Composition containing algae belonging to the class Ideyukogome

Abstract

To provide a composition for farming an aquatic organism.SOLUTION: The present invention provides: a composition for farming an aquatic organism, the composition containing an alga belonging to the class Cyanidiophyceae; or a method for farming an aquatic organism, the method including feeding the farming composition to the aquatic organism.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a composition for culturing aquatic organisms containing algae belonging to the genus Ideyukogome, a method for culturing aquatic organisms including feeding the composition, or a method for enhancing stress tolerance.

Background Art

[0002] Organisms growing in water are known to be sensitive to temperature changes in water temperature and have low tolerance to high temperatures. With recent environmental changes such as abnormal weather and global warming, changes in air temperature and water temperature, particularly the increase in water temperature, are becoming larger than before. Therefore, in the cultivation of aquatic organisms, water temperature changes are becoming a major problem.

[0003] Patent Document 1 discloses a method of feeding fish or crustaceans with a fish feed added with inosine to relieve oxidative stress of fish or crustaceans. However, it does not describe the alleviation of heat stress imposed by high water temperature or emersion stress imposed by exposing fish or crustaceans to air.

[0004] By the way, algae belonging to the genus Ideyukogome are unicellular algae that grow in acidic hot springs. Feeds and cultivation compositions for aquatic organisms containing algae belonging to the genus Ideyukogome are not known. It is also known that algae belonging to the genus Ideyukogome affect the stress tolerance of aquatic organisms.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention aims to provide a composition for cultivating aquatic organisms and a method for enhancing the stress tolerance of aquatic organisms using the composition. [Means for solving the problem]

[0007] The inventors have conducted diligent research and discovered a composition for cultivating aquatic organisms containing algae belonging to the class Ideyukogome, such as Gardelia algae. In other words, the present invention is as follows. [1] A composition for cultivating aquatic organisms, containing algae belonging to the class Ideyukogome. [2] The composition described in [1], which is a feed for the cultivation of aquatic organisms. [3] The composition according to [1] or [2], wherein the content of algae belonging to the class Ideyukogome is 0.01 to 5% (w / w). [4] The composition according to any one of [1] to [3], wherein the algae belonging to the class Ideyukogome is an algae belonging to the genus Gardelia. [5] A composition according to any one of [1] to [4] for enhancing the stress tolerance of aquatic organisms. [6] The composition according to [5], wherein the stress is high temperature stress or drought stress. [7] The composition according to any one of [1] to [6], wherein the aquatic organism is a fish or a crustacean. [8] The composition according to [7], wherein the fish or crustacean is red sea bream, flounder, amberjack, pufferfish, yellowtail, tuna, eel, tilapia, catfish, sea bass, sweetfish, rainbow trout, Atlantic salmon, coho salmon, Chinook salmon, Pacific white shrimp, kuruma prawn, tiger prawn, white leg shrimp, or blue crab. [9] The composition according to [7], wherein the fish or crustacean is Pacific cod, salmon, herring, sweetfish, anchovy, Japanese sardine, black rockfish, scorpionfish, rock cod, striped jack, Japanese jack, crimson sea bream, greenling, marbled flounder, sole, or croaker.

[10] A method for cultivating aquatic organisms, comprising feeding them a composition containing algae belonging to the class Ideyukogome.

[11] A method for enhancing the stress tolerance of aquatic organisms, comprising feeding them a composition containing algae belonging to the class Ideyukogome.

[12] The method according to

[11] , wherein the stress is high temperature stress or drought stress.

[13] The method according to any one of

[10] to

[12] , wherein the aquatic organism is a fish or a crustacean.

[14] The method according to

[13] , wherein the fish or crustacean is red sea bream, flounder, amberjack, pufferfish, yellowtail, tuna, eel, tilapia, catfish, sea bass, sweetfish, rainbow trout, Atlantic salmon, coho salmon, Chinook salmon, Pacific white shrimp, kuruma prawn, tiger prawn, white-legged shrimp, or blue crab.

[15] The method according to

[13] , wherein the fish or crustacean is cod, salmon, herring, sweetfish, anchovy, sardine, black rockfish, scorpionfish, rock cod, striped jack, Japanese jack, crimson sea bream, greenling, flathead flounder, sole, or croaker.

[16] The method according to any one of claims

[10] to

[15] , wherein the content of algae belonging to the class Ideyukogome in the composition is 0.01 to 5% (w / w). [Effects of the Invention]

[0008] The present invention provides a composition for cultivating aquatic organisms or a method for cultivating aquatic organisms, which includes feeding them with the composition. In one embodiment of the present invention, the composition of the present invention can be used as a feed composition or feed for aquatic organisms.

