JP5661028B2 - Stirrer for photosynthesis, photobioreactor using the same, and underwater biological culture method - Google Patents

Description

  The present invention relates to a photosynthesis stirrer for efficiently producing useful substances by utilizing the photosynthetic ability of aquatic organisms such as algae, a photobioreactor using the agitator, and a method for culturing aquatic organisms.

  Utilizing the photosynthetic ability of aquatic organisms such as algae, a method of mass-producing chlorella and spirulina in a shallow pond about 30 cm deep under sunlight is performed. When no sunlight is supplied at night, the photosynthetic products accumulated in the algae during the day are consumed, so the efficiency of growth is low, and the dry matter production efficiency of the algae is unavoidable.

  In order to improve the disadvantages of such a method, a photobioreactor that does not depend on sunlight has been developed, and so far, a rotatable stirring member is provided in the culture tank, and a light emitting part is attached to the stirring member. A stirrer type culture apparatus (see Patent Document 1) in which a light source for supplying light to the light emitting part is disposed outside the culture tank, and a device for supplying light and carbon dioxide into a culture tank containing a living organism having a photosynthetic ability and a culture solution. , A photosynthetic organism culture device (see Patent Document 2) that supplies light with a movable light emitter composed of a flat transparent material provided in the center of the culture tank, for receiving light from an external light source From a photosynthetic culture apparatus (see Patent Document 3) having an irradiation apparatus made of a plurality of independent plate-like light emitters connected to an optical transmission path in a culture tank (see Patent Document 3), a culture vessel, a carbon dioxide supply means, and a light irradiation means Composed The culture vessel has a first zone that generates an upward flow of the culture solution as the bubbles rise due to the supply of carbon dioxide, and a second zone that generates a downward flow of the culture solution. An apparatus for cultivating photosynthetic organisms to be irradiated (see Patent Document 4), a liquid film forming plate that causes a culture solution containing photosynthetic organisms to flow down in a liquid film along the surface, and a culture that supplies a culture solution containing photosynthetic organisms to the upper end thereof A liquid supply means and a light source for irradiating the liquid film on the liquid film forming plate with light; a light reflecting surface around the liquid film forming plate; and an optical fiber between the liquid film forming plate and the light reflecting surface. A culture device for photosynthetic organisms (see Patent Document 5) provided with a light emitting end, and a stirring blade disposed in the center of the culture vessel containing the photosynthetic organisms and the culture solution. The rotation range of the stirring blade and the inner wall of the culture vessel Photosynthetic culture apparatus with a plurality of plate-shaped illuminants placed between them (Patent Literature) Reference), a culture tank equipped with a rotating shaft inside and a field emission lamp fixed to the rotating shaft. The rotating shaft is controlled to rotate and the lamp is rotated around the rotating shaft to stir the culture solution. Light that controls the light intensity and lighting of the lamp while acting as a stirrer to irradiate the culture solution with the required intensity of light, and controls the timing of the blinking of the lamp to control the two light-dark reactions of the photosynthetic organism A bioreactor (see Patent Document 7) has been proposed.

In addition, a light emitting diode is also used as a light source, for example, a water tank having light reflectivity toward the inner surface, and a number of light emitting diodes arranged so that one end thereof is positioned above the culture liquid surface. An apparatus for culturing microalgae equipped with stirring means is known (see Patent Document 8).

JP-A-3-58780 (Claims and others) JP-A-4-84883 (Claims and others) JP-A-7-163331 (Claims and others) JP-A-7-184630 (Claims and others) JP-A-7-227269 (Claims and others) JP-A-7-289236 (Claims and others) JP 2008-283937 A (Claims and others) JP-A-10-98964 (Claims and others)

  The present invention is capable of uniformly dispersing and irradiating light necessary for a photosynthetic reaction in a culture solution without depending on sunlight, and without damaging aquatic organisms in culture by agitation. An agitator for photosynthesis that can cultivate aquatic organisms efficiently while preventing the attachment of aquatic organisms to the wall, and that can extend the life of the light source, and photobio using the agitator The object of the present invention is to provide a reactor and a method for culturing aquatic organisms.

