JP2000344798A - Silver-containing conjugated protein, antimicrobial/ antifungal agent and antimicrobial/antifungal paper using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-insoluble conjugated protein not readily liberating antimicrobial/antifungal silver from a protein, yet having a high silver content and an antimicrobial/antifungal agent and an antimicrobial/antifungal paper using the conjugated protein. SOLUTION: A protein having 0.1-200 μmol/g active thiol group content is not particularly restricted as a water-soluble protein having 0.1-200 μmol/g active thiol group content as long as the protein has the content of an active thiol group in the range. To be concrete, a whey protein, a whey protein hydrolyzate, a water solubilized substance of whey protein, an egg shell membrane protein hydrolyzate and a water solubilized substance of egg shell membrane protein may be cited as the protein and can be preferably used. Since the water-soluble protein retains emulsifiability being one of characteristics of the original protein, an antimicrobial/antifungal agent prepared from the water-soluble protein as a raw material is expected to have excellent stickiness to an object.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel silver-containing composite protein having antibacterial and antifungal properties, and an antibacterial and antifungal agent and antibacterial and antifungal paper using the same.

[0002]

2. Description of the Related Art In recent years, various types of microorganisms such as molds and bacteria have not been propagated in medical equipment, stationery, textiles, paper products, household goods and bath products in consideration of health and hygiene. What has been subjected to antibacterial and antifungal treatment is often used. For example, in hospitals, from the viewpoint of preventing hospital-acquired infection, plastic stationery and instruments provided with antibacterial and antifungal properties are used. As described above, those which come into direct contact with the human body or foods are required to have higher safety, and development of antibacterial and antifungal agents having excellent antibacterial and antifungal properties and products treated with the same is desired.

As such antibacterial and antifungal agents, water-insoluble hard proteins such as eggshell membranes, feathers, wool, silk, and collagen, silk fibroin, and elastin separated therefrom are used as antibacterial agents such as silver, copper, and zinc. A protein antibacterial / antifungal agent having an antifungal metal adsorbed thereon has been proposed (see JP-A-6-65013, JP-A-8-188513 and JP-A-8-258235).

[0004] These protein antibacterial and antifungal agents are obtained, for example, by mixing and stirring an eggshell membrane powder and an aqueous solution of silver nitrate, and filtering, washing, dehydrating and drying the precipitate in the resulting mixed solution. (For example, see JP-A-6-650)
No. 13, [0011]).

[0005] However, the protein antibacterial and antifungal agents obtained in this way could not impart sufficient antibacterial and antifungal activities to various products. This is due to the low content of antibacterial and antifungal metals in protein antibacterial and antifungal agents, and the weak physical or ionic adsorption of proteins to antifungal and antifungal metals. It is considered that the antibacterial and antifungal metal is easily released from the protein by washing with water.

[0006] On the other hand, the Japanese Pharmacopoeia describes silver protein as a compound of silver and protein. Compounds of silver and proteins are classified into water-insoluble peptides that cause higher-order structural changes by binding to silver ions, and water-soluble peptides that hardly bind to silver ions because they have few thiol groups in the molecule. Exists as a peptide assembly constituted by the conjugation of Therefore, when protein silver is used for uses other than pharmaceuticals, the protein silver is easily eluted, and a sufficient effect as an antibacterial / antifungal agent cannot be obtained.

On the other hand, many inorganic metals such as silver, copper and zinc have been developed as active ingredients of antibacterial and antifungal papers. Although the mechanism of action of these inorganic metals is not clear, the active ingredient absorbed into the microbial body as metal ions inhibits basic metabolism such as respiration and electron transport, or mass transfer in cell membranes, and thus provides antimicrobial and antimicrobial activity. It is thought that it exhibits moldiness. However,
There has been a problem that these active ingredients composed of an inorganic metal are difficult to be applied (fixed) to paper unless a resinous binder or the like is used in combination.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a water-insoluble complex protein having a high silver content, in which antibacterial and antifungal silver is not easily released from the protein, and an antibacterial and antifungal using the same. It is an object to provide an antibacterial agent and antibacterial / antifungal paper.

[0009]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, contacted a water-soluble protein containing a specific amount of an active thiol group with a silver salt in water. As a result, a novel complex protein carrying silver efficiently was obtained, and the fact that the complex had extremely high antibacterial and antifungal activities was found, and the present invention was completed.

Thus, according to the present invention, a water-insoluble compound obtained by contacting a water-soluble protein having a content of active thiol groups in a protein of 0.1 to 200 μmol / g with a silver salt in water is provided. Is provided.

Further, according to the present invention, there is provided an antibacterial / antifungal agent comprising the silver-containing composite protein as an active ingredient.

Further, according to the present invention, there is provided an antibacterial / antifungal paper characterized by being treated with the above antibacterial / antifungal agent.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The "active thiol group" in the present invention means a mercapto group (-SH) which easily reacts with an aqueous solution of a heavy metal compound to form a metal mercaptide derivative. The content ratio of the active thiol group of the protein used in the present invention is 0.1 to 200 per protein weight.
μmol / g, preferably 5 to 100 μmol / g.

When the content of the active thiol group is less than 0.1 μmol / g, the amount of silver bound to the active thiol group is small, and an ideal water-insoluble silver-containing composite protein may not be obtained. Absent. On the other hand, when the content ratio of the active thiol group exceeds 200 μmol / g, the bonding of silver to the active thiol group may precipitate as a localized water-insoluble complex, which is not preferable. That is, such a phenomenon results in a decrease in the amount of silver bonding.

The content of the active thiol group is determined by preparing an aqueous solution of the protein which has been quantified in advance, and using the DTNB method (Ellman method).
Can be measured as an equivalent amount of L-cysteine (see Biochemical Experiment Method 10 “Quantification of SH groups”, published by Gakkai Shuppan Center, pages 86 to 93).

The “water-soluble protein having an active thiol group content of 0.1 to 200 μmol / g” in the present invention is not particularly limited as long as the active thiol group content is within the above range. Not done. Specifically, whey protein, whey protein hydrolyzate, whey protein water solubilizate, eggshell membrane protein hydrolyzate and eggshell membrane protein water solubilizate, and these are preferably used it can. In addition, since the water-soluble protein retains the emulsifying property, which is one of the properties of the original protein, antibacterial and antifungal agents prepared using this as a raw material can be expected to have excellent fixation to the object. .

"Whey protein" is a protein originally containing relatively large amounts of cystine and active thiol groups,
An alkali thiol group containing more active thiol groups can be obtained by alkali decomposition, enzymatic decomposition or treatment with a reducing agent described later. This whey protein is composed of α-lactalbumin and β-lactalbumin.
It contains water-soluble proteins such as lactoglobulin and is abundant in whey (by-product) produced as a by-product during cheese production, and is industrially available in large quantities.

A commercially available whey protein is, for example, Sanlac N-5 (trade name) manufactured by Taiyo Kagaku Co., Ltd., and its active thiol group content is 50 μmol / g.
It is about.

Whey contains, in addition to whey protein, lactose, which is a reducing sugar, and minerals. In particular, metallic silver may be precipitated due to the presence of lactose, so it is preferable to remove the silver before contacting with silver ions. For example, when using whey itself or whey protein in which lactose remains, the lactose can be removed by dissolving them in deionized water and dialyzing this solution against deionized water.

The protein containing a large amount of cystine in the molecule includes keratin, a hard protein such as hair, wool and feather. However, hair and feathers are difficult to handle for use as an industrial material as in the present invention. Also, wool has a high cystine content,
Use in the present invention is disadvantageous in terms of cost.

A material comparable to the cystine content of wool is eggshell membrane protein, and its hydrolyzate or water lysate is suitably used as the protein of the present invention. “Eggshell membrane protein” is a water-insoluble protein that constitutes the membrane inside the eggshell of avian eggs, and is used in the present invention in the food industry because of its availability as an industrial material. It is preferable to use chicken eggs, quail eggs, and the like, which are consumed in large quantities in such as raw materials.

Alkali-decomposition of water-insoluble eggshell membrane proteins,
By subjecting to enzymatic decomposition or treatment with a reducing agent, a water-soluble hydrolyzate or water-solubilized product containing a specific amount of an active thiol group can be obtained. That is, the content ratio of the active thiol group in the protein can be adjusted by cleaving the disulfide bond in the eggshell membrane protein and employing the processing conditions for the active thiol group.

Hereinafter, the recovery of eggshell membranes from eggs, the hydrolysis treatment of eggshell membranes, and the water solubilization treatment will be specifically described. (Separation of eggshell membrane) Eggs are eggshell, eggshell membrane, egg white,
It is composed in the order of yolk, and the outermost eggshell and eggshell membrane are in close contact. In order to collect the eggshell membrane, first, the eggshell and eggshell membrane are separated from the albumen and the yolk usually by breaking eggs. The eggshell membrane is then peeled from the eggshell using, for example, tweezers.

In order to industrially collect eggshell membranes in large quantities, the eggshell and eggshell membranes that are in close contact with each other are treated with an acid (for example, hydrochloric acid having a concentration of about 10%) to dissolve calcium carbonate, which is a main component of the eggshell. And it is separated by filtration.

In order to carry out the acid treatment efficiently, it is preferable to mechanically pulverize the eggshell and eggshell membranes in close contact with each other in advance. Further, it is more preferable to classify the pulverized product, to classify the pulverized product according to a difference in specific gravity, and to carry out acid treatment (Japanese Unexamined Patent Publication (Kokai) No. 3-4526).
No. 4). The eggshell membranes separated and recovered by the method described in this publication include, for example, a seasoning called “egg sauce” in which the eggshell membrane is decomposed into amino acids, dipeptides or tripeptides, and epidermal cells and fibroblasts as water-solubilized proteins. It is applied as a component of cosmetics that activates cells.

Next, the eggshell membrane obtained by the above method is subjected to alkali decomposition, enzymatic decomposition, treatment with a reducing agent, or the like as described above to obtain a water-soluble hydrolyzate or a water-soluble hydrolyzate containing a desired ratio of active thiol groups. Obtain a water lysate. Among these treatments, alkali decomposition is industrially preferable.

(Alkali decomposition)
% In an aqueous solution of an alkali metal hydroxide (eg, sodium hydroxide or potassium hydroxide) (eg, an aqueous solution having a water or ethanol concentration of 40%).
The concentration of the alkali metal hydroxide may be appropriately selected depending on conditions such as the amount of the eggshell membrane and the treatment temperature. For example,
When the amount of the eggshell membrane is about 50 g, it is treated with 1000 ml of an aqueous solution of an alkali metal hydroxide adjusted to 1N.

Mixing and stirring the eggshell membrane to which the aqueous solution of the alkali metal hydroxide is added promotes alkali decomposition. Processing temperature is about 40-80 ° C, processing time is 3 ~
About 24 hours is sufficient. The treated aqueous solution is filtered, and the obtained filtrate is dialyzed against deionized water to obtain a hydrolyzate of the eggshell membrane protein.

(Enzymatic degradation) A hydrolyzate can be obtained by treating the eggshell membrane with a protease. Examples of proteolytic enzymes include proteolytic enzymes of plant origin such as papain and bromelain, and proteolytic enzymes of animal origin such as pancreatin, rennin, trypsin, chymotrypsin and pepsin.

This treatment is carried out in a liquid in which the eggshell membrane is dispersed in water, and the temperature and pH during the treatment may be in accordance with the optimum temperature and pH of the enzyme used, and are not particularly limited. For example, when pancreatin is used, the temperature is 35 to 50 ° C., p
H6 to about 8 is appropriate. The treated solution is filtered, and the obtained filtrate is dialyzed against deionized water to obtain a hydrolyzate of the eggshell membrane protein.

(Reducing Agent Treatment) Even if the eggshell membrane is treated with a reducing agent, a water-solubilized product can be obtained. In this method, disulfide bonds in eggshell membranes are reduced with a reducing agent such as sodium sulfide, thioglycolic acid and β-thiopropionic acid or an alkali salt thereof, or 2-mercaptoethanol. The amount of the reducing agent depends on its type, for example,
When using β-thiopropionic acid, eggshell membrane 100
The amount is about 2000 ml of a β-thiopropionic acid aqueous solution adjusted to 5N per g.

This treatment is carried out in a liquid in which the eggshell membrane is dispersed in water. For example, when β-thiopropionic acid is used as a reducing agent, the temperature is preferably 60 to 80 ° C. and the treatment time is about 5 hours. . The treated solution is filtered, and the obtained filtrate is dialyzed against deionized water to obtain a water solubilized egg shell membrane protein.

The whey protein may be used as it is as a water-soluble protein, but may be used as a hydrolyzate or a water-solubilized product obtained by the above-mentioned alkali decomposition, enzymatic decomposition or treatment with a reducing agent. It can also be used.

The "water-insoluble silver-containing composite protein" of the present invention
Can be obtained by bringing a water-soluble protein having an active thiol group content of 0.1 to 200 μmol / g into contact with a silver salt in water.

