JPS6361907B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a feed for improving the skin color of cultured red sea bream. In recent years, red sea bream farming has become widespread, but because the habitat and food sources are different from those of wild red sea bream, the skin of farmed red sea bream is darkish and does not exhibit the red color characteristic of wild red sea bream. Therefore, various studies have been carried out to improve the color tone of the skin of cultured red sea bream, such as culturing by feeding live red shrimp as feed, and using feed supplemented with red pigments such as canthaxanthin (Special Publication No. 1973-33696), capsanthin, zeaxanthin, and capsorubin. (Special Publication No. 51-6078) etc. are used for cultivating red sea bream. However, even with these feeds, the skin of farmed red sea bream does not have a satisfactory color tone compared to that of wild-caught red sea bream. In addition, the red color of the epidermis of natural red sea bream comes from carcinoid pigments, particularly astaxanthin pigments, and the red color is obtained by feeding the red sea bream, shrimp, etc. that contain large amounts of this pigment. However, ordinary shrimp, shrimp, etc. are living organisms (raw animals) that contain 70 to 90% water, so they need to be frozen for preservation. In addition, when considering the use of shrimp, shrimp, etc. as raw materials for compound feed, they must be dried with a moisture content of around 10%, but during the drying process, the astaxanthin contained in shrimp, shrimp, etc. is replaced by astaxin, which has no coloring effect. easy to change. Therefore, the present inventors conducted repeated research with the aim of obtaining a feed that is easy to use and has excellent effects as a feed for improving the skin color tone of red sea bream. When red sea bream were fed culture solution, bacterial cells, bacterial cell decomposition products, and bacterial cell fragments of astaxanthin-producing bacteria [Aquaculture 20 (1980) 123-124], fish species, habitat, and color development sites were found. The present invention was completed by discovering that the skin of red sea bream, which is completely different from that of trout, surprisingly produces a red color tone that is the same or even higher than that of natural red sea bream. The present invention is a feed for red sea bream containing one or more of a culture solution, bacterial cells, bacterial decomposition products, and crushed bacterial cells of astaxanthin-producing bacteria belonging to Huahuia rhodozyma. A typical astaxanthin-producing bacterium belonging to the Phaffia rhodozyma genus used in the present invention is ATCC24202 and is available from The American Type Culture Collection.
Collection) Catalog of Strains 1
Hortains Edition 1980
(Catalogue of Strains I Fourteenth Edition
1980). Many other strains can be used. To select this, yeast extract/malt extract medium is inoculated, strains exhibiting a characteristic red color are picked, and the amount of astaxanthin accumulated is examined by a conventional method, and strains with a high ability to accumulate astaxanthin are used. This bacterium can be used as a carbon source such as glucose, maltose, or
A slightly acidic (PH5-6) medium containing yeast extract/malt extract, organic and inorganic nitrogen sources such as ammonium sulfate, and other trace nutrients at 15-25°C (preferably 20-22°C) under aerobic conditions. By culturing under the following conditions, astaxanthin (3,3'-dihydroxy-β,β-carotene-4,4'-dione) accumulates within the bacterial cells. The feed of the present invention uses this culture solution as it is or a concentrated version thereof. Alternatively, the bacterial cells in the culture solution may be separated and precipitated by centrifugation for use. Furthermore, since this astaxanthin is accumulated within the bacterial body as described above, it is preferable to physically or chemically treat the bacterial cell to destroy the cell wall of the bacteria to some extent and use it as food. To destroy this bacterial cell wall, chemical treatments such as autolysis, enzyme treatment, acid hydrolysis, etc.
Any physical treatment such as grinding ultrasonic treatment or pressure crushing can be employed. In case of autolysis,
The bacterial cells are washed with water and the wet bacterial cells are allowed to stand according to a conventional method. In the case of enzymatic treatment, enzymes capable of dissolving the cell walls of lysozyme, Bacillus circulans, etc. are brought into contact with the bacterial cells by a conventional method. Acid hydrolysis treatment is performed by treating the cell wall of the bacterial body with an acid such as dilute hydrochloric acid to the extent that it becomes easily digestible within the fish body. Pressure crushing involves crushing the cell walls of bacteria using a commonly used pressure crusher such as a French press. In the ultrasonic treatment, the bacterial cells are treated with ultrasonic waves to the extent that the cell walls of the bacterial cells are destroyed. The culture solution, bacterial cells, bacterial