JPH0491781A - Cultivation method and cultivation device for photosynthetic organisms - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a cultivation method and a cultivation device for photosynthetic organisms, and more specifically, to a cultivation method and a cultivation device for photosynthetic organisms, and more specifically, for culturing living organisms such as algae, plant cells, callus, etc. by photosynthetic reaction. The present invention relates to a culture method and a culture device.

[Conventional technology]

Cultivation of photosynthetic organisms requires the supply of carbon dioxide gas and inorganic nutrients at appropriate concentrations, and irradiation with sufficient intensity of visible light in the wavelength range effective for photosynthesis. BACKGROUND ART Conventionally, methods for mass culturing photosynthetic organisms, particularly algae such as chlorella and spirulina, have been investigated for the purpose of using them as food or feed, or utilizing certain components contained in them. For example, a shallow groove-shaped culture tank with no cover is filled with culture medium and culture is carried out with air containing carbon dioxide while aerating and agitating (open aeration method). A method of culturing by constantly circulating part of the culture medium using a horizontal tube while stirring and supplying carbon dioxide gas (open circulation method)
, clear plastic tube or plastic
There are two methods: culturing in a culture tank covered with a sheet with constant perfusion (closed perfusion method), and culturing with a transparent glass wall on one side of the culture tank and constantly stirring the medium (exploratory culture method). be. Although these methods are effective in utilizing natural sunlight, they are not necessarily sufficient in terms of light utilization efficiency. In particular, since it is a method that directly irradiates the culture tank with sunlight, there are problems such as the effects of ultraviolet rays, which are harmful to photosynthetic organisms, and an increase in the temperature of the culture tank due to infrared rays.

In addition, increasing the concentration of photosynthetic organisms would prevent light from reaching deeper parts of the body, forcing the culture tank to be shallower and requiring a large site area for mass cultivation.

[Problem to be solved by the invention]

The present invention was made based on the above-mentioned circumstances, and
To provide a culture method and a culture device for culturing photosynthetic organisms in large quantities by efficiently irradiating the photosynthetic organisms with visible light effective for their photosynthetic reactions using sunlight or light emitted from an artificial light source. The purpose is to

[Means to solve the problem]

The present inventors have discovered that the light that is effective for the photosynthetic reaction of photosynthetic organisms is
Based on the knowledge that visible light in a specific wavelength range varies depending on the composition of photosynthetic pigments contained in photosynthetic organisms, by selectively irradiating visible light with a wavelength distribution effective for the photosynthetic reaction of the target photosynthetic organisms, The inventors have discovered that it is possible to construct a culture device that can improve the efficiency of light utilization and can culture photosynthetic organisms in large quantities, leading to the present invention. That is, the present invention provides a culture container containing a photosynthetic organism suspended in a culture solution, a carbon dioxide supply means having a means for dissolving carbon dioxide in the culture solution, and a method for dissolving sunlight or light emitted from an artificial light source. It is equipped with a means for irradiating the culture solution and a luminescent carrier that generates light in a wavelength range effective for photosynthetic reactions, and converts the light into visible light having a wavelength distribution effective for the photosynthetic reactions of the photosynthetic organisms in the culture container. A cultivation device and a cultivation method for photosynthetic organisms characterized by irradiation. A method for converting visible light in a wavelength range effective for photosynthetic reactions includes a method of applying an inorganic or organic fluorescent light emitter to the surface of a light-transmissive plastic or glass carrier. As the phosphor material, phosphate phosphors such as (S r, Mg)3
(POdz: Sn”, silicate phosphor e.g. CaS
iO3: In addition to P b 2+, M”, etc., Y2O3
: Eu"", Y (P, V) ○ number: Eu", Cd2B2
0r+: Mn', 6Mgo.As2O5:Mn'+ or an organic fluorescent pigment can be used.
l1a-Vlb such as S, Ca S, S rS, BaS, etc.
Group compounds include Eu2+Ce"", Mn2 in the parent crystal.
It is preferable to add 0.01 to 0.5 mol % of an activator such as 10, etc., since it is possible to selectively emit light at a wavelength effective for the photosynthetic reaction of photosynthetic organisms. However, the present invention is not limited thereto.