As a silver salt, silver ions are dissociated in water,
There is no particular limitation as long as the binding between the protein and silver is not inhibited. Specifically, inorganic acid salts such as silver nitrate, silver nitrite, silver sulfate, silver perchlorate, silver oxide and silver chloride, organic acid salts such as silver acetate, silver lactate and silver oxalate, diamine silver nitrate and diamine silver sulfate Examples thereof include complex salts such as salts, and silver nitrate and silver acetate are particularly preferable in view of solubility in water.

As a method for bringing the protein and the silver salt into contact in water, known methods such as mixing, stirring and shaking can be used. Among them, mixing and stirring are industrially preferable. As a specific method using stirring, a method in which a protein and a silver salt are mixed at once in water and stirred, while the protein is stirred in water, a silver salt dissolved in water is gradually added thereto. A method of gradually increasing the silver ion concentration in water, and a method of gradually adding finely ground silver salt to the protein while stirring the protein in water to dissolve the silver ion concentration in the water. While stirring the mixture, a protein aqueous solution is gradually added thereto to finally keep the silver ion concentration in the water constant. Among them, the method is particularly preferable because the silver-containing composite protein can be obtained with high reproducibility and high yield.

The ratio of the protein to the silver salt depends on the conditions of the contact, but usually the silver salt is 0.2 to 3 per gram of the protein.
g is preferable. More specifically, a concentration of 1 to 20 mg
/ 1000 ml of aqueous solution of protein per ml
It is preferable to use a silver salt aqueous solution of about 250 mM in a ratio of about 1000 ml. However, the liquid volume ratio of the aqueous protein solution to the aqueous silver salt solution is not particularly limited as long as a composite protein having a high silver content can be obtained efficiently.

The conditions for bringing the protein into contact with the silver salt may be such that the protein and the silver salt are uniformly mixed and a complex protein having a high silver content can be efficiently obtained. For example, in the case of contact by stirring, it is appropriate that the temperature is about 0 to 70 ° C. and the processing time is 24 hours or less.

The treated mixed solution is filtered, and the residue obtained by filtration is washed with deionized water and ethanol and dried to obtain a silver-containing complex protein. The silver content in the obtained composite protein can be determined, for example, by quantifying the eluted silver using 3% nitric acid.

According to the present invention, there is provided an antibacterial / antifungal agent containing the silver-containing complex protein as an active ingredient, and an antibacterial / antifungal paper treated with the antibacterial / antifungal agent.

The antibacterial and antifungal agent of the present invention can be prepared by a known method using medical equipment, stationery, textiles, paper products,
Antimicrobial and antifungal properties can be exhibited by including it in daily necessities and bath products, but among these target products, excellent antibacterial and antifungal properties should be exhibited, especially for paper products. Can be.

In the present invention, the term "paper" refers to not only a sheet-like material obtained by dispersing cellulosic fibers obtained from plants in water and wet-papermaking but also a fiber-entangled structure and physical properties similar to paper. And a sheet-like material such as synthetic paper. Specific examples include waste paper such as newsprint and paperboard, printing paper, copy paper, and liner paper.

As a method for treating paper with the antibacterial / antifungal agent of the present invention, a silver-containing composite protein dispersed in an appropriate amount of water or an aqueous medium is applied to the paper surface, or dipped and sprayed (shower) or the like. And a method of paper-making the silver-containing composite protein together with the pulp slurry. The coating method is particularly preferable because the existing paper making apparatus can be diverted.

When the antibacterial / antifungal agent of the present invention is applied to paper, the preferred amount of application varies depending on the type of paper and its use, but it is usually 0.01 to 10 g per m ² , more preferably 0.1 to 10 g per m ^2. ５5 g. If the coating amount is less than 0.01 g per 1 m ^2, it is not preferable because sufficient antibacterial and antifungal effects cannot be obtained. On the other hand, when the coating amount exceeds 10 g per 1 m ² , no further antibacterial and antifungal effect can be expected, and the cost is increased, which is not preferable.

[0045]

EXAMPLES The present invention will be described below with reference to Preparation Examples and Test Examples, but the present invention is not limited by these Preparation Examples and Test Examples.

Preparation Example 1 [Preparation of Eggshell Membrane Protein Hydrolyzate by Alkaline Decomposition] A 500-ml round bottom flask has a water content of 74.36 g.
(Dry weight 10.81 g) eggshell membrane, 2N-NaOH1
30 ml and 86 ml of ethanol were added and stirred at 70 ° C. for 64 hours. Next, the mixed solution was filtered, and the obtained filtrate was dialyzed against deionized water to obtain 188 ml of an aqueous solution of a hydrolyzate of eggshell membrane protein (hereinafter, referred to as “solubilized protein A”).

The protein concentration in the solubilized protein A was determined by Lowr
The measurement was performed by the y method, and the content of the active thiol group in the solubilized protein A was calculated from the protein concentration based on the above-mentioned “method for determining SH groups”. The results obtained are shown below. As reference values, the protein concentration and absorbance (280 nm) measured by the biuret method are also shown. However,
Numerical values in parentheses indicate the total amount converted value (absorbance is represented by total absorption).

Liquid volume 188 ml Content of active thiol group 17 μmol / l (3.2 μmol) Protein concentration Lowry method 3.4 mg / ml (639.2 mg) Biuret method 3.8 mg / ml (714.4 mg) Absorbance 6 0.2 (1165.6) The content ratio of the active thiol group in the solubilized protein A determined from the above values is 4.5 to 5.0 μmol / g.

Preparation Example 2 [Preparation of Eggshell Membrane Protein Hydrolyzate by Alkaline Decomposition] Eggshell membrane having a water content of 79 g (dry weight: 11.46 g) was placed in a 500 ml round bottom flask, and 2N-NaOH was 137 m2.
l and 92 ml of ethanol were added, and the mixture was stirred at 70 ° C for 96 hours. Next, the mixed solution is filtered, and the obtained filtrate is dialyzed against deionized water, and an aqueous solution of a hydrolyzate of eggshell membrane protein (hereinafter, referred to as “solubilized protein B”) 64
0 ml was obtained.

In the same manner as in Preparation Example 1, the protein concentration in the solubilized protein B was measured, and the content of the active thiol group was calculated from the concentration. The results obtained are shown below.

Liquid volume 640 ml Content of active thiol groups 55 μmol / l (35.2 μmol) Protein concentration Lowry method 8.0 mg / ml (5120 mg) Biuret method 7.2 mg / ml (4608 mg) Absorbance 15.99 (10231) The content ratio of the active thiol group in the solubilized protein B determined from the above values is 6.9 to 7.6 μmol / g.

Preparation Example 3 [Preparation of silver-containing composite protein using solubilized protein A] 20 ml of solubilized protein A was placed in a beaker having a capacity of 100 ml.
And 20 ml of a 10 mM silver nitrate aqueous solution while stirring.
Was added dropwise over about 20 minutes, and after the addition, the mixed solution was stirred for 1 hour. The resulting mixed solution was allowed to stand overnight and filtered. The residue separated by filtration was washed twice with 20 ml of deionized water and subsequently with a small amount of ethanol, and dried to obtain 59.2 mg of a silver-containing complex protein.

The silver content in the silver-containing composite protein was 3%
4.7 as determined by quantification of silver eluted with nitric acid.
It was 5% by weight. Further, the silver ion concentration in the filtrate was quantified, and the silver content in the silver-containing composite protein was calculated from this numerical value to be 8.8% by weight. This shows that silver was hardly released from the silver-containing composite protein by washing after filtration as compared with the conventional protein antibacterial agent (see Comparative Preparation Examples 1 and 2).

Preparation Example 4 [Preparation of silver-containing composite protein using solubilized protein B] Silver-containing composite protein was prepared in the same manner as in Preparation Example 3 except that solubilized protein B was used instead of solubilized protein A. 11
8.5 mg were obtained. The silver content in the silver-containing composite protein was 7.0% by weight. Further, the silver ion concentration in the filtrate was quantified, and the silver content in the silver-containing composite protein was calculated from this numerical value to obtain 10.8% by weight. This shows that, as in Preparation Example 3, the silver-containing composite protein hardly released silver by washing after filtration.

Preparation Example 5 [Preparation of silver-containing composite protein using whey protein] In a beaker having a capacity of 300 ml, whey protein (manufactured by Taiyo Kagaku Co., Ltd., trade name: Sanlac N-5, protein content 72%, activity) (Content ratio of thiol group: 47 μmol / g)
2 g were dissolved in 200 ml of deionized water. 200 ml of a 50 mM silver nitrate aqueous solution was added to this mixed solution, and the mixture was stirred for 1 hour. The resulting mixed solution was allowed to stand overnight, and filtered (using filter paper No. 2). The residue obtained by filtration was washed twice with 100 ml of deionized water, and dried to obtain 1646 mg of a silver-containing composite protein (115% yield based on the protein used).

The silver content in the silver-containing composite protein was 3%
4.2 as determined by quantitative determination of silver eluted with nitric acid
It was 5% by weight. Further, the silver ion concentration in the filtrate was quantified, and the silver content in the silver-containing composite protein was calculated from this numerical value to find that it was 4.86% by weight. This shows that, as in Preparation Example 3, the silver-containing composite protein hardly released silver by washing after filtration.

Preparation Example 6 [Preparation of silver-containing composite protein using whey protein] In a beaker having a capacity of 300 ml, whey protein (manufactured by Taiyo Kagaku Co., Ltd., trade name: Sanlac N-5, protein content 72%, activity) (Content ratio of thiol group: 47 μmol / g)
2 g were dissolved in 180 ml of deionized water. Next, the mixed solution was dialyzed against deionized water to remove lactose. 20 ml of a 10 mM silver nitrate aqueous solution was added to 20 ml of the collected inner dialysis solution, and the mixture was stirred for 1 hour. The resulting mixed solution was allowed to stand overnight, and filtered (using filter paper No. 2).
The residue obtained by filtration was washed twice with 50 ml of deionized water, and dried to obtain 154.8 mg of a silver-containing complex protein.

The silver content of the silver-containing composite protein was 3%
It was found to be 7.8 by determining the amount of eluted silver using nitric acid.
It was 0% by weight.

Preparation Example 7 [Preparation of silver-containing complex protein using whey protein] Whey protein (manufactured by New Zealand Milk Product, trade name: Arasen 895, protein content 86.5%, active thiol) was placed in a 5 L beaker. Group content 3
30 g (4.5 μmol / g) was dissolved in 3 L of deionized water. In another beaker, an aqueous solution in which 4.575 g of silver nitrate was dissolved in about 300 ml of deionized water was added to the aqueous solution of whey protein, and the mixture was stirred for 1 hour. The resulting mixed solution was allowed to stand overnight and spray-dried. For spray drying, use L-8 type spray dryer (Okawara Kakoki Co., Ltd.)
Under the conditions of hot air inlet temperature 180 ° C and exhaust air outlet temperature 95 ° C,
Spray drying was performed at a flow rate of 2 L / hour to obtain a silver-containing composite protein.

After the obtained silver-containing complex protein was decomposed into organic substances, the silver content was determined by the ammonium thiocyanate titration method described in the Japanese Pharmacopoeia.
Met.

Preparation Example 8 [Preparation of silver-containing composite protein using whey protein] Whey protein (manufactured by New Zealand Milk Product, trade name: Aracene 895, protein content 86.5%, active thiol) was placed in a 5 L beaker. Group content 3
25 g (4.5 μmol / g) were dissolved in 2.5 L of deionized water. In another beaker, an aqueous solution in which 21.24 g of silver nitrate was dissolved in 2.5 L of deionized water was added to the aqueous solution of whey protein, and mixed and stirred for 1 hour. After leaving the obtained mixed solution to stand overnight, it was spray-dried in the same manner as in Preparation Example 3 to obtain a silver-containing composite protein.

After the obtained silver-containing complex protein was decomposed with organic substances, the silver content was determined by an ammonium thiocyanate titration method described in the Japanese Pharmacopoeia to be 31.15% by weight.

Preparation Example 9 [Preparation of silver-containing complex protein using eggshell membrane] About 40 g of a wet eggshell membrane (active thiol group content: 5 μmol / g) separated from a raw egg was wet-weighed, and 50 mM silver nitrate was prepared. It was immersed in 800 ml of an aqueous solution, dispersed by a mixer, and left overnight. Thereafter, the eggshell membranes were collected by filtration, and repeatedly filtered and washed three times with 800 ml of deionized water. The eggshell membrane after washing is dispersed in 400 ml of deionized water,
Wet pulverization was performed using a rotary ball mill. Grinding was continued until the average diameter of the particles in the slurry was less than 20-30 microns. Thereafter, the slurry liquid was recovered, and the pulverized material was filtered and washed, and dried by heating under reduced pressure to obtain a silver-containing composite protein.

After the obtained silver-containing complex protein was decomposed into organic substances, the silver content was determined by the ammonium thiocyanate titration method described in the Japanese Pharmacopoeia.
Met.

