FI95596C - Detergent additive for bleaching stained fabric - Google Patents

Description

95596

The present invention relates to a cleaning additive for bleaching stains on fabrics, comprising an enzyme system capable of providing a bleaching effect on the fabric during the washing process, a cleaning composition comprising a cleaning additive and a process for bleaching the fabric. , which produces a whitening effect.

It is known to use bleaches in washing processes and as ingredients in detergent compositions. Therefore, bleaches 15 are included or sold in most commercially available detergent compositions. Traditionally, important bleaches included in detergent compositions are compounds that act as precursors to hydrogen peroxide during the washing process. Perborates and percarbonates 20 are the main examples of compounds used as cleaning additives and which provide a bleaching effect in this way. The detailed bleaching mechanism of perborate and percarbonate is not currently known, but it is generally assumed that hydrogen peroxide will dye the fabric-stained dyes to a colorless material. by oxidation and that partial oxidation of dyes can occur through their direct interaction with perborate or percarbonate.

30 Although these traditional bleaching systems work quite satisfactorily in many cases and are widely accepted, several attempts have been made over the years to improve their efficiency. One important goal has been to provide bleaching systems that operate at low temperatures and are generally more efficient than conventional systems. An important goal has also been to develop systems to make better use of bleaches stored in fabric cleaner or otherwise used for bleaching fabrics. Among other things, this development has been prompted by the user's desire to perform washing at low temperatures, which are not optimal for conventional bleaching systems with an optimum operating temperature of at least 60 ° C, and environmental considerations due to the release of large amounts of bleach added to the environment. to achieve bleaching, but which are not fully used during the washing process.

10 In order to develop an improved bleaching system for these companies, great attention has been paid to the possibility of using hydrogen peroxide to create a strong and effective bleaching compound from its traditional precursors, such as perborate and percarbonate, during washing. A successful example of such guidelines is the system based on TAED (tetraacetylethylenediamine), which is currently widely used in detergent compositions (cf., for example, the Second World Conference on Detergents. AR Baldwin (ed.), 20 American Oil Chemists' Society, 1987, pages). 177-180).

It has surprisingly been found possible to increase the bleaching efficiency of hydrogen peroxide during the washing process by using a group of enzymes which use hydrogen peroxide as an oxidation substrate for organic or inorganic substances (such enzymes are commonly referred to as peroxidases).

Accordingly, the present invention relates to a cleaning additive capable of initiating a bleaching effect on a carrier gas and containing an enzyme having a peroxidase effect. The cleaning additive according to the invention also contains: hydrogen peroxide or a hydrogen peroxide precursor, preferably perborate or percarbonate. In the present context, the term "enzyme which produces a peroxidase effect" is understood to refer to an enzyme which acts in the same way as peroxidase and is used in the text in this sense.

il «a t nm lua’: s 3 95596

It is well known in the art (cf., e.g., B.C. Saunders et al., Peroxidase. London, 1964, p. 10) that peroxidases act on various amino and phenolic compounds, causing color formation. Thus, it should be considered surprising 5 that peroxidases can also effect the bleaching of dyes. Although the mechanism that controls the ability of peroxidases to affect the bleaching of stains on fabrics caused by such dyes has not yet been elucidated, it is now believed that these enzymes act by reducing hydrogen peroxide (substrate 1) and oxidizing the stain dye (substrate 2). thus colorless substance and correspondingly removing the stain from the fabric. This reaction is shown below in Reaction Scheme 1.

Reaction formula 1: donor (substrate 2) + H 2 O 2 -> oxidized donor + 2H 2 O

Because peroxidase usually shows affinity for dyes in the stain that act as substrates for the enzyme (typically these are natural dyes such as various polyphenols), bleaching targets stains, hence using peroxidase for bleaching; more efficient utilization of hydrogen peroxide is achieved than with conventional bleaching methods, which must involve an excess of hydrogen peroxide in order to achieve a sufficient bleaching effect.

This implies that it may be possible to use the cleaning additive of the invention to bleach fabric stains, reduce the amount of hydrogen peroxide or its precursor in the additive or additive-containing cleaning composition, and still provide a satisfactory bleaching effect. I saw the environmental load, i.e. the amount of unused bleach released into the environment can be reduced by using the cleaning additive of the invention for bleaching. In addition, a smaller amount of hydrogen peroxide is sufficient to achieve effective bleaching, and the overall effectiveness of a detergent composition containing such a bleaching agent (e.g., the effectiveness of detergent enzymes tends to deteriorate when a large amount of bleach is used) may be improved.

