Method of enzyme inactivation

Abstract

The present invention relates to a method for the inactivation of enzymes with a composition comprising a sulfonated peroxycarboxylic acid according to formula (I) wherein: R.sub.1 is hydrogen, or a substituted or unsubstituted C.sub.m alkyl group; R.sub.2 is a substituted or unsubstituted C.sub.n alkyl group; X is a hydrogen atom, a cationic group, or an ester forming moiety; Y is a hydrogen atom, a cationic group, or an ester forming moiety; n is 1 to 10; m is 1 to 10; and n+m is less than or equal to 18, wherein the composition is contacted with the enzyme. ##STR00001##

Claims

1. A method for the inactivation of enzymes, said method comprising: applying an enzyme-based cleaning composition comprising a lipase to a surface; and applying an enzyme-inactivation composition to said surface, wherein said enzyme-inactivation composition comprises a sulfonated peroxycarboxylic acid according to formula 1: ##STR00019## wherein: R1 is hydrogen, or a substituted or unsubstituted Cm alkyl group; R2 is a substituted or unsubstituted Cn alkyl group; X is a hydrogen atom, a cationic group, or an ester forming moiety; Y is a hydrogen atom, a cationic group, or an ester forming moiety; n is 1 to 10; m is 1 to 10; and n+m is less than or equal to 18, wherein said enzyme-inactivation composition is effective for inactivation of said lipase as determined by an ELISA analysis.

2. The method of claim 1, wherein Y is a hydrogen atom.

3. The method of claim 1, wherein said enzyme-inactivation composition further comprises an oxidizing reagent, wherein said oxidizing reagent is not a chlorine-containing compound.

4. The method of claim 1, wherein said enzyme-inactivation composition further comprises hydrogen peroxide.

5. The method of claim 1, wherein said enzyme-inactivation composition further comprises a C1 to C22 carboxylic or peroxycarboxylic acid.

6. The method of claim 1, wherein said applying an enzyme-inactivation composition to said surface is carried out at a temperature in the range of 10 C. to 70 C.

7. The method of claim 1, wherein said enzyme-inactivation composition has a pH of 7 to 9.

8. The method of claim 1, wherein said enzyme-inactivation composition further comprises: 10 to 20 wt-% sulfonated oleic acid; up to 10 wt-% acetic acid; 5 to 10 wt-% peracetic acid; 1 to 5 wt-% octanoic acid; 1 to 5 wt-% peroxyoctanoic acid; 1 to 5 wt-% hydroxyethane diphosphonic acid; and 8 to 35 wt-% hydrogen peroxide.

9. The method of claim 1, wherein said enzyme-inactivation composition of formula 1 is selected from 11-sulfo-undecanoic acid, 10,11-disulfo-undecanoic acid, sulfonated oleic acid, sulfonated linoleic acid, sulfonate palmitoleic acid, and sulfonated stearic acid.

10. The method of claim 1, wherein said surface comprises a surface on process equipment.

11. The method of claim 10, wherein said surface comprises a food or beverage preparation surface.

12. The method of claim 1, wherein said surface comprises a fabric or textile.

13. The method of claim 1, wherein said surface comprises a membrane.

14. The method of claim 1, wherein applying said enzyme-based cleaning composition comprises a clean-in-place procedure.

15. The method of claim 1, further comprising rinsing said surface after applying the enzyme-based cleaning composition to said surface.

16. The method of claim 1, wherein said enzyme-inactivation composition is effective for inactivating enzymes at room temperature.

17. The method of claim 1, wherein said enzyme-inactivation composition is applied to said surface at room temperature.

Description

EXAMPLES

(1) Inactivation of Lipases on Microfiltration Membranes

(2) Tests of lipase inactivation were conducted on a DDS M38 flat sheet MF/UF lab test plant. Microfiltration membranes of type Alfa Laval GRM 0.2 were incubated for 30 minutes to 60 minutes at 50 C. by circulating an aqueous solution containing 0.2% of an enzyme composition at pH 9. The enzyme composition contained 5% to 10% by weight of Rizolipase (a lipase from Rhizopus arrhizus) and 5% to 10% by weight of Subtilisin. Subsequently, the membranes were subjected to one of the cleaning and inactivation procedures described below. Immediately before and after the cleaning and inactivation procedures, samples of the membranes were frozen and stored frozen until the analysis of lipase concentration and activity. Analysis of lipase concentration and activity was performed by enzyme-linked immunosorbent assays (ELISA) by Novozymes A/S. Lipase concentration is reported as g of lipase per g of membrane, the specific lipase activity is reported as KLU per g of lipase.

(3) In procedure 1 (comparative example), membranes were treated by circulating an aqueous solution containing 0.1% by weight of urea, 24% by weight of phosphoric acid, and 29% by weight of nitric acid, supplemented with 0.3% by weight of an aqueous solution containing 26.7% by weight of hydrogen peroxide, 6.7% by weight of acetic acid, and 4.5% by weight of peracetic acid. Circulation was carried out for 30 minutes at 25 C. This treatment reduced the lipase concentration from 295 g/g to 44 g/g and its specific activity from 1.7 KLU/g to 0.26 KLU/g.

(4) In procedure 2 (comparative example), membranes were treated by circulating an aqueous solution containing 0.1% by weight of urea, 24% by weight of phosphoric acid, and 29% by weight of nitric acid, supplemented with 0.3% by weight of an aqueous solution containing 5.1% by weight hydrogen peroxide, 42.09% by weight of acetic acid, 8.6% by weight of peracetic acid, 3.37% by weight of octanoic acid, and 0.7% by weight of peroctanoic acid. Circulation was carried out for 30 minutes at 25 C. This treatment reduced the lipase concentration from 229 g/g to 1.91 g/g and its specific activity from 1.4 KLU/g to 0.011 KLU/g.

(5) In procedure 3, membranes were treated by circulating an aqueous solution containing 0.1% by weight of urea, 24% by weight of phosphoric acid, and 29% by weight of nitric acid, supplemented with 0.3% by weight of an aqueous solution according to the present invention containing 8-35% by weight of Hydrogen peroxide, 10-20% by weight of sulfonated oleic acid, less than 10% by weight of acetic acid, 5-10% by weight of peracetic acid, 1-5% by weight of octanoic acid, 1-5% by weight of hydroxyethane diphosphonic acid, and 1-5% by weight of peroxyoctanoic acid. Circulation was carried out for 30 minutes at 25 C. This treatment reduced the lipase concentration from 220 g/g to a level below the detection limit and its specific activity from 1.3 KLU/g to a level below the detection limit.

(6) In procedure 4 (comparative example), membranes were treated by circulating an aqueous solution containing 0.1% by weight of urea, 24% by weight of phosphoric acid, and 29% by weight of nitric acid. Circulation was carried out for 30 minutes at 50 C. This treatment reduced the lipase concentration from 314 g/g to 0.1 g/g and its specific activity from 1.8 KLU/g to 0.0006 KLU/g.

(7) The following table summarizes the results of the lipase concentration and activity measurements for each procedure. Please note that procedures 1, 2 and 4 are comparative examples, and that procedure 3 represents a method according to the present invention.

(8) TABLE-US-00002 Lipase concentration Lipase activity (g protein/g membrane) (KLU/g protein) Before After Before After Procedure treatment treatment treatment treatment 1 295 44 1.7 0.26 2 229 1.91 1.4 0.011 3 220 n.d. 1.3 n.d. 4 314 0.1 1.8 0.0006

(9) This test demonstrates that the procedure using a composition comprising a sulfonated peroxycarboxylic acid according to the present invention effectively inactivates lipases derived from an enzyme-based cleaning product at a temperature of 25 C. Furthermore, this procedure is more effective than any of the other procedures tested, shown by the fact that lipase concentration and activity were reduced to below the detection limit of the ELISA test in procedure 3. In particular, the composition of the present invention inactivates enzymes more effectively than compositions comprising peroxycarboxylic acids only (procedures 1 and 2) or a conventional acidic treatment at 50 C. (procedure 4).