FIELD OF THE INVENTION
[0001] The invention relates to enzymatic reduction of malodor from laundry.
BACKGROUND
[0002] Clothes that have been used for e.g. sports activities or in other ways have been
exposed to sweat from the wearer during use are often difficult to clean in terms
of the smell of sweat and other body odors (malodor), when subjected to wash in a
laundry machine.
[0003] WO 90/09739 discloses compositions including lysostaphin and nisin, which are used
for treating bacterial infections.
[0004] WO 91/10723 discloses a bacteriolytic enzyme from
Nocardiopsis dassonvillei and it's use in e.g. detergent compositions.
SUMMARY OF THE INVENTION
[0005] We have found that an enzyme having lysostaphin activity is capable of reducing malodor
from laundry. Accordingly, the invention provides a method comprising contacting laundry
with an enzyme having lysostaphin activity.
[0006] In a second aspect, there is provided a composition comprising a surfactant and an
enzyme having lysostaphin activity and one or more other enzymes selected from protease,
lipase, cutinase, amylase, carbohy-drase, cellulase, pectinase, mannanase, arabinase,
galactanase, xylanase, oxidase, laccase, and peroxidase.
DETAILED DESCRIPTION
Lysostaphin
[0007] The enzyme Lysostaphin is a glycyl-glycine endopeptidase from the enzyme class E.C.
3.4.24.75. It hydrolyses the -Gly-Gly- bond in the polyglycine inter-peptide link
joining staphylococcal cell wall peptidoglycans. Lysostaphin is commercially available
from several suppliers, such as from Sigma-Aldrich, Inc.
[0008] An enzyme having lysostaphin activity may be a natural or synthetic variant of lysostaphin,
wherein amino acid substitutions or deletions have been introduced. It may also be
an amino acid fragment with lysostaphin activity, which is optionally fused to one
or more other proteins.
Lysostaphin Activity
[0009] One unit of lysostaphin activity will reduce the turbidity (absorbance at 620 nm)
of a suspension of
Staphylococcus aureus (ATCC 6538) cells by 50%, when the initial absorbance is approximately 0.250, after
10 minutes at pH 7.5 and 37 degrees celcius.
Malodor
[0010] During wear, fabrics are contaminated with microorganisms from the human skin together
with sebaceous lipids, sweat and dead skin cells serving as microbial substrates.
Particularly at mild wash conditions these microorganisms survive laundering. A consequence
of microorganisms surviving household laundering is malodor generation in the fabrics.
We have now found that these microorganisms are mainly
Staphylococcus species.
[0011] The malodor of the method of the invention thus comprises all body odors present
in laundry originating from contact with the human skin. In an embodiment the malodor
may be axillary odors, such as the smell of sweat.
[0012] In another embodiment, the malodor may originate from activity of
Staphylococcus species (such as
S.
aureus, S. epidermis, S. intermedius, S. saprophyticus and
S. hyicus).
[0013] In yet another embodiment the malodor originates from fabrics which have been in
contact with the axilla.
Evaluation of Malodor
[0014] Wet laundry swatches are placed in tinted 200 ml glasses with snap lids. A trained
sensory panel (10 persons) evaluates the odor by sniffing the headspace over the wet
items and indicating the total odor intensity. The odor intensity is indicated on
a scale from 0 to 15 where 0 equals 'no malodor' and 15 equals 'very strong malodor'.
All evaluations are performed twice (double determinations). The swatches are evaluated
after approximately 24 hours and after 48 hours (swatches are kept in the glasses
at all times). An average of all 20 evaluations (10 persons each evaluate twice) is
calculated after both 24 hours and 48 hours. These average values are referred to
as "Malodor index (24 hours)" and "Malodor index (48 hours)".
Laundry
[0015] The laundry of the method of the invention comprises all kinds of textile items or
fabrics suitable for being used as clothes or for personal use in other ways comprising
contact with the human skin.
Methods and Uses
[0016] By contacting laundry with an enzyme having lysostaphin activity, as defined in the
method of the invention, the "Malodor index (48 hours)", as defined above, may be
reduced by at least 10% (preferably 20%, more preferably 30%, most preferably 40%,
and in particular 50%) compared to laundry which has not been contacted with an enzyme
having lysostaphin activity.