In addition, as another means, among the light emitted from sunlight or an artificial light source, only visible light in a wavelength range that has a wavelength distribution effective for the photosynthetic reaction of the target photosynthetic organism is focused, and the photosynthetic organism is By irradiating the photosynthetic organisms with light, the efficiency of light utilization can be improved, and a culture apparatus capable of culturing the photosynthetic organisms in large quantities can be constructed. That is, the present invention provides a culture container containing photosynthetic organisms suspended in a culture solution, a carbon dioxide gas supply means having a means for dissolving carbon dioxide in the culture solution,
A light collecting means that collects light in a wavelength range effective for photosynthetic reactions from sunlight or light emitted from an artificial light source; an optical waveguide system that introduces the light collected by the light collecting means into a culture container; and a light-emitting carrier that irradiates the photosynthetic organisms in the culture container with the light supplied by the optical waveguide system, and selects and collects light having a wavelength distribution effective for the photosynthetic reaction of the photosynthetic organisms in the culture container. A cultivation device for photosynthetic organisms and a method for irradiating light, characterized in that the photosynthetic organisms are irradiated with light. As a method of selectively focusing visible light that is effective for the photosynthetic reaction of the target photosynthetic organisms, after focusing the light emitted from sunlight or an artificial light source, a diffraction grating, prism, dichroic mirror, dichroic filter, etc. However, the present invention is not limited to these methods.

In this case, in combination with the above-mentioned light-emitting carrier having a wavelength conversion means, a light-emitting carrier having a wavelength conversion means for converting a part of the specific wavelength region of the light supplied by the optical waveguide system into visible light with a longer wavelength is used. It is also possible and preferred method to convert light emitted from sunlight or an artificial light source into visible light having a wavelength distribution effective for the photosynthetic reaction of photosynthetic organisms in the culture container.

As the culture progresses and the cell density of photosynthetic organisms in the culture container increases, light will no longer penetrate sufficiently and the rate of the photosynthetic reaction will be determined by the light intensity. It is desirable to arrange the groups so that the photosynthetic organisms in the culture container are evenly irradiated with light.

The photosynthetic reaction of photosynthetic organisms is roughly divided into two parts: the so-called light reaction and the dark reaction. In this case, the light reaction, which requires light irradiation, proceeds faster than the dark reaction, which fixes carbon dioxide gas with oxygen, so it is possible to maintain an appropriate light period without reducing the amount of photosynthetic reaction. You can set up a clear day. In other words, it is equipped with a light introduction system having a light switching device that sequentially connects one light collecting means and a group of luminescent carriers arranged in two or more culture vessels, and the light introduction system is equipped with a light switching device that sequentially connects one light collecting means and a group of luminescent carriers arranged in two or more culture vessels. By irradiating the photosynthetic organisms in the culture container with the light, the light can be used effectively.

Green algae and cyanobacteria are used as photosynthetic organisms. Examples of green algae include Chlorella and Chlamydomonas.
mydomonas).

Examples include Scenedesmus + Botryococcus, Oacystis, and the like. Examples of cyanobacteria include Syneehoccus
occus), Synechocystis
ystis) rSpirulina
+Oscillatoria, Anabaena, Formizoium (Ph
ormidium).

Examples include Nostoc. In particular, when marine green algae or cyanobacteria are selected, seawater is suitable as it can be used directly as a large amount of culture medium. In addition, when thermophilic cyanobacteria are used,
It is suitable because its growth rate is faster than that of room-temperature materials, and it can suppress the growth of other bacteria.