cell decomposition products, and bacterial cell fragments of astaxanthin-producing bacteria belonging to Huahuia rhodochyma obtained as described above may be used as feed for red sea bream as they are, but they do not accumulate in the bacterial cells. In order to prevent astaxanthin from being oxidized, it is preferable to coat it with a coating material such as gelatin or beef tallow and use it as a feed. Further, it is preferable to add an antioxidant such as BHT (butyl hydroxytoluene), BHA (butyl hydroxyanisole), vitamin E, etc. before coating. This feed is formed into pellets or mash by mixing commonly used compound feeds for fish farming, such as fish meal, meat and bone meal, krill meal, soybean oil meal, corn gluten meal, torula yeast, wheat flour, rice bran oil meal, and vitamins. It can be used as a compound feed for red sea bream. In this case, the blending amount of the feed of the present invention is effective at about 3 to 50%, and is adjusted according to the astaxanthin content and the purpose of epidermal coloring. In other words, during the growth of red sea bream, feed for growth purposes that does not contain astaxanthin is fed, and if you want to quickly develop color just before shipping, feed with a high astaxanthin content is intensively fed, and then gradually When developing color, it is sufficient to feed feed with a low astaxanthin content. In addition, the feed of the present invention may be fed to red sea bream at the same time as minced raw fish, without using the above-mentioned mixed feed. As described above, in the feed of the present invention, astaxanthin accumulated in the bacterial bodies and other bacterial components are simultaneously ingested by the red sea bream, so that not only unoxidized astaxanthin is deposited on the skin of the red sea bream, but also bacterial components It also serves as a nutritional source for red sea bream and is an extremely useful food for red sea bream. Next, the red sea bream skin coloring effect of the feed of the present invention and examples will be shown. In order to investigate the skin coloring effect of red sea bream using the feed of the present invention, the following experiment was conducted. Method Test period Example 1 September 21, 1980 - October 30, 1980 Example 2 November 5, 1980 - December 16, 1980 Example 3 February 16, 1981 ~March 23, 1980 Test fish In Experimental Examples 1 and 2, red sea bream were artificially hatched in June 1974 and were consistently raised using only mixed feed (average weight approximately 75 g in Experimental Example 1, and approximately 75 g in Experimental Example 2). (average weight: approximately 88g), 20 specimens of uniform weight per experimental area.
Each tail was used. In Experimental Example 3, red sea bream (average weight 55 g), which were artificially hatched in May 1980 and raised only with compounded feed, were used in each experiment group, with a uniform weight of 30. Breeding conditions Breeding tank: 150 glass-lined aquarium Breeding water: Sand-filtered seawater heated to 25℃ using a boiler Aeration/Water flow: Enough ventilation is performed using a blower, and the water in the tank is changed once every hour. I did it like that. Baiting: Bait was cast twice daily, once in the morning and once in the evening, until the fish were sated. The rearing conditions were the same for Experimental Examples 1, 2, and 3. Method for evaluating color development effect Visual observation of body color At the end of the color development test, body color and caudal fin color were observed and the degree of color development was visually ranked. Ranking guideline for visual coloration ++ The body surface and caudal fin are deep red, and the abdomen is red, and the red tone is equal to or greater than that of wild red sea bream ＋ The body surface and caudal fin have a red tone It is observed, but it is not as dark as ++ - There is almost no red color on the body surface and caudal fin, and it is tinged with black Measurement of the total amount of carotenoid on the body surface After the breeding test, 10 fish were randomly taken from each group. After killing immediately, a certain area of the epidermis (scales and epidermis 100 cm ² /per fish) was removed from a certain part. The exfoliated epidermis was ground with anhydrous sodium sulfate, and the crude carotenoids were extracted with acetone. The crude carotenoid extract was concentrated under reduced pressure and transferred to a separatory funnel containing petroleum ether in order to transfer the carotenoid pigments into petroleum ether. Then, the crude carotenoid-petroleum ether solution was washed with water, dehydrated with anhydrous calcium carbonate, and then concentrated under reduced pressure to obtain a certain amount of solution. The visible absorption curve of the crude carotenoid-petroleum ether solution obtained in this way was determined using a spectrophotometer, and the total carotenoid content was determined by setting the specific extinction coefficient to E ¹ % _1cn = 2000 from the absorbance values of the three maximum absorptions that appear around 470 mμ. I asked for

