JPH0238197B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing high-iodine-containing freshwater chlorella in which iodine components are enriched and immobilized within freshwater chlorella cells. Freshwater unicellular green algae (hereinafter simply referred to as chlorella), such as Chlorella, Scenedesmus, and Chromydomonas, have extremely high growth rates and light utilization efficiency compared to conventionally cultivated plants, and are rich in nutrients such as proteins, lipids, carbohydrates, vitamins, and minerals. It is excellent as food and feed. In addition, the physiologically active substances it contains are known to have the effect of promoting the growth of microorganisms, animals and plants, and the medical effects of chlorella are also attracting attention. There are two types of chlorella: natural marine-produced chlorella and industrially cultivated freshwater-produced chlorella, but the freshwater version is currently produced and sold in large quantities as a health food, while the marine-produced version has problems with productivity and has not been industrialized. I haven't reached it yet. Chlorella is expected to be used as a gastrointestinal ulcer treatment, high blood pressure treatment, cholesterol regulator, anti-cancer agent, etc., and research on its ingredients is being carried out. Natural marine chlorella and commercially available freshwater chlorella There are subtle differences in the medicinal ingredients between the two, and although marine chlorella is said to be significant, the cause has not yet been fully investigated. Normally, chlorella contains about 7% mineral components.
The main components are phosphorus, potassium, magnesium, calcium, sulfur, iron, etc. The high content of these components is a factor that increases the value of chlorella as a health food and in terms of medical effects. It has become one of the The present inventors conducted various studies focusing on the differences between marine chlorella and freshwater chlorella, and found that although natural marine chlorella contains approximately 80 ppm of iodine in terms of iodine, It was discovered that commercially available freshwater chlorella does not contain appreciable amounts of iodine, and furthermore, by culturing this freshwater chlorella under certain conditions in a medium containing iodine ions, etc., marine chlorella was cultivated. The above-mentioned high iodine-containing chlorella was obtained, and the present inventors discovered that its pharmacological effects were even greater than that of marine chlorella, leading to the completion of the present invention. On the other hand, as the so-called iodine eggs have been attracting attention as a health food in recent years, iodine components are not only used to treat hypothyroidism caused by a lack of iodine components, but also to promote growth, improve high blood pressure and allergic predisposition. Chlorella, which contains a high content of iodine, has been recognized to be effective in the treatment of various diseases, and in addition to the original characteristics of chlorella, iodine-based ingredients also exhibit effects as well as effects when used in combination with other ingredients. It has a higher utility value than iodine eggs. It was expected that iodine ions would inhibit the growth of freshwater chlorella, as they are used as disinfectants, but test results showed that contrary to that expectation, even in a medium containing a relatively high concentration of iodine ions, freshwater chlorella It was found that the growth of Chlorella was hardly inhibited. Moreover,
Freshwater chlorella cultured in a medium containing iodine ions contains a higher proportion of iodine than marine chlorella, and even if this chlorella is thoroughly washed, there is almost no decrease in iodine, meaning that iodine atoms are not present in chlorella cells. It was confirmed that iodine ions are fixed in a form that binds to certain components, and that iodine ions are not simply absorbed or adsorbed by chlorella. The present invention relates to a method for producing chlorella enriched with the above iodine component, that is, iodine ions and/or iodate ions are added to 0.1 ppm to
This is a method for producing high-iodine-containing freshwater chlorella, characterized in that the iodine content is 100 ppm or more, obtained by drying freshwater chlorella containing 800 ppm and cultured in the presence of light under a medium condition of pH 4 to 7. Seawater normally contains about 0.06 ppm of iodine ions. As mentioned above, marine chlorella grown in seawater contains about 80 ppm of iodine. On the other hand, according to the present invention, freshwater chlorella having an iodine component content (per dry weight) of 100 ppm or more in terms of iodine can be easily obtained. A more preferable range of the iodine content per dry weight of the iodine-enriched freshwater chlorella obtained in the present invention is approximately
100 to 2000 ppm, but the upper limit does not necessarily have to be within this range. The iodine component content in chlorella is usually easily influenced by the concentration of iodine ions and/or iodate ions (hereinafter both referred to as iodine ions, etc.) in the culture medium. That is, the higher the concentration of iodine ions, etc. in the medium, the higher the iodine component content in chlorella. However, in a medium containing too high a concentration of iodine ions, etc., the growth of chlorella is likely to be inhibited. Therefore, although it depends on the type of Chlorella, the appropriate concentration of iodine ions, etc. in the medium is about 0.5 to 800 ppm, particularly preferably in the range of about 1 to 800 ppm. In the present invention, Chlorella such as Chlorella pyrenoidosa, Chlorella vulgaris, and Chlorella elliplyidea are preferably suitable; however, Chlorella such as Scenedesmus, Chlamydomonas, Selenastrum,
Other chlorella may also be used. The above chlorella is a freshwater chlorella that usually grows in fresh water.
The salt-tolerant variant is called marine chlorella. A medium containing iodine ions and the like can be easily obtained by adding water-soluble iodide, iodate, etc. to a chlorella culture medium. For example, potassium iodide, sodium iodide, calcium iodide and other inorganic iodides, iodine ion sources such as hydrogen iodide, potassium iodate, sodium iodate, calcium iodate, and other iodates and iodates. An iodate ion source may be used. Further, a culture medium can also be produced by adding a nutrient source such as the carbon source described below to underground brine containing iodine ions or the like. The concentration of iodine ions, etc. in the culture medium is preferably maintained within the above concentration range throughout the entire range of iodine culture, but is not necessarily limited to this. In particular, it is preferable to adopt a method in which iodine is cultured to some extent in a medium that does not contain iodine ions, etc., and then iodide, which is an ion source such as iodine ions, is added to the medium and the culture is continued.
In addition, due to reasons such as the concentration of iodine ions, etc. increasing incorporation into iodine during the culture,
There may be cases where the concentration is 0.5 ppm or less.
However, in the medium containing iodine as a seed, the concentration of iodine ions, etc. should always be 0.1 ppm or more.
The most preferred method is to carry out culturing while maintaining the concentration preferably from 0.5 to 800 ppm. For this reason, it is preferable to adopt a method of adding an ion source to the culture medium continuously or intermittently during the culture. Further, the ion source may be added only once, and it is of course possible to maintain the above concentration without adding an ion source. In any case, the iodine culture in a medium containing iodine ions, etc. is carried out for at least 1 hour.
Preferably, the duration is 1 day, especially at least several days. As the iodine culture medium, a normal iodine culture medium can be used except for the presence of the above-mentioned iodine ions. The usual iodine culture medium is fresh water containing the following carbon sources, nitrogen sources, inorganic sources, and others, but depending on the above-mentioned circumstances, salt water such as seawater or brine may be used.
As the carbon source, carbon dioxide gas; acetic acid, citric acid, succinic acid, and other organic acids and their salts; glycol, sucrose, galactose, and other sugars; ethanol, amino acids, peptides, and other organic substances can be used. As the nitrogen source, ammonium salts, nitrates, ammonia, urea, amino acids, etc. can be used. Inorganic sources include compounds such as phosphorus, sulfur, potassium, magnesium, iron, manganese, cobalt, molybdenum, zinc, and copper. Additionally, other nutritional sources and growth promoters may be used, such as yeast extract, molasses, hormones, etc. These components may be included in the compound used as an ion source such as iodine ions. For example, if potassium is required, potassium iodide can be used as a potassium source. Currently, in commercial iodine cultivation, organic compounds such as acetic acid are used as carbon sources along with carbon dioxide gas. However, cultivation using only carbon dioxide gas as a carbon source is also known. In the present invention, an organic acid such as acetic acid, a salt thereof, or a saccharide is preferably used in combination with carbon dioxide gas as the carbon source, but carbon dioxide gas alone may be used as the carbon source.
The concentration of carbon sources in the culture medium, excluding carbon gas, is
Approximately 0.1 to 10% by weight is appropriate. Neither the inorganic sources nor the nitrogen sources are required in particularly large amounts; each is usually 1
% by weight or less, but is not limited thereto. It is preferable that the carbon source in particular be kept at a substantially constant concentration in the culture medium. For example, taking acetic acid as an example, the acetic acid concentration in the medium is preferably maintained at 5±3% by weight during the culture period. This is because acetic acid in this case can be used not only as a carbon source but also as a PH regulator of the medium. Adjusting the pH of the culture medium is important in suppressing the growth of various bacteria. Normally, chlorella can be cultured at a pH of 4 to 7, but if the pH is alkaline, bacteria can easily grow. The preferred pH is approximately 4.5 to 6. When acetic acid is used as a carbon source, this PH range can be maintained at the above acetic acid concentration. Furthermore, when acetic acid is not used, the pH can be adjusted with other acids. After the cultivation is completed, chlorella and water are separated by centrifugation or the like, and at the same time, washing is performed by washing with water to obtain chlorella with a low water content. This chlorella is then dried into products using methods such as spray drying and freeze drying. Drying is important in preventing deterioration of Chlorella, and currently the spray drying method is said to be the most preferred method, while the freeze drying method is said to be more likely to cause product deterioration because the enzyme activity is maintained. However, when extracting and utilizing not only Chlorella itself but also components such as physiologically active substances in Chlorella, the freeze-drying method is considered more preferable because it can extract components without causing deterioration of the components. . EXAMPLES The present invention will be specifically explained below using Examples, but the present invention is not limited to these Examples. Example 1 Chlorella pyrenoidosa and Chlorella ellipridea were cultured using a culture solution having the composition shown in Table 1 below. Table 1 Tap water 20 Acetic acid 1Kg KNO ₃ 5g KH ₂ PO ₄ 5g MgSO ₄・7H ₂ O 10g Iron citrate 0.04g MnCl ₂ 0.02g Add the above culture solution 40 to a 60-liter culture tank, and add about 5g of Chlorella seed stock. (in terms of dry weight) and cultured under a light irradiation intensity of 500 to 20,000 lux while performing aeration at room temperature. The PH of the culture solution was measured, and when the PH increased during the culture period, acetic acid was repeatedly added to keep the PH of the culture solution in the range of 4.5 to 6.5. 0.8g of potassium iodide was added to the culture solution 10 days after the start of culture, and then 13 days after the start of culture.
0.8g was added to the culture solution. The algae were harvested 20 days after the start of culture, and the algal bodies were separated by centrifugation, thoroughly washed with water, and freeze-dried. The yield was about 15g. When the iodine content in the dried chlorella obtained was analyzed using a fluorescent x-ray analyzer, it was found to be approximately 100 ppm.
It contained iodine. On the other hand, when the iodine content of Chlorella cultured in the same manner as above without adding potassium iodide to the culture solution was analyzed, it was confirmed that it did not contain iodine. Example 2 One 500 ml portion of the basic medium for chlorella culture shown in Table 2 was poured into Erlenmeyer flask 1 equipped with a ppm electrode, a medium supply tube, and a culture solution sampling tube, and the conditions were maintained at 120°C for 15 minutes. After sterilizing with
It was added to the medium at concentrations of 100, 300, 500, and 800 ppm. Next, the culture medium shown in Table 2 was cultured at 10Klux and 30°C with light irradiation while aerating air containing 5% carbon dioxide gas.
pyrenoidosa C-28) was planted in the Ellenmeyer flask (1) adjusted above, and irradiated with light at 10 Klux at 30°C, using a PH controller to maintain the pH in the culture medium in the range of 6.5 to 7.0 as shown in Table 3. Shaking culture was performed while automatically adding supplementary medium (PH3.5). Figures 1 to 5 show the growth of Chlorella over time and the amount of iodine taken into the algae.
It is a diagram. Chlorella growth does not contain iodine I ^-
= 0 ppm is the best control, but when the iodine in the medium was in the range of 100 to 800 ppm, both the growth rate of Chlorella and the yield of algae were almost the same. However, the amount of iodine uptake increased as Chlorella multiplied, and the iodine concentration in the medium was high, resulting in a large amount of iodine uptake. In addition, for iodine measurement, chlorella collected over time was thoroughly washed by centrifugation, and the chlorella dried by freeze-drying was subjected to oxidative decomposition using a mixture of chromic acid, chloric acid, and perchloric acid, and the decomposed liquid was treated with thiocyanic acid. The amount of iodine uptake was measured using the iron()-iodine contact reaction method.

