CA2148678A1 - Solid feed and process for producing same - Google Patents

Abstract

Provided is a solid feed and a process for producing the solid feed for culture fishes and shellfishes or animals characterized in that the solid feed contains a specific polysaccharide.
The polysaccharide is used as a binder, and is also effective as an agent for treating or preventing diseases. Further. the polysaccharide is decomposed and absorbed into the fishes and shells or animals as an energy source and nutrient, making it possible to increase a feed effect.

Description

214~78 SOLID FEED AND PROCESS FOR PRODUCINC SAME

FIEED OF THE INVENTION
The present invention relates to a solid feed and a process for producing a solid feed. More specifically, the present invention relates to a solid feed and a process for producing a solid feed for culture fishes and shellfishes as well as for animals such as dogs, cats, domestic animals and domestic fowls, characterized in that the solid feed contains a specific polysaccharide.
BACKGROUND OF THE INVENTION
In recent years, cultivation of fishes and shellfishes has been increasing in an attempt to utilize marine resources at a high level.
However, fishes and shellfishes suffer from bacterial or viral diseases in a farm owing to degradation of a breeding environment such as congested cultivation, water pollution or the like, inviting serious damages to fishing industries.
- It has been indicated that one cause of this fact is that a biological preventability of fishes and shellfishes is decreased in the farm and the fishes and shellfishes tend to be infected with virus or bacteria.
To cope with the fish diseases, antibiotics and vaccines have been developed and used. However, the antibiotics are less effective because of resistant bacteria, and when persons eat the fishes and shellfishes to which the antibiotics are applied, the antibiotics are incorporated into their bodies. For these reasons, the use of the antibiotics tends to be limited. Further, kinds of fishes and shellfishes and diseases 214g~7~
-thereof to which the vaccines can be applied are also limited.
Further, bacterial or viral diseases have often occurred owing to congested breeding, degradation of a breeding environment and the like, inviting serious damages to breeding industries. Breeding of pets such as dogs, cats and the like has been recently increased. However, the pets have not been bred with appropriate feeds, and they have been infected with bacteria or virus, and have suffered from diseases.
It has been indicated that one cause of this fact is that a biological preventability of the pets and domestic animals is decreased in the breeding environment and the pets and domestic animals tend to be infected with virus or bacteria.
To cope with the diseases, antibiotics and vaccines have been developed and used. However, the antibiotics are less effective because of resistant bacteria, and there is a possibility that the antibiotics are incorporated into human bodies. For these reasons, the use of the antibiotics tends to be limited. Further, kinds of animals and diseases to which the vaccines can be applied are also limited.
Under these circumstances, development of a new agent for preventing diseases which is safe and effective has been in demand.
On the other hand, when producing a solid feed for culture fishes and shelIfishes or animals, a binder is required. Typical examples of the binder which has been used so far include starch, dextrin, gluten, agar, gelatin, casein. carrageenan,- sodium alginate, sodium polyacrylate, carboxYmethYlcellulose (CMC), hydroxypropylcellulose (HPC), sodium lignin sulfonate, sodium salt of casein and sodium cellulosic glycolate. The starch and gluten are used in relatively large amounts of from 5 to 20 %, but the binder is commonly added in an 2148~7g amount of from approximately 1 to 10 %, preferably 0.5 to 5 %. It is preferable that the binder is effective in as small an amount as possible. Thus, development of a new substance has been expected.
SUMMARY OP THE INVENTION
The present inventors established a process for producing a tasteless, odorless, water-soluble polysaccharide having physiological activities such as an antitumor activity, activity of adiusting immunity, activity of preventing infection and the like, and made studies with respect to the develoPment of the usage of such a polysaccharide (for example, Japanese Laid-Open Patent Application (Kokai) Nos. 35,791/1991 and 224,494/1991).
During the development of the usage of this polysaccharide, they have focused on the physiological activity such as the activity of preventing infection by the immunological activity of the polysaccharide, and have assiduouslY made extensive investigations.
Consequently, they have found that the polysaccharide gives fishes, shellfishes and animals such a physiological activity, and it can, therefore, be used as an agent for treating or preventing diseases due to such microorganisms as bacteria, virus, etc.
It has been further found that the Polysaccharide is produced as a highly viscous solution, that when the polysaccharide is mixed in the form of a solution, it can firmly bind a powdery raw material because of the high viscosity and when the polysaccharide is dried, it is solidified, for which reason it can be used as a binder in the production of a solid feed.
Consequently, various solid feeds can be produced by directly incorporating the viscous polysaccharide solution into the powdery raw 21~867~

material of the feed for culture fishes and shellfishes or animals without using another binder.
The use of water-soluble glucan as an agent for preventing fish diseases is described in Japanese Laid-Open Patent Application (Kokai) Nos. 218.615/1990 and 256,620/1990. However. a knowledge of using the water-soluble glucan as the binder has not been gained yet.
Moreover, since the feed for culture fishes and shellfishes is supplied in water. there are serious problems of cultivation fishery such as water pollution and decrease in the intake efficiency owing to collapse of the solid feed in water.
There have been examples in which the polysaccharide is used as an agent for preventing or treating diseases of animals. However. a knowledge of utilizing the polysaccharide as a binder has not been gained yet. Also. when using a feed for animals in solid form, collapse of the solid feed and a decrease in the intake efficiency thereof are serious problems. AccordinglY. the binder of the solid feed is the important factor.
However. it has been clarified that non-digestive high polymers such as CMC. sodium polyacrylate and the like which have been currentlY
used in many cases are not only lacking in the immunological activity but also adversely affect growth and digestion of fishes and shellfishes or animals.
On the other hand. since the sPecific polysaccharide used in the present invention is digestive. it is digested and absorbed into fishes.
shellfishes and animals as a nutrient and is utilized in vivo.
The polysaccharide used in the present invention is characterized in that it can be used not only as a binder but also as an agent for 2148fi78 preventing infectious diseases having an immunological activitY and further as a nutrient.
It is advisable that the form of the feed and the stability of the feed in water are secured sufficiently such that the feed in the form of pellets or the like is neither too hard, nor is it collapsed to form a powder. The polysaccharide is extremely suitable as the binder of the feed.
Besides, since the polysaccharide used in the present invention is advantageous in that when solidifying the feed, the polysaccharide exhibits both of a bindability and an ability of forming a surface coating, it is also suitable for the production of a finely divided feed such as a microbinding feed for use in, for example, larvae of crustacea, Iarvae of shells and spawns.
Based on the above-mentioned findings, the present inventors have completed a novel process in which a specific polysaccharide to be described later is used as an agent for preventing diseases and as a binder when producing a solid feed for culture fishes and shellfishes or anlmals.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is to provide a solid feed for culture fishes and shellfishes or animals and a process for producing the solid feed characterized in that the solid feed contains a polysaccharide having specific properties.
That is. the present invention is to provide a solid feed for culture fishes and shellfishes or animals and a process for producing a solid feed for culture fishes and shellfishes or animals characterized in that the solid feed contains a polysaccharide having the following 21~8fi7~

properties:
(1) White, tasteless, odorless, non-crystalline powder

(2) Solubility: soluble in water, formamide and dimethyl sulfoxide but insoluble in alcohol, acetone, benzene, ethyl acetate, hexane, chloroform and carbon tetrachloride

(3) pH of an aqueous solution: neutral or weakly acidic

(4) Constituent sugar: only glucose

(5) Elemental analysis: C: 43.0-45.0 %, H: 6.0-6.3 %

(6) Structure: a -glucan in which a main bond is an a -1,6 bond

(7) Protein: not detected by a Lowry method

(8) Molecular weight: approximately 10,000 or more without passing through a dialysis membrane

(9) Color reaction: positive in an anthrone-sulfuric acid reaction and phenol-sulfuric acid reaction, and passive in a biuret reaction. Lowry-Folin reaction, Elson-Morgan reaction and iodine reaction

(10) Melting point: not showing a clear melting point

(11) UV absorption spectrum: showing no characteristic absorpotion

(12) IR absorption spectrum: showing characteristic absorption ascribable to a -glucan

(13) l3C-NMR spectrum: showing characteristic absorption ascribable to a -1, 6 glucan

(14) Antitumor activity The polysaccharide used in the present invention is a -glucan in which a main bond is a water-soluble a -1,6 bond. This polysaccharide can be obtained by various methods. It is practically advisable that the polysaccharide be obtained as a fermentation product formed by 21~7~

cultivating a specific microorganism using sucrose as a substrate. For example, an intended polysaccharide is obtained as a viscous solution by cultivating one or more microorganisms with sucrose-containing solution or sucrose-containing medium (for example, Japanese Laid-Open Patent Application (Kokai) No. 35,791/1991). The microorganisms are selected from the group consisting of Leuconostoc mesenteroides subspecies dextranicum BL-75 (FERM BP-2242), L. mesenteroides subspecies dextranicum NCFB 517 (FERM BP-2711), L. mesenteroides subspecies dextranicum NCFB 531 (FERM PB-2712), L. mesenteroides subspecies dextranicum NCFB 861 (FERM BP-2713), L. mesenteroides subspecies dextranicum NCFB 864 (FERM BP-2714), L. mesenteroides subspecies dextranicum NCFB 880 (FERM BP-2715), L. mesenteroides subspecies dextranicum 46-1 (FERM BP-2670), L. mesenteroides subspecies dextranicum ATCC 1956 and L. mesenteroides subspecies dextranicum IFO 3349;
Lactobacillus confusus 40-1 (FERM BP-2865), L. confusus 40-3 (FERM BP-2866), L. confusus 77-1 (FERM BP-2867), L. confusus 78-1 (FERM BP-2868) and L. confusus 80-1 (FERM BP-2869); and mutants thereof.
The polysaccharide may be separated from the culture solution in a usual manner. For example, the polysaccharide can be easily separated by filtration or centrifugal separation to remove the microbial cells.
As the crude polysaccharide, the microbial cell-containing culture solution itself or the culture solution being subiected to heat-sterilization can be used. If required, the culture solution may be purified by removing the microbial cells through a procedure such as filtration, centrifugal separation or the like and then applYing appropriate purifying procedure.
Purther, a cell-free polysaccharide having a high purity can be 21~78 produced as a viscous solution directly easilY by reacting sucrose solution with a polysaccharide synthetase extracted from the above-mentioned microorganism (refer to Japanese Laid-Open Patent Application (Kokai) No. 224,494/1991).
Starting materials used to produce the solid feed for culture fishes and shellfishes or animals in the present invention are a fish meal, skim milk, oil meal, corn flour. wheat flour, dry yeast, egg powder, rice bran, wheat bran, meat powder and molasses, alfalfa meal, trace amounts of additives. The starting (raw) materials may be properly selected in consideration of the composition of the feed, kinds of fishes and shellfishes or animals and the like. For example, a composition of a feed for cultivating an ayu (sweetfish) is shown below.
Table 1 Composition of a feed for an ayu (a suitable form of a solid feed is crumbles):
Fish meal 30 %
Meat powder 20 %
Wheat flour 15 %
Soybean flour 5 %
Soybean oil cake 10 X
Wheat bran 5 %
Germ 5 X
Dry beer yeast 5 X
Whole egg powder 3 X
Additives 1 X
Polysaccharide 1 X

