JPH0984528A - Feed for pisciculture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a pisciculture feed containing an oligopeptide produced by hydrolyzing wheat protein and effective for decreasing the damage in fishery by improving the resistance of cultured fish to streptococcicosis and lowering the mortality of fish caused by the deterioration of the culture field environment e.g. by the generation of water mass having low oxygen content. SOLUTION: This feed contains an oligopeptide produced by hydrolyzing wheat protein or corn protein (preferably an oligopeptide having a peptide chain length of 2-6). The hydrolysis can be carried out e.g. by using an alkaline protease originated from alkalophilic bacteria preferably at pH9-11 and 50-60 deg.C for 5-30hr using 0.1-1g (20,000-200,000 unit) of the alkaline protease based on 100g of the protein substrate. The oligopeptide is preferably added to a feed at a ratio of 0.01-1% and administered at a daily rate of 25-500mg in terms of the peptide based on 1kg of the fish.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD [0001] The present invention improves the resistance to streptococcal disease of farmed fish and other bacterial diseases in which the pathogen entry site is mainly the digestive tract and resistance to environmental deterioration such as hypoxic water mass. The present invention also relates to a feed for improving the survival rate and improving the survival rate and growth of these cultured fish.

[0002]

2. Description of the Related Art With the development of aquaculture, the aquaculture farms are integrated into aquaculture areas in all suitable places for aquaculture such as inland bays throughout the country. As a result, pathogenic bacteria of various diseases become resident, and the disease has become chronic. Various antibiotics, synthetic antibacterial agents, etc. are used as measures against this,
Due to the emergence of resistant bacteria to these drugs, complete treatment and control cannot be performed, and a great deal of damage is incurred each year.

Further, damage to the fishing industry due to deterioration of the fishing ground environment such as eutrophication of coastal sea areas and self-pollution of farms in recent years is also a serious problem. The appearance of low oxygen water mass is one of the ocean phenomena that is thought to occur due to the deterioration of the fishing ground environment. This phenomenon frequently occurs during the early fall of the temperature and the cultured fish are exposed to and harmed by the low oxygen water and sulfides and other harmful substances that have risen from the sea floor. However, at present, no effective means has been developed to prevent the fishery damage caused by this low oxygen water mass.

In recent years, as measures against fish diseases, not only symptomatic treatments with these antibacterial antibiotics but also disease prevention with vaccines and immunostimulants have been actively conducted, but it can be said that its practical application has just begun. See. For example,
In fish vaccines, only some fish species such as Vibrio disease vaccines and some diseases have already been put to practical use, and in the immunostimulant, bacterial cell components or glucans extracted from bacterial cell components have been used. The polysaccharides used are only partially utilized [Fish Disease Research 29 , 1, 11 (1994), Fish Disease Research 29 , 2, 73 (1994)].

On the other hand, in the field of food industry, the functionality of plant protein-derived peptides such as corn peptide (corn protein hydrolyzing peptide) and wheat peptide (wheat protein hydrolyzing peptide) has been attracting attention in recent years [food and development 27 , 46
(1992)], the use development of soybean peptides is being promoted for the purpose of nutritional supplementation and suppression of disease occurrence in fish farming [Monthly Food Chemical Foods and Development 8 , 64 (1988)].
However, there are no reports of using corn peptide (maize protein hydrolyzing peptide) or wheat peptide for the prevention of bacterial diseases in fish, and no report of using it for enhancing the resistance of fish.

[0006]

DISCLOSURE OF THE INVENTION The object of the present invention is to improve the anti-disease properties against streptococcal disease, which is chronically observed in cultured yellowtail, and the environment of aquaculture farms such as hypoxic water lumps that suddenly occur. It is intended to provide feed for reducing the mortality rate of farmed fish due to deterioration and reducing damage to fisheries.