[Table] Experimental Example 1 Skin color development test of red sea bream using artificial feed containing the substance of the present invention

【table】

【table】

【table】

[Table] *1 Based on the above-mentioned method for determining coloring effect using naked eye observation.
*2 Based on the method for measuring the total amount of carotenoids on the body surface described above.
Experimental Example 2 Skin coloration test of red sea bream using artificial feed containing the substance of the present invention

【table】

【table】

【table】 Experimental example 3

[Table] *1 Same as Experimental Example 2

[Table] Results (1) Macroscopic color development tendency As is clear from Experimental Examples 1, 2, and 3, red bream that consumed the feed of the present invention had a marked red tone on the body surface and caudal fin, and that of the red sea bream that consumed the feed of the present invention was significantly red. The color tone of the body surface and caudal fin of red sea bream was significantly improved. There was no difference in the color tone of the body surface and caudal fin of red sea bream that consumed frozen krill, which was the control group. Furthermore, the improvement effect does not depend much on the processing method of the feed of the present invention (e.g., decomposition and crushing of bacterial cells), but the feed of the present invention is coated on the surface to prevent astaxanthin from oxidizing during long-term storage of the feed of the present invention, compared to untreated feed. The effect of improving the color tone of the body surface and caudal fin of red sea bream was superior compared to that of the previous method. (2) Total carotenoid accumulation on the body surface The total carotenoid accumulation on the body surface of the red sea bream that consumed the feed of the present invention was significantly higher than that of the red sea bream that did not consume the feed of the present invention. The amount of carotenoids accumulated on the body surface of red sea bream fed on Example Feed of the present invention (Huahuia rhodochyma)
After thoroughly mixing ATCC24202 (filtered culture using the medium of *4 in Experimental Example 1 and decomposing it with lysozyme) and the following compounded feed materials in a mixer,
It was ground to fine particle size using a 100 horsepower high-speed grinder. Then, this was formed into pellets using a 100 horsepower pellet mill to obtain a compounded feed containing the feed of the present invention.

【table】

Claims (1)

[Scope of Claims] 1. A feed for red sea bream containing one or more of a culture solution, bacterial cells, decomposed bacterial cells, and crushed bacterial cells of astaxanthin-producing bacteria belonging to Huafia rhodozyma. 2. The feed for red sea bream according to claim 1, wherein the bacterial cell decomposition product of astaxanthin-producing bacteria belonging to Huahuia rhodozyma is obtained by autolysis, enzyme treatment, or acid hydrolysis of the bacterial cells. 3. The feed for red sea bream according to claim 1, wherein the crushed bacterial cells of astaxanthin-producing bacteria belonging to Huahuia rhodozyma are obtained by grinding the bacterial cells, ultrasonication, or pressure crushing. 4 Astaxanthin-producing bacteria belonging to Huafia rhodochyma are Huafia rhodochyma.
The feed for red sea bream according to claim 1, which is ATCC24202.