2148fi78 Further. a composition of a feed for dog is shown below.
Table 2 Composition of a feed for a dog (pellet type. calculated as anhydrous product):
Fish meal 30 %
Meat powder 20 %
Corn flour 15 %
Soybean oil cake 10 %
Rice bran 5 %
Alfalfa meal 5 %
Germ 5 %
Dry beer yeast 5 %
Whole egg powder 3 %
Additives 1 %
Polysaccharide 1 %

In the production of the solid feed for culture fishes and shellfishes or animals. the amount of the polysaccharide used is usually from 0.01 to 5.0 X by weight, preferably from 0.05 to 2.0 % by wei8ht~
calculated as an anhydrous product. based on the total weight of the feed ingredients. The feed is produced under ordinary conditions except that the polysaccharide is used instead of a conventional binder. In a typical process for producing the feed, a mixture of various feed ingredients corresPonding to kinds of fishes and shellfishes or animals and dry raw materials is kneaded with the polysaccharide (liquid) at a predetermined concentration. and the reaction mixture is formed into fine particles. granules. pellets. or _ g _ 2`~ ~67~

spiral bars which are then dried. Crumbles are obtained by drying and pulverizing the pellets and screening the resulting particles.
When using a powdery polysaccharide, a liquid polysaccharide is powdered by spraY-drying or the like. The powdery polysaccharide is mixed with the powdery feed starting materials, and water is suitably added to the resulting substance. The mixture can be formed into pellets or the like. The powdery polysaccharide is indeed advantageous in storage, transportation and the like, but the powdering takes much cost. Thus, the powdery polysaccharide is not economical.
The fishes and shellfishes which are cultivated with the feed provided by the present invention include fishes, shells and crustacea.
Examples thereof include those cultivated in fresh water, such as a carp, eel, ayu, rainbow trout, loach, goldfish, tilapia, kokanece and catfish; and those cultivated in seawater, such as a young Yellowtai yellowtail, red sea bream, black porgy, horse mackerel, hardtail, silver salmon, trout, flatfish, bluefin, rabbitfish, crimson sea bream, parrot fish, prawn, lobster, scallop and oyster.
The animals which are cultivated with the feed provided bY the present invention include PetS~ domestic animals, domestic fowls, etc.
Examples thereof include mammalia such as dog, cat, etc.; birds such as parakeet, Java sparrow, etc.; domestic animals such as cow, pig, horse, sheep, goat, etc.; domestic fowls such as chicken, duck, etc.
The present invention is characterized in that when producing a solid feed for culture fishes and shellfishes or animals in the form of pellets, crumbles, spiral bars, fine particles, granules or the like, a specific polysaccharide is incorporated into the solid feed. The Polysaccharide is used as a binder, and is also effective as an agent 21~8~78 for treating or preventing diseases. Further, the polysaccharide is decomposed and absorbed into the fishes and shellfishes or animals as an energy source and nutrient, making it possible to increase a feed effect.
Examples The present invention is illustrated more specifically by referring to the following Examples.
Example 1 Production of a polysaccharide:
Leuconostoc mesenteroides subspecies dextranicum BL-75 (FERM BP-2242) was subiected to stab-culture. The cultured cells were inoculated in a test tube filled with 8 ml of a culture medium (comprising 4.0 % sucrose, 0.05 % dry beer yeast, 0.5 % dipotassium hydrogenphosphate and 0.1 % sodium chloride) and having a diameter of 15 mm, and the mixture was statically cultured at 26C for 24 hours.
Subsequently, 20 ml of the above-obtained cells at a concentration of 1 x 107/cm2 were inoculated in a 3-liter conical flask filled with 1 liter of a culture medium having the above-mentioned composition, and were statically cultured at 28C for 20 hours.
Water was added to the thus-obtained viscous culture solution to adiust the concentration of the polysaccharide to 1 %. Then, the culture solution was centrifuged to remove the cells and insoluble matters and to obtain 1.8 liters of the 1 % polysaccharide solution.
This process for producing the polysaccharide is described in detail in Japanese Laid-Open Patent Application (Kokai) No. 35,791/1991.
Production of a feed:
One hundred grams of a fish meal, 70 8 of a skim milk, 10 8 of an 2148~7~

