WO2002046104A1

WO2002046104A1 - High-density adsorbents of bacteria, closed circulatory system containing the same for fish farming and fish fry culture and fishes fed by using this system

Info

Publication number: WO2002046104A1
Application number: PCT/JP2001/010412
Authority: WO
Inventors: Satoshi Yoneda; Kimihiro Egawa
Original assignee: Bicom Corporation
Priority date: 2000-12-08
Filing date: 2001-11-28
Publication date: 2002-06-13
Also published as: JPWO2002046104A1; AU2002224123A1

Abstract

A closed circulatory system for fish farming and fish fry culture containing high-density adsorbents of bacteria in which microbial cells of nitrifying bacteria and denitrifying bacteria are fixed at a high density. This system is composed at least of a water tank unit for fish farming, a pH-controlling unit, an oxygen-supplying unit for elevating the dissolved oxygen concentration, a nitrifying reactor unit and a denitrifying reactor unit. Water discharged from the fish-farming water tank is purified via the pH controlling unit, the oxygen-supplying unit, the nitrifying reactor unit and the denitrifying reactor unit and then returned into the farming fish-water tank. A high-density adsorbent of nitrifying bacteria, in which nitrifying bacteria cultured at a high density have been fixed, is provided in the nitrifying reactor unit, while a high-density adsorbent of denitrifying bacteria, in which denitrifying bacteria cultured at a high density have been fixed, is provided in the denitrifying reactor unit. Also, a chemical solution storage tank is connected directly to the pH-controlling unit so that the pH value of the farming water can be controlled in the pH-controlling unit with a solution of a mixture of sodium carbonate with sodium hydrogencarbonate.

Description

Description Bacterial high-density adsorbent, closed-circulation aquaculture seed and seedling production system incorporating it, and fish and shellfish grown by this system

TECHNICAL FIELD The present invention relates to a high-density bacterial adsorbent, and more particularly, to a high-density bacterial adsorbent comprising a large number of microbial cells fixed on an adsorbent substrate. Or denitrifying bacteria on the body substrate such as non-woven fabric

(cells / m 1), a high-density bacterial adsorbent on which cells are established at a concentration of at least a high concentration, and a closed-circulation cultured seedling production system incorporating the high-density bacterial adsorbent (hereinafter simply referred to as It also refers to “aquaculture systems”), and also relates to fish and shellfish raised by the aquaculture systems.

In the specification of the present application, for example, “a cell concentration of 109 (cells / m 1) or more” means that the corresponding number of bacteria (the number of viable bacteria) is recognized. The measurement of the viable cell count can be determined by a conventionally known method. .

[Background technology] Nitrifying bacteria (ammonium oxidizing bacteria and nitrite oxidizing bacteria) ゃ Denitrifying bacteria (nitrate oxidizing bacteria) have been found to be present because they grow slowly and do not live as colonies. Until today, more than a hundred years ago, there have been no reports of successful industrial high-volume cultivation.

In other words, conventional culture methods are test tube-level small It was an imitation, and the culture medium in the flask was not suspended in about two months, so it could not be said that it was an industrially applicable culture method.

To add an explanation, when nitrification starts in the culture of nitrifying bacteria, the pH drops. Conventionally, it has not been known how to increase this pH effectively. On the other hand, although the carbon source decreases with nitrification, carbon dioxide was conventionally used as a carbon source supply. The supply of carbon dioxide can certainly prevent the depletion of the carbon source, but as mentioned above: the further decrease in H, and in turn the cessation of nitrifying bacteria, is the limit of bacterial growth. there were.

Accordingly, a high-density bacterial adsorbent, in which microbial cells of nitrifying bacteria and denitrifying bacteria are established at a high density, cannot be obtained naturally. For example, the adsorbent can be used as a bioreactor or biosensor. When used as a carrier for holding microbial cells in, or when applied to terrestrial aquaculture systems, there was a problem in terms of efficiency (efficiency).

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a high-density bacterial adsorbent in which microbial cells of nitrifying bacteria, sulfur-oxidizing bacteria, or denitrifying bacteria are established at a high density. The present invention provides a closed-circulation aquaculture and seed production system incorporating the above-mentioned high-density bacterial adsorbent, and further provides fish and shellfish grown by the aquaculture system.

-[Disclosure of the Invention] The first invention is a bacterial high-density adsorbent comprising a large number of microbial cells fixed on an adsorption substrate, wherein the microbial cells are nitrified bacteria or sulfur, each of which is cultured at high density. _C , a bacterial high-density adsorbent characterized by being oxidizing bacteria A second invention is a bacterial high-density adsorbent in which a large number of microbial cells are fixed on an adsorption substrate, wherein the microbial cells are denitrified bacteria cultured at high density. It is a bacterial high density adsorbent.

According to a third aspect of the present invention, the breeding water discharged from the breeding aquarium includes at least a breeding aquarium unit, a pH control unit, an oxygen supply unit for increasing dissolved oxygen, and a nitrification reaction tank unit. A closed-circulation aquaculture and seed production system configured to be purified by passing through an H control section, an oxygen supply section, and a nitrification reaction tank section, and returned to the rearing tank. Further, there is provided a closed circulation type aquaculture and seed production system, wherein the nitrification reaction tank section is provided with the high-density bacterial adsorbent according to any one of claims 1 to 6.

A fourth invention is a fish or shellfish that has been raised by the closed-circulation type culture and seed and seedling production system according to any one of claims 12 to 14.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic explanatory view showing an example of a sludge nitrification acclimation apparatus.

Fig. 2 is a curve showing the concentration of remaining NH4-N 4 hours after injection of NH4-N (10 Om gZ liter), and shows the change of NH4-N concentration during the nitrification acclimation process of sludge. FIG. The symbol “丄” in the figure indicates the introduction of NH4-N (1 O OmgZ liter).

FIG. 3 is a graph showing the daily change of the MLSS concentration during the nitrification acclimation process of sludge.

FIG. 4 is a graph showing the change over time of the sulfur oxidation rate.

FIG. 5 is a schematic explanatory view showing an example of a sludge denitrification acclimation apparatus. Fig. 6 is a graph showing the daily change of NO3-N concentration in the process of denitrification of sludge.

FIG. 7 is a schematic explanatory diagram showing an example of a closed farming seedling production system on land.

[Best Mode for Carrying Out the Invention] Binder

A binder can also be used to fix the microbial cells on the adsorption substrate. The binder that can be used in the present invention and the binder that fixes the cells on the adsorption substrate are not particularly limited as long as the cells can be fixed on the adsorption substrate while they are alive. .

Specific examples include cross-linked polyvinyl pyridinum halide, agar, K-force larginan, calcium alginate, photocurable resin, polyacrylamide, etc., especially nitrifying bacteria, sulfur oxidation Biel-based copolymers such as crosslinked polyvinylpyridinium halides have the property of adsorbing bacteria and sulfur yellow bacteria efficiently and being able to capture and fix the cells at a high density. Preferably, it is used. Since this compound is insoluble or hardly soluble in water and soluble in organic solvents, it can be dissolved in organic solvents and treated as a solution when surface treatment is performed on an adsorption substrate, and used in water In this case, there is no adverse effect such as elution, which is convenient. That is, for example, the above-mentioned vinyl copolymer can be dissolved in an organic solvent such as methanol, and this can be applied to the adsorbent substrate by, for example, spraying or applying (surface processing).

For the preparation of the above-described bridged polyvinyl pyridinylbenzoyloxy © beam sweep de it may follow the conventionally known production method described in _JP-three to 4 7 5 3 6 No. c Briefly, 4-butylpyridine is copolymerized with a monobutyl monomer (eg, ethylene, propylene, styrene, vinylinole acetate, atalinoleic acid, acrylonitrile, etc.), and then the halide (alkyl halide, quinoline, Benzyl genoide, pentaphlorenophenylphenyl phenol).

Adsorption substrate

As the adsorption substrate that can be used in the present invention, a porous substrate is preferable because the surface area is large, so that the cells can be fixed at a higher density. Specific examples of the porous substrate include a nonwoven fabric, a knitted fabric (a knitted fabric, a woven fabric), an aggregate of porous inorganic materials such as silica zeolite, and a foam. One of these may be used alone, or two or more thereof may be used in combination.

It is most preferable to use a nonwoven fabric in terms of ease of processing into a binder, a wide surface area, and easy handling. Above all, the cross-sectional shape of the fibers constituting the non-woven fabric should be ☆ (it should be a three-dimensional non-woven fabric having a radial cross-sectional shape and a linear joint inside). This is preferable in that the surface area is further increased. Such a nonwoven fabric can be manufactured based on the technology disclosed in Japanese Patent No. 2881672.

Further, a product obtained by subjecting a nonwoven fabric produced using a fiber (polyester fiber) having a star-shaped cross section to the above-mentioned cross-linked polypyridinium halide treatment is commercially available (Bioflex®). (Registered trademark), manufactured by Japan Vilene Co., Ltd., with an area of 103 to 106 _m2 per _m3 ).

'' Activated sludge

The activated sludge used in the present invention includes sewage sludge and night soil sludge. This They may be freshwater-diluted or seawater-diluted, but nitrate bacteria ゃ sulfur-oxidizing bacteria or denitrifying bacteria can be obtained from seawater-diluted sludge. If cultured, marine nitrifying bacteria, marine denitrifying bacteria, and marine sulfur-oxidizing bacteria, which are considered to be rare, can be obtained in large quantities, and marine bacterial cells can be established on the above-mentioned adsorption substrate. It is preferable to use seawater-diluted activated sludge.

To add an explanation, natural seawater contains marine nitrifying bacteria, which are considered to have higher salt tolerance than freshwater nitrifying bacteria, but their abundance is very small and pure separation is difficult. However, its research is delayed compared to freshwater nitrifying bacteria. However, according to the culture method of the present invention, a high concentration of marine nitrifying bacteria can be obtained by using the activated sludge that has been subjected to the seawater dilution treatment as described above as a raw material. Marine nitrifying bacteria have multiple cell walls and are strongly resistant to various chemicals that inhibit osmotic pressure change and growth of treated water. The same applies to sulfur oxidizing bacteria and denitrifying bacteria.

Mixture (sodium bicarbonate and sodium carbonate)

The following embodiments can be considered as a mixture for promoting the high-concentration bacterium of the mixture used both in the pH adjustment and the carbon source used in the present invention. That is,,

1. When the autotrophic bacterium is acclimated for a predetermined period of time in order to culture it at a high concentration, the pH of the medium, which is inclined to the acidic side in the acclimation process, is maintained within a predetermined range, and the autotrophic bacterium high-concentration cultivation promoter as a carbon source And a property capable of maintaining the pH of the culture medium that exhibits basicity by dissociation and leans toward the acidic side within a predetermined range, and a property that can serve as a carbon source during growth of the autotrophic bacterium. If the two properties can be provided by one kind of compound, at least one kind of the compound, or if the above two properties can be given by two or more kinds of compounds, a mixture of such compounds It is characterized by being compounded Autotrophic bacteria high concentration culture promoter.

2. The mixture is below the component (A) and (B) be a mixture of ingredients. Autotrophic bacteria-enriched cultures promoters described in paragraph 1 above, wherein the ₍

(A): alkali metal carbonate or alkaline earth metal carbonate.

(B): alkali metal bicarbonate or alkaline earth metal bicarbonate _t

3. The high concentration culture of autotrophic bacteria according to the above item 2, wherein the mixing ratio of the component (A) and the component (B) is 1: 1.4 / 7 to 177 in molar ratio. Accelerator.

4. The autotroph according to any one of the above items 2 or 3, wherein the component (A) is sodium carbonate, and the component (B) is sodium bicarbonate. Bacterial high concentration culture promoter.

(Concrete example)

The components of the above-mentioned accelerator include the property of exhibiting basicity by dissociation and maintaining the pH of the medium, which is inclined toward the acidic side during acclimation, within a predetermined range (7.0 to 9.0), The compound is not particularly limited as long as it has two properties, that is, a property that can serve as a carbon source during the growth of the autotrophic bacterium.

When the above two properties can be imparted by one kind of compound, at least one kind of the compound is a component of the accelerator of the present invention.

Specific examples include trisodium hydrogen bicarbonate (= sodium sesquicarbonate) (Na2C03-NaHCO3.2H2O), and sodium in this compound being converted to potassium magnesium. Compounds partially or wholly substituted are mentioned.

When the above two properties can be provided by two or more compounds, a mixture of the compounds is a component of the accelerator of the present invention. For example, a mixture of (A) a carbonate which is soluble in water and exhibits basicity by dissociation, and (B) a bicarbonate which is soluble in water can be mentioned. Examples of the component include hydroxides such as sodium hydroxide and potassium hydroxide and alkali metal salts such as sodium carbonate. The component (B) includes sodium hydrogen carbonate, magnesium carbonate (4 mg 0 3.. Carbonate such as Mg (OH) 2 · 5H 2 O).

