JP2615393B2 - Closed algae culture system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for continuously culturing algae in a closed system.

[Prior Art] Space development using a space shuttle or the like is performed, but in this case, securing food and oxygen for occupants becomes a problem. If edible algae such as spirulina can be cultured in a space shuttle or space station, it would be very convenient to obtain food and oxygen simultaneously.

When cultivating algae in space, the cultivation is performed under zero gravity, so it is necessary to culture in a closed system. Further, those capable of continuously culturing for a long period of time are preferable. When algae are continuously cultured in a closed system for a long period of time, the concentration of alga bodies is adjusted, the alga bodies are collected and a medium is added, the pH of the culture medium is adjusted and carbon dioxide is added to the culture medium, and the oxygen generated There are various problems, such as recovery and pressure control, which are not problems in an open batch type apparatus.

2. Description of the Related Art Conventionally, there are many batch-type microalgae culturing apparatuses such as chlorella, and among them, there are apparatuses having characteristics in a light supply method and a carbon dioxide supply method. Computers that control them by computer have also been devised. However, for the purpose of long-term continuous cultivation, there is no closed-system cultivation apparatus that has an alga recovery and medium addition device and can separate oxygen.

[Problems to be Solved by the Invention] Accordingly, an object of the present invention is to provide a closed algae culture apparatus capable of continuously culturing algae in a closed system for a long period of time and continuously collecting algal cells and oxygen. To provide.

[Means for Solving the Problems] The present invention provides a closed culture system comprising a culture tank and a pipe line closed through the culture tank, means for circulating the culture in the closed culture system, Means for measuring the pressure in the closed culture system, means for measuring the amount of carbon dioxide in the closed culture system, means for measuring the density of algal cells cultured in the closed culture system, and the closed culture Means for recovering algae from the system;
Provided is a closed algal culture apparatus comprising: means for supplying a medium to the closed culture system; means for supplying carbon dioxide to the closed culture system; and means for recovering oxygen from the closed culture system.

[Effects of the Invention] According to the present invention, there is provided a closed algae culture apparatus capable of continuously culturing algae in a closed system for a long period of time and continuously collecting algal bodies and oxygen. By using the device of the present invention, algal cells and oxygen can be simultaneously and continuously obtained under any external environment. Therefore, when cultivating edible algae in a space shuttle, a space station, or the like using the device of the present invention, algal bodies and oxygen serving as food for the occupant can be simultaneously and continuously obtained, which is extremely advantageous. is there.

[Specific description of the invention] The culture apparatus of the present invention includes a closed culture system including a culture tank and a pipeline closed through the culture tank. The size, shape, structure, and the like of the culture tank are not limited at all, and can be appropriately selected depending on the culture scale, external environment, and other conditions. The culture tank is made of a transparent material, and the algae can be cultured using sunlight.However, in order to ensure that the culture can be performed under any conditions, the culture tank should be provided with a light source. Is preferred. The light source may be of any type, but the one that inserts a bundle of optical fibers into the culture tank and guides light from the light source outside the culture tank to the optical fiber to give light to algae is a culture tank. This is preferable because unnecessary heat is not applied to the filter and ultraviolet rays can be easily cut off using a filter. The culture tank preferably has a means for stirring the culture in the tank.
The stirring means may be a stirring plate, but it is preferable that there is nothing in the culture layer from the viewpoint of light supply. It is preferable that the culture in the culture tank is stirred by the flow of the culture itself flowing into the inside.

The closed culture system including the culture tank and the pipe is provided with a means for circulating the culture in the closed culture system.
The means for circulating the culture may be, for example, a pump inserted in series in the pipeline.

The closed culture system is provided with a means for measuring the pressure in the system. As an example of such means, for example, a pressure gauge installed in a culture layer can be mentioned.

The closed culture system is further provided with a means for measuring the density of algal cells cultured in the closed culture system. As a means for measuring the algal density, for example, a turbidity meter inserted in series in a pipe can be mentioned.

The closed culture system is also provided with a means for collecting algal cells from the culture system. As means for collecting algal bodies,
A branch pipe branched from the above-mentioned conduit is provided, and for example, a pipe provided with a filter and a pump on a cylinder in series is provided in this branch pipe.