[Function] According to the present invention, among light having a wide wavelength distribution emitted from sunlight or an artificial light source, light in a wavelength range that has not been used for the photosynthetic reaction of the target photosynthetic organism can be converted to a wavelength converting means. The luminescent carrier can convert visible light into visible light having a wavelength distribution effective for the photosynthetic reaction of the photosynthetic organisms, thereby improving the efficiency of light utilization and making it possible to cultivate photosynthetic organisms in large quantities. Furthermore, by selecting an appropriate luminescent carrier, it is possible to absorb and remove ultraviolet light that is harmful to photosynthetic organisms, and at the same time, it is possible to convert it into visible light in the wavelength range that is effective for photosynthetic reactions and use it effectively.

According to another means of the present invention, only visible light in a wavelength range effective for the photosynthetic reaction of photosynthetic organisms is selected and concentrated from the light emitted from sunlight or an artificial light source, and used for culturing the photosynthetic organisms. By using visible light in other wavelength ranges for culturing other photosynthetic organisms with different pigment compositions, the entire light can be used efficiently in the same way as described above.

[Examples] Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples.

Example 1 In Fig. 1, 1 is a culture container made of a transparent plastic tube and placed outdoors, 2 is a culture solution contained in the culture container, and 3 is a photosynthetic organism suspended in the culture solution. is a green algae, Chlorella, and on the surface of the culture container,
Fluorescent emitter 4, in this case a phosphate fluorescent emitter S rz
Pz○7:sn” is coated.Furthermore,
Carbon dioxide gas supply device using exhaust gas from thermal power plants 5. It is composed of a cooler 6, a temperature sensor 7 that measures the temperature of the culture solution, a temperature control system 8 that operates the cooler based on the indicated value of the temperature sensor and controls the temperature to the optimum temperature for photosynthesis, and a pump 9 that circulates the culture solution. Ru.

Next, these operations will be explained. Of sunlight, 3
Ultraviolet light with a wavelength of 50 nm or less is absorbed by the phosphate phosphor coated on the surface of the culture vessel, resulting in a wavelength of 460 nm or less.
It emits blue light with a wavelength of nm and irradiates the photosynthetic organisms in the culture container.

Light of this wavelength is absorbed by the photosynthetic pigments of the green algae, together with visible light of a wavelength of 350 nm or more, which is transmitted through the fluorescent light emitter and directly irradiated to the photosynthetic organism, and causes the photosynthetic reaction to proceed. This eliminates ultraviolet light that is harmful to photosynthetic organisms and converts it into visible light that is effective for photosynthetic reactions.
Light can be used effectively and green algae can be cultivated efficiently. In addition, infrared rays raise the temperature of the culture solution, so the temperature is monitored by a temperature sensor and the temperature control system operates a cooler to control the temperature to the optimum temperature for the photosynthesis reaction of green algae.

Example 2 In Fig. 3, 1 is a culture container, 2 is a culture solution contained in the culture container, and 3 is a photosynthetic organism suspended in the culture solution, in this case thermophilic cyanobacteria, which collects sunlight. Light concentrator 10
, an optical waveguide system 11, in this case an optical fiber, which guides the collected light into the culture container and supplies it to the photosynthetic organisms in the culture solution;
A light scatterer 12 that uniformly irradiates the photosynthetic organisms with the light introduced by the optical fiber, and C coated on the surface of the light scatterer.
aS:Eu"+ fluorescent light emitter 4, a stirring propeller 13 that uniformly suspends the photosynthetic organisms in the culture solution by rotation, a motor 14 that rotates the propeller, and a porous pipe that dissolves carbon dioxide in the culture solution. 15. Carbon dioxide gas source 16, in this case a carbon dioxide gas cylinder, a valve that controls the amount of carbon dioxide aeration] 7. Dissolved carbon dioxide concentration sensor 18° A culture solution that operates a valve to control the amount of carbon dioxide gas aeration based on the value of the sensor Intermediate dissolved carbon dioxide concentration control system 19
20. Dissolved oxygen gas concentration measuring system for measuring the photosynthetic activity of photosynthetic organisms by measuring the dissolved oxygen gas concentration in the culture solution. Heater 21. Temperature sensor 22 that measures the temperature of the culture solution
．． Temperature control system that controls the reheater based on the value of the temperature sensor to promote photosynthesis 23. A means 24 for filtering out photosynthetic organisms and discharging a culture solution, in this case a porous ceramic, is composed of a waste solution tank 25 and a medium tank 26 for storing a culture solution for replenishment. Further, reference numerals 27 and 28 are pumps.

