JP2001128663A - Culture substrate for alga - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare an inexpensive culture substrate for algae that can feed prescribed amounts of nutrients almost without adverse effect from external conditions, for example, outside air temperature and can save the labor for nutrient feeding. SOLUTION: Magnesium ammonium phosphate and magnesium potassium phosphate are used as main raw materials to prepare the objective alga culture substrate having a solubility of 0.001-0.5 g in 100 g of water or marine water. The culture substrate preferably includes, as trace nutrients, at least one selected from iron, manganese, zinc, cobalt, copper, silicic acid and their mixtures.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a culture substrate for algae which does not cause excessive concentration damage even when supplied in a large amount. More specifically, the present invention relates to a culture substrate for algae that can supply a fixed amount of nutrients without being substantially affected by external conditions such as the outside air temperature.

[0002]

2. Description of the Related Art There are an extremely large number of types of algae, some of which are artificially cultured in large quantities and used as feed for fish and shellfish, and as raw materials for foods and pharmaceuticals. is there.

It is difficult to prepare a medium suitable for culturing each type of algae, since the requirements for each nutrient vary depending on the type of the algae. Usually, various types of algae such as a Mickel culture substrate and an Elt-Schreiber culture substrate are used. An expensive general-purpose medium prepared to have an average nutrient composition so as to be able to culture is used.

[0004] Among various nutrients required by algae, elements such as nitrogen, phosphorus, and magnesium are essential components for physiological functions such as algal growth and photosynthesis. It is known that even if the amount is too small, the growth rate of algae is reduced.

[0005] Therefore, when mass-cultivating algae, it is important to control the concentration of each nutrient in the culture medium. The concentration is constantly controlled, and a culture medium is supplied each time the concentration falls below a specified concentration so that each nutrient concentration can be adjusted appropriately. The method of keeping it within the range is taken.

On the other hand, magnesium ammonium phosphate and magnesium potassium phosphate are inexpensive compounds generally used as slow-acting, non-burning inorganic fertilizers in the fields of agriculture and horticulture.

[0007]

In a mass culture system of algae, a highly soluble culture medium is preferable in terms of immediate effect because all of the supplied culture medium immediately dissolves and diffuses. Before the high concentration of nutrients is used by algae, some nutrients flow out of the system together with drainage, etc., resulting in inefficient use of the nutrients. There was a problem.

[0008] Therefore, it is necessary to frequently supply a culture substrate having high solubility, and there has been a problem that it is extremely troublesome and costly.

When a culture substrate having high solubility is used,
Since nutrients increase rapidly and temporarily immediately after supply, overgrowth and growth reduction of algae are repeated during long-term culture, resulting in unstable populations and making uniform quality control difficult. I was

On the other hand, in order to solve such a problem,
Development of a culture substrate having a sustained release property is being promoted. For example, Japanese Patent Publication No. 10-510508 discloses a fertilizer composition provided with a sustained release property by coating the culture substrate with a resin polymer or the like. Has been proposed.

[0011] However, the dissolution characteristics of such a coated culture substrate are liable to fluctuate depending on the outside air temperature. In particular, when used in a closed system, the dissolution characteristics of the culture substrate are directly affected by the outside air temperature. It was difficult to control the elution amount.

When a material that is hardly decomposed, such as a resin polymer, is used as the coating material, the resin polymer or the like remains as a shell after the culturing base material has been eluted, and this remains floating in the water. There has been a problem that the device, piping, drain port, and the like are clogged. Therefore, such a coated culture substrate cannot be sprayed freely, and must be used by suspending it in water in an appropriate container or the like. And in such a supply method, supply of a nutrient becomes local, and it was difficult to supply a nutrient uniformly.

[0013] Furthermore, the coating type culture substrate has a problem in terms of cost because the processing cost of coating is high.

Therefore, an object of the present invention is to provide an inexpensive algae culture medium that can supply a fixed amount of nutrients without being largely affected by external conditions such as the outside air temperature, and that does not require much labor for the supply. To provide materials.

[0015]

Means for Solving the Problems In order to achieve the above object, the present inventors conducted research and development on a culture substrate suitable for culturing algae. As a result, surprisingly low solubility of magnesium phosphate and Found that magnesium potassium phosphate stabilizes the growth of algae for a very long time,
The present invention has been completed.

That is, the present invention relates to a culture substrate for algae, which contains magnesium ammonium phosphate and magnesium potassium phosphate, and has a solubility of 0.001 to 0.1 g in 100 g of water and seawater. 5 g of a culture substrate for algae.

[0017] The culture substrate may be used as a trace element,
It is preferable to contain at least one selected from iron, manganese, zinc, cobalt, copper, silica, and a mixture thereof.

The culture substrate for algae of the present invention is mainly composed of magnesium ammonium phosphate and magnesium potassium phosphate having low solubility, so that even if supplied in large quantities, there is no danger of causing excessive concentration damage. In addition, it is possible to supply a certain amount of nutrients almost without being affected by external conditions such as the outside air temperature. Therefore, by supplying a large amount of the main culture substrate at a time, nutrients can be supplied stably over a long period of time, and furthermore, the main culture substrate is completely lost after use, and Nutrients can be supplied evenly by simply dispersing the nuts, and there is no need to supply nutrients.