[0009] In another embodiment, the compositions of the present invention can be used to enhance resistance to stresses such as high-temperature stress and drought stress. The present invention also provides a method for enhancing the stress tolerance of aquatic organisms.

[0010] In the cultivation of aquatic organisms, the increase in water temperature of rivers and seawater due to global warming, as well as the increase in water temperature when cultivating aquatic organisms on land, are problems that cannot be ignored in terms of stress on aquatic organisms and cost. Since the composition or method of the present invention enhances the tolerance of aquatic organisms to these high-temperature stresses, not only cultivation in rivers or oceans but also stress reduction due to increased water temperature during land cultivation is expected. Therefore, the composition of the present invention can be a feed suitable for sea cultivation where temperature rise is a concern. In another aspect, since the composition of the present invention can reduce the cooling cost that contributes to increased costs in land cultivation, it can also be useful as a feed for land cultivation.

[0011] In addition, during cultivation, when moving between cages, transferring tanks, weighing, or shipping, aquatic organisms may be exposed to air (stranded) and stressed. Since the present invention enhances the tolerance to stranding stress, it is expected to reduce the stranding stress during cultivation. Further, thereby, improvement in the handling property and growth promotion of aquatic organisms are expected.

Brief Description of the Drawings

[0012] [Figure 1] It is a figure showing the results of a high-temperature stress test. ○ represents the control group, △ represents the control sand-covered group, □ represents the positive control group, ● represents the death rate of the low-dose example group, and ▲ represents the death rate of the high-dose example group.

Modes for Carrying Out the Invention

[0013] Hereinafter, the present invention will be described in more detail. The scope of the present invention is not limited to these descriptions, and for other than the following examples, it can be appropriately changed and implemented without impairing the gist of the present invention.

[0014] 1. Composition of the Present Invention The composition of the present invention is a composition containing algae belonging to the class Cyanidiophyceae and can be used for the cultivation of aquatic organisms.

[0015] The compositions of the present invention can be used as feed for aquatic organisms. Feeds or feed compositions for aquatic organisms, including algae belonging to the class Cyanidiophyceae, are included in the present invention.

[0016] The compositions of the present invention have been shown in examples to enhance the tolerance of aquatic organisms to stresses such as high-temperature stress and drought stress. Therefore, the compositions of the present invention can be used to enhance the stress tolerance of aquatic organisms.

[0017] The composition of the present invention contains algae belonging to the class Cyanidiofyceae. Taxonomically, the class Cyanidiofyceae is classified under the division Rhodophyta. The class Cyanidiofyceae comprises three genera: Cyanidioschyzon, Cyanidium, and Galdieria. The composition of the present invention may use algae belonging to any of these genera. For example, algae belonging to the genus Cyanidioschyzon, such as Cyanidioschyzon merolae; algae belonging to the genus Cyanidium, such as Cyanidium caldarium; algae belonging to the genus Galdieria, such as Galdieria sulphuraria; or mutants thereof or combinations thereof can be used.

[0018] In the present invention, algae belonging to the class Ideyukogomei are preferably algae belonging to the genus Galdieria. The genus Galdieria is a unicellular red alga classified in the class Ideyukogomei of red algae. Examples of species belonging to the genus Galdieria include, but are not limited to, Galdieria sulphuraria, Galdieria daedala, and Galdieria partita. In one embodiment, unicellular red algae can be prepared using relatively small equipment compared to multicellular red algae.

[0019] In the present invention, algae belonging to the class Ideyukogome may have a haploid or diploid cell morphology.

[0020] In the present invention, the strain of algae belonging to the class Ideyukogomei used is not limited. For example, examples of Galdieria sulphuraria strains include G 127 (diploid; possessing a strong cell wall; available from CCCryo), G 108(1n) (induced from a diploid according to the method described in Japanese Patent Application Publication No. 2020-072698, and then used after creating a single culture strain; does not possess a strong cell wall), or their mutants. The diploids of G 127 and G 108 are readily available from public institutions (for example, G127 (CCCryo 127-00) from CCCryo (Culture Collection of Cryophilic Algae), and G108 (SAG 108.79) from SAG (The Culture Collection of Algae at Goettingen University)).

[0021] Mutant strains can be easily obtained by those skilled in the art by performing a mutation treatment on a strain. Examples of mutation treatments include treatment with a mutagenic agent or irradiation with high-energy rays. Examples of mutagenic agents include ethyl methanesulfonate, N-methyl-N′-nitro-N-nitrosoguanidine, and base analogs such as 5-bromouracil. Examples of high-energy rays include UV, gamma rays, X-rays, and heavy ion beams. Mutation treatments also include methods of mutating specific genes using genetic recombination. Mutant strains also include transformants.