  As a result of extensive research to develop an efficient photosynthesis stirrer suitable for industrial implementation, the present inventors have developed a light emitting diode that generates light having wavelengths of 430 nm, 680 nm, and 700 nm as a light source. A light source, a cathode, a carbon dioxide supply pipe, and a feed pipe for nutrient solution, etc. are arranged at the lower part of the shaft part. Thus, it was found that the object can be achieved, and the present invention has been made based on this finding.

  That is, the present invention also serves as a carbon dioxide gas supply pipe, and a plurality of cylindrical or conical transparent stirring blades are attached to the hollow shaft constituting the rotating shaft in a radial manner and at different intervals, and the attachment portion In the vicinity, one or more light emitting diodes having three different light qualities of blue of wavelength 430 nm, red of wavelength 680 nm and far red of wavelength 700 nm are attached, and nutrient solution or nutrient solution is provided below the hollow shaft. And a supply pipe for supplying a supply liquid containing both an alkali solution for neutralizing carbon dioxide and an upward thrust force generated by the supply of carbon dioxide gas and the supply liquid on the upper outer surface of the hollow shaft A stirrer for photosynthesis of aquatic organisms, characterized in that a buffer mechanism is fixed and a power supply mechanism to a light emitting diode is slidably mounted on a hollow shaft It is.

  The stirring blade is attached to the hollow shaft by changing the direction at the same angle in the range of 10 ° to 180 °, preferably 15 ° to 120 °. However, if the angle is reduced, it is advantageous that many stirring blades are attached.

  As the light source, one blue, one red and one far red light emitting diode must be used. For example, one blue and one far red light emitting diode can be used, and two red light emitting diodes can be used. Good. The range of the preferred red / blue light source intensity ratio (R / B ratio) is 4 to 15, and the range of the red / far red light source intensity ratio (R / FR ratio) is 1.3 to 2.5.

  Moreover, this invention provides the photobioreactor which consists of a culture container which has arrange | positioned the said stirrer inside.

Further, the present invention provides the above-mentioned photosynthesis stirrer in which the photocatalyst for preventing the adhesion of underwater organisms is attached to the surface of the stirring blade is disposed in the culture solution, and is performed while stirring the culture solution. A method for culturing organisms is provided.

  Inside the photobioreactor of the present invention, a light emitting diode having three wavelength ranges is used as a light source, and light emitted from the light source is radiated in a direction perpendicular to the vessel wall surface through a cylindrical or conical transparent stirring blade. . As a result, the photosynthesis of the algae growing in the culture vessel is activated, the carbon dioxide fed in large quantities from the hollow shaft of the stirrer is used to photosynthesis very quickly, and the algae can be propagated in a short time. The dry matter density of the algae in the culture vessel can be 5 to 15 times that of the conventional one.

  Therefore, algae can be produced at a very low cost, and drying these algae can produce starch, lipids and proteins per unit area several hundred to several thousand times that of corn and sugarcane harvested from the field. become.

  Furthermore, carbon dioxide with a mass approximately 1.5 times that of the dry matter density of algae is absorbed, so it becomes a carbon dioxide absorption device that is extremely effective in preventing global warming, and can be reused like a forest. Since carbon dioxide is not absorbed over several decades but is absorbed in a few days, it can be used as a device that always absorbs carbon dioxide regardless of location.

  In addition, the dry matter of algae produced by the present invention is useful as it is as livestock feed, and has the advantage that the lipid contained in the dry matter can be used as fuel oil.

The longitudinal cross-sectional view which shows an example of the stirrer of this invention. Sectional drawing which shows an example of the buffer mechanism part of the stirrer of this invention. Sectional drawing which shows an example of the structure of the stirrer bottom part of this invention.

Next, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a longitudinal sectional view showing an example of a stirrer portion of the present invention. This stirrer portion is stored separately in an upper region and a lower region of a culture vessel, and packing 10 is formed by an upper flange 9 and a lower flange 11. It is connected across.