【table】

[Table] Drug efficacy pharmacology test Antitumor effect (effect on Sarcoma-180 solid cancer) (Method) ⁶ Sarcoma-180 1×10 cells were subcutaneously transplanted into ICR mice (5-week-old male), and from the next day, the results were obtained according to the present invention. 5 g/Kg of freeze-dried freshwater chlorella was mixed into the feed, and after 4 consecutive feedings, 5 consecutive feedings were repeated from the 4th day. Tumor weight was measured on the 21st day after transplantation to determine the effect.

[Table] Chlorella Administration (Results) As shown in Table 4 below, the chlorella obtained according to the present invention showed an antitumor effect of about 37%. On the other hand, common freshwater chlorella promoted tumor growth, and marine chlorella slightly inhibited tumor growth.

【table】

【table】 [Brief explanation of drawings]

Figures 1 to 5 are graphs showing the amount of chlorella proliferation (PCV) and the amount of iodine taken up in the grown chlorella against the culture time, and Figure 1 shows the amount of iodine ions in the culture solution [ ^- ] If is 0,
Figure 2 shows the case of 100ppm, Figure 3 shows the case of 300ppm, Figure 4 shows the case of 500ppm, and Figure 5 shows the case of 500ppm.
The case of 800ppm is shown.

Claims (1)

[Claims] 1 Iodine ion and/or iodate ion
A method for producing high-iodine-containing freshwater chlorella, which is obtained by drying freshwater chlorella containing 0.1 to 800 ppm and cultured in the presence of light under a medium pH of 4 to 7.The iodine content is 100 ppm or more.