Comparative Preparation Example 1 [Preparation of Silver-Containing Composite Protein Using Eggshell Membrane Membrane] In a 50 ml capacity beaker, eggshell membrane crushed product (manufactured by Taiyo Kagaku Co., trade name: Sankakumak P, activated thiol group) Of 2% aqueous silver nitrate solution 1
0 ml was added and suspended. The suspension was stirred at room temperature for 10 minutes and filtered (using filter paper No. 2). The filtered residue was washed three times with 50 ml of deionized water and dried to obtain 1904 mg of a silver-adsorbed eggshell membrane powder.

The silver content in the silver-adsorbed eggshell membrane powder was 3%
When determined by the quantification of eluted silver using nitric acid, 0.0
It was 59% by weight. Further, the silver ion concentration in the filtrate was quantified, and the silver content in the silver-adsorbed eggshell membrane powder was calculated back from this value to find that it was 0.68% by weight. This indicates that silver was released from the silver-adsorbed eggshell membrane powder by washing after filtration.

Comparative Preparation Example 2 [Preparation of Silver-Containing Composite Protein Using Eggshell Membrane Pulverized Product] Eggshell membrane mechanical pulverization obtained by milling and airflow pulverization / classification in place of the egg shell membrane pulverized product Except for using the product, 1928 mg of silver-adsorbed eggshell membrane powder (the content of active thiol groups could not be measured) was obtained in the same manner as in Comparative Preparation Example 1. The silver content in the silver-adsorbed eggshell membrane powder was 0.1%.
026% by weight. Further, the silver ion concentration in the filtrate was quantified, and the silver content in the silver-adsorbed eggshell membrane powder was calculated from this numerical value and found to be 0.67% by weight. This indicates that silver was released from the silver-adsorbed eggshell membrane powder by washing after filtration.

Test Example 1 [Test of antibacterial activity of silver-containing composite protein against Staphylococcus aureus] The antibacterial test of silver-containing composite protein and silver-containing composite protein against Staphylococcus aureus was performed under the following conditions. In addition, a comparative test was performed for a known silver-containing antibacterial agent. The following were used as known silver-containing antibacterial agents. Zeomic [trade name (registered trademark), manufactured by Sinanen Zeomic Co., Ltd., silver content: about 2.5% by weight] Novaron [trade name (registered trademark), manufactured by Toagosei Co., Ltd.] The obtained results are shown in Table 1. In addition, the numerical value in a table | surface is a viable cell count and is shown as an average value of two test substances. Therefore, the data of the number of viable cells is shown in two columns in the column of no addition. In the following tests, the viable cell count is similarly expressed as an average value of two specimens.

Measurement Method Antibacterial Evaluation Test Method II for Inorganic Antibacterial Agents such as Silver (1995 Edition, Edited by the Study Group for Inorganic Antibacterial Agents for Silver, etc.) Based on Measurement of Minimum Bactericidal Concentration (MBC) Test Medium Staphylococcus aureus IFO 12732 Medium SCD agar medium

The silver-containing complex protein and the minimum bactericidal concentration of the silver-containing complex protein against Staphylococcus aureus (MBC
Values) are less than 3.13 ppm and 6.25, respectively.
ppm.

[0071]

[Table 1]

Test Example 2 [Test of antibacterial activity of silver-containing composite protein against Escherichia coli] An antibacterial test of silver-containing composite protein, silver-containing composite protein and silver-containing composite protein against Escherichia coli was performed under the following conditions. Further, similarly to Test Example 1, a comparative test was also performed on a known silver-containing antibacterial agent. In addition, as for the drug addition, 3.
Performed at concentrations ranging from 13 to 800.00 ppm. Table 2 shows the obtained results. In addition, the numerical value in a table | surface shows a viable cell count.

Measurement Method Antibacterial Evaluation Test Method for Silver and Other Inorganic Antibacterial Agents II (1995 edition, edited by the Silver and Other Inorganic Antibacterial Agents Study Group) Based on the measurement of minimum bactericidal concentration (MBC) Test medium Escherichia coli IFO 3972 Medium used Normal Bouillon medium (NB medium) Normal bouillon agar medium (NA medium)

The minimum bactericidal concentrations (MBC values) of the silver-containing complex protein to E. coli were 1.65 ppm, respectively.
Less than 1.65 ppm and 6.25 ppm. In contrast, Zeomic's 6.25 ppm, Novar
On was 50 ppm.

[0075]

[Table 2]

Test Example 3 [Test of antibacterial activity of silver-containing composite protein against Escherichia coli] An antibacterial test of silver-containing composite protein, silver-containing composite protein and silver-containing composite protein against Escherichia coli was performed under the same conditions as in Test Example 2. In addition, drug addition is 0.049-2.
Performed at concentrations in the range of 5.000 ppm. Table 3 shows the obtained results. In addition, the numerical value in a table | surface shows a viable cell count.

The minimum bactericidal concentration (MBC value) of the silver-containing complex protein to E. coli was 0.39 pp.
m, 0.098 ppm and 0.78 ppm.

[0078]

[Table 3]

Test Example 4 [Test of antibacterial activity of silver-containing composite protein against Staphylococcus aureus] Antibacterial activity against mechanically ground eggshell membrane and silver-adsorbed eggshell membrane powder, and mechanically ground eggshell membrane and silver-adsorbed eggshell membrane powder against Staphylococcus aureus The force test was performed under the following conditions.

Measurement Method Antibacterial Evaluation Test Method II for Silver and Other Inorganic Antibacterial Agents (1995 edition, edited by the Silver and Other Inorganic Antibacterial Agents Study Group) Based on measurement of minimum bactericidal concentration (MBC) Test medium Staphylococcus aureus IFO 12732 Medium used SCD Medium SCD agar medium

In the antibacterial activity test, the additive concentration of each drug was adjusted to 1.5
The antibacterial activity against staphylococci was not observed in any of the pulverized eggshell membranes, the silver-adsorbed eggshell membrane powder, the pulverized eggshell membranes, and the silver-adsorbed eggshell membrane powder. .

Preparation Example 10 [Effect of Silver Nitrate Concentration on Formation of Silver-Containing Complex Protein] The concentration of silver nitrate aqueous solution was 0.1 mM, 0.5 mM, 2 mM
A silver-containing composite protein was obtained in the same manner as in Preparation Example 3, except that M, 5 mM, 10 mM and 50 mM were used. The silver ion concentration in the filtrate from which the silver-containing composite protein was separated by filtration was quantified, and the silver content in the silver-containing composite protein was determined by back calculation from this value. In addition, solubilized protein A (Lowr
The yield was determined from 68 mg of the protein having a protein concentration of 3.4 mg / ml and 20 ml according to the y method and the yield of the silver-containing composite protein. The results obtained are shown in FIG.

Preparation Example 11 [Effect of Silver Nitrate Concentration on Formation of Silver-Containing Complex Protein] The concentration of silver nitrate aqueous solution was 0.1 mM, 0.5 mM, 2 m
A silver-containing composite protein was obtained in the same manner as in Preparation Example 4, except that M, 5 mM, 10 mM and 50 mM were used. The silver ion concentration in the filtrate from which the silver-containing composite protein was separated by filtration was quantified, and the silver content in the silver-containing composite protein was determined by back calculation from this value. In addition, the solubilized protein B (Lowr
The yield was determined from the yield of 160 mg of protein having a protein concentration of 8.0 mg / ml and 20 ml according to the y method and the yield of the silver-containing composite protein. FIG. 2 shows the obtained results.

FIG. 1 and FIG. 2 show that a silver-containing composite protein having a high silver content can be obtained in high yield.

Test Example 5 [Comparative test of antibacterial activity between silver-containing composite protein and known silver-containing antibacterial agent] Silver-containing composite protein (silver content: 7.0% by weight) and yellow grape of known silver-containing antibacterial agent A comparative test of antibacterial activity against cocci was performed under the same conditions as in Test Example 1. Known silver-containing antibacterial agents include the aforementioned Zeomic and Nova.
Using ron, silver nitrate was similarly tested for reference. Table 4 shows the obtained results. In addition, the numerical value in a table | surface shows a viable cell count.

[0086]

[Table 4]

Test Example 6 [Comparison test of antibacterial activity between silver-containing composite protein and known silver-containing antibacterial agent] Silver-containing composite protein (silver content: 4.25% by weight) and yellow grape of known silver-containing antibacterial agent A comparative test of antibacterial activity against cocci was performed under the same conditions as in Test Example 1. Known silver-containing antibacterial agents include the aforementioned Zeomic and Nov.
Using aron, silver nitrate was similarly tested for reference. Table 5 shows the obtained results. In addition, the numerical value in a table | surface shows a viable cell count.

[0088]

[Table 5]

Test Example 7 [Comparative test of antibacterial activity between silver-containing composite protein and known silver-containing antibacterial agent] Silver-containing composite protein (silver content: 7.0% by weight) and yellow grape of known silver-containing antibacterial agent A comparative test of antibacterial activity against cocci was performed under the same conditions as in Test Example 1. The following were used as known silver-containing antibacterial agents, and silver nitrate was similarly tested for reference. Bicam AK-LS (manufactured by Otsuka Chemical, silver content: 15% by weight) The results obtained are shown in Table 6. In addition, the numerical value in a table | surface shows a viable cell count.

[0090]

[Table 6]

Test Example 8 [Comparison test of antibacterial activity between silver-containing composite protein and silver protein protein] Antibacterial activity of silver-containing composite protein (silver content: 7.0% by weight) and silver protein protein against Staphylococcus aureus Was performed under the same conditions as in Test Example 1.

Measurement Method Antibacterial Evaluation Test Method II for Silver and Other Inorganic Antibacterial Agents (1995 Edition, edited by Silver and Other Inorganic Antibacterial Agents) Based on Measurement of Minimum Bactericidal Concentration (MBC) Test Medium Staphylococcus aureus IFO 12732 Medium Used SCD Culture medium

The following protein silver was used, and silver nitrate was similarly tested for reference. Pharmacopoeia silver protein (manufactured by Maruishi Pharmaceutical Co., Ltd., silver content: 8% by weight) The obtained results are shown in Table 7. In addition, the numerical value in a table | surface shows a viable cell count.

[0094]

[Table 7]

From the results shown in Tables 1 to 6, it can be seen that the antibacterial and antifungal activities of the silver-containing composite protein of the present invention are superior to those of known inorganic silver-containing antibacterial agents. In particular, the known silver-containing antibacterial agent Bicam AK-LS used in Test Example 7 shown in Table 6
Has an inferior antibacterial and antifungal activity despite having a silver content of 15% by weight. This is presumably because there is no sustained release of an appropriate amount of silver ions when antibacterial activity is to be exhibited. As is clear from the results in Table 7, the antibacterial and antifungal activities of the silver-containing composite protein of the present invention are better than that of the local protein.

Test Example 9 [Comparison test of mold resistance between silver-containing composite protein and known silver-containing antibacterial agent] Silver-containing composite protein, silver-containing composite protein, silver-containing composite protein and known silver-containing antibacterial agent [Zeomic (Trade name, manufactured by Sinanen Zeomic Co., Ltd.)] was performed under the following conditions.

Measurement method Complies with JIS K2911-1981 Mold resistance test method. In particular, refer to the following items. 3. Preparation for test 3.5 Spore suspension General rules of test 4.3.2 Display of test results Table 1 "Display method of test results" Testing of textile products 6.2.2 Wet method

Mold 1st group Aspergillus niger (FERM S-1) 2nd group Penicillium citrinum (FERM S-5) 3rd group Rhizopus stronifer (FERM S-7) 4th group Cladosporium cladosporioides (FERM S) -8) Group 5 Ketomius Globosum (FERM S-11)

Commercially available copy paper was used as the coated paper. Coating was performed using a baker type applicator (manufactured by Yasuda Seiki Seisakusho) under the conditions of a film thickness of 1 to 10 μm. Each drug was prepared at the following concentrations. After coating on both sides, it was blow-dried at 60 ° C. for 1 hour to prepare a test piece (5 cm × 5 cm) having a target coating weight. The silver-containing complex protein drug was prepared by dispersing 256 mg of the silver-containing complex protein in 20 ml of deionized water.
Using this drug, 1 g / m ² , 2 g / m ² and 4 g
/ M ² were prepared.

The drug for the silver-containing composite protein was prepared by dispersing 256 mg and 1280 mg of the silver-containing composite protein in 20 ml of deionized water. Using this drug,
Coated test pieces of 1 g / m ² , 2 g / m ² and 4 g / m ² were prepared.

The silver-containing complex protein drug was prepared by dispersing 256 mg of the silver-containing complex protein in 20 ml of deionized water. Using this chemical, coated test pieces of 1 g / m ² , 2 g / m ² and 4 g / m ² were prepared.

Disperse Zeomic in deionized water and add 1%
And 10% drug was prepared. Using this drug, 1
Coated test specimens of g / m ² , 2 g / m ² and 4 g / m ² were prepared.

The growth state of the mold on the coated test piece with the applied amount of the antibacterial / antifungal agent (double-sided coating) was observed. In each test, uncoated ones were similarly tested and used as controls.

The results obtained are shown in FIGS. FIG.
(A), (b) and (c) show the coating amounts of the silver-containing composite protein at 1 g / m ² , 2 g / m ² and 4 g /
The growth state of the mold when changed to m ² . FIG.
(A), (b) and (c) show the coating amounts of the silver-containing composite protein at 1 g / m ² , 2 g / m ² and 4 g /
The growth state of the mold when changed to m ² . FIG.
(A), (b) and (c) are each Zeomic
Is the growth state of the mold when the coating amount was changed to 1 g / m ² , 2 g / m ² and 4 g / m ² . Table 8 shows the results of the mold resistance test.

[0105]

[Table 8]

From the results shown in Table 8, it was found that the silver-containing composite protein and the silver-containing antibacterial agent exhibited much better mold resistance at the same amount of coating. In addition, silver-containing complex protein and, when the coating amount is increased, discoloration derived from silver is observed, but with respect to the mold resistance effect, a small coating amount that does not cause discoloration is sufficient, and No problem.

Test Example 10 [Mold resistance test of silver-containing composite protein] A mold resistance test was performed on a paper piece coated with a silver-containing composite protein in accordance with JIS K2911-1981. (Used mold) Neosatria

As the coated paper, liner paper was used.
Coating is a baker type applicator (Yasuda Seiki Seisakusho)
Manufactured under the conditions of a film thickness of 1 μm or 3 μm.
After applying each agent on both sides, air dry at 60 ° C for 1 hour
As a result, 0.14 g / m^Two And 0.42 g / m
^TwoA test piece (5 cm x 5 cm) with a coating weight of
did.

The obtained results are shown in FIG. 6 and FIG. FIG. 6 shows the growth state of the mold when the silver-containing composite protein was applied at a coating amount of 0.14 g / m ² . FIG. 7 shows the growth state of the mold when the silver-containing composite protein was applied at a coating amount of 0.42 g / m ² . Table 9 shows the results of the mold resistance test.

[0110]

[Table 9]

From the results shown in FIGS. 6, 7 and Table 9, the silver-containing composite protein was coated at a coating amount of 0.14 g / m ² and 0.4 g / m ^2.
It was found that good mold resistance can be imparted even to liner paper coated at ² g / m ² on both sides.

Test Example 11 [Mold resistance test of silver-containing composite protein] A mold resistance test was performed on a piece of paper coated with the silver-containing composite protein according to JIS K2911-1981.

As the coated paper, liner paper was used.
The coating was performed using a baker-type applicator (manufactured by Yasuda Seiki Seisakusho) under the conditions of a film thickness of 1 μm and 3 μm.
After coating each agent on both sides, it was blow-dried at 60 ° C. for 1 hour to obtain a test piece (5 cm × 5 cm) having the target coating weight.
5 cm). (Use mold) Neosatorium spore suspension

The growth state of the mold was observed by changing the amount of the antibacterial and antifungal agent applied to the coated test piece (double-sided coating). In each test, uncoated ones were similarly tested and used as controls. Table 10 shows the obtained results.

[0115]

[Table 10]

From the results shown in Table 10, the uncoated test piece had a judgment value of 1, whereas the coated test piece containing silver-containing composite protein had a judgment value of 2 or more, indicating good mold resistance. It was found to have. In particular, a coating amount of 0.45 g / m ²
The remarkable effect was shown above.

Test Example 12 [Mold resistance test of silver-containing composite protein] A mold resistance test was performed on a paper piece coated with a silver-containing composite protein in accordance with JIS K2911-1981.

As the coated paper, liner paper was used.
The coating was performed using a baker-type applicator (manufactured by Yasuda Seiki Seisakusho) under the conditions of a film thickness of 1 μm and 3 μm.
After coating each agent on both sides, it was blow-dried at 60 ° C. for 1 hour to obtain a test piece (5 cm × 5 cm) having the target coating weight.
5 cm). (Use mold) The same mold spore suspension as in Test Example 9

The results obtained are shown in FIG. 8 and FIG. FIG. 8 shows the growth state of the mold when the silver-containing composite protein was applied at a coating amount of 0.14 g / m ² . FIG. 9 shows the growth state of the mold when the silver-containing composite protein was applied at a coating amount of 0.42 g / m ² . Table 11 shows the results of the mold resistance test.

[0120]

[Table 11]

From the results shown in FIGS. 8 and 9 and Table 11, the silver-containing composite protein was coated at a coating amount of 0.14 g / m ² and at a coating amount of 0.14 g / m ² .
It was found that good mold resistance can be imparted even to a liner paper coated on both sides at 42 g / m ² .

Test Example 13 [Scanning Electron Microscope Observation of Silver-Containing Composite Protein-Coated Paper] In Test Example 9, copy paper coated with silver-containing composite protein, silver-containing composite protein and Zeomic, a known silver-containing antibacterial agent. Was subjected to surface observation with a scanning electron microscope.

The obtained results are shown in FIGS. FIG.
0 is the surface state of the copy paper coated with the silver-containing composite protein. FIG. 11 shows the surface state of copy paper coated with the silver-containing composite protein. FIG. 12 shows a surface state of copy paper coated with Zeomic.

From FIGS. 10 and 11, it can be observed that the silver-containing composite protein and the paper form a film so as to fill the space between the pulp fibers on the paper surface and adhere to each other.
On the other hand, from FIG. 12, Zeom, which is a known silver-containing antibacterial agent, is shown.
It is observed that ic adheres to the paper surface as fine particles. However, these particles were easily dropped off only by touching the paper surface with a finger.

From this, it is understood that when an inorganic silver antibacterial agent such as Zeomic is applied to the paper surface and used, a resin binder (adhesive or binder) is required. On the other hand, the silver-containing composite protein of the present invention has properties such as a film-forming property and a glue effect derived from the protein as a raw material thereof, so that it can be applied to paper without using an adhesive or a binder. Coating is possible.

Test Example 14 [KB of silver-containing composite protein-coated paper]
B Size Degree Test] In Test Example 9, a KBB size degree test was performed on copy paper coated with silver-containing composite protein, silver-containing composite protein, and Zeomic, which is a known silver-containing antibacterial agent, in accordance with JIS P8122. . For the test, an automatic KBB size measuring device manufactured by Yasuda Seiki Co., Ltd. was used. Table 12 shows the obtained results.

[0127]

[Table 12]

From the results shown in Table 12, it can be seen that in the silver-containing composite protein and the copy paper coated with the silver-containing composite protein, the sizing degree increases as the coating amount increases. In particular, the increase in the size degree of the silver-containing composite protein is remarkable. On the other hand, with copy paper coated with Zeomic,
There is a slight increase in size. This is thought to be because a large amount of Zeomic particles adhered to the paper surface, and as the thickness increased, it took time for the electrolyte to penetrate, which apparently resulted in an increase in size. .

Test Example 15 [Antibacterial test of liner paper coated with silver-containing composite protein] A paper strip coated with silver-containing composite protein was subjected to JI
An antibacterial test was performed according to SL1902. For the test, the test piece coated in Test Example 11 was previously 18 mm
What was cut to 18 mm was used as a test piece.

The test bacterium, Staphylococcus aureus IFO
12732 was streaked on SCD agar medium and incubated at 37 ° C for 24-4
The cells were cultured for 8 hours. After culturing, remove one platinum loop and use SCD medium
Was inoculated into an L-shaped tube containing 5 ml, and cultured at 37 ° C for 18 hours.
Nourished. Further, the culture solution is diluted with sterile physiological saline for 10 minutes.
Dilute it twice, and the absorbance at 660 nm becomes 0.1.
The number of viable cells is reduced to 1-2 × 10
⁸Pieces / ml. 20-fold dilution of ice-cold SCD medium
And dilute the bacterial solution with 1 ± 0.3 × 10 ^FivePieces / m
The test bacterium was designated as l.

Six pieces of uncoated paper and three pieces of coated paper were prepared.
Each specimen was placed at the bottom of a vial autoclaved at 121 ° C. for 15 minutes. Thereafter, 0.2 ml of the test bacterium prepared in advance was evenly inoculated into several places of each test piece, and 37
C. for 18 hours.

After culturing, 20 ml of physiological saline was placed in each vial.
and mix with a test tube mixer (5 times for 5 seconds)
As a result, residual bacteria were washed out. 1m for each washing liquid
1 and added to 9 ml of sterile physiological saline. In addition,
Take 1 ml of diluent and add to 9 ml of sterile saline
A diluent was prepared. Two 1 ml each of the prepared diluent
Put in a Petri dish and inject SCD agar medium.
And cultured for 48 hours. Count the number of colonies after culturing, and
The antibacterial effect on the paper was determined. Table 1 shows the obtained results.
3 to 16. Note that “aE + b” in the table is “a × 1”.
0 ^bMeans

[0133]

[Table 13]

[0134]

[Table 14]

[0135]

[Table 15]

[0136]

[Table 16]

The determination of the antibacterial effect was carried out based on the bacteriostatic activity value, the bactericidal activity value, and the difference between the increase and decrease values, which were obtained by the following formulas.

Bactericidal activity value L = Ma-Mc Bacteriostatic activity value S = Mb-Mc Ma: Common logarithmic value of viable cell count (average of 3 test pieces) immediately after inoculation of uncoated sample Mb: Uncoated sample Logarithmic value of the viable cell count after culturing for 18 hours (average of two test pieces) Mc: common logarithmic value of the viable cell count after 18 hours cultivation of the coated sample

Difference in increase / decrease value = log (B / A) −log (C / A) A: Viable cell count immediately after inoculation of an uncoated sample (average of 3 test pieces) B: 18-hour culture of uncoated sample Viable cell count after cultivation (average of 2 test pieces) C: viable cell count after 18 hours of culturing of the coated sample

In all of the test pieces of the paper pieces coated with the silver-containing composite protein, the number of bacteria in the petri dish was suppressed to zero in many cases. In addition, the bacteriostatic activity value is about 2 or more, the bactericidal activity value is 1 or more, and the increase / decrease value difference is 2 or more.
The above is shown. From the above, the antibacterial effect was confirmed in the coated test piece as compared with the uncoated test piece.

[0141]

The water-insoluble silver-containing composite protein of the present invention has an active thiol group content in the protein of 0.1 to 2%.
It can be obtained by bringing a water-soluble protein (00 μmol / g) into contact with a silver salt in water.

The silver-containing composite protein of the present invention is derived from proteins used in the fields of foods and cosmetics, and has extremely high safety. In addition, antibacterial and antifungal silver is not easily released from the protein, and the silver content is maintained at a high level. Therefore, the silver-containing composite protein of the present invention is useful as an antibacterial / antifungal agent in various fields, especially as antibacterial / antifungal paper.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the concentration of an aqueous silver nitrate solution, the yield of the obtained silver-containing composite protein, and its silver content in the formation of the silver-containing composite protein of the present invention (Preparation Example 10).

FIG. 2 is a graph showing the relationship between the concentration of an aqueous silver nitrate solution, the yield of the obtained silver-containing composite protein, and its silver content in the formation of the silver-containing composite protein of the present invention (Preparation Example 11).

FIG. 3 shows the results of a mold resistance test of the silver-containing composite protein of the present invention (Test Example 9).

FIG. 4 shows the results of a mold resistance test of the silver-containing composite protein of the present invention (Test Example 9).

FIG. 5 is a view showing the results of a mold resistance test of a known silver-containing antibacterial agent (Zeomic) (Test Example 9).

FIG. 6 shows a coating amount of 0.14 of the silver-containing composite protein of the present invention.
FIG. 10 is a view showing a growth state of a mold when applied at g / m ² (Test Example 10).

FIG. 7: Coating amount of the silver-containing composite protein of the present invention of 0.42
FIG. 10 is a view showing a growth state of a mold when applied at g / m ² (Test Example 10).

FIG. 8: Coating amount of the silver-containing composite protein of the present invention of 0.14
It is a figure which shows the growth state of the mold when apply | coated at g / m < ² > (Test Example 12).

FIG. 9 shows a coating amount of the silver-containing complex protein of the present invention of 0.42.
It is a figure which shows the growth state of the mold when apply | coated at g / m < ² > (Test Example 12).

FIG. 10 is a view showing the surface of copy paper coated with the silver-containing composite protein of the present invention (Test Example 13).

FIG. 11 is a diagram showing the surface of copy paper coated with a silver-containing composite protein of the present invention (Test Example 13).

FIG. 12 is a view showing the surface state of copy paper coated with a known silver-containing antibacterial agent (Zeomic) (Test Example 1).
3).

Claims (4)

[Claims] 1. A water-insoluble silver-containing composite protein obtained by contacting a water-soluble protein having an active thiol group content in a protein of 0.1 to 200 μmol / g with a silver salt in water. 2. The silver-containing protein according to claim 1, wherein the water-soluble protein is whey protein or a hydrolyzate or water-solubilized product thereof, or a hydrolyzate or water-solubilized product of eggshell membrane protein. Complex protein. 3. An antibacterial agent comprising the silver-containing composite protein according to claim 1 or 2 as an active ingredient.
Antifungal agent. 4. An antibacterial / antifungal paper treated with the antibacterial / antifungal agent according to claim 3.