oyster shell powder, 200 g of a chicken meal. 200 g of an oil meal, 250 g of a corn flour, 10 g of a wheat germ. 80 g of a rice bran and 10 g of dry beer yeast and other additives were uniformly mixed, and further mixed with 150 g of the above-obtained lX polysaccharide solution. The resulting mixture was formed into pellets having a diameter of 5 mm by means of a pelleter. The pellets were steam-sterilized, and then dried to yield 1 kg of the pelletized feed for trouts. This feed was not collapsed in water, and was taken in by trouts at good efficiency without water pollution.
Example 2 Production of a polysaccharide:
One hundred milliliters of a sterilized 1 % polysaccharide solution (crude enzymatic solution) obtained in the same manner as in Example 1 were added to 1 liter of a heat-sterilized culture medium comprising 28 % sucrose, 0.1 % yeast extract, 0.5 % potassium hydrogenphosphate and 0.1 % sodium chloride. The mixture was statically reacted at 30C for 24 hours. Water was then added thereto to obtain 2 liters of a 10 %
polysaccharide solution. This process for producing the polysaccharide is disclosed in detail in Japanese Laid-Open Patent Application (Kokai) No. 224,494/1991.
Production of a feed:
A fish meal (450 g), 200 g of a skim milk, 150 g of a wheat flour, 50 g of a bread crumb, 50 g of an oil meal and 40 g of dry beer yeast and other additives were uniformlY mixed, and further mixed with 150 g of the above-obtained polysaccharide solution. The mixture was then formed into pellets having a diameter of 6 mm by means of a pelleter.
The pellets were steam-sterilized, and dried with hot air to yield l kg 21~78 of a pelletized feed for eels. The feed was applied to eels in a farm.
It was found that the feed was not collapsed in water and was taken in by eels at good efficiency without water pollution.
Example 3 Production of a polysaccharide:
Lactobacillus confusus 40-1 (FERM BP-2865) was subiected to stab-culture. The cultured cells were inoculated in a test tube filled with 5 ml of a culture medium (comprising 2.0 % sucrose, 0.5 % yeast extract and 2.0 % dipotassium hydrogenphosphate, pH 7.4) and having a diameter of 15 mm, and the mixture was statically cultured at 26C for 24 hours.
Subsequently, 10 ml of the culture solution were added to a 1-liter conical flask filled with 500 ml of a culture medium having the above-mentioned composition, and were statically cultured at 26C for 24 hours.
The thus-obtained culture solution was heat-sterilized, and then centrifuged to remove the cells and to obtain 470 ml of a 1 %
polysaccharie solution. This process for producing the polysaccharide is detailed in Japanese Laid-Open Patent Application (Kokai) No.
36,187/1992.
Production of a feed:
Five-hundred grams of a fish meal, 200 g of a wheat flour, 100 8 of a meat bone meal, 50 8 of an oil meal, 50 g of a rice bran and 50 g of dry beer yeast and other additives were uniformly mixed, and further mixed with 180 g of the above-obtained lX polysaccharide solution. The mixture was formed into pellets having a diameter of 5 mm by means of a pelleter. The pellets were steam-sterilized, and then dried to yield 1 kg of a pelletized feed for red sea breams. This feed was not 2i~8~7a collapsed in water and was taken in by red sea breams at good efficiency without water pollution.
Example 4 Production of a polysaccharide:
Leuconostoc mesenteroides subspecies dextranicum BL-75 (FERM BP-2242) was subiected to stab-culture. The cultured cells were inoculated in a test tube filled with 8 ml of a culture medium (comprising 5.0 X sucrose, 0.05 X dry beer yeast, 0.5 % dipotassium hydrogenphosphate and 0.1 % sodium chloride) and having a diameter of 15 mm, and the mixture was statically cultured at 30C for 18 hours.
Subsequently, 20 ml of the above-obtained cells at a concentration of 1 x 107/cm2 were inoculated in a 3-liter conical flask filled with 1 liter of a culture medium having the above-mentioned composition, and were statically cultured at 28C for 20 hours.
Water was added to the thus-obtained viscous culture solution to adiust the concentration of the polysaccharide to 2 %. Then, the culture solution was centrifuged to remove the cells and insoluble matters and to obtain 1.0 Iiter of the 2% polysaccharide solution.
This process for producing the polysaccharide is described in detail in Japanese Laid-Opn Patent Application (Kokai) No. 35,791/1991.
Production of a feed:
One hundred grams of a fish meal, 70 g of a skim milk, 60 g of a meat bone meal, 150 g of a chicken meal, 50 g of an alfalfa meal, 200 g of an oil meal, 250 g of a corn flour, 10 g of a wheat germ, 80 g of a rice bran and 10 g of dry beer yeast and other additives were uniformlY
mixed, and further mixed with 200 g of the above-obtained polysaccharide solution. The resulting mixture was formed into pellets - 21~8~i7~

having a diameter of 10 mm by means of a pelleter. The pellets were steam-sterilized. and then dried to yield 1 kg of the pelletized feed for puppies.
Example 5 Production of a polysaccharide:
One hundred milliliters of a sterilized 1 X polysaccharide solution (crude enzymatic solution) obtained in the same manner as in Example 4 were added to 1 liter of a heat-sterilized culture medium comprising 26 % sucrose. 0.1 % yeast extract. 0.5 % potassium hydrogenphosphate and 0.1 % sodium chloride. The mixture was statically reacted at 30C for 20 hours. Water was then added thereto to obtain 2 liters of a 10%
polysaccharide solution. This process for producing the polysaccharide is detailed in Japanese Laid-Open Patent Application (Kokai) No.
224.494/1991.
Production of a feed:
A fish meal (550 g). 100 g of a skim milk. 150 g of a wheat bran.
30 g of a meat bone meal. 70 g of an oil meal and 40 8 of dry beer yeast and other additives were uniformly mixed. and further mixed with 180 g of the above-obtained polysaccharide solution. The mixture was then formed into pellets having a diameter of 7 mm by means of a pelleter. The pellets were steam-sterilized. and dried ~ith hot air to yield 1 kg of a pelletized feed for cats.
Example 6 Production of a polysaccharide:
Lactobacillus confusus 40-1 (FERM BP-2865) was subiected to stab-culture. The cultured cells were inoculated in a test tube filled with

15 ml of a culture medium (comprising 3.0 X sucrose. 0.5 % yeast extract 2148~78 and 2.0 % dipotassium hydrogenphosphate. pH 7.4) and having a diameter of 15 mm, and the mixture was staticallY cultured at 26C for 24 hours.
Subsequently. 10 ml of the culture solution was added to a 1-liter conical flask filled with 500 ml of a culture medium having the above-mentioned composition. and statically cultured at 26 C for 24 hours.
The thus-obtained culture solution was heat-sterilized, and then centrifuged to remove the cells and to obtain 450 ml of a 1.3X
polysaccharide solution. This process for producing the polysaccharide is detailed in Japanese Laid-Open Patent Application (Kokai) No.
36.187/1992.
Production of a feed:
Five-hundred grams of a fish meal. 200 g of a wheat bran. 50 g of an oyster shell powder. 50 g of an oil meal. 50 g of a rice bran. 50 g of a dry vegetable and 50 g of dry beer yeast and other additives were uniformly mixed. and further mixed with 170 g of the above-obtained 1.3 % polysaccharide solution. The mixture was formed into pellets having a diameter of 3 mm by means of a pelleter. The pellets were steam-sterilized, and then dried to yield 1 kg of a pelletized feed for chickens.