  The hollow shaft 2 constituting the rotating shaft of the stirrer also serves as the carbon dioxide supply pipe 1 and penetrates up and down through the entire culture vessel. The upper end forms a carbon dioxide inlet and the lower end is a carbon dioxide outlet. It has become. The lower end of the hollow shaft is supported via the holding part 24 while maintaining a gap of 50 to 200 μm with the support member 14. The support member 14 is fixed to the fixed bearing 15. A supply pipe 16 is connected to the fixed bearing 15 to supply a supply liquid (hereinafter referred to as a supply liquid) containing a nutrient solution or both a nutrient solution and a carbon dioxide neutralizing alkaline solution into the lower end portion of the hollow shaft.

  On the upper part of the hollow shaft 2 arranged in the upper region of the culture vessel, as a power supply mechanism, a cathode 5 is arranged in direct contact with the hollow shaft to form a cathode of a light emitting diode, and an insulator 4 is formed on the upper part. The anode 3 is annularly connected without being in contact with the hollow shaft, and power is supplied to the light emitting diode through the anode 3.

  When this stirrer is immersed in a culture solution between the cathode 5 and the upper flange 9, a power supply mechanism for supplying power from the light source electrode to the upper stirrer driving portion and the stirrer A shock absorbing mechanism such as a mechanical spring or hydraulic means that generates a force acting in the downward direction against the thrust acting in the upward direction is attached, so that a certain amount of light energy can be supplied into the photobioreactor. It is like that.

  On the other hand, a plurality of stirring blades 19 are attached to the hollow shaft 2 belonging to the lower stirrer via mounting cylinders 17. The plurality of agitating blades 19 are cylindrical bodies or conical bodies, and are attached at positions where the heights are changed radially at an angle in the range of 10 ° to 180 ° and at equal intervals. This figure shows the case where the angle is 120 °. A0 ° B120 ° and C240 ° in the figure indicate the directions of the stirring blades. The stirring blade 19 is preferably formed of a transparent material as a hollow body, and has three light emitting diodes 21, 21 ′, and 21 ″ having blue, red, and far red light qualities in the vicinity of the mounting plate 18 (see FIG. (Not shown).

  In the present invention, blue (430 nm), red (680 nm), and far red (700 nm) light emitting diodes are used because the effective light quality in photosynthesis of aquatic organisms is limited to 430 nm, 680 nm, and 700 nm. These light emitting diodes are preferably those in which the light intensity ratio (R / B ratio) of red / blue is adjusted to 4 to 15 by combining light emitting diodes having a light output of 0.25 to 10 mW with respect to the cross section of the stirrer. Further, the red / far red light source intensity ratio (R / FR ratio) is preferably 1.3 to 2.5.

  The light emitting diodes 21, 21 ′, 21 ″ are attached to the hollow shaft 2 by cathode mounting screws 12,..., And an anode lead wire (not shown) for power supply is connected through the hole 13. The hollow shaft 2 is held by a holding portion 24 at the lower end and is supported by a fixed bearing 15 via a support member 14.

  The hollow shaft of the stirrer is made of a metal such as stainless steel, aluminum or copper, and the stirring blade is made of a light transmissive material such as transparent plastic or glass.

  Next, FIG. 2 is a sectional view showing an example of a buffer mechanism portion of the stirrer in the present invention, and shows an upper portion of the upper flange 9 of the hollow shaft 2 that also serves as the carbon dioxide supply pipe 1. . In this portion, a power supply mechanism including an anode 3, a cathode 5 of a light emitting diode, and an insulator 4 for maintaining an insulating state therebetween is provided so as to be slidable with respect to the hollow shaft. A lead wire (not shown) is connected to the anode 3 via a fixture, and power is supplied from the power source to the light emitting diodes 21, 21 ', 21 ".

  On the other hand, between the upper flange 9 and the cathode 5, buoyancy or supply and supply of carbon dioxide by a gas filled in a space portion generated vertically upward in the stirrer, for example, a space portion accompanying installation of the light source, is provided. In order to counter the thrust force resulting from the supply of the liquid, a buffer mechanism for generating a thrust downward is attached.

  The buffer mechanism in this figure is composed of a spring 6, a thrust bearing 7 and a collar 8 that supports them, but other mechanical impacting means, hydraulic means, and the like can also be used.

  FIG. 3 is a cross-sectional view showing an example of the structure of the bottom of the agitator in the present invention in more detail. A holding portion 24 is provided by being joined to the lower end 2 ′ of the hollow shaft of the stirrer, and this holding portion 24 has a space that becomes a gas-liquid mixing portion 26 and faces the fixed bearing 15, and is 50 to 200 μm. It is supported by the support member 14 with a certain gap. A check valve 25 is attached to the upper part of the holding part 24 to prevent liquid from entering the hollow shaft when the supply of carbon dioxide or the supply liquid is stopped.

  On the other hand, the portion of the support member 14 that faces the lower end portion of the hollow shaft is constituted by the porous portion 23, and the supply liquid is supplied into the gas-liquid mixing portion 26 inside the hollow shaft 2 through the porous portion. The fixed bearing 15 has a plenum chamber 22 to which a supply liquid supply pipe 16 is connected. The supply liquid is mixed in the gas-liquid mixing section 26 with the carbon dioxide sent from the carbon dioxide supply pipe 1 through the porous section 23.

  When the supply of carbon dioxide or the supply liquid is urgently stopped, the bottom of the stirrer comes into close contact with the fixed bearing 15 due to the elastic force of the spring 6, thus preventing liquid from entering the hollow shaft. In addition, the action of the check valve 25 is added to prevent the liquid from entering twice.

  In the photosynthesis stirrer of the present invention, when the aquatic organism, for example, algae, adheres to the transparent rotating blade portion close to the light source or the vessel wall surface that receives light from the light source of the culture vessel in which it is disposed, the light quantity decreases, and the aquatic organism Therefore, it is preferable to apply a photo-oxidation catalyst to these surfaces. In this way, the growth rate of aquatic organisms can be increased, the dry matter density can be improved in a short time, and a dry matter density 5 to 15 times that of a conventional photobioreactor can be obtained. As the photocatalyst used at this time, platinum-supported titanium oxide is preferable, but other photocatalysts can also be used.

  In general, it is known that in photosynthesis, the production rate is controlled by the supply amount of carbon dioxide. And in the present invention, as described above, the alkaline liquid is supplied from below the hollow shaft 2, neutralizing carbon dioxide, and reducing the gas volume, so that a large amount of carbon dioxide can be supplied, The production efficiency of aquatic organisms can be significantly increased.

  On the other hand, it is known that the light source temperature during the reaction can be suppressed, for example, if it is always performed at room temperature, the life of the light source can be extended. Therefore, in the present invention, the light source mounting base 20 to which the light source is mounted is known. Can be reacted with carbon dioxide cooled in advance and maintained at room temperature. In this way, the light source replacement time can be increased by 5 to 10 times by maintaining the light source lifetime below 30% of the theoretical value.

  The carbon dioxide used in the present invention is not necessarily pure, and may be one in which oxygen, nitrogen or other inert gas is mixed as long as the required photosynthetic reaction is not inhibited. Examples of the alkaline solution include aqueous solutions of water-soluble alkali compounds such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, and potassium hydrogen carbonate. Used as nutrient solutions in cultures, eg, nitrates, hydrochlorides, sulfates, phosphates, etc. of metals such as sodium, potassium, magnesium, calcium, manganese, zinc, iron, cobalt Is used.

  There is no restriction | limiting in particular as a density | concentration of these liquids, It can select arbitrarily in the range currently used at the time of culture | cultivation of normal photosynthesis reaction.

  The size of the photosynthesis stirrer of the present invention depends on the size of the culture vessel to be used. Usually, the hollow shaft of the stirrer has an inner diameter of 10 to 200 mm, a length of 150 to 2500 mm, a wall thickness of 2 to 25 mm, The ratio of diameter to length is selected from the range of 1: 5 to 1:50, preferably 1:10 to 1:20.

  The material for the photosynthesis stirrer is a transparent part, that is, the part of the stirring blade 19 and its mounting cylinder 17 is a transparent material such as a transparent hard plastic such as acrylic resin, polycarbonate, ABS resin, polyvinyl chloride, polyester, or the like. It is necessary to use glass, but other than that, it can be arbitrarily selected from materials commonly used in ordinary chemical equipment, such as metal, plastic, and wood.