Among them, the component (A) is an alkali metal carbonate or an alkaline earth metal salt that is soluble in water, such as sodium carbonate, sodium potassium carbonate, potassium carbonate, etc., and the component (B). Is a water-soluble alkaline metal bicarbonate or an alkaline earth metal bicarbonate that is soluble in water, such as sodium bicarbonate and lithium bicarbonate. It is preferable in that it can be added to the water, and among them, a combination of sodium carbonate and sodium hydrogen carbonate is most preferable.

Closed-circulation aquaculture and seed production system

The culture system of the present invention enables not only fry, but also fertilized eggs (fertilized eggs such as o 'nikkoze, flounder, and tiger gull) to grow into fry and produce so-called seeds and seedlings. Since such seedling production does not allow seawater to enter from outside, there is no transmission by pathogens that enter the breeding water during breeding without vertical transmission from the parent fish.

In addition, since it is possible to produce up to the time of landing without replenishing seawater during the breeding period, the amount of breeding water used is 30- There is a 60-fold difference, and it is thought that the location conditions of the production site will be expanded while saving breeding water.

Culture (acclimation) conditions for nitrifying bacteria

The culture of nitrifying bacteria contained in the activated sludge is performed by nitrifying the activated sludge with a sludge treatment wastewater such as a sludge dewatered filtrate (anaerobic) digestion / desorption solution for a predetermined period (for example, 1 month, 2 months or more). The nitrification must be performed aerobically, and the dissolved oxygen (D O) must be 2 mg / liter or more. However, for the first time in this experiment, it was found that if the dissolved oxygen concentration was too high, the growth rate would tend to decrease. The details will be described below.

It was thought that the higher the dissolved oxygen, the higher the rate of nitrification by nitrifying bacteria, and the higher the dissolved oxygen, the higher the rate of nitrification acclimation. It was found that the accumulating rate of nitrifying bacteria using sludge as raw material was reduced at a rate exceeding about 5 mgZ liter of dissolved oxygen (DO). The dissolved oxygen (DO) concentration is most preferably 2 to 4 mg Z liter.

Further, the pH must be 7.0 to 9.0, (especially when using activated sludge diluted with seawater), preferably 7.5 to 8.5, and more preferably 7.5 to 7.8. preferable.

Regarding the cultivation temperature, the growth speed is high in the range of 20 to 40 ° C, and more preferably 25 to 35 ° C.

In the course of the cultivation, the pH decreases and the alkalinity decreases. That is, the oxidation of NH4 + to NO 2-by the ammonia-oxidizing bacteria and the oxidation of NO 2-to NO 3-by the nitrite-oxidizing bacteria are as follows:

(A) and (B). Equation (C) is an equation for the entire nitrifying bacteria.

(Ammonia oxidizing bacteria)

NH4 + + 1.502 → N02- + H2〇 + 2H + …… (A) (Nitrite oxidizing bacteria)

N〇2 一 + 0.5 02 → Νθ3 一 ( ⁰ no

(Mixed system)

ΝΗ4 + + 2.0 02 → Ν03- + Η2〇 + 2Η + …… (C) From these, 4.57 mg O 2 / mg NH4-N oxygen is required to oxidize NH4-N to Νθ3-N, and hydrogen ions are released as the nitrification reaction proceeds. It can be seen that as the pH of the culture system decreases, the degree of reaction decreases. Since the culture speed decreases with a decrease in pH, unless the pH is maintained at a predetermined value by using a buffer or the like, the activity of the microorganisms stops as in the conventional method.

Therefore, in the present invention, it is considered that a compound having a buffering effect by mixing a normal salt and an acid salt with pH, which is inclined toward the acidic side in the culture process, is suitable. As a result of repeated trial and error with the compounds, it was found that it is most preferable to restore pH by introducing a culture promoter composed of a combination of sodium carbonate and sodium hydrogencarbonate.

In general, it is known that the synthesis reaction of bacterial cells can be expressed by the following equation c

4C02 + HC03 + NH4 + + H20 → C5H7N02 + 502

If this is applied to the biochemical reaction formula of the mixed culture system (C) described above, it is roughly as follows.

ΝΗ4 + + 1.86 02 + 1.98 HC〇3-→

0.021 C5H7N02 + 0.98 Νθ3- + 1.04 Η2θ + 1.88 H2C03

As is clear from the above equation, culturing nitrifying bacteria requires a large amount of carbon source even when compared to the energy substrate, ammonium ion.

As mentioned above, the combination of sodium carbonate and sodium bicarbonate By supplying a cultivation promoter consisting of a mixture, a carbon source for carbonic assimilation of nitrifying bacteria can be supplied at the same time. The explanation is added below.

When only sodium carbonate is used, the effect of increasing pH is sufficiently recognized even though the sodium carbonate is strong, but the effect of increasing pH is large, so that a large amount of sodium carbonate is used. They are unusable and unsuitable for providing sufficient carbon sources. On the other hand, when only sodium bicarbonate is used, there is no problem in terms of supply as an inorganic carbon source, but a large amount of supply is required in terms of maintaining pH, which is not preferable.

In view of such advantages and disadvantages, a mixture of sodium carbonate and sodium hydrogencarbonate can be suitably used. By using an aqueous solution of the mixture, it became possible to effectively supply an inorganic carbon source for assimilation of carbonic acid in a living body while maintaining a gradually decreasing pH.

The mixture ratio of sodium carbonate and sodium hydrogencarbonate in the mixture is preferably sodium carbonate: sodium hydrogencarbonate in a molar ratio of 1: 4/7 to 17-7, specifically, carbonic acid Sodium hydrogencarbonate is 4 7 (0.571) ... mo 1 / litre to 1 7 "7 (2.428 8 ■■) mo for 1 mo 1 / liter of sodium A 1 / litre mixed aqueous solution is effective.

The monitoring of the pH of the culture system may be performed continuously or at predetermined time intervals. It is preferable to use a continuous pH monitoring device such as a pH controller, but the present invention is not limited to this, and it is also possible to carry out manually by using a pH indicator such as phenol red.

The concentration of ammonia in the NH 4 —N-containing liquid is preferably not less than 100 mgZ liter and not more than 300 mgZ liter, and more preferably not more than 200 mg / liter. Ammonia is an energy source for the growth of ammonia-oxidizing bacteria, which are chemoautotrophic bacteria, by assimilating carbon dioxide. There is, however, an excess may rather inhibit growth. In addition, nitrite oxidizing bacteria contained in activated sludge, like ammonia oxidizing bacteria, are weak against high nitrite concentrations, despite being oxidized by taking over nitrous acid produced by ammonia oxidizing bacteria. The initial concentration cannot be set unnecessarily high. Therefore, the concentration of ammonia

If it exceeds 300 mg / liter, it is preferable to appropriately dilute with seawater or fresh water.

