Emulsion for inhibiting the growth of microorganisms

Abstract

An emulsion comprising water and an immiscible predominantly hydrocarbon-based liquid, wherein the emulsion further comprises at least one protein for inhibiting the growth of microorganisms, said protein containing or being capable of binding to one of: a monosaccharide and an oligosaccharide. Uses of the invention include, but are not limited to: applications in oil well/fracking operations where it is necessary or desirable to neutralise bacteria in the extracted liquid; as an additive emulsion for bio-diesel to reduce emissions, such as NOx etc.; and as an additive in the water of heating/cooling systems for its biocidal properties.

Claims

1. A method of inhibiting the growth of microorganisms in a storage tank, receptacle, or pipe containing oil, the method comprising: combining the oil with an aqueous mixture comprising: water; and an intact glycoprotein capable of binding to or containing a monosaccharide or an oligosaccharide; thereby forming an emulsion of the water, glycoprotein, and oil; and inhibiting the growth of microorganisms in the storage tank, receptacle, or pipe.

2. The method of claim 1, wherein the glycoprotein is lipophilic.

3. The method of claim 1, wherein the glycoprotein is a milk protein.

4. The method of claim 1, wherein the glycoprotein is lactoferrin, apolactoferrin, lactoglobulin, or -casein.

5. The method of claim 1, wherein the glycoprotein is fetuin.

6. The method of claim 1, wherein the glycoprotein is a first protein, and wherein the aqueous mixture further comprises a second protein that is capable of binding to or containing a monosaccharide or an oligosaccharide.

7. The method of claim 6, wherein the first protein has a polarity that is opposite the second protein.

8. The method of claim 7, wherein the first protein is apolactoferrin and the second protein is lactoglobulin.

9. The method of claim 1, wherein the glycoprotein comprises a lectin.

10. The method of claim 1, wherein the oil is a fuel oil, a non-fuel oil, a biofuel, a vegetable oil, an animal oil, a fish oil, or any blend thereof.

11. The method of claim 1, wherein the emulsion contains at least 1% water.

12. The method of claim 11, wherein the emulsion contains 5-50% water.

13. The method of claim 1, wherein, in the aqueous mixture, up to 10 grams of the glycoprotein is dissolved or dispersed per liter of water.

14. The method of claim 1, wherein the storage tank, receptacle, or pipe is closed to the atmosphere.

15. The method of claim 1, wherein the oil is biodiesel.

16. The method of claim 1, wherein the glycoprotein reduces water absorption in the oil.

17. The method of claim 1, wherein: the glycoprotein is lactoferrin; the emulsion contains 5-50% water; and in the aqueous mixture, up to 10 grams of the lactoferrin is dissolved or dispersed per liter of water.

18. The method of claim 1, wherein the aqueous mixture contains 1-10 grams of the lactoferrin per liter of water and the oil is a fuel oil.

19. The method of claim 18, wherein 0.5-1.5 grams of the aqueous mixture is added per liter of fuel oil.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) In order that the invention may be more clearly understood an embodiment thereof will now be described, by way of example only.

(2) It is to be noted that the following example is provided with exclusive reference to the embodiment of the invention in which a water-in-oil emulsion is formed comprising a glycoprotein, specifically lactoferrin, and this emulsion is then added to a much larger volume of a hydrocarbon-based fuel to inhibit the growth of microorganisms therein, and possibly also eliminate existing microorganisms extant therein.

(3) According to a first example (E1) a solution which is capable of inhibiting the growth of microorganisms in fuel storage tanks was prepared by providing 0.1-10 g of Lactoferrin and then adding the Lactoferrin to 1 litre of water. The solution was then stirred at room temperature and pressure until the Lactoferrin was fully dissolved as determined by visual inspection.

(4) 1 litre of diesel fuel was then provided in a sterilised vessel and the bacterial count was quantified. 1.5 g of the Lactoferrin solution above was then added to the diesel and the resultant mixture was stirred so as to form a water-in-oil emulsion. The emulsion was kept at standard temperature and pressure and was monitored over a period of 10 days. After 10 days had elapsed the bacterial count was quantified to determine the extent of bacterial growth in the vessel. As a comparative example (C1) 1 litre of diesel obtained from the same diesel source as in E1 was provided in a sterilised vessel and was monitored for the same period and under the same conditions. Bacterial counts were also taken after a period of 10 days had elapsed.

(5) The results of the test showed that the bacterial count in emulsion E1 was less than the bacterial count in comparative example C1. This shows that the presence of Lactoferrin at the fuel/water interface is effective at inhibiting the growth of bacteria in fuel/water emulsions.