  Next, culture conditions such as temperature, pressure, carbon dioxide supply rate, supply liquid supply rate, etc. can be used as they are in the conventional photosynthesis reaction by aquatic organisms. In order to extend the life of the light source, it is desirable to keep the temperature below room temperature as described above.

  Examples of aquatic organisms that can be used in the photobioreactor of the present invention include green algae such as Chlorella, Chlamydomonas, Potriococcus oocystis, and cyanobacteria such as Spirulina, Anabena, Oshiratoria, Formidium, and Nostock. Can be mentioned.

  Next, the present invention will be described in more detail by way of examples.

  In addition, the stirrer for photosynthesis used in the Example is a prototype shown in FIG. 1 in which the product name “MD-501” manufactured by Maruhishi Bioengineer Co., Ltd. is improved by Tsukuba Biotech Laboratories.

As a culture solution, 0.5 g of K ₂ HPO ₄ , 0.1 g of NaNO ₃ , 0.5 g of K ₂ SO ₄ , 0.2 g of MgSO ₄ .7H ₂ O, CaCl ₂ .2H ₂ O are contained in 1 liter. 0.04 _g, was used containing FeSO ₄ · 7H 2 O 0.001g and trace elements (pH 9) 3 mL. However, the contents of the trace components were as follows.


Compound content
H ₃ BO ₃ 2.86 g
MnCl ₂ .4H ₂ O 1.81 g
ZnSO ₄ · 7H ₂ O 0.22g
CuSO ₄ · _5H 2 O 0.08g
Na ₂ MoO ₄ 0.021 g
1000mL pure water

  4 liters of a culture solution is placed in a container of a photobioreactor composed of a 5 L volume glass container in which the stirrer for photosynthesis shown in FIG. 1 is placed, and 1 g of spirulina is added thereto, and 100% concentration carbon dioxide gas is added at 20 mL / It was fed to the photosynthesis stirrer at a rate of minutes. This stirrer had a circular stirring blade with a glass tube in which three light emitting diodes each having a wavelength of 430 nm, 680 nm, and 700 nm were disposed. The cells were cultured for 24 hours at an R / B ratio of 10, an effective irradiation power of 3 W, and a rotation speed of 5 rotations per minute.

  Thereafter, the spirulina was filtered and the first culture was discarded, and the total amount of spirulina filtered again was added to 4 liters of the culture that had been doubled, and the carbon dioxide gas supply rate was increased to 40 mL / min. As a result of time culture, the dry matter concentration reached 10 ± 1 g / L. Thereafter, the culture solution formulation was quadrupled, the entire amount of Spirulina filtered by the same method was added, and the carbon dioxide gas supply rate was 80 mL / min, and the treatment was performed for 24 hours, and 15 g ± 1 g / L was obtained in 75 hours.

  100% carbon dioxide gas was supplied to the photosynthesis stirrer in the same manner as in Example 1 except that 1 g of chlorella was used instead of 1 g of Spirulina used in Example 1. This stirrer had a circular stirring blade with a glass tube in which three light emitting diodes each having a wavelength of 430 nm, 680 nm, and 700 nm were disposed, and platinum on titanium oxide on the glass surface of the stirring blade. The photocatalyst carrying A was mixed with an adhesive and applied, and this was further applied to the inside of the glass wall of the photobioreactor.

  Next, the culture is continued for 24 hours at a rotation speed of 5 revolutions per minute, and the culture solution is continuously supplied from the supply pipe at a rate of 1 mL / min with a metering pump, and is pulled out at a level of 4 liters for HRT 2.8 hours continuous culture. Switching was continued for 10 days. Thereafter, the adhesion of the algae on the surface of the stirring blade glass surface and the inside of the glass wall inside the bioreactor was examined, and no adhesion of the algae wall surface was observed.

  Thereafter, the photocatalyst carrying platinum on titanium oxide applied to the stirring blade and the inner wall portion was washed away with a solvent and subjected to the same continuous culture.From around 6 days after the start of the culture, algae was attached to the stirring blade, Algal adhesion was also noticeable on the wall. From this result, it was found that application of a photocatalyst in which platinum was supported on titanium oxide applied to the stirring blade and the inner wall portion was extremely effective in preventing the adhesion of algae.