As the NH 4 —N-containing liquid, it is preferable to use sludge treatment waste liquid such as sludge dewatered filtrate or digestion / desorption liquid generated in the water treatment plant.

Under the above culture conditions, activated sludge is nitrified by sludge treatment wastewater such as sludge dewatered filtrate and digestion desorbent, so that nitrifying bacteria slightly contained in the activated sludge can be cultured at a high concentration. However, in addition to this, according to the present invention, the activated sludge can be reduced to 1Z3 to 1Z4 in 2 months, and nitrified sludge having a large specific gravity can be obtained.

In other words, nitrifying bacteria are 0.35 ° / in the activated sludge. It is said to contain a certain amount. By accumulating activated sludge using such activated sludge as a raw material in an NH4-N-containing liquid for about two months, the content of nitrifying bacteria in the activated sludge can be increased by about 10 times (3.5%). ). In the process, other germs cannihilate and die because no external nutrients (feeds) are provided. As a result, when almost all of the _c- bacteria that reduce the amount of activated sludge cease to die, they become highly refractory organic matter called "granules", which are attached to nitric bacteria around the core. Persistent organic matter attached to nitrifying bacteria sediments in the culture system due to its specific gravity. In order to culture nitrifying bacteria at a high concentration, this good sedimentation property is required. In other words, nitrifying bacteria generally have a low specific gravity and float in pure culture. Therefore, nitrifying bacteria flow out of the culture system.

12 Therefore, high concentration culture cannot be expected. As a result, the production of nuclei (refractory organic substances) as described above is required for high-concentration culture, but nucleation is not seen in pure culture of nitrifying bacteria, and is not active. Only seen when sludge is used as raw material.

Culture (acclimation) of denitrifying bacteria

Cultivation of the denitrifying bacteria contained in the activated sludge is performed by subjecting the activated sludge to a predetermined period.

(For example, 1 month, 2 months or 3 months), it is carried out by denitrification with NO3-N containing solution.

The denitrification reaction is a reaction that oxidizes an organic energy source (described later) as a hydrogen donor using molecular oxygen in NO 3-in a NO 3 -N-containing liquid. In other words, the denitrification reaction is an organic oxidation reaction that uses NO 3-instead of oxygen as the final hydrogen acceptor, and is expressed by the following equation.

Νθ3-+ AH2, → A + Η2θ + N2

Therefore, since the denitrification habit must be performed anaerobically, the dissolved oxygen (DO) is 2 mgZ liter or less, preferably lmg / liter or less. More preferably, 0.5 mg gZ liter or less. (That is, it is necessary to create conditions that allow nitric acid respiration).

The pH may be in the range of 6.0 to 9.0, but if anything, it is preferable to be inclined toward the alkali side. Specifically, pH 6.5 to 8.5 is preferable, pH 7.0 to 8.5 is more preferable, and ρρ7.5 to 8.5 is more preferable.

The cultivation temperature must be 10 to 40 ° C, since the activity is rapidly reduced if the temperature is lower than 10 ° C, preferably 15 to 30 ° C, and 25 to 30 ° C. ° C is more preferred. As the NO3-N-containing liquid, a nitrification acclimation treatment liquid generated when culturing nitrifying bacteria using activated sludge as a raw material (see the preceding section) can be used.

As mentioned above, organic matter must be supplemented externally as a hydrogen donor and as a carbon source for cell synthesis. As such an external organic substance, the use of methanol is preferred because a higher growth speed can be obtained. It is preferable in that it is inexpensive and easily available. In addition, ethanol can be used instead of methanol or in combination with methanol.

The concentration of methanol and / or ethanol to be added is not particularly limited, but the concentration of CH30H (mg / liter) / NO3-N (mgZ liter) must be 3.0 or more in terms of methanol. Is preferred. According to the present invention, it is possible to provide a high-density bacterial adsorbent in which microbial cells of nitrifying bacteria and denitrifying bacteria are colonized at a high density. Incorporation into a seed and seedling production system makes it possible to purify breeding water extremely efficiently, and furthermore, by raising fish and shellfish using the aquaculture system, it is possible to obtain a very pure and safe fish and shellfish that is not infected by viruses. Kind can be obtained.

Hereinafter, an example of the present invention will be described, but the present invention is not limited thereto.

Example 1

(High concentration culture of nitrifying bacteria (manufacture of activated nitrifying sludge))

Batch culture was performed in a 2-day cycle in a fillanddraw type culture tank (30 liters) shown in Fig. 1. That is, urine sludge diluted with seawater and anaerobic digestion / desorbed liquid (diluted in seawater so that the concentration of NH4-N is 10 OmgZl) are put into the culture tank, and the temperature in the culture tank is thermostated. The pH and the pH of the pH controller and culture promoter (Na 2 CO 3 at 0.5 mo 1 Z liter and 1 mo 1 liter) (Na HCO 3 buffer) was used to maintain the culture at 7.5 to 8.5 (when the initial pH was 8.5 or more, dilute sulfuric acid was added. 8.5 or less). The amount of aeration was adjusted with a baloon so that the dissolved oxygen (DO) concentration was 4 mg / "liter.

One day after the start of the aeration, the replenisher / desorbed solution was added so that the final concentration would be lOOmgZ liter. On the second day, the aeration was stopped, the sludge was settled for 1 hour, and the supernatant was removed. Then, the digestion / desorption solution was added, and the aeration was restarted.

Since the salt concentration of the original seawater diluted urine sludge reaches 80% of the seawater ratio, the habituation starts from the seawater ratio of 80%, and lO Omg / liter of NH4—N is completely NO 3— after one day of culture. The seawater ratio was raised to 100% when nitration began to occur.

Since the NH4-N concentration decreases linearly for several hours after the start of aeration, the remaining NH4-N concentrations at 0, 1, 2, 3, and 4 hours after the start of aeration are measured, and the NH4-N concentration is measured. The rate of change was determined from the slope of the section where changes linearly, and the value obtained by dividing this by the MLSS concentration was used as the nitrification rate (see the following equation).

R d NH4— N 1

NH4-N = ''

d S

ΡΐΝΗ4-Ν: Nh — N decrease rate (mg—NH4—NZg—MLSS · hr)

S: Sludge MLSS concentration (gZ litre) SV30 and SVI of seawater acclimated nitrifying activated sludge (AMNS) that had been acclimatized after a seawater acclimation period of about 60 days were measured, and sedimentation characteristics were examined. Next, the state of floc formation was observed using an optical microscope.

The graph of Fig. 2 shows the process of acclimating human sludge to seawater (the figure shows the concentration of NH4-N at a concentration of 10 Omg / liter after 4 hours).

From the graph in Fig. 2, it can be seen that two months after the start of acclimation, it is possible to prepare AMN S that can almost completely nitrify 100 nig Z liter of NH4-N at a seawater ratio of 100% in 4 hours. . In order to prevent the loss of nitrification activated sludge due to the shortage of inorganic carbon sources, pH adjustment using an inorganic carbon source combining NaHC03 and Na2C〇3 was adopted. As shown in Fig. 3, the MLSS concentration of AMNS could be doubled compared to that before acclimation.

The nitrification rate of nitrifying bacteria in AMN S is shown in the table below.

[table 1 ]

* Unit of nitrification rate: mg—NH4—NZg—MLSS · hr

It is reported that the abundance of nitrifying bacteria in activated sludge is about 0.35%. From this calculation, it was found that nitrifying bacteria in seawater acclimated nitrifying activated sludge (AMNS) had a high concentration (about 3.5 %).

(Cell density: 1 09 or more _{_{_{(c e 1 1 s / m}}} 1)

When the culture tank is allowed to stand, bacterial flocs can be confirmed, and most of the bacterial flocs precipitate because the specific gravity is heavier than seawater. This is not seen in the pure culture of each of the ammonia oxidizing bacteria and the nitrite oxidizing bacteria. It appears in mixed culture using mud as a raw material. Microscopic observation of the AMNS floc revealed that the sludge consisted of flocs of 50 to 100 µm in diameter. In addition, the observation of AMNS with a scanning electron microscope (SEM) revealed that the sludge floc contained granules consisting of 20 to 100 filamentous fungi-adhesives. Then, when SV30 and SVI of AMNS were determined, they were 9% and 42.6 as shown in Table 1 above, indicating that the sedimentation was excellent. From this, it was clarified that nitrification-activated sludge having high activity in seawater (and even in freshwater) can be mass-produced in a very short period of time from seawater-diluted human waste treatment plant sludge.

The advantages of mixed cultivation using activated sludge as compared with pure cultivation of individual ammonium oxidizing bacteria and nitrite oxidizing bacteria are as follows.

In a pure culture system, ammonia and nitrite are separately required as energy substrates, but in a mixed culture system, only ammonia needs to be supplied as an energy substrate. In a pure culture system, it is extremely difficult to grow the cells at a high concentration, but in a mixed culture system, it is easy to grow to the extent that the medium is suspended. This is presumed to be due to the ecology of ammonia-oxidizing bacteria and nitrite-forming bacteria that do not form colonies and flocs within their cognate and live a floating life.

The marine nitrifying bacteria obtained in this way have been deposited at the National Institute of Advanced Industrial Science and Technology (FERM BP-7150, Tsukuba East 1-chome, Ibaraki, Japan 1-1-1 Central No. 6 [TEL: 0298-61-62029], Date of deposit: April 27, 2000, Identification: BI COM Nitrifying Bacteria S WA QSP—78).

Example 2 (Culture of sulfur oxidizing bacteria)

Basically, it is sufficient to follow the same culture method as for the high concentration culture of nitrifying bacteria described above. Therefore, a brief description is given below.

Put the sludge returned from the sewage sludge treatment plant in a 5-liter beaker so that the MLSS concentration becomes 1300 mg ZL, and use the sulfur-oxidizing bacterial medium shown in [Table 2] below to limit the amount of the repetitive half-day cycle. The oxidized sludge was acclimated by the operation method (CF-ROM method). The culture temperature was maintained at 25 to 27 with a heater and thermostat, and the pH was a mixture of NaHCO3 and Na2CO3 (NaHC03: Na2C03 = l. 0: 0.5) was adjusted within the range of 7.0 to 7.8.

As a result, the MLSS concentration could be increased to 600 mg ZL.

[Table 2]

Na2S203-5H20 1 g K2HP04 4 g,

KH2 Ρθ4 4 g NH4C 10 .5 g

Mg S04-7Η2θ 0.8 trace metal mixture * 0.1 ml yeast extract 300 mg deionized water 1 V bottle trace metal mixture *

Z n S 04 70 Omg C o C.12,6Η2θ 3 Om g

NaMo 2-2Η2θ 10 Omg KC 1 10 Om g

Mn S 04 100 Omg KA1 (S04) 2 2H20 10 Oing

CuS04-7H20 5 Omg EDTA 975 mg Deionized water 1 liter

The resulting sulfur-oxidizing bacteria (cell density:. 1 0 ⁹ or more (measured sulfur oxidation rate of the ce 1 1 s _ m 1) The measurement method described below, shows the results in Figure 4.

Method: Measure the sulfate ion concentration in the medium over time, and calculate the sulfate ion change rate from the slope of the section where the sulfate ion changes linearly. The value divided by the LSS concentration was defined as the sulfate ion generation rate (MLSS = 600 mg / L). As a result, a result was obtained in which the sulfate ion generation rate was 100 mg / g · r or more (specifically, 160 mgZg'hr).

Attempts to deposit the sulfur-oxidizing bacteria obtained in this way at the Patented Microorganisms Depositary Center of the National Institute of Advanced Industrial Science and Technology were rejected ([Identification of microorganisms: BIC OM Sulfur B acteri urn FWAQ]). However, the sulfur-oxidizing bacteria that have been rejected are stored by the following corporations, and a system is in place to receive an application for sale from a third party. Must be concluded. The following is the request for the microbial distribution contract and the application for the microbial distribution application.

“Pycom Co., Ltd., Toyonaka, Osaka Prefecture, 1-4-2, Shinsenri-Higashi-cho, Senri Life Science Center (〒 560-0-082), TEL: 06—4 8 6 3—75 0 0 (alternative)].

Example 3

(High concentration culture of denitrifying bacteria (production of denitrification activated sludge))

Batch culture was performed in a two-day cycle in a fililanddraw type culture tank shown in FIG.

In other words, 12 liters of activated sludge from a human wastewater treatment plant, which had been diluted with seawater, was placed in a denitrification tank, and then diluted with seawater to 20 liters. Next, a nitrification acclimation treatment solution (a solution containing NO 3 —N) generated by culturing nitrifying bacteria and methanol having a concentration three times the NO 3 —N concentration were added.

