JPH0723767A - Photo-bioreactor - Google Patents

Abstract

PURPOSE:To provide a photo-bioreactor having easy cleanability and effective for preventing the contamination and deterioration of light sources to keep high culture efficiency by fixing plural protection tubes made of a transparent material to a fixing plate, placing the tubes in a culture tank and removably inserting a rod light-source in each protection tube. CONSTITUTION:A culture tank 10 opened at one end is provided with a fixing plate 12 having plural holes to close the open end of the culture tank 10. Plural protection tubes 16 made of a transparent material and each having an insertion opening at one end and closed at the other end are fixed to the fixing plate 12 parallel to each other by bonding the circumference of each hole to the outer circumference of the insertion opening. The fixed tubes are put into the culture tank 10. A rod light-source 20 is removably inserted into each protection tube 16 and a lid 24 is applied to the fixing plate 12 at the side opposite to the side holding the protection tubes 16. The circumference of the opening of the culture tank 10 is detachably fixed to the circumference of the fixing plate 12 in liquid-tight state with an engaging means to provide this photo- bioreactor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photobioreactor used for culturing microorganisms such as algae such as Chlorella and Spirulina which require light for reproduction in a culture tank at high density.

[0002]

2. Description of the Related Art Algae such as chlorella and spirulina, which receive sunlight, absorb carbon dioxide in the atmosphere, perform photosynthesis, and generate and release oxygen, which breed. It is widely known that the photosynthetic ability of these algae is several hundred times higher than that of general plants. Algae such as chlorella have a wide range of uses as feed, food, fuel, etc., and are cultivated in large quantities by utilizing their great fertility. Further, in recent years, large-scale cultivation of algae is expected to be useful for preventing global warming, since a large amount of carbon dioxide in the atmosphere is absorbed by photosynthesis.

[0003] Cultivation of algae has conventionally been generally carried out by utilizing natural sunlight in a pool-shaped culture pond.
In addition, a photobioreactor is used to produce algae at high speed, high efficiency, and low cost. In this photobioreactor, an algae is cultivated by using an artificial light source and irradiating light from around the culture tank formed of a transparent material toward the inside of the culture tank. Further, a photobioreactor has also been proposed in which an artificial light-emitting body is placed inside a culture tank, and light is emitted toward the periphery of the light-emitting body as a center to culture algae.

[0004]

However, in the method of cultivating algae in a culture pond using sunlight, the light transmission below the liquid surface becomes worse as the algae grows.
The depth of the culture pond will be limited. Therefore, large-scale culture of algae requires a large area, and the culture efficiency is poor.

On the other hand, in a conventional photobioreactor for cultivating algae in a culture tank having a transparent wall surface using an artificial light source, when the diameter of the culture tank becomes large, the permeability of light to the culture solution inside the tank is increased. However, there is a problem in that the culture efficiency is extremely reduced due to the deterioration of the temperature.

Further, in a photobioreactor in which a light-emitting body is placed in a culture tank for culturing algae, the surface of the light-emitting body comes into contact with the culture solution. It will be polluted and deteriorated. In particular, if the surface of the luminescent material is contaminated, the irradiation of the light from the luminescent material into the culture solution is hardly performed, which is a fatal situation for this type of photobioreactor. Therefore, in such a case, it is necessary to wash the luminescent body, but it is impossible to sterilize the culture tank at a high temperature with the luminescent body built therein because the luminescent body may be damaged. Therefore,
After removing the luminescent material from the culture tank, the surface of the luminescent material is washed and the inner wall surface of the culture tank is sterilized at high temperature, which makes cleaning the culture tank including the luminescent material very troublesome. Become.

The present invention has been made in view of the above circumstances, and the culture efficiency does not decrease even if the diameter of the culture tank increases, and the light emitter itself is contaminated or deteriorated. It is an object of the present invention to provide a photobioreactor in which the inside of a culture tank can be cleaned relatively easily without the need for a cell.

[0008]

According to the present invention, a fixing plate having a plurality of holes is provided in a culture tank having one end surface opened.
A plurality of protective tubes, which are arranged so as to close the opening surface of the culture tank and which are made of a transparent material and have an insertion opening at one end and the other end being closed, are provided on the fixing plate, and the periphery of each of the holes. The outer peripheral portion of the insertion port is fixed to each part and held so as to be arranged in parallel to each other, and a plurality of protective tubes held by the fixing plate are housed inside the culture tank, A rod-shaped light-emitting body is removably disposed inside each of the protection tubes, and a lid is provided on the side of the fixing plate opposite to the side on which the protection tube is held, and the opening of the culture tank. The photobioreactor was constructed by attaching the peripheral portion and the peripheral portion of the fixing plate in a liquid-tight manner and detachably by an attaching means.

In the photobioreactor having the above construction, a washing liquid supply means may be additionally provided in the culture tank.

[0010]

In the photobioreactor having the above-mentioned structure, a plurality of rod-shaped luminous bodies are respectively arranged inside the plurality of protection tubes held by the fixing plate and accommodated inside the culture tank, and
The lid side into which the rod-shaped luminous body is inserted and the inside of the culture tank in which the protection tube is housed are fixed by a fixing plate and a protection tube whose peripheral edge is liquid-tightly connected to the peripheral edge of the opening of the culture tank by the engaging means. , It is divided so as not to communicate with each other. Therefore,
The surface of the rod-shaped luminous body does not come into contact with the culture solution, and the surface of the luminous body is not contaminated or deteriorated by the culture solution. Also, the irradiation of the culture solution in the culture tank is performed from the rod-shaped light emitter toward the periphery of the protection tube through a plurality of parallel transparent protection tubes housed inside the culture tank. Therefore, by appropriately determining the number and arrangement of the protective tubes, even if the diameter of the culture tank becomes large, the culture solution in the tank can be well irradiated with light.
And, since the rod-shaped light emitter is disposed inside the protection tube so that it can be inserted and removed freely, if the rod-shaped light emitter is extracted from the inside of the protection tube when cleaning the inside of the culture tank,
The culture tank can be subjected to high temperature sterilization treatment, and the peripheral edge of the opening of the culture tank and the peripheral edge of the fixing plate are detachably attached by an attaching means, so that they can be integrated with a plurality of protective tubes. With the fixed plate removed from the culture tank, the inner wall surface of the culture tank and the surface of the protection tube can be easily washed.

Further, when the cleaning liquid supply means is attached to the culture tank, the cleaning liquid can be easily flowed into the culture tank by the cleaning liquid supply means with the fixing plate attached to the culture tank. The inner wall surface can be washed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical sectional view showing a schematic structure of a photobioreactor according to one embodiment of the present invention. This photobioreactor consists of a culture plate 10 with an open top end and a fixed plate 12
Are arranged so as to close the opening surface of the culture tank 10.
The fixed plate 12 is made of, for example, a ceramic material, and the fixed plate 12 is provided with a plurality of holes 14 as shown in the plan view of FIG. A plurality of protective tubes 16 are provided on the lower surface side of the fixed plate 12, and the outer peripheral surface of the upper end portion of the protective tube 16 is provided on the inner peripheral edge of each hole 14 of the fixed plate 12 as shown in the partially enlarged vertical sectional view of FIG. It is fixedly held. The protection tube 16 is
It is made of a transparent material such as transparent glass or transparent plastic and has an insertion opening 18 at the upper end and a closed lower end. The diameter of the protection tube 16 is, for example, 5 to 50 mm.
Is. In addition, the distance between the outer peripheral surfaces of the adjacent protection tubes 16 is, for example, 1 to 50 mm in consideration of replacement of the culture solution, the light reaching distance, and the securing of the culture solution holding amount in the culture tank 10. Appropriate. The plurality of protection tubes 16 are arranged parallel to each other in a vertical posture with respect to the fixed plate 12. Then, the plurality of protective tubes 16 held by the fixing plate 12 are inserted into the inside of the culture tank 10 through the opening surface thereof, so that the plurality of protective tubes 16 are housed inside the culture tank 10. . It is needless to say that the arrangement of the plurality of protection tubes 16 shown in FIG. 2 is only an example, and other arrangement methods may be used.

A rod-shaped luminous body 20 is provided inside each of the plurality of protective tubes 16 held by the fixed plate 12. The rod-shaped light emitting body 20 can be inserted into the inside of the protection tube 16 through the insertion opening 18 at the upper end thereof, and can be pulled out from the inside through the insertion opening 18. Rod-shaped light emitter 20
Is connected to an optical fiber 22 at the upper end thereof, the plurality of optical fibers 22 respectively connected to the plurality of rod-shaped light emitting bodies 20 are bundled and led out to the outside, and the end is connected to a light emitting source (not shown). Has been done. A plurality of rod-shaped light emitters 20 can be inserted into the plurality of protective tubes 16 at once by bundling and fixing the optical fibers 22 as in the illustrated example. As the rod-shaped illuminator, the one having the configuration shown in the drawing is preferable because it is easy to handle, but an elongated fluorescent lamp or the like may be used.

A lid 24 is provided so as to cover the side of the fixed plate 12 opposite to the side on which the protective tube 16 is held. Then, the peripheral portion of the fixed plate 12 is inserted between the flange portion 26 integrally formed at the opening peripheral edge portion of the upper end of the culture tank 10 and the flange portion 28 integrally formed at the lower peripheral edge portion of the lid body 24, By bringing them into close contact with each other and fixing them in a liquid-tight manner with the cap 30, they are assembled into the form as shown in FIG. On the other hand, by removing the cap 30, the fixing plate 12 and the plurality of protection tubes 16 can be separated from the culture tank 10.

The outer periphery of the culture tank 10 has a warm water jacket
32 is formed, hot water is made to flow into the hot water jacket portion 32 through the inflow port 34, the hot water is made to flow inside the hot water jacket portion 32, and then the hot water jacket portion 32 is passed through the outflow port 36.
By flowing out to the outside, the culture solution in the culture tank 10 is maintained at a desired temperature. 38 in FIG. 1,
40 is a thermometer. The bottom of the culture tank 10 is provided with an inlet 42 for mixed gas and cleaning water, and the mixed gas or cleaning water is selectively supplied into the culture tank 10 through the inlet 42 by a switching valve 44. It has become so. Also, the culture tank 10
An outlet 46 of the culture solution and the wash water is provided in the upper part of the above, and a discharge port 48 of the culture solution and the wash water in which an electromagnetic opening / closing valve 50 is provided is provided in the lower part of the culture tank 10. There is.

When culturing algae such as Chlorella using the above-mentioned photobioreactor, the lid 24 and the fixing plate 12 are removed from the culture tank 10 and the inside of the culture tank 10 is opened from the upper end opening surface. Inflow the culture medium. Next, the protective tube 16 is inserted into the culture tank 10, and the peripheral portion of the fixed plate 12 is placed in the culture tank 10.
10 After connecting to the upper flange 26,
While inserting the rod-shaped light emitting body 20 into 16 respectively, the lid body 24 is covered on the upper surface side of the fixing plate 12, the flange portion 28 of the lower end peripheral portion of the lid body 24 is joined to the peripheral portion of the fixing plate 12, and the culture tank. (10) The flange portion (26) at the upper end, the peripheral portion of the fixing plate (12) and the flange portion (28) at the lower end of the lid body (24) are brought into close contact with each other, and they are liquid-tightly attached by the cap (30). Then, in the state shown in FIG. 1, while the warm water is allowed to flow into the warm water jacket portion 32 to maintain the culture solution in the culture tank 10 at a desired temperature, the mixed gas is passed through the introduction portion 42 at the bottom of the culture tank 10 to the culture tank 10. It is supplied to the inside and the chlorella is cultured. At this time, the plurality of rod-shaped light emitters 20 are respectively disposed inside the plurality of protection tubes 16 held by the fixing plate 12, and the lid body 24 side and the inside of the culture tank 10 do not communicate with each other. Since it is partitioned as described above, the surface of the rod-shaped light-emitting body 20 does not come into contact with the culture solution in the culture tank 10, and the surface of the rod-shaped light-emitting body 20 may be contaminated or deteriorated by the culture solution. Absent. Then, the irradiation of the culture solution in the culture vessel 10 is performed from the plurality of rod-shaped light emitting bodies 20 through the transparent wall surface of each protective tube 16 toward the periphery thereof.

Using the photobioreactor shown in FIG.
The experimental results of culturing chlorella by adding 8 g of chlorella per liter of culture solution are shown in FIGS. 4 and 5. As can be seen from FIG. 4, the increase amount of chlorella per hour is (1
0.5-8) /8=0.3125 [g / l.hour]
Therefore, the increase in chlorella per day is 0.
It becomes 3125 × 24 = 7.5 [g / l · day]. This indicates that the bacterial cells were produced at a efficiency 10 times higher than that in the case of culturing Chlorella in a general culture pond. However, in reality, as shown in FIG. 5, the rate of increase of chlorella decreases from the point where 10 hours have passed after the start of the culture due to the relationship between the chlorella concentration and the stirring of the culture solution.
Moreover, when this photobioreactor is used, it is 100 to 50 times more than that of chlorella culture in a general culture pond.
It was possible to carry out cultivation at a high concentration of 00 g / l.

In the photobioreactor shown in FIG. 1,
When algae adhere to the inner wall surface of the culture tank 10 or the outer peripheral surface of the protection tube 16, in order to clean them, the culture solution is completely discharged from the inside of the culture tank 10 through the outlet port 46 and the discharge port 48. After that, in that state, high-pressure water or a cleaning solution in which a detergent is dissolved is introduced into the inside of the culture tank 10 through the introduction part 42 at the bottom of the culture tank 10, and the high-pressure water or the like is transferred from the bottom to the top in the culture tank 10. It is made to flow toward and the high-pressure water etc. are made to flow out from the outflow port 46. Alternatively, the culture tank 10 is irradiated with ultrasonic waves, and vibration is applied. By these washing operations, the protective tube 16 can be easily restored to the transparent state. Further, the lid 24 and the fixed plate 12 are removed from the culture tank 10, and the rod-shaped light-emitting bodies 20 are respectively extracted from the plurality of protective tubes 16 held by the fixed plate 12, and then the plurality of fixed tubes are held by the fixed plate 12. Protect tube 16 of the autoclave at high temperature
High-pressure sterilization treatment or gas sterilization treatment can also be performed.

In the above-described embodiment shown in the figure, the culture tank is placed vertically, but it may be placed horizontally, and it is arranged so that it is upside down from FIG. Good.

[0021]

Since the present invention is constructed and operates as described above, the use of the photobioreactor according to the present invention makes it possible to remarkably compare the method of culturing algae in a culture pond with sunlight. Algae can be cultivated with high efficiency, and space is not required even for large-scale culturing of algae. Further, even if the diameter of the culture tank becomes large, the culture efficiency does not decrease. Further, the illuminant is not contaminated or deteriorated by the culture solution, and the inside of the culture tank can be cleaned relatively easily.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a schematic configuration of a photobioreactor according to an embodiment of the present invention.

FIG. 2 is a plan view showing an example of a fixing plate which is one of the constituent elements of the photobioreactor.

FIG. 3 is an enlarged vertical cross-sectional view showing a part of a fixing plate and a protective tube, which are one of the constituent elements of the photobioreactor.

4 is a graph showing the experimental results when culturing Chlorella using the photobioreactor shown in FIG.

5 is a graph showing the experimental results when culturing Chlorella using the photobioreactor shown in FIG.

[Explanation of symbols]

10 Incubator 12 Fixing plate 14 Hole in fixing plate 16 Protective tube 18 Protective tube insertion port 20 Rod-shaped light emitter 22 Optical fiber 24 Lid body 26 Flange part integrally formed at the peripheral edge of the upper end of the incubator tank 28 Lower end of lid Flange part integrally formed on the peripheral edge 30 Cap 42 Introducing part for mixed gas and cleaning water

Claims (2)

[Claims] 1. A culture tank having one end surface opened, a fixing plate having a plurality of holes formed therein and arranged so as to close the opening surface of the culture tank, and a fixing member formed of a transparent material and having one end. While having an insertion port, the other end is closed, the fixing plate,
A plurality of protective tubes, which are fixed to the peripheral portions of the holes and are arranged and held in parallel with each other, and are housed inside the culture tank, and the inside of each protective tube. A plurality of rod-shaped light-emitters that can be inserted into and removed from each other, a lid that covers the fixing plate on the side opposite to the side on which the protective tube is held, and an opening peripheral edge of the culture tank. A photobioreactor comprising: a fixing portion and a peripheral portion of the fixing plate, which are liquid-tightly and detachably attached. 2. The photobioreactor according to claim 1, wherein the culture tank is provided with a cleaning liquid supply means.