5

In addition, it is contemplated that peroxidases that are well-defined for a particular class of colorant (e.g., betalins, carotenes, flavonoids, etc.) may be used for specific purposes, while peroxides that have less than 10 well-defined purposes (i.e., affect several natural colorants) can be used for more unspecified enzyme bleaching.

It has been previously reported that peroxidases can remove the color of certain pigments (cf., e.g., W. Schreiber, Biochem. Biophys. Res. Commun. 63 (2), 1975, pages 509-514, which describes the decomposition of 3-hydroxyfllavone by horseradish peroxidase; A. Ben Aziz, Phytochemistry 10. 1971, pages 1445-1452, which describes the bleaching of carotene with peroxy-20ase, and BP Wasserman, J. Food Sci., 49, 1984, pages 536-538, which describes the decolorization of betalin with horseradish peroxidase). . These publications all describe test methods in which the pigment in question is oxidized with an enzyme solution. Thus, they do not in any way indicate that peroxidases can be effective in bleaching ordinary fabric-dried stains, whereby the dye (s) may be absorbed into the fabric or partially absorbed into the fibers of the fabric so that they are more difficult to achieve by enzyme activity, and / or the oxygen in the air-30 circumference may have oxidized the dyes so that a dye other than what it could have been formed was in that dye solution.

Ben Aziz et al. and Wasserman et al. mention the problem of the peroxidase bleaching function of carotene 35 and betalin, respectively, if these pigments are used as food colors, a problem which must be prevented by the inclusion of an antioxidant in the food in question. Thus, they are of the opinion that peroxidase-assisted bleaching of these pigments is not in itself of practical significance.

On the other hand, bleaching of paper pulp with peroxidases 5 has been proposed, cf. for example US 4,690,895.

Peroxidases that can be used as cleaning additives for the present purpose can be isolated and produced by plants (e.g. horseradish peroxidase) or by microorganisms such as basidiomycites, fungi, actinomycites or bacteria. Some preferred microorganisms include Fusarium species. especially Fusarium oxysporum. Streptomyces-to it. especially Streptomyces thermoviolaceus or Streptomyces viridosporus. Pseudomonas -15 species, preferably Pseudomonas putida or Pseudomonas fluo-rescens. Coprinus-lai it. especially Coprinus cinereus. Coprinus macrorhizus or Coprinus cinereus f. Microsporus. Streptoverticillium- to it. especially Streptoverticillium Verticillium ssp. verticillium. Bacillus species, especially Bacillus stearot-20 hermophilus. and Coriolus-lai it. preferably Coriolus versicolor. Phanerochaete-lai it. especially Phanerochaete chrvsosporium.

Specific examples of preferred species are Coprinus cine-25 Reus f. Microporus IFO 8371, Coprinus cinereus IFO 30114,

Pseudomonas fluorescens NRRL B-II, Streptoverticillium Verticillium ssp. Verticillium IFO 13864, Streptomyces thermoviolaceus CBS 278.66, Streptomyces viridosporus. ATCC 39115, Streptomyces badius ATCC 39117, Streptomyces phaeochromo-30 genes NRRL B-3559, Pseudomonas pyrrocinia ATCC 15958, Fusarium oxysporum DSM 2672 and Bacillus stearothermophilus ATCC: 12978.

Other potentially useful peroxidases are listed in B.C. Saunders et al., Pp. 41-43.

6 95596

Particularly preferred peroxidases are those which are active at the typical pH of the washing solution, i. pH 6.5-10.5, preferably 6.5-9.5, and most preferably 7.5-9.5. More specifically, peroxidases of interest for the present purpose are those having at least 25% of their optimal activity (i.e., activity at optimal pH) in these pH ranges, e.g., as determined by the ABTS assay described in Example below. 1. Such peroxidases can be isolated by filtration to produce peroxidase from alkalophilic microorganisms, e.g. by the ABTS assay described in Example 1 below.

Other preferred peroxidases are those which give good thermal stability, especially those with at least 25% of the initial activity remaining after 20 minutes at 40 ° C, and good stability with commonly used detergent components, especially nonionic, cationic or anionic surfactants. against active detergents, detergent builders, phosphates, etc .; particularly preferred are those which retain at least 25% of their initial activity after being exposed to such detergent ingredients for 20 minutes.