[0017] The method of the invention may also result in killing or inhibiting growth of microbial
cells in laundry. In an embodiment the microbial cells are bacteria, such as
Staphylococcus species. In another embodiment, the method of the invention may result in a reduction
in the number of living microbial cells of at least 25%, preferably at least 50%,
more preferably at least 90%, and most preferably at least 99%.
[0018] In the context of the present invention the term "inhibiting growth of microbial
cells" is intended to mean that the cells are in the non-growing state, i.e., that
they are not propagating. The term "microbial cells" denotes bacterial cells (such
as
Staphylococcus species), fungal cells or algae, and the term "microorganism" denotes a fungus (including
yeasts) or a bacterium
[0019] The present invention covers use of an enzyme for reducing malodor from laundry items.
In an embodiment, the enzyme may have lysostaphin activity. The invention may also
be used for reducing the number of living bacteria in laundry; for reducing allergens
in laundry; or for sterilizing laundry.
Detergent composition
[0020] Lysostaphin may be added to and thus become a component of a detergent composition.
[0021] The detergent composition of the invention may for example be formulated as a hand
or machine laundry detergent composition including a laundry additive composition
suitable for pre-treatment of stained fabrics and a rinse added fabric softener composition,
or be formulated as a detergent composition for use in general household hard surface
cleaning operations, or be formulated for hand or machine dishwashing operations.
[0022] In a specific aspect, the invention provides a detergent additive comprising lysostaphin.
The detergent additive as well as the detergent composition comprises one or more
other enzymes selected from protease, lipase, cutinase, amylase, carbohydrase, cellulase,
pectinase, mannanase, arabinase, galactanase, xylanase, oxidase, laccase and peroxidase.
[0023] In general the properties of the chosen enzyme(s) should be compatible with the selected
detergent, (i.e. pH-optimum, compatibility with other enzymatic and non-enzymatic
ingredients, etc.), and the enzyme(s) should be present in effective amounts.
[0024] Proteases: Suitable proteases include those of animal, vegetable or microbial origin. Microbial
origin is preferred. Chemically modified or protein engineered mutants are included.
The protease may be a serine protease or a metallo protease, preferably an alkaline
microbial protease or a trypsin-like protease. Examples of alkaline proteases are
subtilisins, especially those derived from
Bacillus, e.g., subtilisin Novo, subtilisin Carlsberg, subtilisin 309, subtilisin 147 and subtilisin
168 (described in WO 89/06279). Examples of trypsin-like proteases are trypsin (e.g.
of porcine or bovine origin) and the
Fusarium protease described in WO 89/06270 and WO 94/25583.
[0025] Examples of useful proteases are the variants described in WO 92/19729, WO 98/20115,
WO 98/20116, and WO 98/34946, especially the variants with substitutions in one or
more of the following positions: 27, 36, 57, 76, 87, 97, 101, 104, 120, 123, 167,
170, 194, 206, 218, 222, 224, 235 and 274.
[0026] Preferred commercially available protease enzymes include Alcalase™, Savinase™, Primase™,
Everlase™, Esperase™, and Kannase™ (Novozymes A/S), Maxatase™, Maxacal™, Maxapem™,
Properase™, Purafect™, Purafect OxP™, FN2™, and FN3™ (Genencor International Inc.).
[0027] Lipases: Suitable lipases include those of bacterial or fungal origin. Chemically modified
or protein engineered mutants are included. Examples of useful lipases include lipases
from
Humicola (synonym
Thermomyces), e.g. from
H. lanuginosa (
T. lanuginosus) as described in EP 258 068 and EP 305 216 or from
H.
insolens as described in WO 96/13580, a
Pseudomonas lipase, e.g. from
P. alcaligenes or
P.
pseudoalcaligenes (EP 218 272),
P.
cepacia (EP 331 376),
P.
stutzeri (GB 1,372,034),
P.
fluorescens, Pseudomonas sp. strain SD 705 (WO 95/06720 and WO 96/27002),
P.
wisconsinensis (WO 96/12012), a
Bacillus lipase, e.g. from
B.
subtilis (Dartois et al. (1993), Biochemica et Biophysica Acta, 1131, 253-360), B.
stearothermophilus (JP 64/744992) or
B.
pumilus (WO 91/16422).
