Enzymatic Detergent Composition

The present invention relates to an enzymatic detergent composition. More particularly it relates to an enzymatic detergent composition which contains a lipolytic enzyme.

Enzymatic detergent compositions are well known in the art. Enzymes of many types have been proposed for inclusion in detergent compositions, but the main attention has been focussed on proteases and amylases. Although lipases have been mentioned as possible enzymes for detergent compositions, there is relatively little prior art directly concerned with lipases for detergent compositions in general. Thus, our British Pat. No. 1,372,034 discloses the use of lipases produced by microorganisms of the Pseudomonas group, such as Pseudomonas stutzeri ATCC 19.154, in detergent compositions for soaking fabrics which contain specific nonionic detergent actives, optionally with a specific anionic detergent active. However, it was made clear that "the mere addition of lipoiytic enzymes to any and all detergent compositions does not produce, (as was shown) a satisfactory and acceptable detergent composition both regarding the enzyme activity and the cleaning efficiency. Various ingredients of detergent compositions have been found to exert a negative influence on lipolytic enzymes".

In British Pat. Nos. 1,442,418 and 1,442,419 a two-stage laundering process is described wherein a soaking step with a lipase-containing liquor is followed by a washing step with a detergent-containing wash liquor.

In British Pat. No. 1,442,419 the "lipase-containing liquor" consisted of the claimed lipase(s) and a water soluble borax salt. Optional inclusion of conventional detergent surfactants or builders was mentioned but effectiveness in the presence of surfactants and builders was not demonstrated. In British Pat. No. 1,442,418 the "lipase-containing liquor" consisted of the claimed lipase(s) plus borax and Ca.sup.++ or Mg.sup.++ ions. Surfactants were again mentioned but again no evidence relating to effectiveness in surfactant solutions was provided. Builders which bind Ca.sup.++ and/or Mg.sup.++ ions were specifically excluded in these pre-wash liquors. Overall, the wash process described by these specifications needed two separate formulated products; it was cumbersome and it would be of limited applicability in practice.

In a more recent article in Journal of Applied Biochemistry, 2 (1980), pages 218-229, Andree et al. report on their investigations of lipases as detergent components. They concluded that the two tested commercially available lipases (pancreatic lipase and Rhizopus lipase) were unstable in solutions of active systems containing mixtures of typical detergent anionic and nonionic surfactants. They deduced that the lipases were inactivated by the presence of the anionic detergents, the pancreatic lipase somewhat less so than the Rhizopus lipase. Andree et al. further concluded that the tested lipases can improve the washing efficiency of full nonionic detergent formulations but that this improvement can be matched by increasing the concentrations of nonionic active in detergent formulations.

A recently published European patent application, No. 0130064, describes the use of a lipase from Fusarium oxysporum as detergent additive. The detergent compositions exemplified in this patent application contain a nonionic and an anionic detergent, or consist solely of a nonionic detergent.

The above prior art therefore either teaches to use a specific lipase in detergent compositions, or to formulate specific detergent compositions and/or wash regimes for inclusion of lipases therein.

It is an object of the present invention to provide lipase-containing detergent compositions which have an improved overall detergency performance and which show significant detergency improvements by the inclusion of lipases therein.

We have now discovered that the inclusion of a certain class of lipases in a detergent composition which contains an anionic and a nonionic detergent-active material provides an improved overall detergency.

In contrast with the above prior art, complete, lipase-containing detergent compositions are provided by the present invention with which a normal washing process can be carried out, also at lower temperatures, whereby the benefits of the lipases are obtained without having to resort to special carefully selected detergent compositions or special washing or soaking steps or without having to treat the fabrics for long periods with the lipase-containing composition.