[0019] Since magnesium ammonium phosphate and magnesium potassium phosphate are very inexpensive compounds, the culture substrate itself can be produced at low cost.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The culture substrate for algae of the present invention contains magnesium ammonium phosphate and magnesium potassium phosphate as main components.

Magnesium ammonium phosphate is hardly soluble in water, and its solubility at 25 ° C. is 0.014 g for monohydrate and 0.018 g for hexahydrate per 100 ml of water. Similarly, potassium magnesium phosphate is poorly soluble in water, and its solubility is 0.21 g for monohydrate and 0.1 g for hexahydrate.
23 g.

In the present invention, both magnesium ammonium phosphate and magnesium potassium phosphate have the same meaning.
Either hydrate or hexahydrate may be used, but monohydrate is preferred from the viewpoint of nutritional component concentration and heat stability.

In the culture substrate for algae of the present invention, the mixing ratio of magnesium ammonium phosphate and magnesium potassium phosphate is 80 to 50:20 to 50, more preferably 75 to 60:25 to 40 by weight. And the total amount is 50 to 100% by weight, more preferably 80 to 100% by weight.

The culture substrate for algae of the present invention preferably further contains, as a trace element, at least one selected from iron, manganese, zinc, cobalt, copper, silica and a mixture thereof.

The above-mentioned trace elements are appropriately selected depending on the type of algae to be cultured.
01-1.0%, manganese 0.01-1.0%, zinc 0.005-1.0%, cobalt 0.005-1.0
%, Copper 0.001-0.5%, silicic acid (as Si) 1
It is preferable to add in the range of 10% to 10%. Specifically, the following compounds can be exemplified.

Iron: FeNH ₄ PO ₄ .H ₂ O Manganese: MnNH ₄ PO ₄ .H ₂ O Zinc: ZnNH ₄ PO ₄ .H ₂ O Cobalt: CoNH ₄ PO ₄ .H ₂ O Copper CuNH ₄ PO ₄ .H ₂ O • Silicic acid: lime, silicate, potassium silicate, sodium silicate In addition to the above-mentioned trace elements, Na is also selected depending on the type of algae.
_An appropriate amount of other elemental components such as ₂ SO ₄ , K ₂ SO ₄ , and MgSO ₄ may be added.

The culture substrate for algae of the present invention having the above composition preferably has a solubility in water at 25 ° C. and 100 g of seawater of 0.001 to 0.5 g. When the solubility is less than 0.001 g, nutrients cannot be sufficiently supplied into the culture medium even when the culture substrate is supplied, and when the solubility exceeds 0.5 g, when the culture substrate is supplied in a large amount. It is not preferable because there is a possibility that an excessive concentration disorder may occur.

In the present invention, the algae preferably refers to those belonging to the green plant phylum, the yellow plant phylum, the haptophyte, the cryptophyta, or the red plant phylum, and include, for example, brassinophyta, haptoalga, and true-eye algae. And diatoms. Specific examples of these algae include pavlova, nannochlorosis, tetracermis, isochrysis, salaceosila, thietoceros, and the like. These algae are algae that are good foods for shellfish such as oysters.

The culture substrate for algae of the present invention can be produced, for example, by the method described in JP-A-5-319966 by the present applicant. That is, 0.5 to 10% by weight of water is added to a mixture of monoammonium phosphate, monopotassium phosphate and basic magnesium and mixed, then finely pulverized, and further water is added, and the pulverized material is placed in a container. Preferably, it can be produced by stirring and aging while maintaining the temperature at 75 ° C. or higher. After aging, granulation may be performed using an appropriate means such as an extruder.

When the above-mentioned trace elements and other elemental components are added, it is preferable to add them in the above-mentioned production method when water is added to each of the culture base material mixtures and mixed.

The method of using the culture substrate for algae of the present invention is not particularly limited, and may be used by appropriately dispersing it in an algae culture tank or the like. Further, the present invention can be applied not only to cultivation of algae but also to cultivation of fish and shellfish which feed on algae. That is, by supplying the culture substrate for algae of the present invention to a fishery pond or the like, stable growth of the algae becomes possible, and promotion of the growth of fishes and shellfishes that feed on the algae is also expected.

[0032]

EXAMPLES The present invention will be described below in detail with reference to production examples and examples. Production Example 1 50.7 kg of monoammonium phosphate (N: 12.0%, soluble phosphate: S · P ₂ O ₅ : 54.0%), potassium monophosphate (W · K ₂ O: 34.4%, W · P ₂ O ₅ : 51.9
%) 17.7 kg, magnesium hydroxide (C.MgO:
64.0%) To 31.6 kg, add 2000 cc of water,
The mixture was mixed by a mixer (ribbon mixer) for 5 minutes, and immediately pulverized by a pulverizer (hammer mill) so as to pass through an 80-mesh sieve. This pulverized product was placed in a ribbon mixer kept at 80 ° C., and aged while stirring for 30 minutes. During the ripening, steam was violently generated and the water was boiling. As a result, a dry powder having a moisture content of 3% by weight was obtained without drying.

