1. A composition comprising a mixture of peroxy-α-ketocarboxylic acid (PKCA), which may contain α-keto ester. 2. The composition of claim 1, wherein said mixture further comprises α-keto acid. The composition of claim 2, wherein said α-keto acid is decarboxylated α-keto acid of said PKCA. 4. The composition of claim 1, wherein said α-ketoester comprises alkyl α-ketoester. 5. A composition according to claim 4, wherein said alkyl α-ketoester is pyruvic acid alkyl ester. The composition of claim 1, wherein the molar ratio of said α-ketoester to said RCA is from about 0.02: 1 to 10: 1.7. A composition according to claim 1, wherein said RCA comprises peroxy-α-ketopyruvic acid, peroxy-α-ketobutyric acid, peroxy-α-ketovaleric acid or a mixture thereof. The composition according to claim 1, wherein said composition is prepared in the form of: gel, liquid, lotion, transdermal patch, irrigation gel, spray, dressings, film, granules, disk, tissue or fiber. A method of reducing the number of microorganisms on a surface, comprising contacting the surface with a composition containing an effective amount of a mixture of peroxy-α-ketocarboxylic acid, and which may contain α-ketoester. 10. The method of claim 9, wherein the microorganism comprises vegetative bacteria. The method of claim 9, wherein the microorganism comprises bacterial spores, mycobacteria, gram-negative bacteria, vegetative gram-positive bacteria, a virus, prions, or a combination thereof. A method of reducing the number of infectious vegetative bacteria on a substrate, comprising contacting the substrate with a composition containing an effective amount of a mixture of peroxy-α-ketocarboxylic acid, which may contain1. Композиция, содержащая смесь перокси-α-кетокарбоновой кислоты (РКСА), которая может содержать α-кетоэфир.2. Композиция по п. 1, где указанная смесь дополнительно содержит α-кетокислоту.3. Композиция по п. 2, где указанной α-кетокислотой является декарбоксилированная α-кетокислота указанной РКСА.4.