[0022] Algae belonging to the class Ideyukogomei can be collected from high-temperature, high-sulfur, low-pH environments, such as sulfate springs, according to previously reported methods (De Luca P. et al., 1978, Webbia, 33, 37-44), and can be maintained and cultured in Allen medium or modified Allen (MA) medium (Allen, MB, 1959, Arch. Mikrobiol., 32, 270-277; Kuroiwa, T. et al., 1993, Protoplasma, 175, 173-177; Ohnuma M. et al., 2008, Plant Cell Physiol., 117-120; Kuroiwa T. et al., 2012, Cytologia, 77(3), 289-299).

[0023] The content of algae belonging to the class Ideyukogome in the composition or feed of the present invention can be appropriately determined according to various conditions such as the type of aquatic organism and its growth stage (e.g., juvenile stage, adult stage). The content of algae belonging to the class Ideyukogome in the composition or feed of the present invention may be, for example, 0.01-10% (w / w), 0.01-5% (w / w), 0.01-1% (w / w), 0.1-5% (w / w), 0.3-5% (w / w), 0.3-3% (w / w), 0.5-5% (w / w), 0.5-3% (w / w), 0.5-1% (w / w), 1-5% (w / w), or 1% (w / w).

[0024] The content of algae belonging to the class Ideyukogome in the composition of the present invention is preferably 0.01 to 5% (w / w) or 0.01 to 1% (w / w).

[0025] In the present invention, as algae belonging to the class Ideyukogome, cultures of algae belonging to the class Ideyukogome, processed products thereof, or combinations thereof may be used. As algae belonging to the class Ideyukogome, commercially available products may be used, or algae belonging to the class Ideyukogome may be used, which may be produced appropriately using algae belonging to the class Ideyukogome. The method for producing algae belonging to the class Ideyukogome is not particularly limited, and known methods can be used.

[0026] In the present invention, algae belonging to the class Ideyukogomei can be cultured as appropriate, and the resulting culture can be used as algae belonging to the class Ideyukogomei. Any culture method is acceptable as long as the conditions are suitable for the growth of algae belonging to the class Ideyukogomei, and those skilled in the art can appropriately select and modify known methods. Algae belonging to the class Ideyukogomei can be cultured under normal conditions, such as those described in the examples of this specification, or in MA2 medium supplemented with at least one additional component, such as glucose.

[0027] Those skilled in the art can, based on known techniques, further concentrate, dry (freeze-drying, heat-drying, spray-drying, vacuum-drying, etc.), heat, irradiate with ultraviolet light and / or radiation, pulverize with a mill or glass beads, extract or purify with water or organic solvents, and use the resulting precipitate concentrate, dried product, extract or purified product, or combination thereof, as algae belonging to the Ideucogomei class in the present invention. In one embodiment, in the present invention, dried products or pulverized dried products of algae belonging to the Ideucogomei class can be used as algae belonging to the Ideucogomei class. In the present invention, the form of algae belonging to the Ideucogomei class is not particularly limited as long as it is a form that can be contained in a composition for aquatic organisms, and may be, for example, powder, granules, pellets, flakes, sheets, paste, solution, or suspension.

[0028] In this invention, commercially available dried microbial cells of algae belonging to the class Ideyukogomei can also be used. For example, Protealg® (Toxicology Research and Application, Volume 3: 1-13, 2019) can be cited as such a commercially available product.

[0029] Commercially available Ideyukogome species, or the resulting cultures, precipitates, concentrates, dried cells, extracts, or purified products, or combinations thereof, may be directly incorporated into basic feed compositions conventionally used for aquaculture, or they may be adsorbed onto excipients before being incorporated into the basic feed composition. Examples of excipients include those commonly used in aquatic feed, such as feed oil, bran, wheat flour, defatted rice bran, silica, corn cob meal, and talc.

[0030] A composition containing, for example, 0.01 to 5% of algae belonging to the class Ideycogome, such as algae belonging to the genus Gardenia, can be used for the cultivation of aquatic organisms. This composition can be used as feed for aquatic organisms, and by feeding this composition to aquatic organisms, they can be raised.