The temperature of the denitrification tank was maintained at 27 ° C with a thermostat and a heater, and the rising pH was maintained at 7.0 to 8.5 with a pH controller and hydrochloric acid or sulfuric acid. Stir at 70 rpm with a stirrer, settle sludge for 1 hour on the second day, remove the supernatant, and then nitrate acclimation treatment containing methanol three times the concentration of -NO3-N Pour the liquid And stirring was resumed. Seawater acclimation started at a seawater ratio of 75% because the original salinity of the sludge was at a seawater ratio of 75%.

Fig. 6 shows the process of acclimating seawater to human waste treatment plant sludge. The figure shows the initial NO3-N concentration, the residual Νθ3-N concentration after 4 hours of culture, and the seawater ratio. The seawater ratio was increased to 100% when the N03-N concentration of 10 OmgZ liters was completely denitrified one day after culture. After 10 days of habituation, 10 Omg / liter of Νθ3-N was almost denitrified after 1 day of culture, so the seawater ratio was increased to 100% and the denitrification activity was further increased. To increase the sludge activity and MLSS concentration, the initial NO3-N concentration was increased to 150 mg / litre and 200 mg Z litre.

As a result, after 25 days of seawater acclimatization (within 1 month), seawater acclimated denitrification activated sludge (AMD S), which can denitrify and remove 20 Omg of NO3-N in 4 hours of culture, was developed. Could be prepared. (Cell density: 1 0 ⁹ or (cells / m 1))

The denitrification rate of sludge from the night soil treatment plant and the denitrification rate of AMD S before habituation were calculated based on the following formula, and are shown in [Table 3] below. The rate of change was determined from the slope of the section where NO3-N changes linearly within a few hours after the start of stirring, and the value was divided by the sludge concentration to obtain the denitrification rate (see the following equation).

D H dN〇3— N

N03-N =

d S h N03-N: Νθ3— N decrease rate (mg— Νθ3— NZg— MLSS · hr)

S: Sludge MLS S concentration (gZ liter) [Table 3]

* Unit of denitrification rate: mg—N〇3—NZg—MLSS · h

One month after acclimation in seawater, a denitrification activated sludge having a denitrification activity of 16.1 mg-NO3-N / g-MLSS / hr in seawater was prepared. The denitrification rate of AMD S is one order of magnitude higher than the specific denitrification rate reported in sewage treatment (0.04 to 0.08 g—N / g—ML SS · day). It is thought that nitrifying bacteria have become the dominant species.

The above-mentioned denitrification activity is more than 25 1111 £ -N-g-MLSS Shr after two months of acclimation in seawater.

AMD S was observed with a scanning electron microscope (SEM).

A granule of 00 μm was formed. When the flocs of AMDS were observed with an optical microscope, there were many flocs with a diameter of 20 to 100 μπι in the sludge. As shown in Table 3, SVI and SV30 of AMD S showed good sedimentation characteristics at 34.4 and 11 ° / ₀ .

An attempt was made to deposit the marine denitrifying bacteria obtained in this manner at the Patented Microorganisms Depositary Center of the National Institute of Advanced Industrial Science and Technology, and it was rejected (a rejection certificate was obtained. Marine denitrifying bacteria [Identification of microorganisms: BIC OM D enitrifying B acter

1 a S WAQ SP— 2 1] is stored by the following corporation and The company has a system to receive an application for the sale of a microorganism, but it is necessary to conclude a contract with the microbiological custodian prior to the application for the sale. Microbial consignment contract request The request for microbial consignment application form is also below. "Bicom Co., Ltd., Toyonaka, Osaka Prefecture, Chisen Higashicho, 1-4-2, Senri Life Science Center (〒 560-00 82), TEL: 06-48 63-750 ].

Example 4 (a)

(Manufacture of high-density adsorbent for nitrifying bacteria)

A non-woven fabric (Pyofrex (registered trademark), manufactured by Nippon Pyreen Co., Ltd., 1 L of dice-like filter medium) is placed in a nitrifying bacteria culture tank (ML SS = 6,000 mg / L) for 24 hours (infiltration), and drained for 1 minute. As a result, a high-density nitrifying bacteria adsorbent was obtained in which the high-concentration nitrifying bacteria were fixed on the adsorption substrate.

The nonwoven fabric described above is obtained by copolymerizing 4-vinylpyridine and a monobutyl monomer, and then subjecting a vinyl copolymer obtained by the action of a halide to a surface treatment on a base material. The type of fiber used is a polyester fiber with a fineness of 22.5 denier, a thickness of 9 mm, and a basis weight of 250 g / m 2.

Example 4 (b)

'' (Manufacture of high-density adsorbent for denitrifying bacteria and sulfur-oxidizing bacteria)

Although the description is omitted, the high-density denitrifying bacteria and the high-density sulfur-oxidizing bacteria artificially cultured as described above are also treated in the same manner as the nitrifying bacteria (see Example 4 (a)), and the nonwoven fabric (Bioflex ( (Registered trademark) and Nippon Vilene Co., Ltd.) to obtain a high-density adsorbent for denitrifying bacteria and a high-density adsorbent for sulfur-oxidizing bacteria.

Example 5

The measurement conditions were as follows, comparing the retention capacity (adsorption amount) of microbial cells using various adsorption substrates. In other words, the bacteria used were nitrifying bacteria (a 10 L culture medium in CGY medium; viable cell count: 4.1 X 109 (cells no m 1)), which was used for pretreatment for viable cell count measurement. An ultrasonic treatment device (manufactured by Kaijo, CA—44488Z, 38KHZ) was used.

The results are shown in [Table 4] below.

[Table 4]

* 1: (Pioflex (registered trademark), manufactured by Japan Vilene Co., Ltd.)

* 2: Beads (diameter 3 mm)

* 3: Beads (diameter 3 mm)

Example 6

(Onshore closed circulation type aquaculture system)

As an example of using the bacterial high-density adsorbent obtained by the present invention, a land-based closed-circulation aquaculture system will be described with reference to FIG. As shown in the figure, from the breeding aquarium (1), which contains a large number of fish and shellfish, for example, larvae o-kokose and prawns, together with artificial seawater (breeding water). Is discharged. This effluent contains ammonia nitrogen (NH4-N). In the sedimentation tank, solids precipitate and the supernatant is filtered through a micro-staring filter (3) by a pump, where fine solids are removed.

The artificial seawater that has passed through the filter flows into a pH control tank (4) also serving as a water level control tank, where the pH of the artificial seawater is maintained at about 7.7. This pH adjustment has a mechanism in which a chemical solution flows from a pH chemical solution storage tank (16) to a pH control tank (4) by a pump as appropriate. In this example, the composition of this chemical solution is composed of a mixture of sodium carbonate and sodium hydrogen carbonate, and the molar ratio thereof is, for example, sodium carbonate: sodium hydrate carbonate = 0.5: 1.0. It is.

The artificial seawater whose pH has been adjusted is discharged in two directions from the _PH control tank (4). One of them flows into the gas-liquid contact tank (9) through the titanium chiller (7), which is thermally connected to the air conditioner (8), by the circulation pump (5). The gas-liquid contact tank (9) is supplied with liquid oxygen from the liquid oxygen tank (14), which increases the amount of dissolved oxygen in the artificial seawater.

On the other hand, the water flows into the ozone tank (10) by the circulation pump (6) through the titanium chiller (7), which is thermally connected to the air conditioner (8), as described above. Ozone is supplied to the ozone reaction tank (10), and the artificial seawater is sterilized by the ozone. The ozone is supplied from the oxygen generator (13) by the ozone generator (1). Since it was converted by 2), the amount of dissolved oxygen also rises slightly here. The ozone reaction tank (10) has a foam separation function, so Bubbles generated when raw can be removed. As the foam separation mechanism, a conventionally known mechanism can be adopted.

The artificial seawater via the gas-liquid contact tank (9) and the ozone reactor (10) flows into the microbial nitrification reactor (11), respectively. In this example, the microbial nitrification reaction tank (11) into which the artificial seawater flows through the gas-liquid contact tank (9) and the microbial nitrification reaction tank into which the artificial seawater flows through the gas-liquid contact tank (9) Although the two tanks (11) are provided, the present invention is not limited to this, and a single microbial nitrification reactor (11) may be used.

In any case, inside the microbial nitrification reaction tank (11), a plurality of the nitrifying bacteria high-density adsorbents (not shown) obtained in the above example are mounted in a stacked state.

A portion of the artificial seawater heading for the microbial nitrification reactor (11) is piped to flow to the denitrification tank (15). Inside the denitrification tank (15), similarly to the microbial nitrification reaction tank (11), a plurality of sheets of the high-density adsorbent for denitrifying bacteria (not shown) obtained in the above example are mounted in a stacked state. ing.

In other words, part of the artificial seawater circulating in this closed-circulation type aquaculture system is taken out and taken into the denitrification tank (15), and the artificial seawater generated by the microbial nitrification reaction tank (11) is denitrated in the denitrification tank (15) After converting nitrate ions in the seawater to nitrogen gas, the artificial seawater is returned to the circulation flow.

In short, the ammoniacal nitrogen generated by breeding (farming) of fish and shellfish in the breeding aquarium (1) is oxidized by nitrifying bacteria at a high concentration fixed on the nitrifying bacteria high-density adsorbent to be converted to nitrate nitrogen, Nitrogen is further oxidized to nitrogen gas by the denitrifying bacteria contained in the high concentration of the denitrifying bacteria high-density adsorbent. After the nitrogen compounds in the wastewater have been converted to nitrogen gas in this way, they are returned to the rearing tank (1) again. The denitrification tank (15) must capture organic matter from the outside as a hydrogen donor and as a carbon source for cell synthesis. For this purpose, in the present embodiment, as shown in the figure, a storage tank for supplying methanol, that is, a methanol chemical storage tank (17) is provided. Methanol is supplied from the methanol chemical storage tank (17) to the denitrification tank (15) by a pump. The denitrification tank (15) is provided with a denitrification tank stirring pump (18) for stirring the inside.

In the closed land circulation type aquaculture system in this example, all environmental conditions such as breeding water temperature, dissolved oxygen, pH, illuminance, and water flow are controlled by a computer in a room such as a factory. Since it can be managed, labor is not required and breeding costs are low, so production costs can be reduced. In addition, there is no need to continuously or intermittently pump artificial seawater from the ocean into the breeding aquarium, so there is no need to worry about invasion of pathogens such as viruses, and there is no need to discharge breeding water. There is no need to worry about causing contamination. In other words, the conventional culture involves pumping seawater from the ocean and putting it into a breeding aquarium, so there was always a risk that the farmed fish would be infected by viruses in the ocean. However, in the aquaculture system of the present embodiment, since the breeding water is circulated and used, there is no fear of virus invasion.

Therefore, the seafood obtained by the on-shore closed circulation type aquaculture system of the present invention is very pure, and it can be said that it is a safe seafood that could not exist on the earth until now.

Further, as described above, the land-based closed-circulation aquaculture system of the present invention provides a pH chemical solution storage tank (16) capable of adding a chemical solution comprising a mixture of sodium carbonate and sodium hydrogencarbonate to a breeding aquarium. It has. This not only makes it possible to adjust the pH of the circulating water, but also makes the chemical Since it becomes a carbon source for nitrifying bacteria, it has the effect of two birds with one stone that nitrifying bacteria can grow on the high-density adsorbent for nitrifying bacteria.For example, in the breeding aquarium, the ammonia concentration increases with the growth of fish and shellfish. Even if it increases, it is not necessary to increase the amount of the nitrifying bacteria high-density adsorbent, and even if the ammonia concentration increases transiently, the already-supplied nitrifying bacteria high-density adsorbent should be sufficient. Can be.

Example 7

The change in NH4-H concentration due to the temperature of nitrifying bacteria in the microbial nitrification reactor (11) in the closed circulation type culture system was measured.

The results are shown in [Table 5] below.

^C " ^5] (Unit: mgZL)

adjusted to keep pH at 8.0 c

As can be seen from [Table 5], the nitrifying bacteria used in the culture system of the present invention can achieve a nitrification rate of lmg / g · hr or more even at a low temperature of 10 ° C. It is a very good fungus Call

Example 8

(Onshore closed circulation seedling production system)

Instead of putting fry in the breeding aquarium (1), 60,000 fermented eggs of Onyokoze were thrown in, and except as described below, seedling production (from fertilized eggs) Fry rearing).

That is, the breeding water temperature was maintained at 23 ° C to 23.5 ° C from fertilized egg storage to hatching, and was maintained at 24 ° C to 26 ° C after hatching.