The solubility of this culture substrate in 100 g of water and seawater is 0.42 g (water) and 0.35 g at 25 ° C.
(Seawater), at 45 ° C., 0.71 g (water) and 0.60 g (seawater).

Production Example 2 Ferrous chloride 198.8 g, manganese chloride 19.8 g, zinc chloride 1.36 g, cobalt chloride 1.0 g, copper chloride 1.
To 70 g of the mixture, 155 g of 85% phosphoric acid and 2500 water
g was added to the reaction vessel, and then neutralized to pH 7.5 with 25% aqueous ammonia, followed by heating and aging at 80 ° C. for 3 hours.
After aging, the reaction solution was cooled to 30 ° C. and filtered under reduced pressure to collect a precipitate. The precipitate was dried at 100 ° C. for 3 hours to obtain 197.1 g of a powder.

10 g of this powder (iron 5.
4 g, manganese 0.5 g, zinc 0.06 g, cobalt 0.06 g, and copper 0.06 g) and 90 g of the culture substrate obtained in Production Example 1 were mixed to obtain a culture substrate containing a trace element.

The solubility of this culture substrate in 100 g of water and seawater is 0.29 g (water) and 0.24 g at 25 ° C.
(Seawater), at 45 ° C., 0.49 g (water) and 0.41 g (seawater).

Example 1 Algae were cultured by the following method, and the amount of proliferation was determined by measuring the change over time in the cell density.

Culture conditions Test plot: Using the algae culture substrate obtained in Production Example 1, the concentration of phosphorus contained in the Mikkel culture medium (phosphorus 29
(0 mg / L), and the amount was changed so as to be equivalent, 10-fold, and 100-fold. Control group: Concentration of commonly used main components (nitrogen 17
5 mg / L, phosphorus 290 mg / L, potassium 181 mg / L
L) Mickel's culture medium was used. Test phytoplankton: Prasinoalga Tetraselmis sp. The initial density of the plankton was 300,000 cells / ml. Incubator: Flat flask Amount of culture solution: 3 L Incubation temperature: 20 ° C. Incubation period: 15 days Light source: A halogen lamp is irradiated from one side of the incubator so that the light irradiation intensity becomes 500 μm. Time, dark 8 hours.

The results are shown in FIG. 1 (in FIG. 1, Δ: Mickel culture substrate, Δ: Culture substrate of the present invention (equal amount), ●: Culture substrate of the present invention (10-fold amount), ▲: The culture substrate of the present invention (10
0 times the amount)).

From the results shown in FIG. 1, it was found that the culture substrate for algae of the present invention had the same growth effect as the Mickel culture substrate. In addition, even when the main culture substrate was supplied in a large amount (10 to 100 times), a decrease in proliferation which was considered to be caused by excessive concentration damage was hardly observed.

Example 2 Example 1 was performed using the culture substrate for algae obtained in Production Example 2.
In the same manner as the plasinoalga Tetrasel
mis sp) was measured. The results are shown in FIG. 2 (in FIG. 2, Δ: Mickel culture substrate, Δ: culture substrate of the present invention (equivalent), ●: culture substrate of the present invention (10 times), ▲: culture substrate of the present invention Material (100 times amount)).

From the results shown in FIG. 2, it was found that the culture substrate for algae of the present invention had the same growth effect as the Mickel culture substrate. In addition, even when the main culture substrate was supplied in a large amount (10 to 100 times), a decrease in proliferation which was considered to be caused by excessive concentration damage was hardly observed.

[0043]

As described above, the culture substrate for algae of the present invention does not cause excessive concentration damage even when supplied in a large amount (10 to 100 times the usual amount) at one time. It is possible to supply a certain amount of nutrients almost without being affected by external conditions such as the outside air temperature. Furthermore, the nutrients can be supplied uniformly over a long period of time only by dispersing them in place without completely disappearing after use and remaining in the culture medium, so that the supply method is very simple.

[0044] Magnesium ammonium phosphate and magnesium potassium phosphate, which are the main components of the main culture substrate, are very inexpensive compounds, and the culture substrate itself can be produced at low cost.

[Brief description of the drawings]

Fig. 1 Effect of the concentration of the main culture substrate on the culture of tetracelmis

Fig. 2 Influence of the concentration of the main culture substrate to which a trace element is added in the culture of tetracelmis

Claims (3)

[Claims] 1. A culture substrate for algae, comprising magnesium ammonium phosphate and magnesium potassium phosphate, wherein the solubility of the culture substrate in 100 g of water and seawater is 0.001 to 0.5 g. Substrates for culture. 2. The culture substrate for algae according to claim 1, further comprising at least one selected from the group consisting of iron, manganese, zinc, cobalt, copper, silica and a mixture thereof as a trace element. 3. The phylum green plant, the yellow plant phylum,
The culture substrate for algae according to claim 1 or 2, which is an algae belonging to the phytophyta, the cryptophyta, or the red plant phylum.