  4 liters of the culture solution was placed in a 5 L glass container, 1 g of chlorella was added thereto, and supplied to the photosynthesis stirrer used in Example 1 at a rate of 20 mL / min of 100% concentration carbon dioxide gas. This stirrer had a circular stirrer blade with three glass tubes each having three light-emitting diodes each having a wavelength of 430 nm, 680 nm, and 700 nm disposed in advance. The light reflecting material was spirally applied in an area of 1/3. In addition, two light source mounting bases with three pairs of light emitting diodes fixed outside the photobioreactor were installed to create a light environment adjusted to have an R / B ratio of 5.

  Furthermore, a photocatalyst carrying platinum on titanium oxide was mixed and applied to the glass surface of the stirring blade, and further applied to the inside of the glass wall of the photobioreactor. Next, after culturing for 24 hours at a rotational speed of 5 revolutions per minute, a nutrient solution obtained by diluting the culture solution twice with distilled water is continuously supplied from the supply pipe at a rate of 1 mL / min with a metering pump, and pulled out. The operation was switched to continuous culture for 8 days and operated continuously for 10 days.

  As a result, after 36 hours, the dry matter concentration was 12 ± 1 g / L, and stable production was achieved. Similarly, the power source was changed to a pulse wave, and production was carried out for 10 days in a light environment with a cycle of 0.2 seconds and a duty ratio of 50%, but the dry matter concentration was hardly changed. As a result, light irradiation from the outer wall of the reactor was effective for algae production, and it was clarified that the decrease in yield was not observed even by pulse wave irradiation, leading to energy saving of the power source.

  A power supply mechanism that supplies power to the light source power source as shown in FIG. 2 and a spring (mechanical coil spring) that generates a downward force opposite to the thrust acting upward of the stirrer are disposed above the thrust bearing. 4 L of water was placed in a 5 L photobioreactor equipped with a photosynthesis stirrer used in Example 1, and 1 mL of 1% strength potassium hydroxide aqueous solution was added from the porous portion of the support member installed at the bottom of the reactor. / Min.

  Next, a labyrinth packing is attached to the upper part of the stirrer, and a mechanical system installed at the upper part is operated at a rotational speed of 5 revolutions while supplying a pressure of 0.05 MPa and 100% carbon dioxide gas at a rate of 40 mL / min. When the pH of the liquid was measured while adjusting the downward force of the coil spring, the gap between the lower support member and the carbon dioxide outlet at the lower end of the hollow shaft of the stirrer was stabilized between 90 and 120 μm. did.

  From the above results, the effectiveness of the spring and the hydraulic device opposed to the upward thrust applied to the stirrer was confirmed.

  In the same manner as in Example 4 above, a 1% strength aqueous potassium hydroxide solution was supplied at a rate of 1 mL / min from the porous portion of the support member installed in the lower part of the photobioreactor, and the pressure was 0.05 MPa, 100 from the upper part of the stirrer. While supplying carbon dioxide gas with a concentration of 40% / min, it was operated at a rotation speed of 5 rpm, and a pressure of 0.05 MPa and 100% carbon dioxide gas were supplied from the top of the stirrer at a rate of 40 mL / min. .

  Next, the supply of carbon dioxide gas having a pressure of 0.05 MPa and a concentration of 100% was instantaneously stopped from the aqueous potassium hydroxide and the upper part of the stirrer. The state of the poor condition was set so that the function of the check valve installed at the lower part of the agitator could not be exhibited, and this was carried out several times. As a result, the lower part of the agitator was joined to the opposing support member. Thereafter, the water in the photobioreactor was drained, and when water intrusion into the hollow shaft of the stirrer was examined, almost no water intrusion into the hollow shaft was observed.