The closed culture system is further provided with a means for supplying a medium to the culture system. As a means for supplying the culture medium, there may be mentioned a means in which a branch pipe branched from the above-mentioned conduit is provided, and a medium tank and a pump are provided in series in the branch pipe.

Further, the closed culture system is provided with a means for supplying carbon dioxide to the closed culture system. As a means for giving carbon dioxide, for example, a bundle of fibers having a large number of holes that allow gas to pass but not liquid (hereinafter, referred to as a fiber bundle)
Hollow fiber) is inserted in series in a pipe, and a carbon dioxide cylinder is connected to the hollow fiber via a valve and a flow meter in order to supply carbon dioxide to the hollow fiber. The hollow fiber used here can be a commercially available one.

Further, the closed culture system is provided with means for recovering oxygen from the culture system. As a means for recovering oxygen, a hollow fiber may be inserted in series in the above-mentioned conduit, and a gas pump and an oxygen storage cylinder may be connected in series to the hollow fiber. In this case, it is preferable to insert an oxygen flow meter, a carbon dioxide flow meter, and a gas flow in series, since the amount of recovered oxygen and its carbon dioxide content can be known.

Further, the closed culture system is preferably provided with a temperature controller for controlling the temperature.

Next, a method of operating the above-described device will be described. During normal culture, a means for circulating the culture in the closed culture system, for example, operating a pump, circulates the culture containing the medium and algal cells in the closed culture system while irradiating the culture tank with light. At this time, the density, pressure and carbon dioxide amount of the algal cells in the closed culture system are constantly monitored. Further, the oxygen recovery means is constantly operated to constantly recover oxygen generated in the culture system. That is,
When the oxygen recovery means is a hollow fiber inserted in series in the above-mentioned conduit, and a gas pump and an oxygen storage cylinder are connected in series to the hollow fiber, the gas pump is constantly pulled to separate the gas and liquid by the hollow fiber. Perform
Algae undergo photosynthesis in the culture tank and proliferate.

As a result of the algal body multiplying, if the algal body density measurement means such as a turbidity meter indicates that the algal body density has increased by a certain value or more, for example, 30% in the initial stage of the culture, the algal body is collected. And add medium. That is, the algal body collecting means is provided with a branch pipe branched from the pipe, and the branch pipe is provided with, for example, a filter and a pump on a cylinder in series, and the medium supply means is branched from the pipe. In the case where a pipe is provided, and a medium tank and a pump are provided in series in this branch pipe, the pump of the alga body recovery means is operated to filter the culture with the filter, and at the same time, the medium supply means is provided. The pump is operated to supply the medium from the medium tank to the closed culture system. The used medium separated from the algal cells by the filter can be stored in a tank and discarded, or can be recirculated into a closed culture system if desired.

When the means for measuring the pressure in the closed culture system indicates that the pressure in the culture system has exceeded a certain value,
The algal body collecting means is operated to collect only the algal bodies. Further, when it is indicated that the pressure in the culture system has become equal to or less than a certain value, the medium supply means is operated to supply only the medium to the culture system.

When the carbon dioxide measuring means, for example, a pH meter indicates that the concentration of carbon dioxide in the culture system is insufficient (the pH has become higher than a certain value), carbon dioxide is supplied from the carbon dioxide supplying means. Is done.

In this way, oxygen is recovered from the culture system, and when the density of the algal body is higher than a certain value, the algal body is recovered and the medium is supplied, and when the pressure is higher than a certain pressure, only the alga body is recovered, When the pressure falls below a certain pressure, only the medium is supplied, the inside of the closed culture system is always kept under a certain range of conditions, and the cultivation of algal cells and the recovery of oxygen and algal cells are performed continuously.

The above operation can be performed manually, but is preferably performed by automatic control using a computer in order to reduce labor. That is, each measuring means (pressure,
All measured values from algal density and carbon dioxide concentration and, if desired, oxygen concentration, oxygen flow rate, carbon dioxide flow rate and concentration) are input to the computer online, and the current run status is displayed on the CRT screen, The change is represented by a line graph, and further, the carbon dioxide measuring means and the carbon dioxide supplying means, the algal body density measuring means and the algal body collecting means and the medium supplying means, the pressure measuring means and the algal body collecting means and the medium supplying means are linked to each other. It is preferable to perform automatic control by a computer. In this manner, the cultivation of the algal cells, the recovery of the algal cells and the recovery of oxygen, the supply of the culture medium, and the supply of carbon dioxide can be continuously performed automatically.

The algae cultured by the apparatus of the present invention are not particularly limited, and any algae can be cultured. Further, the composition of the medium and the culture temperature are appropriately determined according to the algae to be cultured.

EXAMPLES Hereinafter, the present invention will be described more specifically based on examples. It is clear that the device of the present invention can be variously modified in addition to the embodiments described below, and is not limited to the following embodiments.

The accompanying drawings show a preferred embodiment of the device of the present invention. The illustrated apparatus includes a closed culture consisting of a culture vessel 10 and a conduit 12 closed through the culture vessel 10. A pump 14 is inserted into the pipe 12, and the culture in the culture tank 10 and the pipe 12 circulates in the direction of arrow a. A pressure gauge 16 is provided in the culture tank.
The portion of the conduit 12 entering the culture tank is branched into three, and the culture in the culture tank is agitated by the flow of the inflow culture itself. The culture tank 10 has a bundle of optical fibers extending from a light source 18.
20 is inserted, and light from the light source 18 is supplied into the culture tank 10 through a bundle 20 of optical fibers.

A pH meter 22, an oxygen separator 24 composed of hollow fibers, a carbon dioxide feeder 26 composed of hollow fibers, a turbidity meter 28, and a temperature controller 30 are inserted in series in the pipe 12, respectively. In the oxygen separator 24, a gas pump 32, an oxygen flow meter 34, a carbon dioxide flow meter 36, a gas flow meter 38, and an oxygen storage cylinder 40 are arranged in series. The carbon dioxide supply device 26 includes a carbon dioxide cylinder 42, a valve 44, and a gas flow meter 46.
Are connected in series.

A first branch pipe 48 branches from the pipe 12, and this branch pipe 48
, A pump 52 and an algal body collector 54 are arranged in series via an electromagnetic valve 50. Solenoid valve 50 is A → C or B → C shown
A passage is opened in either one. An air reservoir 51 is connected to B of the solenoid valve 50. Algae collector 54 includes a filter 56 on a cylinder. The algal bodies collected by the algal body collecting device 54 are stored in the algal body storage container 58. A pump 60 and a waste tank 62 are connected in series on the outlet side of the algal body recovering unit 54, and a water tank 64, a pump 66 and a valve 68 are connected in series on the inlet side of the algal body collecting unit 54. .

Also, a second branch pipe 70 branches from the pipe 12 and
An electromagnetic valve 72 is connected to 70. The solenoid valve 72 opens a passage in either A → B or A → C. solenoid valve
A pipe 70a is connected to A of 72, and the pipe 70a is connected to the pump 52.
And the medium valve 74 is connected to B of the solenoid valve 72.

Pressure gauge 16, pH meter 22, turbidity meter 28, oxygen flow meter 34,
All the measured values from the carbon dioxide flow meter 36 and the gas flow meter 38 are input online to the computer and displayed on the CRT screen. Also, the change of each measurement value is displayed on the CRT screen as a line graph.

Further, the turbidity meter 28, the pumps 52 and 60 and the solenoid valves 50 and 7
2; the pH meter 22 and the valve 44; the pressure gauge 16, the pumps 52 and 60, and the solenoid valves 50 and 72 are electrically maintained via a computer, respectively.

Next, a method of operating the above-described device will be described. During normal culture, the pump 14 is operated while supplying light from the light source 18 to the culture tank 10 through the bundle of optical fibers 20, and the culture containing the alga bodies and the medium in the culture tank 10 and the conduit 12 is indicated by an arrow a. Circulate in the direction of. At this time, the solenoid valve 50 is B → C, the solenoid valve 72 is A →
Since the pump is open to B and the pumps 52 and 60 are stopped, the culture does not flow through the branch pipes 48 and 70. During the culture, the pressure gauge 16, the pH meter 22, and the turbidity meter 28 are constantly operating, and the measured values are input to the computer online as described above. The temperature of the culture system is maintained at a desired temperature by the temperature controller 30. Further, the gas pump 32 is operating, and oxygen is separated by the oxygen separator 24 and stored in the oxygen storage cylinder 40.

As a result of the culture, when the turbidimeter 28 indicates that the alga bodies multiplied and the density of the alga bodies increased to a certain value, for example, 30% of the initial density, the turbidity meter electrically connected to the computer. The connected solenoid valves 50 and 72 are A → C and A → C respectively.
Automatically open and the pumps 52 and 60 operate automatically. As a result, the culture is drawn by the pumps 52 and 60, flows through the branch pipe 48 in the direction of arrow b, reaches the alga body collector 54 via the solenoid valve 50 and the pump 52, and is filtered by the cylindrical filter 56. Is collected in the algal cell storage container 58, and the used medium separated from the algal cells by the cylindrical filter 56 is discarded into the waste tank 62 via the pump 60. If the cylindrical filter 56 is clogged, open the valve 68 and operate the pump 66 to draw water from the water tank 64 and drain it in the opposite direction to filter the culture to remove the filter clogging . On the other hand, by the function of the pump 52, the medium is drawn from the medium tank 74, flows through the branch pipe 70a in the direction of arrow c, flows through the solenoid valve 72 from A to C, and flows into the pipe 12 through the branch pipe 70. Inflow. In this way, the recovery of the algal cells and the supply of the culture medium to the culture system are performed simultaneously.

If the pressure gauge 16 indicates that the value of the pressure gauge 16 has reached a certain value or more, for example, 0.06 kg / cm ² or more, a solenoid valve electrically connected to the pressure gauge 16 via a computer 50 and 72 open automatically from A to C and A to B, respectively, and pumps 52 and 60 operate automatically. As a result, the culture flows in the branch pipe 48 in the direction of the arrow b in the same manner as described above, and the algal cells are collected by the algal cell collecting device 54. On the other hand, the culture medium from the culture tank 74 flows in the direction of arrow c in the branch pipe 70a by the function of the pump 52, but the culture medium does not flow into the pipeline 12 because the solenoid valve 7 is opened from A to B. . In this way, when the pressure of the culture system becomes higher than a certain value, only the algal cells are collected without supplying the medium, and the pressure in the culture system is reduced.

Conversely, the pressure in the system is kept constant by the pressure gauge 16, for example,
When it is shown that the pressure becomes 0.01 kg / cm ² or less, the solenoid valves 50 and 72 are automatically opened from B → C and A → C, respectively,
Pumps 52 and 60 operate automatically. Solenoid valve 50 is B → C
Therefore, only the air from the air reservoir 51 flows into the algal cell recovery device 54, and the culture does not flow into the alga body recovery device 54. On the other hand, by the action of the pump 52, the culture medium from the culture tank 74 flows through the branch pipe 70a in the same manner as described above, flows through the electromagnetic valve 72 from A to C, and flows into the pipe 12 via the branch pipe 70. . Thus, only the medium is supplied without collecting the algal cells, and the pressure in the culture system increases.

On the other hand, the pH in the culture system is kept constant by the pH meter 22,
For example, if it is indicated that the value has reached 10 or more, a valve electrically connected to the pH meter 22 via a computer
44 is automatically opened, and carbon dioxide is supplied from the carbon dioxide cylinder 42 to the culture in the conduit 12 via the carbon dioxide supply device 26. In this way, when the pH rises due to a shortage of carbon dioxide in the culture system, carbon dioxide is supplied, resulting in a lower pH.

According to the apparatus of the above-described embodiment, algae can be continuously cultured for a long period of time under a certain range of conditions without requiring manual operation, and alga bodies and oxygen can be continuously collected. .

The device shown in the figure was prototyped. The diameter of the culture tank was 17 cm, the height of the cylindrical portion was 25 cm, and the content was 6. Also,
The conduit 12 was made of silicone rubber having an inner diameter of 1 cm, and its total length was 2 m.

Spirulina maxima was continuously cultured for 20 days using this apparatus. The culture was circulated at 2 / min by pump 14. As a result, alga bodies of 1 g or more in dry weight are collected,
A gas having an oxygen concentration of 40% or more was obtained at a rate of 50 to 150 ml per minute.

[Brief description of the drawings]

The drawing is a view schematically showing one embodiment of the closed algae culture apparatus of the present invention. 10: Culture tank, 12: Pipe line, 14: Pump, 16: Pressure gauge, 18: Light source, 20: Optical fiber bundle, 22: pH meter, 24: Oxygen separator, 26 ... Carbon dioxide supply, 28
… Turbidity meter, 30… temperature controller, 32… gas pump, 40
…… Oxygen storage cylinder, 42 …… Carbon dioxide cylinder, 48, 70
… Branch pipe, 50, 72… Solenoid valve, 54… Algae recovery device, 5
2, 60 pump, 74 medium tank

Continuation of the front page (72) Inventor Koharu Otsubo 5-7-1, Toyooka, Tama-shi, Tokyo No. 201 201 (72) Inventor Keiji Nitta 2-4-2, Omon-cho, Higashi-Kurume-shi, Tokyo Higashi-Kurume Second Housing 5 Building No.502

Claims (10)

(57) [Claims] 1. A closed culture system comprising a culture tank and a pipe line closed through the culture tank, means for circulating the culture in the closed culture system, and measuring the pressure in the closed culture system. Means,
Means for measuring the amount of carbon dioxide in the closed culture system,
Means for measuring the density of algal cells cultured in the closed culture system, means for collecting algal cells from the closed culture system, means for supplying a medium to the closed culture system, A closed algal culture apparatus comprising: means for supplying carbon; and means for recovering oxygen from the closed culture system. 2. The apparatus according to claim 1, wherein the means for measuring the amount of carbon dioxide is a pH measuring device, and the means for measuring the density of the algal cells is a turbidimeter. 3. The means for supplying carbon dioxide and the means for recovering oxygen each include a hollow fiber having a hole sized to be permeable to gas but impermeable to liquid, inserted into the conduit. 1 is the device according to 2. 4. The means for measuring the pressure, the means for recovering the algal cells, and the means for supplying the medium are connected to each other, so that the pressure in the closed culture system is equal to or higher than a predetermined value. The means for recovering the alga bodies automatically recovers the alga bodies when the condition has been reached, and the means for supplying the medium automatically when the pressure in the closed culture system becomes a certain value or less. The device according to any one of claims 1 to 3, which supplies a medium. 5. The means for measuring the amount of carbon dioxide and the means for supplying carbon dioxide are connected, and supply the carbon dioxide when the concentration of carbon dioxide in the closed culture system falls below a certain value. Apparatus according to any of the preceding claims, wherein the means automatically supplies carbon dioxide. 6. The means for measuring the density of the algal bodies, the means for collecting the algal bodies, and the means for supplying the medium, wherein the algal body density in the closed culture system is equal to or higher than a certain value. 7. The method according to claim 1, wherein the means for automatically collecting the algal cells automatically collects the algal cells, and the means for supplying the medium automatically supplies the medium into the closed culture system. An apparatus according to claim 1. 7. The apparatus according to claim 1, further comprising means for irradiating the culture tank with light. 8. The apparatus according to claim 4, wherein said automatic operation is automatically controlled by a computer. 9. A means for measuring a pressure in the closed culture system,
Measured values from the means for measuring the amount of carbon dioxide in the closed culture system and the means for measuring the density of the algal cells cultured in the closed culture system are input to a computer online, and the pressure is measured. Means for recovering the algal bodies and means for supplying the medium, means for measuring the amount of carbon dioxide and means for supplying the carbon dioxide, and measuring the density of the algal bodies 9. The apparatus according to claim 8, wherein the means for performing the operation, the means for collecting the algal cells, and the means for supplying the medium are connected via the computer. 10. A means for measuring the pressure in the closed culture system, a means for measuring the amount of carbon dioxide in the closed culture system, and a means for measuring the density of algal cells cultured in the closed culture system. 10. The apparatus according to claim 9, wherein the measured values are input online to a computer and displayed on a CRT screen of the computer.