Next, these operations will be explained. The stirring propeller prevents the photosynthetic organisms in the culture solution from settling and disperses them, allowing for uniform light irradiation. The temperature control system controls the temperature of the culture solution at a temperature suitable for the growth and photosynthesis of photosynthetic organisms, in this case thermophilic cyanobacteria, at 55° C. in this case. The dissolved carbon dioxide concentration control system in the culture fluid operates a valve based on the indicated value of the dissolved carbon dioxide concentration sensor to control the optimal carbon dioxide concentration for the photosynthetic reaction of photosynthetic organisms.

The dissolved oxygen gas concentration measurement system measures the photosynthetic activity of photosynthetic organisms based on the dissolved oxygen gas concentration in the culture solution. The culture solution exchanger filters out photosynthetic organisms and collects the culture solution into a waste solution tank, and also replenishes the culture solution with fresh culture solution from the culture medium tank. A concentrator installed outdoors captures 4 of the sunlight.
Only visible light of 00 to 700 nm is collected, guided into the culture vessel by an optical fiber, and radiated into the culture vessel by a light scatterer. At this time, the light with a wavelength of 400 to 550 nm is converted into red light with a wavelength of 650 nm, which is effective for photosynthesis of thermophilic cyanobacteria in the culture solution, by the fluorescent material coated on the light scatterer.

On the other hand, light with a wavelength of 550 nm to 700 nm is transmitted as it is with the same wavelength. This eliminates ultraviolet light, which is harmful to the growth of photosynthetic organisms, and improves light utilization efficiency.

Example 3 Two culture vessels having the same configuration as in Example 2 are arranged as shown in FIG. 4, and connected to a light concentrator by a light switch 29 provided in the light introduction system. The sunlight concentrated by one concentrator is switched by a light switch every fixed time, in this case every 2 minutes.
Light is distributed alternately to the two culture containers. In each culture container, as in Example 2, the red light is converted into red light having a peak light intensity at a wavelength of 650 nm, and is irradiated to the thermophilic cyanobacteria. In this case, under the light-dark cycle, the amount of photosynthetic reaction in each culture container was almost the same as in the case of continuous light irradiation. Therefore, approximately twice the amount of photosynthetic organisms could be cultured under the same light concentration conditions.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to selectively irradiate visible light having a wavelength distribution effective for the photosynthetic reactions of the target photosynthetic organisms, thereby improving the light utilization efficiency and promoting photosynthesis. Organisms can be cultivated in large quantities.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the cultivation device for photosynthetic organisms according to the present invention, FIG. 2 is a sectional view of the culture container shown in FIG. 1, and FIG. FIG. 4, a detailed diagram of the embodiment, is a configuration diagram showing a third embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Culture container, 2...Culture solution, 3...Photosynthetic organism, 4...Fluorescent material, 5...Carbon dioxide supply device,
6... Cooler, 7... Temperature sensor, 8... Temperature control system, 9... Pump, 10... Concentrator, 11...
Optical waveguide system, 12... Light scatterer, 13... Stirring propeller, 14... Motor, 15... Porous pipe, 16
... Carbon dioxide gas source, 17... Valve, 18... Dissolved carbon dioxide concentration sensor, 19... Dissolved carbon dioxide concentration control system, 2o... Dissolved oxygen gas concentration measurement system, 21... Heater , 22... Temperature sensor, 23... Temperature control system, 2
4...Culture solution discharge means, 25...Waste liquid tank, 26
...Medium tank, 27.28...Pump, Fig.

Claims (1)

[Scope of Claims] 1. A culture solution in which photosynthetic organisms are suspended is irradiated with sunlight or light emitted from an artificial light source to dissolve carbon dioxide gas, thereby causing a photosynthetic reaction and thereby producing photosynthetic organisms. A method for culturing photosynthetic organisms, characterized in that the light is converted into visible light in a wavelength range that is effective for photosynthetic reactions, and then irradiated onto the culture solution. 2. A method for culturing photosynthetic organisms by irradiating a culture solution in which photosynthetic organisms are suspended with sunlight or light emitted from an artificial light source to dissolve carbon dioxide gas, thereby causing a photosynthetic reaction. 1. A method for culturing photosynthetic products, characterized in that visible light in a wavelength range effective for photosynthetic reactions is collected from light and irradiated onto the culture solution. 3. A culture container containing a culture solution in which photosynthetic organisms are suspended, a carbon dioxide gas supply means for dissolving carbon dioxide gas in the culture solution in the culture container, and a sunlight or artificial light source applied to the culture solution in the culture container. A cultivation device for photosynthetic organisms that is equipped with a light irradiation means that irradiates light emitted by A cultivation device for photosynthetic organisms, characterized in that light is irradiated onto the culture solution in the culture container through the luminescent carrier. 4. A culture container containing a culture solution in which photosynthetic organisms are suspended, a carbon dioxide supply means for dissolving carbon dioxide gas in the culture solution in the culture container, and a sunlight or artificial light source applied to the culture solution in the culture container. A cultivation device for photosynthetic organisms, comprising a light irradiation means for irradiating light emitted by the light irradiation means, comprising a light collection means for collecting light in a wavelength range effective for photosynthetic reaction from among the light emitted by the light irradiation means. Prepare,
An apparatus for culturing photosynthetic organisms, characterized in that the light collected by the light collecting means is irradiated onto the culture solution in the culture container. 5. The apparatus for culturing photosynthetic organisms according to claim 3, characterized in that one or more luminescent carriers are arranged so that the photosynthetic organisms in the culture container are uniformly irradiated with light. 6. Equipped with a light introduction system having a light switching device that sequentially connects one light collecting means and a group of luminescent carriers arranged in two or more culture vessels, and is equipped with a light introduction system having a light switching device that sequentially connects one light collecting means and a group of luminescent carriers arranged in two or more culture vessels, 5. The apparatus for culturing photosynthetic organisms according to claim 4, wherein said light introduction system irradiates the photosynthetic organisms in the culture container with said light. 7. The apparatus for cultivating photosynthetic organisms according to any one of claims 3 to 6, characterized in that the culture container is equipped with a temperature control system that promotes the photosynthetic reaction of the photosynthetic organisms. 8. Cultivation of photosynthetic organisms according to any one of claims 3 to 7, characterized in that the culture container is equipped with a system for controlling the concentration of carbon dioxide dissolved in the culture solution to promote the photosynthetic reaction of the photosynthetic organisms. Device. 9. The cultivation of photosynthetic organisms according to any one of claims 3 to 8, characterized in that the culture container is equipped with a system for measuring dissolved oxygen gas concentration in the culture solution for measuring the photosynthetic activity of the photosynthetic organisms. Device. 10. The apparatus for culturing photosynthetic organisms according to any one of claims 3 to 9, characterized in that the culture container is equipped with a culture solution stirring device for uniformly suspending the photosynthetic organisms. 11. The cultivation device for photosynthetic organisms according to any one of claims 3 to 6, wherein the luminescent carrier is a fluorescent light emitter made of a IIa-VIb group compound. 12. The method for culturing photosynthetic organisms according to claim 1 or 2, wherein the photosynthetic organisms are green algae or cyanobacteria. 13. The method for culturing photosynthetic organisms according to claim 1 or 2, wherein the photosynthetic organisms are marine green algae or cyanobacteria, and the culture solution is seawater or diluted seawater.