The class of lipases to be used according to the present invention embraces those lipases which show a positive immunological cross-reaction with the antibody of the lipase, produced by the microorganism Pseudomonas fluorescens IAM 1057. This lipase and a method for its purification have been described in Japanese Patent Application No. 53-20487, laid open to public inspection on Feb. 24, 1978. This lipase is available from Amano Pharmaceutical Co. Ltd, Nagoya, Japan, under the trade name Lipase P "Amano", hereinafter referred to as "Amano-P". The lipases of the present invention should show a positive immunological cross reaction with the Amano-P antibody, using the standard and well-known immunodiffusion procedure according to Ouchterlony (Acta. Med. Scan., 133, pages 76-79 (1950)).

The preparation of the antiserum is carried out as follows:

Equal volumes of 0.1 mg/ml antigen and of Freund's adjuvant (complete or incomplete) are mixed until an emulsion is obtained. Two female rabbits are injected with 2 ml samples of the emulsion according to the following scheme:

day 0: antigen in complete Freund's adjuvant

day 4: antigen in complete Freund's adjuvant

day 32: antigen in incomplete Freund's adjuvant

day 60: booster of antigen in incomplete Freund's adjuvant

The serum containing the required antibody is prepared by centrifugation of clotted blood, taken on day 67.

The titre of the anti-Amano-P-lipase antiserum is determined by the inspection of precipitation of serial dilutions of antigen and antiserum according to the Ouchterlony procedure. A 2.sup.5 dilution of antiserum was the dilution that still gave a visible precipitation with an antigen concentration of 0.1 mg/ml.

All lipases showing a positive immunological cross reaction with the Amano-P antibody as hereabove described are lipases according to the present invention. Typical examples thereof are the Amano-P lipase, the lipase ex Pseudomonas fragi FERM P 1339 (available under the trade name Amano-B), lipase ex Psuedomonas nitroreducens var. lipolyticum FERM P 1338 (available under the trade name Amano-CES), lipases ex Chromobacter viscosum, e.g. Chromobacter viscosum var. lipolyticum NRRLB 3673, commercially available from Toyo Jozo Co., Tagata, Japan; and further Chromobacter viscosum lipases from U.S. Biochemical Corp., U.S.A. and Diosynth Co., The Netherlands, and lipases ex Pseudomonas gladioli.

Preferably, the lipases of the present invention should also show a positive immunological cross reaction with the antibody of one of the the following lipases: lipase ex Chromobacter viscosum var. lipolyticum NRRLB 3673, as sold by Toyo Jozo Co., Tagata, Japan, and lipase ex Pseudomonas gladioli.

Typical examples of such lipases showing such further cross reaction are Amano-P, Amano-B, Amano-CES, lipases ex Chromobacter viscosum, e.g. Chromobacter viscosum var. lipolyticum NRRLB 3673, commercially available from Toyo Jozo Co., Tagata, Japan; and further Chromobacter viscosum lipases from U.S. Biochemical Corp., U.S.A. and Diosynth Co., The Netherlands, and lipases ex Pseudomonas gladioli.

The lipases of the present invention are included in the detergent composition in such an amount that the final detergent composition has a lipolytic enzyme activity of from 100 to 0.005 LU/mg preferably 25 to 0.05 LU/mg of the composition.

A Lipase Unit (LU) is that amount of lipase which produces 1 .mu.mol of titratable fatty acid per minute in a pH stat. under the following conditions: temperature 30.degree. C.; pH=9.0; substrate is an emulsion of 3.3 wt.% of olive oil and 3.3% gum arabic, in the presence of 13 mmol Ca.sup.2+ and 20 mmol NaCl in 5 mmol Tris-buffer.

Naturally, mixtures of the above lipases can be used. The lipases can be used in their impurified form, or in a purified form, e.g. purified with the aid of well-known adsorption methods, such as a phenylsepharose-packed column technique.

The detergent composition incorporating the lipases of the present invention contains as active detergent material a mixture of one or more nonionic synthetic detergent-active materials and one or more anionic synthetic detergent-active materials. Both types of detergent-active materials are well known in the art, and suitable examples are fully described in Schwartz, Perry and Berch, Surface-Active Agents and Detergents, Vol. I (1949) and Vol. II (1958) and in Schick, Nonionic Surfactants, Vol. I (1967).