[0028] Other examples are lipase variants such as those described in WO 92/05249, WO 94/01541,
EP 407 225, EP 260 105, WO 95/35381, WO 96/00292, WO 95/30744, WO 94/25578, WO 95/14783,
WO 95/22615, WO 97/04079 and WO 97/07202.
[0029] Preferred commercially available lipase enzymes include Lipolase™, Lipolase Ultra™
and Lipoprime™(Novozymes A/S).
[0030] Amylases: Suitable amylases (α and/or β) include those of bacterial or fungal origin. Chemically
modified or protein engineered mutants are included. Amylases include, for example,
α-amylases obtained from
Bacillus, e.g. a special strain of
B.
licheniformis, described in more detail in GB 1,296,839.
[0031] Examples of useful amylases are the variants described in WO 94/02597, WO 94/18314,
WO 96/23873, and WO 97/43424, especially the variants with substitutions in one or
more of the following positions: 15, 23, 105, 106, 124, 128, 133, 154, 156, 181, 188,
190, 197, 202, 208, 209, 243, 264, 304, 305, 391, 408, and 444.
[0032] Commercially available amylases are Duramyl™, Termamyl™, Fungamyl™ and BAN™ (Novozymes
A/S), Rapidase™ and Purastar™ (Genencor International Inc.).
[0033] Cellulases: Suitable cellulases include those of bacterial or fungal origin. Chemically modified
or protein engineered mutants are included. Suitable cellulases include cellulases
from the genera
Bacillus, Pseudomonas, Humicola, Fusarium, Thielavia, Acremonium, e.g. the fungal cellulases produced from
Humicola insolens, Myceliophthora thermophila and
Fusarium oxysporum disclosed in US 4,435,307, US 5,648,263, US 5,691,178, US 5,776,757 and WO 89/09259.
[0034] Especially suitable cellulases are the alkaline or neutral cellulases having colour
care benefits. Examples of such cellulases are cellulases described in EP 0 495 257,
EP 0 531 372, WO 96/11262, WO 96/29397, WO 98/08940. Other examples are cellulase
variants such as those described in WO 94/07998, EP 0 531 315, US 5,457,046, US 5,686,593,
US 5,763,254, WO 95/24471, WO 98/12307 and PCT/DK98/00299.
[0035] Commercially available cellulases include Celluzyme™, and Carezyme™ (Novozymes A/S),
Clazinase™, and Puradax HA™ (Genencor International Inc.), and KAC-500(B)™ (Kao Corporation).
[0036] Peroxidases/Oxidases: Suitable peroxidases/oxidases include those of plant, bacterial or fungal origin.
Chemically modified or protein engineered mutants are included. Examples of useful
peroxidases include peroxidases from
Coprinus, e.g. from
C.
cinereus, and variants thereof as those described in WO 93/24618, WO 95/10602, and WO 98/15257.
[0037] The detergent enzyme(s) may be included in a detergent composition by adding separate
additives containing one or more enzymes, or by adding a combined additive comprising
all of these enzymes. A detergent additive of the invention, i.e. a separate additive
or a combined additive, can be formulated e.g. as a granulate, a liquid, a slurry,
etc. Preferred detergent additive formulations are granulates, in particular non-dusting
granulates, liquids, in particular stabilized liquids, or slurries.
[0038] Non-dusting granulates may be produced, e.g., as disclosed in US 4,106,991 and 4,661,452
and may optionally be coated by methods known in the art. Examples of waxy coating
materials are poly(ethylene oxide) products (polyethyleneglycol, PEG) with mean molar
weights of 1000 to 20000; ethoxylated nonylphenols having from 16 to 50 ethylene oxide
units; ethoxylated fatty alcohols in which the alcohol contains from 12 to 20 carbon
atoms and in which there are 15 to 80 ethylene oxide units; fatty alcohols; fatty
acids; and mono- and di- and triglycerides of fatty acids. Examples of film-forming
coating materials suitable for application by fluid bed techniques are given in GB
1483591. Liquid enzyme preparations may, for instance, be stabilized by adding a polyol
such as propylene glycol, a sugar or sugar alcohol, lactic acid or boric acid according
to established methods. Protected enzymes may be prepared according to the method
disclosed in EP 238,216.
