JPH07106124B2 - Feed for Artemia and production method thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a feed for artemia having an animal amino acid composition.

(Prior art and its problems) At present, larvae immediately after hatching from eggs are sequentially administered with biological feeds such as the water rotifer, Artemia and Daphnia according to the length of the fish. ) No biological feed of appropriate size has been found since then, and plankton collected from natural seawater is used. However, natural plankton collection is easily affected by the season and climate, and stable acquisition is difficult. Therefore, attempts have been made to train Artemia to make Artemia larger than before (body length 2-4 mm), but wheat flour, soybean flour, baker's yeast, rice bran and feeds containing these as feeds for Artemia training. In all cases, the mortality rate of Artemia in the training process was extremely high, and 20 to 40% of them grew to a body length of 3 to 4 mm. Therefore, in recent years, it has been proposed to train artemia by using a bait obtained by subjecting marine chlorella or unicellular algae to cell wall destruction treatment (JP-A-62-87060 and JP-A-6-87060).
2-115241). However, such a dietary feed has a difficulty in culturing, it is difficult to stably supply it at a low cost, and further, since its cell wall is polysaccharide, it has poor digestibility, and its cell wall must be destroyed. However, there is a problem that the amino acid composition of the protein is in a plant form and is inferior to the animal amino acid composition in terms of dietary nutrition.

(Object of the Invention) An object of the present invention is to provide a feed for artemia having an animal amino acid composition, good digestibility, and capable of stable supply.

(Structure of the Invention) In the present invention, although Euglena which is a protozoa has not been used as a bait for fisheries in the past, other freshwater, marine unicellular algae having an appropriate size that Artemia can ingest. Unlike that, its extracellular membrane consists of only a proteinaceous membrane called pellicle, so it has excellent digestibility without pretreatment of cell wall-destroying sugars, and the protein is an animal protein containing a large amount of sulfur-containing amino acids. It has characteristics similar to those of lactic acid, has a nutritional value comparable to that of casein, and contains various vitamins, especially C, E, β-carotene and polyunsaturated fatty acids, and tank culture using glucose as a carbon source is possible. It has been completed by discovering that it can grow relatively quickly and can be stably supplied, and its gist is to describe "fish-and-seafood oil rich in ω-3 highly unsaturated fatty acids. Added Artemia for feed containing Euglena separated from the culture broth cultured with "and" omega-3
Euglena culture cultivated by adding seafood oil rich in polyunsaturated fatty acids to a method of producing a feed for artemia by centrifugation, concentration, and concentration under conditions of 3000 xg or less, followed by drying, refrigeration or freezing. is there.

In the present invention, euglena is a protozoan belonging to the genus Euglena (genus Euglena) in terms of zoology, and includes all species, variants and mutants belonging to it. A typical example is Euglen.
a gracilis), Euglena gracilis var.bacillaris, Euglena viridis, Astasia longa.

The medium used to culture such Euglena is
Known methods such as Hattner's medium (Journal of Protozoology, Vol. 14 (1967), Supplement 17, page 17) and Hattner's medium (Journal of Protozoology, Vol. 6, 1959, page 23) A medium can be used. Further, glucose, starch hydrolyzate, sugar condensate, glutamic acid, acetic acid, ethanol and the like are used as carbon sources, and inorganic nitrogen sources such as ammonium nitrate, dibasic ammonium phosphate and ammonium sulfate as nitrogen sources, and amino acids such as glutamic acid and aspartic acid. , Or peptone, casamino acid, yeast extract, corn steep liquor and other organic nitrogen sources are combined appropriately, and inorganic salts such as calcium, magnesium, manganese, iron, etc., and a medium in which vitamins B1 and B12 are added in trace amounts are used. You can also do it. It is also possible to use Euglena photosynthesis without using a carbon source.

The proper Euglena culture temperature is 20-33 ℃, and the initial pH is
3.0 to 7.0 is suitable. The culturing may be carried out either under light irradiation or in the dark. Further, at the time of culturing, it is preferable to perform shaking 50 to 250 times per minute and appropriate aeration and stirring.

The term "artemia" used in the present invention refers to a seawater zooplankton typified by Artemia salina, which is generally used as a feed for living organisms.

The feed for Artemia according to the present invention can be concentrated by filtering or collecting the Euglena culture solution by centrifugation or filtration to give a good dispersible feed, and particularly when the cells are centrifuged under conditions of 3000 x g or less, It has excellent dispersibility in water after freeze-drying, refrigerating, or freezing storage, and 90% by light stirring
The above is preferable because it can be dispersed into a single cell (20 to 40 micron diameter).

In addition, Euglena which is the main component of the feed for Artemia according to the present invention, when the content of ω-3 highly unsaturated fatty acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is insufficient as a feed, culture Ω
By treating with a fish and shellfish oil containing a large amount of -3 polyunsaturated fatty acid, ω-3 polyunsaturated fatty acid can be enriched and taken into Euglena cells, and as a result, Oxidation stability will be improved.

Therefore, it is possible to provide an extremely excellent feed as compared to the conventional marine chlorella or the like that has been proposed as an artemia feed.

Hereinafter, the present invention will be described in detail based on examples.

Comparative Example An artemia feed was manufactured by the following method.

Glucose 600 g, diammonium hydrogen phosphate 210 g, magnesium sulfate heptahydrate 15 g, dipotassium dihydrogen phosphate 15
g, calcium carbonate 6g, EDTA disodium salt 1.5g, Mohr salt 1.5g, manganese sulfate tetra-pentahydrate 0.54g, zinc sulfate heptahydrate 0.75g, corn steep liquor 150g, vitamin B1 150mg, vitamin B12 300μg Was dissolved in 30 tap water and charged into a 50 volume jar fermenter for sterilization. The culture solution 1.5 of Euglena gracilis, which had been pre-cultured in the same medium in advance, was inoculated into this, and aeration culture was carried out at pH 4.5 and 28 ° C. for 48 hours.

After completion of the culturing, the culture broth was centrifuged for about 10
The cells were collected by centrifugation at 00 × g to obtain 860 g of a semi-fluid cake having a solid content of about 35%.

Divide the above cake into 3 parts, i) store as it is at −20 ° C. for freezing, ii) add 0.1% sorbic acid and store at 0-4 ° C. for refrigeration, iii) freeze-dry to a water content of about 10%, then refrigerate saved.

(Example) In the comparative example, when aeration culture was performed for 30 hours, i) cod oil, ii) cod liver oil fatty acid obtained by hydrolyzing cod liver oil, iii) methyl ester of fatty acid enriched with EPA and DHA ( 90g of "ω-60 Esters" manufactured by Nippon Kagaku Feed Co., Ltd.
After the addition, the aeration culture is continued for another 18 hours, and thereafter, the feed for artemia according to the present invention is obtained in the same manner as in Comparative Example.

(Test Example 1) 0.5 g of each sample prepared in Comparative Example was added to 100 ml of seawater,
After gently stirring with a glass rod, the dispersibility of the cells was observed with a microscope. In each sample, 90% or more consisted of a single dispersed cell and a combination of two cells, and it was confirmed that the uniform dispersion was excellent.

Test Example 2 The oxidative stability of fatty acids in the feed fortified in the examples was tested as follows.

As a sample, freeze-dried according to the comparative example, a mixture of 20% cod liver oil fatty acid lyophilized according to the comparative example, fortified cod liver oil according to the example,
Lyophilized, enriched with cod liver oil fatty acid according to the example, lyophilized, according to the example "ω-60
Freeze-dried samples fortified with "Ester" were stored in the dark at 30 ° C for 4 weeks, and the peroxide value (POV, meq / kg) of the extracted lipid was measured and used as an index of oxidation. The results are shown below.

As a result, according to the examples, it is understood that, among oils and fats containing ω-3 highly unsaturated fatty acids, the hydrolyzate and methyl ester thereof are well taken up into cells and are excellent in oxidative stability.

(Test Example 3) The Euglena obtained in Comparative Example was dispersed in water so that the solid content concentration was about 5 to 15%, and treated with a high-pressure homogenizer, the cells were finely crushed and the Euglena form was not retained. , Was dissolved in water and was not suitable as a feed for artemia.

(Example of aquaculture) Artemia larvae were hatched for 24 hours in natural seawater, and Artemia reared larvae immediately after hatching were collected and subjected to a training test using the following foods.

Training conditions with the feeds obtained in Comparative Examples and Examples Artemia larval density: 30,000 individuals / Euglena feeding amount: 2 × 10 cells // day Cells were collected from the culture solution of marine chlorella by centrifugation,
After washing, artemia larvae were cultivated using the cell disrupted feed.

The dose is 2 ml // day with a solution having a concentration of 1.5 × 10 6 cells / ml.

Comparing the above-mentioned effects of Artemia training, the survival rate of Artemia on day 7 was 70% in all cases.
That was all. No difference was observed depending on the form of the sample (refrigeration, freezing, freeze-drying). In addition, the content of EPA + DHA in the fatty acid composition of Artemia that was trained for 7 days was 6.6% when the sample in Table 1 was fed, 14.3% when the sample was fed, and 25.3% when the sample was fed.

(Effects of the Invention) According to the present invention, since Euglena which has never been used as a bait for fisheries is used as a bait for fisheries, its outer membrane is pellicle unlike other freshwater and marine unicellular algae. It consists of a proteinaceous membrane, which is said to have excellent digestibility without pretreatment such as cell destruction.
Moreover, tank culture using glucose as a carbon source is possible, growth is relatively fast and stable supply is possible, and dispersibility in water is excellent, and single cells (20 to 40 As a result of being able to disperse even up to the micron size, Artemia will provide an animal feed that can be fully consumed.

Furthermore, the protein has properties close to those of animal protein containing a large amount of sulfur-containing amino acids, has a nutritional value comparable to casein, and contains a large amount of various vitamins, especially C, E and β-carotene, and has a nutritional value as a feed. Excellent, even if the content of ω-3 highly unsaturated fatty acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is insufficient as a feed, it has a seafood oil containing a large amount of such ω-3 highly unsaturated fatty acid. By the treatment, the ω-3 highly unsaturated fatty acid can be strengthened, and as a result of being taken up into the Euglena cells, the oxidative stability of the ω-3 highly unsaturated fatty acid is improved and the storage stability is excellent.

Therefore, it is possible to provide an extremely excellent feed as compared to the conventional marine chlorella or the like that has been proposed as an artemia feed.

Continuation of front page (56) References JP-A-62-115241 (JP, A) JP-A-61-52275 (JP, A)

Claims (2)

[Claims] 1. A feed for artemia containing euglena separated from a culture broth added with fish and shellfish oil rich in ω-3 highly unsaturated fatty acid. 2. A Euglena culture broth cultivated by adding fish and shellfish oil rich in ω-3 highly unsaturated fatty acid, concentrated and concentrated by centrifugation at 3000 × g or less, and then dried, refrigerated or frozen. A method for producing a feed for artemia, which comprises: