Antibacterial and antifungal composition

#The present invention relates to a composition useful as antibacterial and antifungal agent, and more particularly to a composition mainly containing dehydroacetic acid, sorbic acid or their alkali metal salts.

#It is well known that dehydroacetic acid, sorbic acid and their alkali metal salts are useful as antibacterial and antifungal agents. The toxicity of these antibacterial and antifungal agents is so low that their addition to foods is permitted, and they are agents of very high safety. Therefore, if these agents are usable in any fields such as general industrial products and agricultural products, to say nothing of foods, the usefulness of these agents becomes very great. However, the antibacterial and antifungal effects thereof are not always satisfactory, and they are restricted in the application to industrial products such as paints, sizing agents and adhesives.

#In accordance with the present invention, there is provided an antibacterial and antifungal composition comprising (A) at least one member selected from the group consisting of dehydroacetic acid, sorbic acid and their alkali metal salts and (B) at least one member selected from the group consisting of o-phenylphenol and its alkali metal salts, p-chloro-m-xylenol, 2-(4-thiazolyl)-1H-benzimidazole, 8-hydroxyquinoline and its salts and chelates, methyl 1-(butylcarbamoyl)-2-benzimidazolecarbamate, tetrachloroisophthalonitrile and N-(fluorodichloromethylthio)phthalimide. The synergistic effect on the antibacterial and antifungal properties is very remarkable, when the component (A) is employed in combination with the component (B), and the composition of the invention can be availably employed as antibacterial and antifungal agents in various industrial products and agricultural products.

#The present invention is more particularly described and explained by means of the following Examples, in which all % are by weight unless otherwise noted.

#A liquid culture medium of pH 7.0 containing 1% of peptone, 1% of meat extract and 0.1% of sodium chloride was prepared and sterilized, and 10 ml. portions thereof were poured into L-shaped tubes. After adding a prescribed amount of an antibacterial, antifungal composition consisting of the components (A) and (B) as shown in Table 1 to each tube, 0.1 ml. (number of cells: 5.times.10.sup.4 cells/ml.) of an aqueous suspension of bacteria as shown in Table 1 was added to each tube. The thus prepared culture liquor contained 5.times.10.sup.2 cells per milliliter. The culture was carried out at 37.degree. C. for 48 hours with reciprocal shaking, and the state of the growth of bacteria was then observed by measuring the number of cells in 1 ml. of the culture liquor.

#The results are shown in Table 1.