JP2001095560A - Production of chlorella containing specific component and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely produce chlorella having high protein content, chlorella having high carbohydrate content and chlorella having high lipid content. SOLUTION: A culture medium is supplied when the intensity of detected sunlight is within a prescribed range. The intensity range of sunlight to perform the supply of the medium and the component of the liquid medium are selected to be stronger than a prescribed relatively strong intensity and a medium having the optimum nitrogen content for chlorella having high protein content, within a prescribed relatively weak intensity and a medium having the optimum nitrogen content for chlorella having high carbohydrate content and stronger than a prescribed relatively strong intensity and a nitrogen-deficient medium for chlorella having high lipid content.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for producing chlorella having a special component under irradiation of sunlight which causes chlorella to cause photosynthesis (that is, in natural open culture).

[0002]

2. Description of the Related Art Conventionally, chlorella has been mass-cultured under irradiation of sunlight which causes photosynthesis of chlorella. In that case, the culture medium is divided into a basal medium (Basal medium) and a supplemented medium (Feeding medium). On the first day, the cells are cultured in a fixed amount of the basal medium only. After that, a method of culturing by supplying a liquid supplemented medium only at daytime (stop at night) at a constant flow rate, or a similar method has been performed.

[0003] By such a conventional culture technique, chlorella having a certain amount of components could be obtained. However, chlorella having a protein content higher than usual, chlorella having a sugar content higher than normal, or a lipid content higher than normal was obtained. Chlorella having special components, such as chlorella more than usual, could not be obtained with high certainty.

The present invention has been made in view of the above-mentioned problems in the prior art, and has as its object the purpose of the present invention is to provide chlorella having a high protein content, chlorella having a high sugar content, An object of the present invention is to provide a method and an apparatus for producing a special component chlorella which can obtain chlorella having a lipid content with high reliability.

[0005]

Means for Solving the Problems (1) The chlorella culturing method of the present invention is a method of culturing chlorella while supplying a liquid medium to the chlorella under irradiation of sunlight which causes photosynthesis of the target chlorella. Thus, the intensity of the irradiated sunlight is detected, and if the detected intensity of the sunlight is within a predetermined range, the culture medium is supplied, and the chlorella to be obtained by the culturing is of high protein content, Depending on whether the sugar content is high or the lipid content is high, the range of sunlight intensity for supplying the medium and the components of the liquid medium to be supplied are relatively strong, respectively. It is a medium with a proper nitrogen content that is equal to or higher than a predetermined sunlight intensity, or a nitrogen concentration is appropriate and is relatively low within a predetermined sunlight intensity range, or a nitrogen content deficiency is higher than a predetermined sunlight intensity and higher. Select medium or (Claim 1).

According to this culturing method, chlorella having a high protein content (for example, a chlorella algae aggregate whose protein is 60 or 65% by weight or more) and chlorella having a high sugar content (for example, 25 or 30 weight%) % Or more of a carbohydrate is a carbohydrate) or a chlorella having a high lipid content (for example, a chlorella algae aggregate of 45 or 50% by weight or more of a lipid) can be obtained with high certainty. it can.

[0007] The above liquid medium is prepared so as to be suitable for culturing a target chlorella. The nitrogen content appropriate medium can be prepared so as to be suitable for culturing the target chlorella including the nitrogen content, and the nitrogen content deficient medium has a nitrogen content deficient more than an appropriate amount. Others can be prepared so as to be suitable for culture of the target chlorella.

(2) Further, this method is applicable to the following (2-1) to (2)
It can also be carried out separately for each culture method of -3).

(2-1) A chlorella culturing method for obtaining chlorella having a high protein content is a method of culturing chlorella while supplying a liquid medium to the chlorella under irradiation of sunlight which causes photosynthesis of the target chlorella. The method is characterized in that the intensity of the irradiated sunlight is detected, and when the detected intensity of the sunlight is higher than a relatively high predetermined sunlight intensity, the nitrogen-containing appropriate medium is supplied (claim 2).

According to this culturing method, chlorella having a high protein content (for example, a chlorella algae aggregate having 60 or 65% by weight of protein) can be obtained with high reliability.