In general, the weight ratio of the nonionic to the anionic detergent varies from 12:1 to 1:12, preferably from 8:1 to 1:8, and particularly preferably from 4:1 to 1:4.

The amount of nonionic and anionic detergent-active material together in the detergent composition ranges from 1 to 30%, usually 2 to 20% and preferably 6 to 16% by weight.

Detergent materials of other types, such as soaps, cationic and zwitterionic detergents, may also be included.

The detergent composition may furthermore include the usual detergent ingredients in the usual amounts. They may be unbuilt or built, and may be of the zero-P type (i.e. not containing phosphorus-containing builders). Thus, the composition may contain from 1-45%, preferably from 5-30% by weight of one or more organic and/or inorganic builders. Typical examples of such builders are the alkali metal ortho-, pyro- and -tripolyphosphates, alkali metal carbonates, either alone or in admixture with calcite, alkali metal citrates, alkali metal nitrilotriacetates, carboxymethyloxysuccinates, zeolites, polyacetalcarboxylates and so on. Furthermore, it may contain from 1-35% of a bleaching agent or a bleaching system comprising a bleaching agent and an activator therefor. In this respect it has been surprisingly found that the lipases of the present invention often are significantly less affected by the bleaching agent or bleaching system in the composition than other lipases, not according to the invention.

The compositions may furthermore comprise lather boosters, foam depressors, anti-corrosion agents, soil-suspending agents, sequestering agents, anti-soil redeposition agents, perfumes, dyes, stabilising agents for the enzymes and bleaching agents and so on. They may also comprise enzymes other than lipases, such as proteases, amylases, oxidases and cellulases. In this respect it has surprisingly been found that, although the lipases of the present invention rapidly lose activity in the presence of proteases in clean model systems, under practical wash conditions in washing machines a substantial benefit is still delivered by the lipases in the presence of proteases.

The compositions of the present invention can be formulated in any desired form, such as powders, bars, pastes, liquids etc.

As said before, the compositions of the present invention show an improved overall detergency performance, particularly at lower temperatures. It is surprising that fully formulated detergent compositions incorporating the lipases of the present invention do show such an improved overall performance, when the prior art hitherto has indicated that lipases would only give some effect under particular conditions.

The invention will now further be illustrated by way of Examples.

With the following particulate detergent composition, washing experiments were carried out with several lipases:

The lipases tested were Amano-P as described heretofore, furthermore SP 225, a lipase producible by Mucor miehei ex Novo Industri A/S and Esterase MM, a lipase producible by Mucor miehei ex Gist-Brocades.

The washing experiments were carried out under the following conditions:

washing process: 30 minutes at 30.degree. C.

water hardness: 8.degree. GH

monitor: cotton test cloths soiled with a mixture containing inorganic pigments, protein, olive oil or palm oil, respectively and in the presence of cloth to give the desired cloth/liquor ratio.

lipase concentration: 15 LU/ml

cloth/liquor ratio: 1:6.

dosage of composition: 6 g/l

The number of soil/wash cycles was 4, and after the fourth wash the reflectance of the test cloths and the residual percentage of fatty material on the test cloths were determined. The reflectance was measured in a Reflectometer at 460 nm with a UV filter in the light pathway and the fatty matter by extracting the dried test cloths with petroleum ether, distilling off the solvent and weighing the resulting fatty matter.

The following results were obtained:

These results show that the lipase of the present invention (Amano-P) is superior to the other two prior art lipases.

Replacing Amano-P by Diosynth as heretofore described in Example I gave similar results.