Claims (5)

WHAT IS CLAIMED IS:

1. A solid feed comprises containing a polysaccharide having the following properties:
(1) White, tasteless, odorless, non-crystalline powder (2) Solubility: soluble in water, formamide and dimethyl sulfoxide but insoluble in alcohol, acetone, benzene, ethyl acetate, hexane, chloroform and carbon tetrachloride (3) pH of an aqueous solution: neutral or weakly acidic (4) Constituent sugar: only glucose (5) Elemental analysis: C: 43.0-45.0 %. H: 6.0-6.3 %
(6) Structure: .alpha. -glucan in which a main bond is an .alpha. -1.6 bond (7) Protein: not detected by a Lowry method (8) Molecular weight: approximately 10,000 or more without Passing through a dialysis membrane (9) Color reaction: positive in an anthrone-sulfuric acid reaction and phenol-sulfuric acid reaction, and passive in a biuret reaction, Lowry-Folin reaction, Elson-Morgan reaction and iodine reaction (10) Melting point: not showing a clear melting point (11) UV absorption spectrum: showing no characteristic absorption (12) IR absorption spectrum: showing characteristic absorption ascribable to .alpha. -glucan (13) l3C-NMR spectrum: showing characteristic absorption ascribable to .alpha. -1.6 glucan (14) Antitumor activity

2. A process for producing a solid feed characterized in that the solid feed contains a polysaccharide having the following properties:
(1) White, tasteless, odorless, non-crystalline powder (2) Solubility: soluble in water, formamide and dimethyl sulfoxide but insoluble in alcohol, acetone, benzene, ethyl acetate, hexane, chloroform and carbon tetrachloride (3) pH of an aqueous solution: neutral or weakly acidic (4) Constituent sugar: only glucose (5) Elemental analysis: C: 43.0-45.0 %, H: 6.0-6.3 %
(6) Structure: .alpha.-glucan in which a main bond is an .alpha.-1,6 bond (7) Protein: not detected by a Lowry method (8) Molecular weight: approximately 10,000 or more without passing through a dialysis membrane (9) Color reaction: positive in an anthrone-sulfuric acid reaction and phenol-sulfuric acid reaction, and passive in a biuret reaction, Lowry-Folin reaction, Elson-Morgan reaction and iodine reaction (10) Melting point: not showing a clear melting point (11) UV absorption spectrum: showing no characteristic absorption (12) IR absroption spectrum: showing characteristic absorption ascribable to .alpha.-glucan (13) 13C-NMR spectrum: showing characteristic absorption ascribable to .alpha.-1,6 glucan (14) Antitumor activity

3. The process of claim 2 wherein the polysaccharide is used as a binder when producing the solid feed and as an agent for treating or preventing diseases of fishes and shellfishes or animals.

4. The process of claim 1 wherein the polysaccharide is produced from one or more microorganisms selected from the group consisting of Leuconostoc mesenteroides subspecies dextranicum BL-75 (FERM BP-2242), L. mesenteroides subspecies dextranicum NCFB 517 (FERM BP-2711), L.
mesenteroides subspecies dextranicum NCFB 531 (FERM PB-2712), L.
mesenteroides subspecies dextranicum NCFB 861 (FERM BP-2713), L.
mesenteroides subspecies dextranicum NCFB 864 (FERM BP-2714), L.
mesenteroides subspecies dextranicum NCFB 880 (FERM BP-2715), L.
mesenteroides subspecies dextranicum 46-1 (FERM BP-2670), L.
mesenteroides subspecies dextranicum ATCC 1956, L. mesenteroides subspecies dextranicum IF0 3349, Lactobacillus confusus 40-1 (FERM BP-2865). L. confusus 40-3 (FERM BP-2866). L. confusus 77-1 (FERM BP-2867), L. confusus 78-1 (FERM BP-2868), L. confusus 80-I (FERM BP-2869), and mutants thereof.

5. The process of claim 2 wherein the feed is a feed for culturing fishes, shells and crustacea or animals.