[0039] The detergent composition of the invention may be in any convenient form, e.g., a
bar, a tablet, a powder, a granule, a paste or a liquid. A liquid detergent may be
aqueous, typically containing up to 70 % water and 0-30 % organic solvent, or nonaqueous.
[0040] The detergent composition comprises one or more surfactants, which may be non-ionic
including semi-polar and/or anionic and/or cationic and/or zwitterionic. The surfactants
are typically present at a level of from 0.1 % to 60% by weight.
[0041] When included therein the detergent will usually contain from about 1 % to about
40% of an anionic surfactant such as linear alkylbenzenesulfonate, alpha-olefinsulfonate,
alkyl sulfate (fatty alcohol sulfate), alcohol ethoxysulfate, secondary alkanesulfonate,
alpha-sulfo fatty acid methyl ester, alkyl- or alkenylsuccinic acid or soap.
[0042] When included therein the detergent will usually contain from about 0.2% to about
40% of a non-ionic surfactant such as alcohol ethoxylate, nonylphenol ethoxylate,
alkylpolyglycoside, alkyldimethylamineoxide, ethoxylated fatty acid monoethanolamide,
fatty acid monoethanolamide, polyhydroxy alkyl fatty acid amide, or N-acyl N-alkyl
derivatives of glucosamine ("glucamides").
[0043] The detergent may contain 0-65 % of a detergent builder or complexing agent such
as zeolite, diphosphate, triphosphate, phosphonate, carbonate, citrate, nitrilotriacetic
acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, alkyl-
or alkenylsuccinic acid, soluble silicates or layered silicates (e.g. SKS-6 from Hoechst).
[0044] The detergent may comprise one or more polymers. Examples are carboxymethylcellulose,
poly(vinylpyrrolidone), poly (ethylene glycol), poly(vinyl alcohol), poly(vinylpyridine-N-oxide),
poly(vinylimidazole), polycarboxylates such as polyacrylates, maleic/acrylic acid
copolymers and lauryl methacrylate/acrylic acid copolymers.
[0045] The detergent may contain a bleaching system which may comprise a H
2O
2 source such as perborate or percarbonate which may be combined with a peracid-forming
bleach activator such as tetraacetylethylenediamine or nonanoyloxybenzenesulfonate.
Alternatively, the bleaching system may comprise peroxyacids of e.g. the amide, imide,
or sulfone type.
[0046] The enzyme(s) of the detergent composition of the invention may be stabilized using
conventional stabilizing agents, e.g., a polyol such as propylene glycol or glycerol,
a sugar or sugar alcohol, lactic acid, boric acid, or a boric acid derivative, e.g.,
an aromatic borate ester, or a phenyl boronic acid derivative such as 4-formylphenyl
boronic acid, and the composition may be formulated as described in e.g. WO 92/19709
and WO 92/19708.
[0047] The detergent may also contain other conventional detergent ingredients such as e.g.
fabric conditioners including clays, foam boosters, suds suppressors, anticorrosion
agents, soil-suspending agents, anti-soil redeposition agents, dyes, bactericides,
optical brighteners, hydrotropes, tarnish inhibitors, or perfumes.
[0048] It is at present contemplated that in the detergent compositions any enzyme, in particular
lysostaphin, may be added in an amount corresponding to 0.01-100 mg of enzyme protein
per liter of wash liquor, preferably 0.05-10 mg of enzyme protein per liter of wash
liquor, more preferably 0.1-5 mg of enzyme protein per liter of wash liquor, and most
preferably 0.1-1 mg of enzyme protein per liter of wash liquor.
[0049] Lysostaphin may additionally be incorporated in the detergent formulations disclosed
in WO 97/07202.
[0050] The present invention is further illustrated in the following examples, which are
not in any way intended to limit the scope of the invention as claimed.
EXAMPLES
[0051] The chemicals used in the following examples were commercial products of at least
reagent grade.
[0052] The Malthus Flexi M2060 instrument is available from Malthus Instruments Limited,
England.
[0053] Tryptone Soya Broth (TSB) is available from Oxoid, England.
CFU: Colony Forming Units.
EXAMPLE 1
Evaluation of odour in swatches soiled with human axillary sweat and sebum
[0054] The odour reducing effect of lysostaphin is tested in a one-cycle washing trial carried
out in a thermostated Terg-O-tometer (available from United States Testing Co, 1415
Park Ave, Hoboken NJ07030).