(2-2) A chlorella culturing method for obtaining chlorella having a high carbohydrate content is a method of culturing chlorella while supplying a liquid medium to the chlorella under irradiation of sunlight which causes photosynthesis of the target chlorella. And detecting the intensity of the irradiated sunlight, and supplying the medium having a proper nitrogen content when the detected intensity of the sunlight is within a predetermined range of relatively low sunlight intensity (claim 3). .

According to this culturing method, chlorella having a high carbohydrate content (for example, a chlorella algae aggregate whose carbohydrate is 25 or 30% by weight or more) can be obtained with high reliability.

(2-3) A chlorella culturing method for obtaining a chlorella having a high lipid content is a method of culturing chlorella while supplying a liquid medium to the chlorella under irradiation of sunlight which causes photosynthesis of the target chlorella. Then, the intensity of the irradiated sunlight is detected, and when the detected intensity of the sunlight is equal to or higher than a predetermined relatively high sunlight intensity, the nitrogen-deficient medium is supplied (claim 4).

According to this culturing method, chlorella having a high lipid content (for example, a chlorella algae aggregate in which 45 or 50% by weight or more is lipid) can be obtained with high reliability.

(3) In carrying out the chlorella culture method,
The following chlorella culture apparatus can be used.

(3-1) Medium supply means for supplying a liquid medium to chlorella, detection means for detecting the intensity of sunlight that causes photosynthesis in the target chlorella, and sunlight detected by the detection means A medium supply control unit that supplies a medium when the intensity of sunlight is equal to or higher than a predetermined relatively high sunlight intensity, and that substantially does not supply a medium when the intensity of sunlight is less than the predetermined sunlight intensity. A chlorella culture device comprising: (Claim 5).

By supplying a culture medium with an appropriate nitrogen content using this culturing apparatus, chlorella having a high protein content (for example, a chlorella algae aggregate having 60 or 65% by weight or more protein) can be obtained with high reliability. Obtainable. Further, by supplying a nitrogen-deficient medium using this culture apparatus, chlorella having a high lipid content (for example, 4
Chlorella algae aggregates in which 5 or 50% by weight or more are lipids can be obtained with high certainty.

(3-2) Medium supply means for supplying a liquid medium to chlorella, detection means for detecting the intensity of sunlight that causes photosynthesis in the target chlorella, and sunlight detected by the detection means The medium is supplied when the intensity of sunlight is within a predetermined sunlight intensity range, which is relatively weak based on the intensity of the sunlight. A medium supply control unit that does not supply a medium substantially when the temperature exceeds the range (claim 6).

By supplying a culture medium with a proper nitrogen content using this culturing apparatus, chlorella having a high carbohydrate content (for example, a chlorella algal aggregate whose carbohydrate is 25 or 30% by weight or more) can be reliably obtained. You can get high.

(3-3) The chlorella culturing apparatus of (3-1) or (3-2) is provided with an incubator for culturing the target chlorella by containing a culture solution of the target chlorella, and the medium supply means is: A medium may be supplied into the incubator.

[0021]

DETAILED DESCRIPTION OF THE INVENTION (1) Chlorella to be cultured in the present invention is mainly Chlorella pyrenoidosa, but Chlorella Vulgaris and Chlorella ellipsoidia ( Chlorella such as Chlorella ellipsoidea and Chlorella minutissima (Chlorella minutissima), and may be marine nannochloropsis (Nano).
chloropsis) including algae.

The liquid medium supplied for culturing Chlorella may be continuous, for example, intermittent. The medium to be supplied usually has a fixed composition, but when the supply amount of the medium per fixed time is increased or decreased, it is also possible to increase or decrease only the supply amount of one or more specific components.

The detection of the intensity of sunlight that causes the target chlorella to cause photosynthesis can be performed by appropriately using detection means such as various optical sensors.

(2) In culturing chlorella under irradiation of sunlight which causes photosynthesis of the target chlorella,
Depending on whether the chlorella to be obtained by the culture has a high protein content, a high carbohydrate content, or a high lipid content, the sunlight is supplied to the medium. And the components of the liquid medium to be supplied are selected.

The term “chlorella with a high protein content, chlorella with a high carbohydrate content, or chlorella with a high lipid content” to be obtained by culturing means one chlorella alga out of many chlorella alga bodies. It does not mean that the whole Chlorella alga body (ie, Chlorella algae aggregate) has a high protein content, a high carbohydrate content, or a high lipid content.

The aggregate means, for example, that the dry weight is 1
The chlorella algae aggregate of 00 g, or the whole chlorella algae obtained by culturing, for example.