Methods for producing the enzymes * 'used in accordance with the invention have been described in the art, cf. for example FEBS

Letters 1625. 173 (1), Applied and Environmental Microbiology. Febuary. 1985, pages 273-278, Applied Microbiol. Biotec-nol. 26. 1987, pp. 158-163, Biotechnology Letters 9 (5).

30 1987, pages 357-360, Nature 326. 2 Feb. 1987, FEBS Let ters 4270. 209 (2), pp. 321.

• ·

Another group of useful peroxidases are lignins: these enzymes, which develop strong peroxidase activity, promote the cleavage of lignin (e.g. from wood) and are produced by several tree root fungi. They have previously been proposed for use in paper. ' bleaching of rice (cf. e.g. US-4,690,895). In addition, useful peroxidases include haloperoxidases such as chloro and bromoperoxidases because they are capable of oxidizing halon ions to typohalones, which are potent bleaches, instead of being able to oxidize organic compounds.

The peroxidase may further be one that can be produced by a method comprising culturing a host cell modified with a recombinant DNA vector having 10 sets of DNA encoding said peroxidase, as well as sets of DNA encoding functions that allow culturing a series of DNA encoding peroxidase, in a culture medium under conditions that allow peroxidase to be grown and peroxidase to be recovered from the culture.

15

Transformation of bacterial cells can be performed according to conventional methods, e.g., as described in T. Maniatis et al., Molecular Cloning: A Laboratory Manual. Cold Springs Harbor, 1982.

20

Filtration of suitable DNA sets and construction of vectors can also be performed by conventional procedures, cf. T. Maniatis et al., supra.

25 The medium used for culturing the modified host cell may be any conventional medium suitable for growing such host cells. The specific peroxidase may conveniently be introduced into the culture medium and recovered therefrom by known procedures, including separation of cells from the medium by centrifugation or filtration, precipitation of the proteinaceous components of the medium by a salt such as ammonium sulphate followed by chromatographic procedures such as ion exchange chromatography or affinity chromatography. 3 5 sky.

Due to the possibility of reducing the amount of hydrogen peroxide required to bleach fabric stains, using a peroxidase such as that described above, it is possible to utilize an enzymatic process to form hydrogen peroxide, which has not previously had any technical interest due to difficulties in generating sufficient amounts of hydrogen peroxide.

Thus, the cleaning additive of the invention may further comprise an enzyme system (i.e., an enzyme and a medium therefor) capable of producing hydrogen peroxide.

One such category of hydrogen peroxide producing systems includes an oxidase capable of converting molecular oxygen and an inorganic substrate to hydrogen peroxide and an oxidized substrate, respectively. As such, these enzymes are unsuitable and have no use in bleaching stained fabrics because they produce too little hydrogen peroxide, but can be used to enhance the cleaning additive of the invention because the presence of peroxidase ensures efficient utilization of the hydrogen peroxide produced, as indicated above.

20

Preferred oxidases are those that act on inexpensive and already available substrates that can be conveniently incorporated into detergent compositions. For example, such a substrate is glucose, which can be used to produce hydrogen peroxide by glucose oxidase. Other suitable oxidases include urate oxidase, galactose oxidase, alcohol oxidase, amine oxidase, amino acid oxidase and cholesterol oxidase.

The cleaning additive according to the invention is suitable as a dust-free granulate, a liquid, in particular a stable liquid, * * or a protected enzyme. The dust-free granulate can be produced, e.g. as described in IJS-4,106,991 and 4,661,452 (both in the name of Novo Industri A / S), and can be coated by methods known in the art. Liquid enzyme preparations may be stabilized, for example, by the addition of a polyol such as propylene glycol, sugar or; sugar alcohol, lactic acid or boric acid according to generally known methods. Other methods for stabilizing the enzyme are known in the art. Protected enzymes can be prepared by the method described in EP 238 216.

5

The cleansing additive may further include one or more other enzymes, such as protease, lipase or amylase, which have traditionally been included in the cleansing additives.

10

In another aspect, the present invention relates to a detergent composition comprising an enzyme having peroxidase activity and hydrogen peroxide or a medium thereof, preferably perborate or percarbonate. These and other components (e.g., oxidase and substrate therefor) that are essential and / or preferred to achieve bleaching of the stained fabric may be added to the detergent composition separately or may be included in a cleaning additive in the form described above.

The detergent compositions of the invention further contain surfactants which may be of the anionic, nonionic, cationic, amphoteric or zwitterionic type, as well as mixtures of such surfactant types.

. Typical examples of anionic surfactants are linear alkyl benzene sulfonates (LAS), alpha-olefin sulfonates (AOS), alcohol ethoxysulfates (AES) and alkali metal salts of natural fatty acids.

30

The detergent compositions of the invention may contain other cleaning ingredients known in the art, e.g.

builders, corrosion inhibitors, release agents, anti-redeposition agents, perfumes, enzyme-35 additives, etc.

% 10 95596 It is currently contemplated that the detergent composition of the invention may contain peroxidase in an amount corresponding to 0.1-100 mg peroxidase per liter of detergent solution.

The detergent composition of the invention may be formulated in any suitable form, e.g. as a powder or liquid. The enzyme can be stabilized in the detergent liquid by incorporating enzyme stabilizers as noted above. Liquid detergents may additionally contain stabilized hydrogen peroxide precursors. Usually the pH of the detergent composition solution is 7-12 and in some cases 7.0-10.5. Other scavenging enzymes, such as proteases, lipases, or Amylases, may be included in the detergent composition of the invention either separately or, as described above, in a combined additive.

The present invention can be used to bleach a fabric, comprising treating the fabric with a cleaning additive or detergent composition as described above. The invention is also applicable to a bleaching process in which a fabric is treated with an enzyme that exhibits peroxidase activity in the presence of hydrogen peroxide or a precursor thereof, alternatively in the presence of an oxidase or oxidase substrate. As stated above, the process is particularly well suited for bleaching stains caused by natural. colorants, such as polyphenols, such as those found in fruit juice, wine, tea and the like. The bleaching treatment can be suitably subjected to a soaking, washing and rinsing process. It is assumed that the cleaning additive or the pe-30 can also be used for bleaching textiles, e.g. during their manufacture.

(t

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention in any way.

„95596 j

Example 1

Cotton knits homogeneously soiled with unsweetened blackcurrant juice were subjected to a model wash treatment to evaluate the bleaching effect of the horseradish peroxidase + 5 hydrogen peroxide system. An amount of 10 mmol / l H 2 O 2 (corresponding to about 1.6 g sodium perborate per liter of washing solution) was found to be a preferred dose of 5 mg / l horseradish peroxidase (Boehringer-Mannheim).

The experimental conditions were: washing solution: 0.01 M borax adjusted to pH 7.5 with phosphoric acid.

15 Duration of washing treatment: 30 min

Temperature: 25 ° C

textile / solution ratio: 10 g / l

Bleaching effect evaluation: The washed sweaters were rinsed with 20 salts-purified water, then dried overnight in the dark, after which the remission in the wavelength range of 400-700 nm was measured with a Datacolor Elrephometer 2000.

The following table shows the relative purity values achieved, the purity function itself being determined by the formula purity = R (soiled.washed) - Rdiattu.not washed) R (uncontaminated, not washed) - R (soiled, not washed) 30 where R indicates remission. The comparative treatment was performed with a borax solution as above, but without any bleaching.

• The results of treatment with 10 mmol Γ1 H 2 O 2 without peroxidase are presented for comparison.

12 95596

Wavelength (nm) delta purity relative to non-bleach washing (%) H 2 O 2 alone H 2 O 2 + peroxidase 5 _ 400 1.2 3.3 420 1.4 3.4 440 1.8 3.4 460 2.3 3.6 10 480 2.5 3.6 500 2.6 3.5 520 2.7 3.6 540 2.9 3.9 560 3.4 4.5 15 580 4.0 5.4 600 5.3 7.3 620 7.8 10.6 640 10.6 14.7 660 13.6 18.7 20 680 15.4 20.3 700 17.4 23.0

Relative enzyme activity was analyzed before and after the wash assay by conventional techniques (described in R. E. Childs and W. G. Bardsley, Biochem. J.

, 1145. 1975, pages 93-103), which includes H 2 O 2 oxidation of ABTS at pH 7.5, monitoring at 418 nm (ABTS = 2,2'-azino-bis- (3-ethylbenzthiazoline-6-sulfonic acid) , supplied by Boehringer-Mannheim as diammonium salt). After washing, the Akti-30 activity was 70% of the initial activity.

Example 2

Cotton sweaters homogeneously soiled with unsweetened blackcurrant juice, red wine, and tea were subjected to a model wash treatment to evaluate the horseradish peroxidase / H 2 O 2 bleaching effect of the system.

il. »» ·) Mm 11-1-3 i 13 95596

The experimental conditions were:

Wash solution: 0.05 M sodium phosphate buffer, pH 7.5, prepared with water, 5 with a hardness corresponding to 1.6 mM Ca 2+

Washing time: 60 min

Temperature: 24 ° C

Bleach: H 2 O 2, dose amount 10 mM

Enzyme: Sigma P-8125 horseradish peroxidase, 10 doses 2 mg / l textile / solution ratio: 10 g / l

Tap water was used to rinse the knits.

At 15,460 nm, the purity values for enzyme + H 2 O 2 treatment and for H 2 O 2 treatment alone were found to be: purity 2 0 (enzyme + H 2 O 2) (H 2 O 2 alone) blackcurrant 40.2% 36.8% red wine 31.1% 27.3% tea 29.7% 24.6% 25 undefined 80.6% 75.2% ·. (The different sweaters were washed together and uncleaned knitwear was added. The last row in the table concerns uncleaned knitwear).

30

Similar experiments were performed at pH 8.3 and each pH together with anionic surfactant (linear alkyl benzene sulfonate) and nonionic surfactant. None of these changes significantly affected the bleaching effect, and the activity of the enzyme in the washing solution, as examined by the ABTS assay described in Example 1, was essentially the same in all experiments (relative activity +/- 30%).

40 x4 95596

Example 3

Cotton knits homogeneously soiled with beetroot juice were subjected to several model washing treatments to evaluate the bleaching effect of the H 2 O 2 + peroxidase system derived from Coprinus macrorhizus + H 2 O 2.

The experimental conditions were: 10 Wash solution: 0.05 M potassium phosphate buffer (see

below) with a pH of 7.0

Washing time: variable, as shown below

Temperature: 24 ° C

Textile / solution ratio: 11 g / l Hydrogen peroxide: 0.2 mM

Enzyme: 20 mg / L peroxidase from Coprinus macrorhizus (Chemical Dynamics Corporation, New Jersey, 20 U.S., prod. No. 70-9590-00).

Bleaching effect evaluation: determined as described in Example 2.

25 The results were as follows: purity (enzyme + H 2 O 2) (H 2 O 2 alone) 30 460 nm 600 nm 460 nm 600 nm (1) Washing 70 min 75.2% 81.9% 75.9% 75.7% i (2) Wash 15 min 61.8% 72.6% 57.9% 68.3% (3) Wash 1 min 48.5% 63.3% 45.2% 59.4% 35 (4) Wash 1 min 51, 0% 63.6% 48.8% 57.2%

In Experiment (1), washing was performed after soaking overnight. In Experiments (2) and (3), a buffer solution was prepared with water having a hardness of 1.6 mM Ca 2+, in (1) and (4), 40 buffer was made with water purified from salts.

Claims (10)

A detergent bleaching agent for bleaching of stained fabrics, characterized in that it includes (a) an enzyme exhibiting peroxidase activity, which enzyme is in the form of a non-dusting granule, liquid, especially a stable liquid, or a protected enzyme, and (b) hydrogen peroxide, a precursor of hydrogen peroxide or an enzymatic system which enhances hydrogen peroxide. Detergent additive according to claim 1, characterized in that the peroxidase is one which can be produced by a microorganism, e.g. bacteria, fungi, actinomycet or basidiomycetes. Detergent additive according to claim 1, characterized in that the peroxidase is of plant origin. 4. Detergent additive according to any one of claims 1-3, characterized in that the peroxidase is active at a pH of 6.5-30 10.5, preferably 6.5-9.5 and most preferably 7.5-9.5. 5. Detergent additive according to claim 1, characterized in that the precursor of the hydrogen peroxide is perborate or percarbonate. 6. Detergent composition, characterized in that it comprises a detergent additive according to any one of claims 1-5. 35 il »i Hiili lii 4 $ 1 95596 7. Detergent composition, characterized in that it comprises (a) an enzyme that exhibits peroxidase activity and (b) hydrogen peroxide, a precursor of hydrogen peroxide or an enzymatic system which enhances hydrogen peroxide. 5 Detergent composition according to claim 7, characterized in that the precursor of the hydrogen peroxide is perborate or percarbonate. 10 Method for bleaching stains in fabric, characterized in that the fabric is treated with a detergent additive according to any of claims 1-5 or with a detergent composition according to claims 6 or 7. Method according to claim 9, characterized in that the treatment of the fabric is carried out in a soaking, washing or rinsing process.