[0007]

[Means for Solving the Problems] As a result of intensive studies to solve the above problems, the present inventors have found that a feed containing a peptide derived from a plant protein such as wheat protein hydrolyzed peptide and corn protein hydrolyzed peptide has been added. To improve the disease resistance against bacterial diseases such as Streptococcus pneumoniae, and to enhance resistance to deterioration of the farm environment such as hypoxic water mass, thereby increasing the mortality rate of these cultured fish. It was found that the above-mentioned decrease was achieved, and the present invention was completed. TECHNICAL FIELD The present invention relates to a fish feed containing a peptide derived from a plant protein such as a wheat protein hydrolyzed peptide and a corn protein hydrolyzed peptide.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the cultured fish of the present invention include yellowtail, amberjack, red sea bream, flounder, and tiger puffer fish. The wheat or corn protein-derived hydrolyzed peptide used in the present invention is a peptide having a peptide chain length of 2 to 20, which is obtained by hydrolyzing a protein of wheat or corn origin by acid, alkali, heat, or enzymatic treatment with various proteases. Among them, a peptide containing an oligopeptide consisting of 2 to 6 amino acids as a main component is preferable.

The peptide is described in JP-A-2-295437,
It can be obtained according to the method described in JP-A-2-49579, JP-A-5-236909, JP-A-6-245790 and the like. That is, it can be obtained by combining acidic, neutral, and alkaline protease treatments. Examples of the acidic protease include microbial proteases such as rapitase (manufactured by Takeda Chemical Co., Ltd.), morcin (manufactured by Sigma), and animal-derived proteases such as trypsin and pepsin.

The acid protease is used in a proportion of 0.05 to 2 g (10,000 to 800,000 units), preferably 0.1 to 1 g (20,000 to 400,000 units) per 100 g of the substrate protein. The hydrolysis treatment with acidic protease is usually performed at pH 3 to 4, 20 to 60 ° C. for 5 to 24 hours.

The alkaline proteases are microbial-derived proteases such as Alcalase 0.6L, Esperase 8.0L, Savinase 8.0L (all manufactured by Novo Industry Japan), Orientalase 2
2 (manufactured by Ueda Chemical Industry Co., Ltd.), Protin A (manufactured by Daiwa Kasei Co., Ltd.), alkaline protease (manufactured by Meito Sangyo Co., Ltd.) derived from an alkalophilic bacterium ( Bacillus No. 221), and the like.

Alkaline protease is a substrate protein 10
0.05 to 2 g per 0 g (10,000 to 400,000 units),
It is preferable to use it at a rate of 0.1 to 1 g (20,000 to 200,000 units). The hydrolysis treatment with alkaline protease is usually pH 8 to 12, preferably pH.
9-11, 40-70 ° C, preferably 50-60 ° C, 5
Do for ~ 30 hours.

As the neutral protease, a microbial or plant-derived neutral protease can be used. Protease Amano N (manufactured by Amano Pharmaceutical Co., Ltd.), Aroase AP-
10 (manufactured by Yakult), Orientase 90N (manufactured by Ueda Chemical Industry Co., Ltd.), Protin PC10F (manufactured by Daiwa Kasei Co., Ltd.) and the like. The neutral protease is used in a ratio of 0.05 to 2 g (20,000 to 800,000 units), preferably 0.1 to 1 g (10,000 to 400,000 units) per 100 g of the substrate protein.

Hydrolysis treatment with a neutral protease is
Usually pH 5-8, 40-60 ° C, preferably 50-6
Perform at 0 ° C. for 5 to 30 hours. The hydrolysis treatment with the protease may be performed alone or in combination. The hydrolyzed peptides derived from wheat or corn protein used in the present invention include, in addition to the peptides obtained by the above-mentioned hydrolysis treatment, plant protein SK-5.
(Chiba Flour Milling Co., Ltd.), Pepcino (Nippon Shokuhin Kako Co., Ltd.), and other commercially available peptide chain lengths of 2 to 20, especially 2 to 6
It is also possible to use a wheat or corn protein-derived hydrolyzed peptide having an oligopeptide consisting of individual amino acids as a main component.

As the feed to which the hydrolyzed peptide derived from wheat or corn protein is added, an extruder molding machine is used in which gluten, alpha starch and water are added as binders to powder raw materials such as fish meal, krill meal, wheat flour, fats and oils, vitamins and minerals. Solid dry blended feed molded into pellets and dried with fresh fish such as sardines, mackerel, lizard, minced frozen fish, and powder of the above compounded feed not minced into pellets and minced raw feed. After mixing at a ratio of 1: 1 to 1: 5, a moist pellet feed molded by a pelleter can be used.

The hydrolyzed peptide derived from wheat or corn protein is added to a commonly used feed in a proportion of 0.01 to 1%, and 10 mg to 1000 mg / day, preferably 25 mg, of peptide per 1 kg of cultured fish weight. Dosage of ~ 500 mg / day. The administration method was as follows.
The intermittent administration is performed at a rate of -10% every day, every other day, or 5 days a week.

[0017]

The present invention will be described below in detail with reference to examples. [Example 1] Wheat protein (gluten) was added to 50 parts of sardines minced and 50 parts of powdered yellowtail compound feed (New Hamachi Moist S manufactured by Maruha Co., Ltd.) to make a total of 100 parts.
1% or enzymatically hydrolyzed wheat protein (hereinafter referred to as "wheat peptide") obtained in Reference Example 1 below, and corn peptide "pepticino" (peptide obtained by enzymatically hydrolyzing corn protein: Nippon Food Chemistry) (Manufactured by the company) was mixed with 0.01%, 0.1%, and 1% to prepare mixed feeds. The moist feed shown in Table 1 was prepared from the mixed feed using a moist pelleter (manufactured by Sanko Techno Co., Ltd.). The shape of the moist pellets was 5 mm in diameter and 10 mm in length.

[0018]

[Table 1]

1m ^{3 of} 160 juvenile yellow-tailed fish with an average weight of about 100 g were divided into 8 groups of 20 fish each and placed in the laboratory.
It is housed in 8 round plastic water tanks, and
1, 2, 3, 4, 5, 6, 7, and 8. Test area-
1, the test feed-1 shown in Table 1, the test plot-2, the feed-2, the test plot-3, the feed-3, the test plot-4, the feed-4, and the test plot- 5 was fed with feed-5, test plot-6 was fed with feed-6, test plot-7 was fed with feed-7, and test plot-8 was fed with feed-8, respectively, and raised for 3 weeks. .
About 5% of the body weight of the test fish was administered. Therefore, the dose of pepticino per 1 kg of fish weight was
5 mg / day in 3 and test section-6, test section-4 and test section-
50 mg / day for 7 and 50 for test plots 5 and 8
It became 0 mg / day.

After 3 weeks from the breeding test, an infection attack test with streptococcal causative bacteria was carried out on each test plot. The infection attack test method was carried out by orally administering the Streptococcus erieriocida ( Enterococcus seriolicida ) cells cultured in a brain heart infusion liquid medium at 25 ° C. for 24 hours to the test feed-1 shown in Table 1. The dose was 3 × 10 ⁸ cells / day as the viable cell count per test fish, which was administered for 3 days.

After the administration of the bacteria, the above test feed was again administered to each test section and the breeding was continued for 2 weeks, and the mortality during the period was observed. Water temperature was 25 ± 1 ° C., and the water exchange rate was 10 times / day. The test results are shown in Table 2.

[0022]

[Table 2]

[Example 2] A wheat peptide administration test was conducted on three net cages owned by one aquaculture producer in a yellowtail aquaculture fishery where 30 net cages measuring 10 m x 10 m x 8 m were installed. Carried out. Two sardines with three fish cages each containing 8,000 fish weighing about 750g and two frozen sardines
Oral feed consisting of moist pellets consisting of 1 part of mash for malt (Maruha Co., Ltd.), feed containing 0.1% wheat protein (gluten) in normal feed or 0.1% wheat peptide in normal feed Each of the prepared diets was administered in an amount of 4 to 5% of fish body weight per day.

The test is from August 1st to September 30th 2
It was carried out for a month, and the occurrence of diseases and deaths during that period were observed. The results are shown in Table 3.

[0025]

[Table 3]

During the test period, streptococcal disease occurred, and in the test group to which normal feed and wheat protein were added, death of 1.7 to 2.4 fish per day was observed on average per day, but wheat peptide was added. In the administered test group, the average of 1.0 fish per day in the cage was dying half that in the control group, and resistance to this disease was observed. In addition, a hypoxic water mass appeared in the sea area where the test was conducted on September 30, causing a large number of deaths of the cultured yellowtail in the sea area, and a large number of deaths were also seen in the cage during the test.

There were 1800 and 1750 dead fish in the cages of the test group to which the normal feed and wheat protein were added, respectively, but 180 cages were killed in the cage of the test group to which the wheat peptide had been administered, which was the control. It stayed at 1/10 of the ward. From this result, it was considered that the resistance of the cultured yellowtail to the deterioration of the fishing ground environment was significantly enhanced by the administration of the wheat peptide.

Reference Example 1 Production of Wheat Protein Enzyme Hydrolyzate 40 kg of wheat protein (gluten) was suspended in 400 L of water, and the pH was adjusted to 5.5 by adding dilute hydrochloric acid, and the raw starch degrading enzyme “Daviase” (Daikin Industry Co., Ltd.) was used. 50g)
Was added and reacted at 50 ° C. for 5 hours, followed by solid-liquid separation with a filter press to obtain a wet cake of wheat protein 35
I got kg. This wet cake was resuspended in 350 L of distilled water, sodium hydroxide was added to adjust the pH to 12, 80 g of alkaline protease / alcalase (manufactured by Novo Industry Japan) was added, and pH was 9.0.
It was made to react for 20 hours while adjusting to. After the reaction, the mixture was neutralized to pH 5.5 with sulfuric acid or hydrochloric acid, and then solid-liquid separated with a filter press to obtain an enzymatic hydrolyzate.

The hydrolyzate is desalted with an ion exchange resin,
Decolorization, deodorization, activated carbon treatment, heat sterilization and drying were performed to obtain a wheat protein enzyme hydrolyzate "wheat peptide" which was a white to pale yellow powder. The amino acid composition of the wheat peptide is shown in Table 4, and the HPLC pattern using a Shodex OHpak KB802.5 column is shown in FIG. HPLC was performed under the following conditions.

Column: Shodex OHpak KB802.5 Mobile phase: Acetonitrile: Water: Acetic acid = 40: 59.9: 1 (V / V) Flow rate: 0.5 ml / min Pressure: 30 kg / m ² Temperature: Room temperature Detector: HITACHI UV monitor L-4000,280nm Data processor: HITACHI D-2500

[0031]

[Table 4]

[0032]

INDUSTRIAL APPLICABILITY According to the present invention, improved resistance to bacterial diseases such as streptococcal disease of farmed fish whose pathogen entry site is mainly the digestive tract, and resistance to environmental deterioration such as low oxygen water mass. It is possible to provide a feed for improving the survival rate, improving the survival rate and promoting the growth of these cultured fish.

[Brief description of drawings]

FIG. 1 is a diagram showing an elution curve when the peptide composition obtained in Reference Example 1 was subjected to high performance liquid chromatography (HPLC).

[Explanation of symbols]

1 ... Albumin (molecular weight 43,000) 2 ... Ribonuclease A (molecular weight 13,700) 3 ... Tyrosine (molecular weight 187) and phenylalanine (molecular weight 165)

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Ichiro Matsuura 3-27 Nakadai, Itabashi-ku, Tokyo K-212

Claims (4)

[Claims] 1. A feed for cultured fish comprising an oligopeptide obtained by hydrolyzing wheat protein or corn protein. 2. The oligopeptide has a peptide chain length of 2 to 2.
The feed for cultured fish according to claim 1, which is an oligopeptide of No. 0. 3. The oligopeptide has a peptide chain length of 2 to 6
The feed for cultured fish according to claim 1, which is the oligopeptide of 4. The feed for farmed fish according to claim 1, wherein the oligopeptide is an oligopeptide obtained by hydrolyzing wheat protein or corn protein with an alkaline protease derived from an alkalophilic bacterium. .