(3) The above-mentioned relatively high predetermined sunlight intensity is preferably, for example, 4 klx (kilolux) or more, but may be, for example, 5 klx, 6 klx or 7 klx or more.

The relatively weak predetermined sunlight intensity range is preferably, for example, 2 klx (illuminance corresponding to a light compensation point) to 4 klx. For example, the upper limit is 3 klx.
It can also be.

The medium supply amount per fixed time can be increased or decreased in proportion to the sunlight intensity. In this case, the medium supply amount per fixed time and the speed at which the target chlorella absorbs nutrients in the medium can be made to correspond well.

When the medium is supplied when the intensity of the sunlight is higher than a relatively high predetermined sunlight intensity, the supply amount of the medium per a certain period of time is determined by adjusting the intensity of the sunlight to a constant intensity (for example, a saturation point of light related to photosynthesis of the target chlorella). If the intensity is less than or equal to, for example, about 10 klx, the intensity is increased or decreased in proportion to the intensity of sunlight, and if the intensity exceeds the above-mentioned intensity, the intensity can be made substantially constant. In this case, the medium supply amount per fixed time and the speed at which the target chlorella absorbs nutrients in the medium can be made to correspond well.

[0031]

(4) In the chlorella culturing method for obtaining chlorella having a high protein content, when the medium having an appropriate nitrogen content contains an appropriate amount of iodine, chlorella having a high iodine content can be obtained.

Further, in the chlorella culturing method for obtaining a chlorella having a high lipid content, the nitrogen-deficient medium may comprise:
For example, when the medium is a mineral-deficient medium and the chlorella to be cultured is marine chlorella, marine chlorella with high eicosapentaenoic acid (EPA) can be obtained.

(5) The medium supply means in the chlorella culturing apparatus can be constituted by, for example, an elevated tank for supplying the medium, and a supply pipe for supplying the medium from the elevated tank to an incubator such as a culture pool.

As the detecting means, various optical sensors and the like can be appropriately used.

When the sunlight intensity is less than the predetermined sunlight intensity, the medium supply control means which does not supply the culture medium substantially receives, for example, an output voltage signal of an optical sensor for detecting the sunlight intensity and converts it to the predetermined sunlight intensity. Compared with the corresponding reference voltage, if the output voltage of the optical sensor is equal to or higher than the reference voltage (the intensity of sunlight is equal to or higher than the predetermined sunlight intensity), a predetermined positive voltage is output, and the output voltage of the optical sensor is lower than the reference voltage (daylight If the intensity is less than a predetermined sunlight intensity), a voltage signal processing unit that sets the output voltage to 0 when the input voltage signal from the voltage signal processing unit is a predetermined positive voltage is provided to the supply pipe, It can be constituted by an on-off valve that closes when the voltage is 0 and controls the flow of the culture medium in the supply pipe.

Further, the medium supply control means for supplying the medium when the sunlight intensity is within a predetermined sunlight intensity range and not supplying the culture medium outside the other range, for example, receives an output voltage signal of an optical sensor for detecting the sunlight intensity. Then, it is compared with the lower reference voltage corresponding to the lower limit of the predetermined sunlight intensity range, and when the output voltage of the optical sensor is equal to or higher than the lower reference voltage, a predetermined positive voltage is output. A first voltage signal processing unit for setting the output voltage to 0 when the output voltage is less than 0, an output voltage signal of the optical sensor, and comparing the input voltage signal with an upper limit reference voltage corresponding to an upper limit of a predetermined sunlight intensity range; A second voltage signal processing unit that outputs a predetermined positive voltage when the output voltage of the optical sensor is equal to or lower than the upper limit reference voltage, and sets the output voltage to 0 when the output voltage of the optical sensor exceeds the upper limit reference voltage; Signal processing part and A third voltage signal processing unit for inputting an output voltage of the voltage signal processing unit and outputting a logical product thereof, and a third voltage signal processing unit provided in the supply pipe, wherein the input voltage signal from the third voltage signal processing unit is a predetermined positive voltage. It can be constituted by an on-off valve that opens in cases and closes when the voltage is 0 and controls the flow of the culture medium in the supply pipe.

Further, it is of course possible to perform the same processing by using a computer or a microcomputer instead of such a processing circuit.