Experimental conditions:
Soiling
[0055] Swatches of 100% polyester or 100% cotton (10 x 14 cm, previously cleaned by solvent
extraction - hexane for polyester, chloroform for cotton - using a Soxhlet) are soiled
by applying human male axillary sweat and sebum from the armpits and upper body of
male runners after extensive exercise. Two swatches (10 x 14 cm) are used for each
male - one swatch is made of 100% polyester and one is made of 100% cotton. The left
armpit and left part of the upper body is wiped with one swatch, and the right armpit
and right part of the upper body is wiped with the other swatch after exercising.
This procedure is performed twice before washing. Prior to the washing, each swatch
is cut into 12 equally sized pieces and distributed between four Terg-O-tometer wash
beakers. Cotton and polyester textiles are kept apart.
Washing
[0056] Washing is done in Terg-O-tometer using phosphate buffer (0.05 M, pH 7.5).
| Temperature: |
32°C |
| Lysostaphin dose: |
5 mg/L (Sigma L4402) |
| Wash time: |
12 minutes |
| Wash liquid: |
1000 mL per wash beaker |
| Rinsing: |
15 minutes in running tap water |
Sensory evaluation
[0057] After wash the wet swatches are evaluated and "Malodor index (24 hours)" and "Malodor
index (48 hours)" are calculated. The results show that a lower "Malodor index (48
hours)" is obtained with the swatches that has been washed with lysostaphin compared
to those that has not been washed with lysostaphin.
EXAMPLE 2
Removal of bacteria from textile by lysostaphin
[0058] Staphylococcus aureus (ATCC 6538) was grown overnight (TSB; Tryptone Soya Broth) and inoculated to approximately
10
3 Colony forming units/ml (CFU/ml) in diluted TSB (1:1). Sterile cotton swatches were
inoculated overnight in the diluted TSB allowing
S.aureus to grow on the textile. The swatches were rinsed in sterile water for 30 seconds
and dried in sterile air for 30 minutes. Swatches were washed in a beaker with stirring
at 32°C for 20 minutes in either phosphate buffer (0.05 M, pH 7.5) or in a liquid
U.S. detergent of a commercial type (0.75 g/liter) with and without addition of 5
mg/L Lysostaphin (Sigma L4402). Three swatches were washed in each beaker. After wash
all swatches were rinsed in sterile water for 10 minutes and dried in sterile air.
The number of living
S.
aureus on the swatches was determined by incubation of the swatches in Malthus tubes with
CASO medium (Merck 1.05459). The bactericidal activity was determined by incubation
in Malthus. The detection times (dt) measured by the Malthus instrument were converted
to CFU/swatch by a calibration curve (Johansen et al. 1999, Methods in Enzymology,
vol 310, p. 353-360). Direct Malthus measurements were used when enumerating total
survival cells. By the direct measurements, the cell metabolism was determined by
conductance measurements in the growth substrate. The swatches were after enzyme treatment
transferred to the Malthus cell. As cells attached to the textile are growing, the
cell metabolism will change the conductance in the growth medium. When the conductance
change is measurable by the Malthus, a detection time (dt) will be recorded. The dt's
were converted to colony counts by use of a calibration curve relating CFU/swatch
to dt.
Results:
[0059]
| Swatch |
Beaker |
Average number of S. aureus on each swatch |
| |
|
(three swatches washed in each beaker) |
| Reference swatches before wash |
|
8.8 x 107 CFU/swatch |
| Washed in phosphate buffer |
1 |
2.2 x 107 CFU/swatch |
| |
2 |
7.3 x 106 CFU/swatch |
| Washed in phosphate buffer with |
1 |
4.6 x 106 CFU/swatch |
| lysostaphin (5 mg/L) |
2 |
1.2 x 105 CFU/swatch |
| |
3 |
4.8 x 105 CFU/swatch |
[0060] Lysostaphin resulted in a reduction of the microbial cell number of approximately
10
1 to 10
2 CFU/swatch. A reduction in cell number was also determined after lysostaphin treatment
in detergent, however, the determination of the exact cell number was not possible
by using the Malthus. But a delay in outgrowth of the microorganism was observed visually
from the swatches washed in detergent with lysostaphin, this delay corresponds to
a lower cell number on the swatches compared to the swatches washed without lysostaphin.