  Used in Example 1 in which a power supply mechanism and a spring (mechanical coil spring) as shown in FIG. 2 are disposed on the upper part of a thrust bearing in a 200 liter volume donut-shaped closed solar cell culture device having a depth of 18 cm. One stirrer for photosynthesis was installed, and a 1% strength potassium hydroxide aqueous solution was added at a rate of 1 mL / min from the porous part of the support member installed at the lower part of the stirrer, and the pressure was 0.05 MPa, 100% from the upper part of the stirrer. While supplying carbon dioxide gas at a concentration of 40 mL / min, the system was operated at a rotational speed of 5 revolutions per minute. Set the gap between the holding part installed at the lower part of the stirrer and the lower end of the hollow shaft of the stirrer to 100 μm, adjust the downward force of the spring installed at the upper part, and turn on the light source for only 5 days at night. As a result of driving using solar energy directly, 5 ± 1 g / L was obtained in the dry matter concentration of Spirulina. Since the dry matter concentration obtained by the doughnut-shaped closed solar cell culture device is about 1.5 g / L, it can be seen that the supply of artificial light at night is effective.

Since the photosynthesis stirrer of the present invention can perform a rapid photosynthesis reaction, it can mass-produce aquatic organisms such as algae, and is useful for the production of livestock feed and fuel oil.
Moreover, since this photosynthesis can absorb a large amount of carbon dioxide of about 1.5 times the dry mass of algae, it is also useful as a carbon dioxide absorber.

DESCRIPTION OF SYMBOLS 1 Carbon dioxide supply pipe 2 Hollow shaft 2 'Hollow shaft lower end part 3 Anode 4 Insulator 5 Cathode 6 Spring 7 Thrust bearing 8 Collar 9 Upper flange 10 Packing 11 Lower flange 12 Cathode mounting screw 13 Hole 14 Support member 15 Fixed bearing 16 Supply Pipe 17 Mounting cylinder 18 Mounting board 19 Stirring blade 20 Light source mounting base 21, 21 ', 21 "Light emitting diode 22 Plenum chamber 23 Porous part 24 Holding part 25 Check valve 26 Gas-liquid mixing part

Claims (10)

A carbon dioxide gas supply pipe is also used, and a plurality of cylindrical or conical transparent stirring blades are attached to a hollow shaft constituting a rotating shaft in a radial manner and at different intervals, and a wavelength of 430 nm is provided in the vicinity of the attachment portion. One or more light emitting diodes with three different light qualities , blue, 680nm red and 700nm far red, are attached, and nutrient solution or nutrient solution and carbon dioxide neutralized below the hollow shaft And a buffer mechanism for countering the upward thrust force generated by the supply of carbon dioxide gas and the supply liquid on the upper outer surface of the hollow shaft. A stirrer for photosynthesis of aquatic organisms, characterized in that a mechanism for supplying power to a light emitting diode is provided so as to be slidable with respect to a hollow shaft. 2. The power supply mechanism for the light emitting diode comprises a cathode made of a conductor provided in contact with the hollow shaft and an anode power source provided to face the cathode through an insulator. Stirrer for photosynthesis of underwater organisms . The stirrer for photosynthesis of aquatic organisms according to claim 1, wherein the stirring blade is formed of a hollow body. The stirrer for photosynthesis of aquatic organisms according to claim 1, wherein the stirring blades are attached to the hollow shaft while changing directions at the same angle in the range of 10 ° to 180 °. The stirrer for photosynthesis of aquatic organisms according to claim 1, further comprising a check valve mechanism provided below the hollow shaft for preventing liquid from entering the hollow shaft hollow portion when the supply of carbon dioxide gas and the supply liquid is stopped. A photobioreactor comprising a culture vessel in which the agitator for photosynthesis of aquatic organisms according to claim 1 is disposed. The stirring blade surface or the culture vessel wall or both, photobioreactor according to claim 6, wherein the photocatalyst was deposited for underwater anti-biofouling. The agitator for photosynthesis of aquatic organisms according to claim 1, wherein a photocatalyst for preventing adhesion of aquatic organisms is attached to the surface of the agitating blade, is placed in the culture solution, and is performed while stirring the culture solution. An underwater organism culture method. The method for culturing underwater organisms according to claim 8, wherein cooling gas is introduced from the upper end of the hollow shaft of a stirrer for photosynthesis of underwater organisms and the light emitting diode is cooled. The aquatic organism culture method according to claim 8, wherein the aquatic organism is an algae.

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