Anti-microbial additive for use in flower vase water

Abstract

The present invention relates to anti-microbial compositions that may advantageously be added to vase water of cut flowers in order to prevent microbial growth, especially in vase water containing added cut flower nutrients and/or water uptake stimulants. One aspect of the invention relates to the use of an EC 1.1.3 oxidoreductase as an antimicrobial additive for vase water of cut flowers. Another aspect of the invention concerns a method of putting cut flowers into vase water, said method comprising immersing the stems of one or more cut flowers into vase water and adding an antimicrobial composition containing an EC 1.1.3 oxidoreductase to the vase water before, after or at the same time as the cut flowers are immersed into the vase water

Claims

1. A method of extending the life of cut flowers, the method comprising immersing stems of one or more cut flowers into water and, separately, adding a dosage unit of a composition to the water before, after or at the same time as the stems are immersed into the water to provide 0.5-20 g of a dry matter per liter of water, the dosage unit comprising: (a) glucose oxidase in an amount of 0.1-200 SRU per gram of dry matter of the composition; (b) a carbohydrate selected from the group consisting of glucose, fructose, sucrose, lactose, maltose and combinations thereof.

2. The method according to claim 1, wherein the composition is added to the water in an amount of 0.1-40 g/l.

3. The method according to claim 1, wherein the composition is added to the water in an amount of 0.5 to 20 g/l.

4. The method according to claim 1, wherein the glucose oxidase is added in an amount of 1 to 200 SRU per litre of water.

5. The method according to claim 4, wherein the glucose oxidase is added in an amount of 5 to 100 SRU per litre of water.

6. The method according to claim 1, wherein the glucose oxidase is added in an amount of 10 to 50 SRU per litre of water.

7. The method according to claim 1, wherein the carbohydrate is glucose.

8. The method according to claim 1, wherein at least 90 wt. % of the composition dissolves in distilled water of 20 C. when added thereto in a concentration of 5 g/L.

9. The method according to claim 1, wherein the dosage unit comprises glucose oxidase in an amount of 0.5 to 100 SRU per gram of dry matter of the composition.

10. The method according to claim 1, wherein the dosage unit comprises glucose oxidase in an amount of 1-200 SRU.

11. The method according to claim 1, wherein the addition of the dosage unit to the water causes a pH-reduction of 1.0 to 4.0 pH units.

12. The method according to claim 1, wherein the addition of the dosage unit to the water causes the pH to be reduced to less than pH 5.5.

13. The method according to claim 1, wherein the dosage unit further comprises 50 to 700 mg of an acidulant selected from the group consisting of gluconic acid, glucono-deltalactone, citric acid, tartaric acid, propionic acid, glycolic acid, fumaric acid, sorbic acid, malic acid, aluminium sulphate and combinations thereof.

14. The method according to claim 1, wherein the dosage unit further comprises a biocide.

15. The method according to claim 14, wherein the biocide is added to the water in a concentration of 0.5-1000 mg/L.

16. The method according to claim 14, wherein the biocide is selected from the group consisting of quaternary ammonium compounds containing at least one hydrocarbon residue, guanidine compounds containing at least one C6-C24 hydrocarbon residue, bromo-nitrogen compounds, isothiazolinones, hydroxyquinolines, 1,3-dihalo-5,5-dimethylhydantoins, chloramphenicol, spectinomycin, alkyl parabens, salicylic acids and salts thereof, benzoic acids and salts thereof, sorbates, thiabendazole, 1,3-dichloro-5,5-dimethylhydantoin, N-chlorosulfonamides, isocyanurates, lysozymes and combinations thereof.

Description

EXAMPLE

(1) A mixed bouquet of 12 flowers composed as follows:

(2) Rosa Passion (2 stems)

(3) Chrysanthemum santini Noki (2 stems)

(4) Chrysanthemum santini Quinty (2 stems)

(5) Gerbera Baya (2 stems)

(6) Gerbera Sardana (2 stems)

(7) Antirrhinum (1 stem)

(8) Solidago Tara (1 stem)

(9) was placed in a vase with 1 litre of solution. The solution was either tap water or an aqueous base solution containing 10 g/l of a composition containing 94.66% glucose, 5% citric acid, 0.34% conventional biocides.

(10) The following components were added or not to the base solution (quantities per litre solution):

(11) BZC: 0 or 30 ppm of benzalkonium chloride GOX: 0 or 100 SRU of glucose oxidase
The results are given in terms of flower life (FL in days), water clearness after x days (WCx, rating from 1poor to 5good) and bacterial contamination after 7 days (CFU, in 1000 CFU/g stem: below 10 hardly or not contaminated, 10-100 moderately contaminated, 100-1,000 contaminated, above 1,000 heavily contaminated). The vases with flowers were placed under 12 per 24 hours of 1000 lux, at 20 C.

(12) TABLE-US-00001 TABLE Results of treatments with different preservative solutions BZC GOX FL CFU Base (ppm) (SRU) (days) WC7 WC10 (1000) (water) 0 0 5.1 1.0 1.0 n.d. + 0 0 12.5 1.5 1.0 24,600 + 0 100 12.7 4.0 3.0 4,400 + 30 0 12.0 2.5 1.5 900 + 30 100 12.5 3.0 3.0 16 n.d. = not determined
The results show that the individual components have a clear effect on each parameter. Glucose oxidase has a strong effect on water clearness, whereas glucose oxidase as well as BZC has a strong effect on bacterial contamination. Furthermore, these results demonstrate a synergetic effect resulting from the combined use of glycose oxidase and quarternary ammonium biocide (BZC).