(6) Uses of the invention include, but are not limited to:

(7) Applications in oil well/fracking operations where it is necessary or desirable to neutralise bacteria in the extracted liquid.

(8) The invention makes it possible to form colloids comprising water and at least two polar glycoproteins of opposite polarities suspended in the water (for example, the first glycoprotein being apolactoferrin and the second glycoprotein being lactoglobulin).

(9) The resultant colloid can be added to oil to make an emulsion. That emulsion can then be added to bio-diesel and emulsified and then that mixture added to regular diesel to reduce emissions, such as NOx etc.

(10) Alternatively, the emulsion can be added to water used in heating/cooling systems, e.g. cooling plant, HVAC, etc. to sterilise the water are thereby reduce or prevent, in certain cases, the occurrence of Legionella.

(11) Alternatively, the colloid can be added to water used in oil extraction processes. The treated water could mix with, say, the crude oil being extracted to form emulsion. This could lead to biocidal activity in the extracted oil, thereby increasing its life.

(12) The following statements are not the claims, but relate to various features of possible embodiments of the invention:

(13) Statement 1. An emulsion comprising water and a fuel, wherein the emulsion comprises a protein for inhibiting the growth of microorganisms at an interface between the fuel and water, and wherein the protein contains or is capable of binding to a saccharide.
Statement 2. An emulsion according to statement 1, wherein the protein is a protein that is capable of binding to a cell wall of the microorganism.
Statement 3. An emulsion according to statement 1 or statement 2, wherein the protein comprises a glycoprotein,
Statement 4. An emulsion according to statement 3, wherein the glycoprotein comprises a milk protein.
Statement 5. An emulsion according to statement 3, wherein the protein comprises Lactoferrin, Kappa Caesin, or Fetuin
Statement 6. An emulsion according to statement 1 or statement 2, wherein the protein comprises a lectin.
Statement 7. An emulsion according to any one of the preceding statements, wherein the water is dispersed in the fuel.
Statement 8. An emulsion according to either statement 1 or statement 2, wherein the water comprises the glycoprotein.
Statement 9. An emulsion according to any one of the preceding statements, wherein the emulsion contains at least 1% water.
Statement 10. An emulsion according to any one of the preceding statements, wherein the emulsion contains 5-50% water.
Statement 11. An emulsion according to any one of the preceding statements, wherein the fuel comprises a fuel oil.
Statement 12. An emulsion according to any one of the preceding statements, wherein the fuel oil comprises diesel, petrol or kerosene.
Statement 13. An emulsion according to any one of the preceding statements, wherein the fuel comprises a blend of fuel oil and a biofuel.
Statement 14. An emulsion according to statement 13, wherein the blend comprises up to 2% biofuel.
Statement 15. An emulsion according to statement 13 or statement 14, wherein the blend comprises up to 5% biofuel.
Statement 16. An emulsion according to any one of statements 13-15, wherein the blend comprises up to 10% biofuel.
Statement 17. An emulsion according to statement 13, wherein the blend comprises more than 10% biofuel.
Statement 18. An emulsion according to any one of statements 1-10, wherein the fuel is a biofuel.
Statement 19. An emulsion according to any one of statements 13-18, wherein the biofuel comprises biodiesel.
Statement 20. Method for inhibiting the growth of microorganisms in a fuel/water emulsion, which comprises the steps of: a) providing a solution comprising a protein that contains or is capable of binding to a saccharide, and b) adding the solution to the fuel to form the emulsion.
Statement 21. Method according to statement 20, wherein the solution is prepared by dissolving the protein in water.
Statement 22. Method according to statement 21, wherein the solution is prepared by dissolving up to 10 g of the protein per litre of water.
Statement 23. Method according to any one of statements 20-22, wherein the protein comprises a glycoprotein or a lectin.
Statement 24. Method according to any one of statements 20-23, wherein the emulsion is formed by adding up to 1.5 g of solution per litre of fuel.
Statement 25. Use of a protein which contains or is capable of binding to a saccharide for inhibiting the growth of microorganisms in a fuel/water emulsion.
Statement 26. Use of a protein that contains or is capable of binding to saccharides for reducing water absorption in fuel.
Statement 27. Use of a protein that contains or is capable of binding to saccharides for reducing NOx emissions resulting from the combustion of fuel.

(14) The invention is not restricted to the details of the foregoing embodiments, which are merely exemplary of the invention. The foregoing embodiments are described by way of example only and many variations are possible without departing from the scope of the invention, which is set forth in the appended claims.