[0031] The basic feed composition containing algae belonging to the class Ideyukogome is not particularly limited, as long as it is a feed commonly used for the cultivation of aquatic organisms. For example, Ambrose, Ambrose EP, Ambrose EP Float, Ambrosia, Force, Synergy, for growth, Harios EX Unagi Suiken, Sakura (Feed One Co., Ltd.), Otohime, Hirame, Maguroshin, Sea Diamond, Giant Tuna (Nisshin Marubeni Feed Co., Ltd.), Farm Choice (Farm Choice Co., Ltd.), Marine, Tuna Food, Umakaburi (Hayashikane Sangyo Co., Ltd.), Sodachimori, Madai Hana Hana, Abalone, α-1, M-1 (Nippon Nosan Kogyo Co., Ltd.), Kinko, Buriou, Hamachi Maru, Calorie Rich, Gold Prawn, Hime Sakura, Sakuraou, Taiko, Sango, Kuroshio, Aji Taro, Ginrin, Kanmuri Buri Mash (Higarimaru Co., Ltd.), Kaisan Soft, Hamachi Soft DRY, Gold Power, Hamachi Hyper Moist 75, Hamachi Perfect II, Madai New Gold II, Madai Pellet L, Madai Soft Examples include Dry, Madai Dash Moist, Kanpachi Slider, Kanpachi Soft C, Aji Jugo, Aji New Cultivation (Sakamoto Feed Co., Ltd.), Optima, New Sustain, Nutra, Extreme Madai, Sustain, Next Madai, Begin, Maxim Madai, MaGro (SKRETTING), INICIO, DFICO ENVIRO, INTRO, ORBIT (BioMar), and others.

[0032] The components included in the composition of the present invention include algae belonging to the class Ideyukogome, and are not particularly limited as long as they can be ingested by aquatic organisms. They can be appropriately selected according to various conditions such as the type of aquatic organism and its growth stage. For example, in addition to algae belonging to the class Ideyukogome, the composition of the present invention may contain components similar to those contained in basic feeds for the cultivation of ordinary aquatic organisms. Examples of components in basic feeds for ordinary aquatic organisms include fish meal, fish oil, vitamins, vitamin mixtures, mineral mixtures, metals, basic substances, calcium phosphate, wheat flour, wheat gluten, α-starch, binders, bone meal, yeast, eicosapentaenoic acid, docosahexaenoic acid, and antibiotics. Furthermore, the composition of the present invention may contain vitamin C.

[0033] The composition of the present invention is produced by combining algae belonging to the class Ideyukogomei with a basic feed composition. The method of producing the composition of the present invention is not particularly limited. For example, the composition of the present invention can be produced using the same components as the basic feed composition and by the same method, except that algae belonging to the class Ideyukogomei are added to the basic feed composition.

[0034] Furthermore, the form of the composition of the present invention is not particularly limited, as long as it is in a form that can be ingested by the target aquatic organism, and may, for example, be a form used in ordinary feed for aquatic organisms. The composition of the present invention may be in any form, such as powder, granules, pellets, cubes, paste, or liquid. The composition of the present invention may be molded into pellets, such as dry pellets or moist pellets. Those skilled in the art may further add excipients such as thickeners, depending on the form.

[0035] In the present invention, aquatic organisms are not particularly limited as long as they are organisms that inhabit water or the water's edge, and include, for example, fish or crustaceans. In the present invention, examples of fish or crustaceans include one or more selected from the group consisting of red sea bream, flounder, amberjack, pufferfish, yellowtail, tuna, eel, tilapia, catfish, sea bass, sweetfish, rainbow trout, Atlantic salmon, coho salmon, Chinook salmon, Pacific white shrimp, kuruma prawn, tiger prawn, white-legged shrimp, and swimming crab.

[0036] In another embodiment of the present invention, the fish or crustacean may include, for example, fish belonging to the order Pleuronectiformes, such as flounder, sole, flathead, and halibut.

[0037] The compositions of the present invention can be used to enhance high-temperature stress tolerance. Fish and crustaceans that inhabit low-temperature regions are more susceptible to the effects of rising seawater temperatures; therefore, the aquatic organisms targeted by the present invention may be those with low preferred temperatures. Accordingly, in another embodiment of the present invention, the compositions of the present invention can be preferably used for fish or crustaceans with low preferred temperatures. The preferred temperatures of aquatic organisms are known. For example, Table 9 of Marine Research Institute Research Report No. 4, 11-66, 2002 lists the preferred temperatures of several fish, and the preferred temperature of the flounder used in the examples is 25°C. Accordingly, the present invention is expected to enhance high-temperature stress tolerance in fish or crustaceans (e.g., salmon) with preferred temperatures similar to or lower than those of flounder, for example, 30°C or lower or 25°C or lower. Examples of fish with a preferred temperature of 30°C or lower include Pacific cod, salmon, herring, sweetfish, anchovy, Japanese sardine, black rockfish, scorpionfish, rock cod, striped jack, Japanese jack, crimson sea bream, greenling, flathead flounder, halibut, croaker, red sea bream, Japanese whiting, black sea bream, Japanese butterfish, grunt, yellowtail, mullet, tiger pufferfish, striped beakfish, filefish, snapper, blue whiting, black sea bream, starry whiting, sea bass, or scorpionfish. In another embodiment, the present invention can be used for fish with a preferred temperature of 25°C or lower, and examples of fish with a preferred temperature of 25°C or lower include Pacific cod, salmon, herring, sweetfish, anchovy, Japanese sardine, black rockfish, scorpionfish, rock cod, striped jack, Japanese jack, crimson sea bream, greenling, flathead flounder, halibut, or croaker.

[0038] Furthermore, the aquatic organisms targeted in this invention can also be selected based on their UDT (Ultraviolet Duration) and CTMax (Critical Maximum Temperature). The critical maximum temperature is the temperature at which abnormalities such as the inability to maintain equilibrium in aquatic organisms occur, even if they do not die. For example, Table 4 of Marine Research Institute Research Report No. 4, 11-66, 2002 lists the UDT and CTMax of several fish, and among them, the values ​​for flounder (body length 6.8 cm) at an acclimatization temperature of 20°C are 35.2±0.20°C and 33.9±0.23°C (mean ± SD), respectively. Therefore, fish or crustaceans with a UDT or CTMax of similar or lower than that of flounder, for example, UDT: 35.2±0.20°C and CTMax: 33.9±0.23°C at an acclimatization temperature of 20°C, are expected to have enhanced high-temperature stress tolerance in this invention. Fish or crustaceans with a UDT lower than 35.2±0.20℃ and a CTMax lower than 33.9±0.23℃ at an acclimatization temperature of 20℃ include, for example, herring, sardine, anchovy, sweetfish, salmon, cod, horse mackerel, striped jack, yellowtail, grunt, red sea bream, crimson sea bream, croaker, greenling, black rockfish, scorpionfish, rock cod, marbled flounder, black sea bream, Japanese whiting, and filefish.

[0039] The composition of the present invention can be used for the cultivation of aquatic organisms. In another embodiment of the present invention, the composition of the present invention is a feed for the cultivation of aquatic organisms. Aquatic organisms can be grown by feeding them the composition of the present invention. "Feeding the composition of the present invention (or feed or feed composition)" is not limited to contacting aquatic organisms with a pre-prepared composition of the present invention, but also includes contacting aquatic organisms with a combination of the components contained in the composition of the present invention as described above. For example, the components may be prepared separately and mixed before or during feeding, or fed separately.

[0040] The composition of the present invention may be fed once a day or in multiple doses. Alternatively, the composition of the present invention may be fed once every few days. The amount of the composition of the present invention fed at each feeding may be constant or vary. The amount of the composition of the present invention fed is not particularly limited. Those skilled in the art can appropriately adjust the amount of the composition of the present invention fed based on the type of aquatic organism, such as fish or crustaceans, the size of the fish, and the rearing or aquaculture method. The composition of the composition of the present invention at each feeding may be constant or vary. The content of algae belonging to the class Ideyukogome in the composition of the present invention at each feeding may be constant or vary.

[0041] The feeding method for the composition of the present invention can be appropriately selected depending on the type and growth stage of the aquatic organism, the water temperature, etc. For example, it may be manual feeding, or mechanical feeding such as feeding from a feeding boat or automatic feeding. Furthermore, those skilled in the art can adjust the amount and timing of feeding based on the energy requirements of the aquatic organism.

[0042] The period for feeding the composition of the present invention can be appropriately selected according to various conditions such as the type of aquatic organism being fed. The composition of the present invention may be fed continuously for the entire period of cultivation, or it may be fed only for a part of the period. Furthermore, the feeding of the composition of the present invention may be repeated with continuation and interruption at any time. The period for feeding the composition of the present invention is not limited, but may be, for example, 1 to 12 months or 1 to 4 months, or about 1 month. "A part of the period" may be, for example, 10% or more, 20% or more, 30% or more, 50% or more, 70% or more, or 90% or more of the entire period of cultivation.

[0043] The cultivation of aquatic organisms can be carried out by conventional methods for raising aquatic organisms, except for feeding them with the composition of the present invention. Cultivation can be carried out, for example, in cages on the sea or rivers, or in tanks on land. Furthermore, cultivation includes both aquaculture that produces only juvenile fish and aquaculture that produces adult fish.

[0044] Aquatic organisms cultivated using the composition of the present invention can be recovered from aquaculture environments such as sea cages or land-based tanks. Recovery can be carried out by conventionally known methods.

[0045] 2. Strengthening stress tolerance In one embodiment of the present invention, by cultivating aquatic organisms using the composition of the present invention, the stress tolerance of the aquatic organisms can be enhanced compared to using feed that does not contain algae belonging to the class Ideyukogome. Therefore, the composition of the present invention can be used to enhance the stress tolerance of aquatic organisms. A stress tolerance enhancer containing algae belonging to the class Ideyukogome or a stress tolerance enhancer containing the composition of the present invention is also included in the present invention. Furthermore, the present invention includes a method for enhancing the stress tolerance of aquatic organisms, which includes feeding the aquatic organisms with the composition of the present invention, or the composition of the present invention used to enhance the stress tolerance of aquatic organisms. Moreover, the present invention includes a method for enhancing the stress tolerance of aquatic organisms, which includes feeding the aquatic organisms with algae belonging to the class Ideyukogome, or algae belonging to the class Ideyukogome used to enhance the stress tolerance of aquatic organisms. Aquatic organisms, feeding methods, etc., can be found in the description herein.

[0046] The stress-enhancing effect of a composition containing algae belonging to the class Ideyukogome can be evaluated by observing the state of aquatic organisms when they are fed the composition of the present invention, the water temperature is gradually increased during cultivation, and then they are placed under high temperatures such as 33°C, as described in the examples. For example, if the cumulative number of deaths over a predetermined period of time is lower than that of the control, or if the time elapsed to reach the predetermined cumulative number of deaths is shorter, it is evaluated that the composition enhances stress tolerance, especially high-temperature stress tolerance. The temperature in the high-temperature stress test is higher than the preferred temperature, for example, a temperature 5 to 15 degrees higher than the preferred temperature can be used.

[0047] "High-temperature stress" is the stress imposed on aquatic organisms by high temperatures. High temperature refers to water temperatures higher than normal in aquaculture environments such as fish farms at sea or tanks on land. For example, if the water temperature is more than 1 degree Celsius higher than the average water temperature for the same period in the past, high-temperature stress can be imposed on aquatic organisms.

[0048] Furthermore, the stress-enhancing effect of compositions containing algae belonging to the class Ideyukogome can be evaluated, as described in the examples, by measuring the blood cortisol concentration after, for example, 1 hour after exposure of aquatic organisms fed the composition of the present invention to air. Blood cortisol concentration is known as a stress marker, and a higher blood cortisol concentration indicates a higher stress state in fish. For example, if the blood cortisol concentration after air exposure is below the control level, it is evaluated as having an effect of enhancing stress tolerance, particularly tolerance to drought stress. The duration of air exposure in the drought stress test is, for example, 10 seconds to 10 minutes, but is not particularly limited.

[0049] "Extension stress" is the stress imposed on aquatic organisms by removing them from the water and exposing them to air. For example, aquatic organisms may be exposed to air (exposed to the air) when moved between cages during aquaculture, transferred to different tanks, weighed, or shipped, and such air exposure imposes stress on the aquatic organisms. "Extension stress" is used as an indicator to check the health of seedlings (juvenile fish), and the higher the tolerance to extension stress, the healthier the organism is considered to be.

[0050] In the present invention, the stress is preferably high-temperature stress or drought stress.

[0051] The control used to evaluate the stress tolerance-enhancing effect is a basic feed that does not contain algae belonging to the class Ideyukogome, and is a basic feed commonly used in the cultivation of aquatic organisms. Feeds containing substances known to enhance stress tolerance, such as vitamin C, or feeds containing substances intended to enhance stress tolerance, are not used as controls.

[0052] In this specification, when numerical ranges are described using "~", unless otherwise specified, both the lower limit and the upper limit are included. For example, the description "1~40" includes both the lower limit "1" and the upper limit "40". In other words, "1~40" has the same meaning as "1 or more and 40 or less".

[0053] In this specification, values ​​of "%" and "ppm" mean weight ratios. In this specification, "1 mg / kg" is equivalent to "1 ppm". In this specification, content is expressed by mass or weight ratio unless otherwise specified. [Examples]

[0054] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0055] 1. Materials and Test Methods • Gardelia stock The following studies used strain number CCCryo 127-00 Galdieria sulphuraria (Galdieri) Merola 1982, deposited at the Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics and Bioprocesses IZI-BB.

[0056] Preparation of Gardenia powder CCCryo 127-00 (haploid) was pre-cultured in a flask. The pre-culture solution was placed in a 7L jar fermenter (Marubishi Bioengin, Bioneer) containing 5L of MA2 medium (Ohnuma et al. Plant Cell Physiol. (2008) 49:117-120) with glucose added in the same manner as Schmidt et al. Biotechnol Bioeng. (2005) 90:77-84, and cultured for 7-10 days under conditions of 5 L / min aeration, 40°C, and 100 rpm. After culturing, the culture medium was centrifuged, the supernatant was removed, and the mixture was freeze-dried and powdered. The following tests were then conducted.

[0057] [Each test area] The feed amounts for each test plot were as follows: Control group: Standard feed Control group with sand substrate: Standard feed Positive control group: Standard feed + Vitamin C (5%) Example: Low-dose group: Standard feed + 1% Gardelia algae powder added. Example: High-dose group: Standard feed + 5% Gardelia algae powder added.

[0058] For the standard feed, three types of feed were used, tailored to the growth stage of the flounder: "Otohime EP1 Flounder" (particle size 1.5 mm), "Flounder EP F-1" (particle size 2 mm), and "Flounder EP F-2" (particle size 2.5 mm) (all manufactured by Nisshin Marubeni Feed Co., Ltd.). Vitamin C was supplied as "Iwaki" vitamin C (manufactured by Iwaki Pharmaceutical Co., Ltd.). In the control sand-covered plot, sand was laid on the bottom of the water layer during the feeding trial period, but not during the high-temperature stress test or drought stress test after the feeding trial. In the other plots, nothing was placed on the bottom of the water layer.

[0059] Gardelia algae powder and vitamin C were suspended in feed oil and spread onto the standard feed. In addition, the same amount of feed oil as in the example group and the positive control group was added to the standard feed in the control group and the control sand-bedding group.

[0060] [Feeding experiment] 120 flounder were placed in a 2-ton circular tank and raised for 28 days under conditions of continuous flow of filtered seawater at natural temperature. The seawater temperature was 10-20°C.

[0061] The daily feeding amount was set at 3% of the animal's body weight, and was divided into three meals (morning, noon, and evening). In addition, the animal's weight was measured once a week, and the amount of food was adjusted according to the weight.

[0062] [High-temperature stress test] The experiment began with 30 flounder from each test group after the feeding trial. During the trial, two flounder from the sand-bottomed group jumped out of the tank, so a stress test was conducted with the remaining 28 flounder from the sand-bottomed group. The flounder from the feeding trial were placed in tanks equipped with filtration systems and reared under still water and aeration conditions. The acclimatization period was set to 3 days, and the water temperature was raised using a heater to 24°C on day 1, 26°C on day 2, and 28°C on day 3. On day 4, the water temperature was set to 33°C, and the condition was observed every hour until 8 hours after the temperature was set. Any dead individuals were removed from the water tank as they occurred.

[0063] [Exhaustion stress test] Cortisol is a stress marker, and higher blood cortisol levels indicate a higher level of stress in fish. After feeding trials, flounder from each group were exposed to air (dried out), and blood cortisol levels were measured before and after exposure.

[0064] ·Measurement method For each test group, flounder were exposed to air (dried out) after the feeding trial. Air exposure was carried out by leaving the flounder in the air for 10 minutes. Blood samples were taken from three flounder in each test group before air exposure (dried-out stress), 1 hour after drying-out stress, and 24 hours after drying-out stress, and blood cortisol concentrations were measured. Cortisol concentrations were measured using a measurement kit (DetectX Cortisol ELISA Kit (Arbor Assays)).

[0065] 2. Results [High Temperature Stress Test] The results of the high-temperature stress test are shown in Figure 1. Figure 1 shows the mortality rate for each test group. ○ represents the control group, △ represents the control sand-covered group, □ represents the positive control group, ● represents the low-dose example group, and ▲ represents the high-dose example group.

[0066] In the high-temperature stress test, the time to death was shown to be longest in the following order: high-dose group (Garderia 5%), low-dose group (Garderia 1%), positive control group (Vitamin C), control sand group, and control group. Furthermore, it was confirmed that the number of deaths decreased in all groups compared to the control group after 2 hours of elapsed time. In particular, the sample group (feed containing algae belonging to the genus Gardenia) had an effect of enhancing high-temperature stress tolerance equivalent to or greater than that of the positive control group (feed containing vitamin C). This indicates that a feed containing algae belonging to the genus Gardelia as a base feed has the effect of enhancing the tolerance of aquatic organisms to high temperatures.

[0067] 3. Results [Drought Stress Test] The results of the drought stress test are shown in Table 1. Table 1 shows the average values ​​for each test plot.

[0068] [Table 1]

[0069] Since flounder are known to experience stress when the bottom of a tank is smooth, while stress is alleviated by covering the bottom with sand, a control group with sand was used as a positive control. The control group with sand had the lowest blood cortisol concentration among the four groups, both under normal conditions and at 1 hour and 24 hours after exposure to sunlight.

[0070] Under normal conditions (before drought stress), the groups treated with Gardelia (low-dose and high-dose groups) had lower blood cortisol levels than the control group. This result suggests that the addition of Gardelia alleviated stress originating from the aquarium during the feeding period.

[0071] The blood cortisol level one hour after exposure to air (exposure) stress indicates the degree of stress caused by exposure to air. In the cases containing Gardelia (low-dose and high-dose groups), the blood cortisol levels one hour after exposure to air stress were lower compared to the control group. These results indicate that feed containing Gardenia has an effect of enhancing tolerance to drought stress.

[0072] Blood cortisol levels 24 hours after drought stress showed that stress levels returned to normal levels 24 hours after drought stress.

[0073] These results indicate that feed containing Gardenia can enhance not only stress tolerance due to high temperatures but also stress tolerance due to drought. [Industrial applicability]

[0074] The present invention provides a composition for cultivating aquatic organisms or a method for cultivating aquatic organisms, which includes feeding them with the composition. In one embodiment of the present invention, the composition of the present invention can be used as a feed composition or feed for aquatic organisms.

[0075] In another embodiment, the compositions of the present invention can be used to enhance stress tolerance, such as stress caused by high temperatures or drought stress. The present invention also provides a method for enhancing stress tolerance in aquatic organisms.

[0076] Rising water temperatures in rivers and seawater due to global warming, as well as rising water temperatures when cultivating aquatic organisms on land, are problems that cannot be ignored in aquaculture. The composition or method of the present invention enhances the tolerance of aquatic organisms to these high-temperature stresses, and is therefore expected to reduce stress caused by rising water temperatures not only in river or ocean aquaculture but also in land-based aquaculture. Accordingly, the composition of the present invention can serve as a suitable feed for marine aquaculture where rising temperatures are a concern. In another embodiment, the composition of the present invention can reduce cooling costs, which are a contributing factor to increased costs in land-based aquaculture, and therefore may also be useful as a feed for land-based aquaculture.

[0077] Furthermore, aquatic organisms are exposed to air (drifted) during movement between cages, transfer to tanks, weight measurement, and shipping, which can cause stress. This invention is expected to reduce drying stress during aquaculture by enhancing tolerance to drying stress. This is also expected to improve handling and promote growth.

Claims

1. A composition for the cultivation of aquatic organisms, which are fish or crustaceans, containing algae belonging to the class Ideyukogome, for the purpose of enhancing the stress tolerance of the aquatic organisms.

2. The composition according to claim 1, which is a feed for the cultivation of aquatic organisms.

3. The composition according to claim 1 or 2, wherein the content of algae belonging to the class Ideyukogome is 0.01 to 5% (w / w).

4. The composition according to any one of claims 1 to 3, wherein the alga belonging to the class Ideyukogome is an alga belonging to the genus Gardelia.

5. The composition according to any one of claims 1 to 4, wherein the stress is high temperature stress or drought stress.

6. The composition according to claim 1, wherein the fish or crustacean is red sea bream, flounder, amberjack, pufferfish, yellowtail, tuna, eel, tilapia, catfish, sea bass, sweetfish, rainbow trout, Atlantic salmon, coho salmon, Chinook salmon, Pacific white shrimp, kuruma prawn, tiger prawn, white leg shrimp, or blue crab.

7. The composition according to claim 1, wherein the fish or crustacean is Pacific cod, salmon, herring, sweetfish, anchovy, Japanese sardine, black rockfish, scorpionfish, rock cod, striped jack, Japanese jack, crimson sea bream, greenling, marbled flounder, sole, or croaker.

8. A method for enhancing the stress tolerance of an aquatic organism, which is a fish or a crustacean, wherein the cultivation of the aquatic organism comprises feeding the aquatic organism with a composition containing algae belonging to the class Ideyukogome.

9. A method for enhancing the stress tolerance of an aquatic organism, comprising feeding the organism, which is a fish or crustacean, a composition containing algae belonging to the class Ideyukogome.

10. The method according to claim 8 or 9, wherein the stress is high-temperature stress or drought stress.

11. The method according to claim 8 or 9, wherein the fish or crustacean is red sea bream, flounder, amberjack, pufferfish, yellowtail, tuna, eel, tilapia, catfish, sea bass, sweetfish, rainbow trout, Atlantic salmon, coho salmon, Chinook salmon, Pacific white shrimp, kuruma prawn, tiger prawn, white leg shrimp, or blue crab.

12. The method according to claim 8 or 9, wherein the fish or crustacean is cod, salmon, herring, sweetfish, anchovy, sardine, black rockfish, scorpionfish, rock cod, striped jack, Japanese jack, crimson sea bream, greenling, flathead flounder, sole, or croaker.

13. The method according to any one of claims 8 to 12, wherein the content of algae belonging to the class Ideyukogome in the composition is 0.01 to 5% (w / w).

Images