The lipase stability of various lipases in a bleach containing detergent composition (5 g/l) containing 3% TAED, 8% sodium perborate monohydrate and 0.3% Dequest.RTM. was compared at 30.degree. C. in water of 22.degree. GH. The balance of the formulation was equal to the one as described in Example VIII; now Savinase.RTM. or other proteolytic enzyme was present.

The stability of the lipases was tested in clean wash liquors, using the detergent formulation of Example V with and without the bleaching system and/or proteolytic enzymes. The water hardness was 22.degree. GH.

The following results were obtained:

The stability of lipases of the invention in bleach containing detergent formulations is further demonstrated. In these clean detergent solutions the sensitivity of the lipases to proteolytic attack is also shown.

The performance in washing machines of Amano P in the presence of strong bleach (6/12; TAED/perborate) and high levels of a proteolytic enzyme (Savinase; 30 GU/ml) was determined. The formulation of Example I was used at a water hardness of 8 GH and using the wash conditions given in Example I.

Following results were obtained after the fourth wash:

In the same manner as described in Example I, the lipase Amano-P was compared with a lipase producible by Fusarium oxysporum according to EP 0130064. The test cloths were cotton and polyester fabrics, the soiling contained a mixture of palm oil, protein and inorganic pigment and the water hardness was 8.degree. and 22.degree. GH.

The following results were obtained:

The lipase according to EP 0130064 had a lipolytic activity of 90 LU/mg, but also showed a proteolytic activity of 120 GU/mg. Amano P does not show any detectable proteolytic activity. Although the effects of lipase ex Fusarium on % FM are negligible/small, the effects on R*.sub.460 are quite marked. This however, is easily explainable by the proteolytic activity in this lipase sample if a comparison with Example V (powder+Savinase versus powder+lipase) is made.

Comparing in the manner as described in Example I the lipase Amano-P with a lipase of the same manufacturer, not according to the invention, Amano CE, and with two other lipases according to the invention, Amano B and Amano CES gave the following results:

The Amano CE lipase had an activity of 17 LU/mg, but also showed a proteolytic activity of 16 GU/mg. Amano-P, Amano-B and Amano CES had comparable LU/mg activities, but do not show any detectable proteolytic activity. Again the good result on R*.sub.460 but not on %FM of Amano CE are explained by its contaminated proteolytic activity.

With the following particulate detergent composition, further washing experiments were carried out to show compatibility with bleach and proteolytic enzymes during the wash process.

The washing experiments were carried out under the following conditions:

washing machine with a load of 3.5 kg dirty laundry

washing process: 30 minutes of 30.degree. C.

water hardness: 8 and 22.degree. GH lipase concentrations: 15 LU/ml

dosage of compositions 3.5 g/l.

The following results were obtained after the fourth wash:

A similar experiment as in Example VIII was done using lipase according to the invention with different resistance against proteolytic enzymes as shown in Example IV.

Lipase concentration was 5 LU/ml.

Textile used was cotton.

Residual activities in the wash liquor after the 30 minutes wash process:

Detailed comparison with Example IV shows that in the realistic, practical wash conditions used in this Example lipases of the invention are substantially less sensitive to attack by proteases such as Savinase used in detergent products.

The test of Example 1 was repeated, but using 4 g/l of the detergent composition and using lipases in an amount of 1 LU/ml. The following results were obtained:

In the same manner as is Example I, washing experiments were carried out, using either 5 g/l of the detergent composition of Example VIII (water hardness 22.degree. GH) or 4 g/l of the detergent composition of Example I (water hardness 8.degree. GH). The lipases were used at 1 and 3 LU/ml. The test cloths were either polyester/cotton (P/C) mixed fabrics, or pre-washed cotton (PWC).

The following results were obtained:

Repeating Example I, using the detergent composition of Example I at 4 g/l in water of 8.degree. GH, or the detergent composition of Example VIII at 5 g/l in water of 22.degree. GH, at various temperatures gave the following results:

In the manner as described in Example I, the following detergent compositions were tested.

The following results were obtained: