown in Fig. 1, but having 6 circulation pipes and 7 bubble pipes.
[0054] Methylococcus capsulatus Bath was used as the microorganism for cultivation, and a mixture of methane and air was used as the feed gas.
[0055] Feed gas was supplied to the gas supply device (7), due to the movement of the medium under the action of gas bubbles, circulation was carried out between the upper (1) and lower chambers (2) with saturation of the medium with the gas phase, excess gas was removed from the upper chamber (1) through the degassing channel (6), while microorganisms were cultivated in the bioreactor.
[0056] The bubbler and circulation pipes had an internal diameter of 50 mm.
[0057] Microorganism cultivation was carried out in several reactor configurations, with tubes of different lengths used for each configuration.
[0058] During the operation of the bioreactor, the average temperature in the reactor was maintained at 42-43°C; water was supplied to the thermostatic jacket for thermostatting.
[0059] The gas consumption per bubbler tube ranged from 1.5 to 8 Nm 3 / h.
[0060] Table 1 shows the characteristics of the pipes and the indicators established during the operation of the reactor, where L is the length of the pipe, d is the inner diameter of the pipe, “Offset” is the distance from the lower ends of the circulation pipes to the lower ends of the bubble pipes, “Root mean square deviation from the average volumetric gas content” is a characteristic of the uniformity of saturation of the liquid with the gas phase in the reactor, “Average mass transfer coefficient” is a characteristic of mass transfer in the reactor.
[0061] No gas leakage from the gas supply device into the circulation pipes was observed during operation of all reactor configurations.
[0062] As can be seen from the indicators in the table, effective distribution of the gas phase in the bioreactor for cultivating microorganisms and effective mass transfer were ensured.
[0063] Table 1
[0064]
[0065] Example #2
[0066] Microorganisms were cultivated in a bioreactor similar to Example 1, with the difference that the reactor design used pipes with an internal diameter of 150 mm, and reactor configurations with different pipe lengths were used.
[0067] Table 2 shows the characteristics of the pipes and the indicators established during the operation of the reactor configurations.
[0068] The gas flow rate per bubbler tube ranged from 12 to 65 Nm 3 / h.
[0069] No gas leakage from the gas supply device into the circulation pipes was observed during operation of all reactor configurations.
[0070] Table 2
[0071]
[0072] Example #3
[0073] Microorganisms were cultivated in a bioreactor similar to Example 1, with the difference that the reactor design used pipes with an internal diameter of 250 mm, and reactor configurations with different pipe lengths were used.
[0074] Table 3 shows the characteristics of the pipes and the indicators established during the operation of the reactor configurations.
[0075] The gas flow rate per bubbler tube ranged from 35 to 130 Nm 3 / h.
[0076] No gas leakage from the gas supply device into the circulation pipes was observed during operation of all reactor configurations.
[0077] Table 3
[0078]
[0079] Example #4
[0080] Microorganisms were cultivated in a bioreactor similar to Example 1, with the difference that the reactor design used pipes with an internal diameter of 400 mm, and reactor configurations with different pipe lengths were used.
[0081] Table 4 shows the characteristics of the pipes and the indicators established during the operation of the reactor configurations.
[0082] The gas flow rate per bubbler tube ranged from 85 to 210 Nm 3 / h.
[0083] No gas leakage from the gas supply device into the circulation pipes was observed during operation of all reactor configurations.
[0084] Table 4
[0085]
[0086] Example #5
[0087] Microorganisms were cultivated in a bioreactor similar to Example 1, with the difference that the lower ends of the bubble tubes had an extension made in the form of a cone.
[0088] No gas leakage from the gas supply device into the circulation pipes was observed during operation of all reactor configurations.
[0089] Example #6
[0090] Microorganisms were cultivated in a bioreactor similar to Example 1, with the difference that Candida tropical was used as the microorganism and synthesis gas was used as the feed gas.
[0091] Efficient distribution in the gas phase reactor and effective mass transfer were also ensured.
[0092] Example #7
[0093] Microorganisms were cultivated in a bioreactor similar to Example 1, with the difference that Methylophilus methylotrophus was used as the microorganism and air was used as the feed gas.
[0094] Efficient distribution in the gas phase reactor and effective mass transfer were also ensured.
Claims
1. A bioreactor for cultivating microorganisms, comprising an upper cultivation chamber, a lower cultivation chamber, circulation pipes, bubble pipes, a thermostatic housing, a degassing channel and a gas supply device, wherein the degassing channel is located in the upper chamber, the upper and lower chambers are connected to each other through bubble pipes for lifting the culture liquid from the lower chamber to the upper chamber and through circulation pipes for flowing the culture liquid from the upper chamber to the lower chamber, the lower ends of the circulation pipes in the lower chamber are below the lower ends of the bubble pipes, at least part of the bubble or circulation pipes pass through the thermostatic housing, which provides for regulation of the temperature of the culture liquid, the gas supply device provides for the supply of gas to the area above the lower ends of the circulation pipes, but below the lower ends of the bubble pipes,the internal diameter of the bubble and circulation pipes is from 50 to 400 mm, the length of the bubble and circulation pipes is from 30 to 100 of their internal diameters, the lower ends of the circulation pipes in the lower chamber are below the lower ends of the bubble pipes at a distance of 1 to 10 internal diameters of the bubble pipes.
2. A bioreactor for cultivating microorganisms according to paragraph 1, characterized in that the lower part of the bubble tubes has an expansion.
3. A method for cultivating microorganisms, which includes placing microorganisms in the volume of the bioreactor according to paragraph 1 with a nutrient medium corresponding to their type, feeding a feed gas corresponding to the type of microorganisms into the gas supply device of the reactor, saturating the nutrient medium with the feed gas with its circulation between the upper and lower chambers of the reactor, removing excess gas from the upper chamber of the reactor through a degassing channel, thermostatting the nutrient medium by placing a medium with a given temperature in a thermostatting casing, and consuming nutrients and feed gas by the microorganisms with the formation of target products.
4. A method for cultivating microorganisms according to claim 3, characterized in that at least one gas selected from methane, oxygen, nitrogen, synthesis gas, hydrogen, carbon monoxide, carbon dioxide, or a mixture thereof is used as the feed gas.