The hatched larva opened on the second day after hatching and was ready for feeding. The feeds were pemushi (concentrated nannochlorobsis [concentrated nanno] and cultured for 24 hours in PSB (manufactured by Takara Shuzo KK)), Artemia larvae (Marin _α [manufactured by Nisshin Science KK]) and PSB [Takara Shuzo kk's cultured for 24 hours] and mixed feed (mixed feed for flounder, S-1 and S-2 [Higashimaru kk]) were used. In addition, during the feeding period of the deer, 250 ml of concentrated Nanno was added to the breeding water every morning.

Feeding Artemia larvae on day 10 confirmed feeding. On the 16th day after hatching, yellow pigment began to appear on the body surface, and on the 18th day, some individuals settled. On day 30, the average total length grew to 15 mm. At this time, the number of picked fish was 15,000, and the survival rate from hatched larvae was 30.0%.

The hatched larvae obtained by producing seeds and seedlings in this manner are further grown to adult fish by the aquaculture system of the present invention (see Example 6), so that they can be completely infected with 100% pure (pathogenic microorganisms such as viruses). No) Very safe seafood can be obtained. [Reference to deposited biological material]

① Name of the depositary institution:

National Institute of Advanced Industrial Science and Technology (AIST) Patent Organism Depositary Center (former depository name:

Ministry of International Trade and Industry, Institute of Industrial Technology, Institute of Biotechnology and Industrial Technology)

Address: Postal code 305—8 5 6 6

1-1-1, Higashi, Tsukuba, Ibaraki, Japan 1 Chuo No. 6 (former destination: 1-1-1, Tsukuba-Higashi, Ibaraki, Japan 3) TE L: 0 2 9 8-6 1-60 2 9

② Deposit date: April 27, 2000

③ Accession number: F ERM B P— 7 1 5 0

Claims

The scope of the claims

1. A high-density bacterial adsorbent in which a large number of microbial cells are established on an adsorbent substrate.

A high-density bacterial adsorbent, wherein the microbial cells are nitrifying bacteria or sulfur-oxidizing bacteria, each of which is cultured at high density.

2. The high-density bacterial adsorbent according to claim 1, wherein the nitrifying bacteria or sulfur-oxidizing bacteria are high-density bacteria of 109 (ceIls / ml) or more.

3. The high-density bacterial adsorbent according to claim 1, wherein the nitrification rate of the nitrifying bacteria at a water temperature of 10 ° C. is not less than 1. O Om gZ g-hr.

4. A high-density bacterial adsorbent in which a large number of microbial cells are established on the adsorbent substrate.

The microbial cells are nitrifying bacteria,

The nitrifying bacterium converts activated sludge such as sewage sludge and night soil sludge into dissolved oxygen for at least 2 mgZ liter, pH 7.0 to 9.0, and temperature of 20 to 40 ° C for a predetermined period. And nitrification with an NH4-N-containing solution, and the pH of the medium, which leans toward the acidic side during the acclimation process, is always maintained within the above range by introducing a culture promoter comprising a mixture of sodium carbonate and sodium hydrogen carbonate. A high-density bacterial adsorbent characterized by being a high-density nitrifying bacterium obtained by acclimatizing and accumulating nitrifying bacteria contained in the activated sludge.

5. A large number of microbial cells are fixed on the adsorption substrate via a binder, and the binder is a polybutylpyridinium halide that is insoluble or hardly soluble in water and soluble in an organic solvent. The high-density bacterial adsorbent according to any one of claims 1 to 4, characterized in that:

6. The high-density bacterial adsorbent according to any one of claims 1 to 5, wherein the adsorption substrate is a nonwoven fabric.

7. A high-density bacterial adsorbent in which a large number of microbial cells are established on the adsorbent substrate.

A high-density bacterial adsorbent, wherein the microbial cells are denitrified bacteria cultured at high density.

8. The high-density bacterial adsorbent according to claim 7, wherein the denitrifying bacterium is a high-density denitrifying bacterium of not less than 109 (cells / m 1).

9. A high-density bacterial adsorbent in which a large number of microbial cells are established on the adsorbent substrate.

The microorganism cells are denitrifying bacteria,

The denitrifying bacteria convert activated sludge such as sewage sludge and night soil sludge into dissolved oxygen of 2 mg or less at Z liter, pH 6.0 to 9.0, temperature of 10 to 40 ° C, and ROH as an external carbon source. (R is CH 3− and / or C 2H 5−) in the presence of NO 3 _N-containing solution for a predetermined period of time under denitrification and acclimation to accumulate denitrification bacteria contained in the activated sludge. Bacterial high-density adsorbent characterized by being a high-density denitrifying bacterium:

10. A large number of microbial cells have been established on the adsorption substrate via the binder.

The high-density bacterial bacterium according to any one of claims 7 to 9, wherein the binder is a polybutylpyridinium halide that is insoluble or hardly soluble in water, and is soluble in an organic solvent. Adsorbent.

1 1. The high-density bacterial adsorbent according to any one of claims 7 to 10, wherein the adsorption substrate is a nonwoven fabric.

1 2. A breeding aquarium unit, a pH control unit, an oxygen supply unit for increasing dissolved oxygen, and a nitrification reaction tank unit are provided at least. Closed-circulation culture and seedling constructed so that the breeding water discharged from the breeding water is purified by passing through the pH control part, the oxygen supply part, and the nitrification reaction tank part, and is returned to the breeding water tank again. Production system

A closed-circulation aquaculture and seed production system, wherein the high-density bacterial adsorbent according to any one of claims 1 to 6 is mounted in the nitrification reaction tank section.

3. The closed-circulation type culture and seed production system according to claim 12, wherein the pH of the breeding water in the pH control unit is adjusted by a chemical solution comprising a mixture of sodium carbonate and sodium bicarbonate. In addition, a chemical solution storage tank directly connected to the pH control unit is provided, so that the chemical solution serves as a carbon source for nitrifying bacteria. A closed circulation type aquaculture and seed and seedling production system, characterized in that it is not necessary to increase the bacterial high-density adsorbent even when the molar concentration increases.

4. The breeding water discharged from the breeding aquarium is provided with at least a breeding aquarium, a pH control unit, an oxygen supply unit for increasing dissolved oxygen, a nitrification reaction tank, and a denitrification tank. Is purified by passing through the pH control unit, the oxygen supply unit, the nitrification reaction tank unit, and the denitrification tank unit, and is returned to the breeding aquarium again. A seedling production system,

12. A closed circulation type aquaculture and seed / seedling production system, wherein the denitrification tank is equipped with the high-density bacterial adsorbent according to any one of claims 7 to 11.

5. A fish or shellfish that has been raised by the closed-circulation-type aquaculture and seedling production system according to any one of claims 12 to 14.