The medium may be supplied continuously, for example, intermittently.

(6) The medium is supplied when the sunlight intensity is equal to or higher than the predetermined sunlight intensity, and the medium supply amount per fixed time is increased or decreased in proportion to the sunlight intensity when the sunlight intensity is equal to or lower than the predetermined intensity. If the intensity exceeds a certain level, the medium supply control means for assuming that the level is substantially constant, for example, inputs an output voltage signal of an optical sensor for detecting the intensity of sunlight and performs necessary amplification such as amplification at a required amplification factor. A voltage signal processing unit that performs processing, and a proportional control valve that is provided in the supply pipe and that increases or decreases the opening according to the input voltage signal from the voltage signal processing unit to increase or decrease the flow rate of the culture medium flowing in the supply pipe. can do. The voltage signal processing unit in this case compares, for example, the input voltage with a constant value corresponding to the lower limit of the predetermined range and outputs 0 when the input voltage is lower than the fixed value, and outputs the constant value when the input voltage is higher than the fixed value. By amplifying the voltage obtained by subtracting the required voltage at the required amplification factor and providing a circuit that outputs the smaller of the amplified voltage and the constant voltage corresponding to the upper limit of the predetermined range, When the voltage is equal to or lower than a certain value corresponding to the lower limit of the predetermined range, the output voltage is 0, and when the voltage is equal to or higher than a certain value corresponding to the upper limit of the predetermined range, a voltage larger than the output obtained by amplifying the certain value is not output. can do. Of course, the same processing can be performed using a computer or a microcomputer instead of such a processing circuit.
The proportional control valve is set so that, for example, when the input voltage from the voltage signal processing unit is 0, the opening is 0, and when the input voltage is a positive value, the opening is proportional to the opening. By this, when the intensity of sunlight is within a predetermined range,
Increase or decrease the medium supply amount per fixed time according to the increase or decrease of the intensity of sunlight, if the intensity of sunlight is smaller than the predetermined range, substantially no medium is supplied, if the intensity of sunlight is larger than the predetermined range, It can be controlled so that the medium supply amount per fixed time is substantially constant.

When the constant voltage corresponding to the upper limit of the predetermined range is higher than the amplified voltage, the amplified voltage is output as it is, and when the constant voltage is lower, the output voltage becomes 0. By controlling the medium supply amount per unit time in accordance with the increase or decrease in the intensity of sunlight when the light intensity is within the predetermined sunlight intensity range, the medium is not supplied outside the predetermined sunlight intensity range. Can be.

(7) FIG. 1 is a schematic diagram of a chlorella culture apparatus as an example of an embodiment of the present invention.

The chlorella culturing apparatus mainly includes a medium preparation tank 10, an elevated tank 12 for supplying a medium, a feed pipe 14 for feeding a liquid medium from the medium preparation tank 10 to the elevated tank 12, A pump 16 for pumping the medium through the feed pipe 14 and an elevated tank 12
, A main supply pipe 20 and a branch supply pipe 22 for supplying a culture medium to one or more culture pools 18 (incubators), a self-recording sunshine meter 24, an automatic controller 26, and a main supply pipe provided in the main supply pipe 20. An on-off valve 28, a main flow meter 30, and an on-off control valve 32;
It comprises a branch on-off valve 34 and a branch flow meter 36 provided in each branch supply pipe 22, and one or two or more culture pools 18 provided in a place where the irradiation intensity of sunlight is as high as possible and the irradiation amount is as large as possible.

The culture medium preparation tank 10 contains a raw material for preparing a culture medium, and stirs the raw material with a stirrer to prepare the culture medium. The medium prepared in the medium preparation tank 10 is supplied to the elevated tank 12 by the pump 16 at an appropriate time.

The medium stored in the elevated tank 12 flows from the elevated tank 12 through the main supply pipe 20, branches off from the main supply pipe 20, and flows through the branch supply pipes 22 reaching the respective culture pools 18. Chlorella and its culture solution are supplied to each culture pool 18. These elevated tank 12, main supply pipe 20 and branch supply pipe 22
The medium supply means is configured.

The self-recording sunshine meter 24 includes an optical sensor (detection means) such as a photoelectric plate for detecting the intensity of sunlight near the culture pool 18, and outputs a voltage signal according to the intensity of sunlight. The automatic controller 26 performs processing such as inputting an output signal from the self-recording sunshine meter 24 and comparing it with a reference voltage corresponding to a predetermined sunlight intensity, and outputs the signal to the open / close control valve 32 to output the open / close control valve 32. Control the opening. These automatic controllers 2
6 and the open / close control valve 32 constitute a medium supply control means.

In the case of culturing chlorella having a high protein content, the automatic controller 26 outputs 0 V when the voltage signal input from the self-recording sunshine meter 24 is less than the voltage corresponding to 4 klx, for example, and outputs 4 Vlx. If the voltage is higher than the corresponding voltage, a setting is made so as to output a predetermined positive voltage. The medium to be supplied is an appropriate nitrogen content medium.

The open / close control valve 32 receives the output voltage of the automatic controller 26, and opens when the input voltage is a predetermined positive voltage and closes when the input voltage is 0.

[0049]

According to the method and apparatus of the present invention, chlorella having a high protein content, chlorella having a high sugar content, and chlorella having a high lipid content can be obtained with high certainty.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a chlorella culture device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Medium preparation tank 12 Elevated tank 14 Supply pipe 16 Pump 18 Culture pool 20 Main supply pipe 22 Branch supply pipe 24 Self-recording sunshine meter 26 Automatic controller 28 Main open / close valve 30 Main flow meter 32 Open / close control valve 34 Branch open / close valve 36 Branch Flowmeter

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4B029 AA02 BB05 CC01 DA01 DA03 DF05 4B065 AA84X BC13 BC18 BC48 CA41

Claims (6)

[Claims] 1. A method of culturing chlorella while supplying a liquid medium under irradiation of sunlight which causes photosynthesis of a target chlorella, comprising detecting the intensity of the irradiated sunlight and detecting the detected intensity of the sunlight. The medium is supplied when is within a predetermined range, and the chlorella to be obtained by culturing is of high protein content, of high saccharide content, or of high lipid content. Depending on whether the medium is supplied, the range of sunlight intensity for supplying the medium and the components of the liquid medium to be supplied are respectively relatively strong at or above a predetermined sunlight intensity and a nitrogen content appropriate medium, or A chlorella cultivation method, which comprises selecting a medium having an appropriate nitrogen content within a range of relatively weak predetermined sunlight intensity or a medium having a relatively low predetermined sunlight intensity and a nitrogen content deficient. 2. A method of culturing chlorella while supplying a liquid medium under irradiation of sunlight which causes photosynthesis of the target chlorella, comprising detecting the intensity of the irradiated sunlight and detecting the detected intensity of the sunlight. A chlorella culturing method for obtaining a chlorella having a high protein content, wherein a medium having a proper nitrogen content is supplied when the intensity is higher than a predetermined strong sunlight intensity. 3. A method of culturing chlorella while supplying a liquid medium under irradiation of sunlight which causes photosynthesis of the target chlorella, comprising detecting the intensity of the irradiated sunlight and detecting the detected intensity of the sunlight. A chlorella culturing method for obtaining a chlorella having a high carbohydrate content, wherein a medium having an appropriate nitrogen content is supplied when the temperature is within a predetermined range of relatively low sunlight intensity. 4. A method for culturing chlorella while supplying a liquid medium under irradiation of sunlight which causes photosynthesis of the target chlorella, comprising detecting the intensity of the irradiated sunlight, detecting the detected intensity of the sunlight. A chlorella culturing method for obtaining a chlorella having a high lipid content, wherein a medium having a nitrogen content deficiency is supplied when is higher than a predetermined strong sunlight intensity. 5. A medium supply means for supplying a liquid medium, a detection means for detecting the intensity of sunlight which causes photosynthesis in a target chlorella, and a sunlight intensity detected by the detection means. Medium supply means for supplying a medium when the sunlight intensity is equal to or higher than a predetermined relatively high sunlight intensity, and substantially not supplying a medium when the sunlight intensity is lower than the predetermined sunlight intensity. Chlorella culture device. 6. A medium supply means for supplying a liquid medium, a detection means for detecting the intensity of sunlight causing photosynthesis in the target chlorella, and a sunlight intensity detected by the detection means. Medium supply control means for supplying a medium when the sunlight intensity is within a predetermined weak sunlight intensity range, and substantially not supplying a medium when the sunlight intensity is outside the predetermined sunlight intensity range. Chlorella cultivation device characterized by the following.