Detergent Formulations Research Articles

An organic solvent-stable lipase from a newly isolated Staphylococcus aureus ALA1 strain with potential for use as an industrial biocatalyst.

In this study, a new strain, ALA1, was identified as Staphylococcus aureus by biochemical tests, and its 16S ribosomal DNA sequence was isolated from dromedary milk. ALA1 lipase production was optimized in shake flask experiments and measured with varying pH (3-11), temperature (20-55°C) and substrate concentrations. The maximum lipase production was recorded at pH 8 and 30°C for up to 30H of culture period for the S. aureus ALA1 strain. Among the substrates tested, selected carbon sources, xylose, nitrogen source, yeast extract, and olive oil (1%) were suitable for maximizing lipase production. The effects of surfactants were investigated and showed that Tween 20, Tween 80, and Triton X-100 prevented lipase production. Interestingly, isolate ALA1 was able to grow in high concentrations of benzene or toluene (up to 50% (v/v)). Moreover, the lipolytic activity of the S. aureus ALA1 lipase was stimulated by diethyl ether, whereas almost 100% of S. aureus ALA1 lipase activity was retained in 25% acetone, acetonitrile, benzene, 2-propanol, ethanol, methanol, or toluene. Because of its stability in organic solvent, the S. aureus ALA1 lipase was used as a biocatalyst to synthesize high levels of added value molecules. S. aureus ALA1 lipase could be considered as an ideal choice for applications in detergent formulations because of its high stability and compatibility with various surfactants, oxidizing agents, and commercial detergents.

Are Lipases Still Important Biocatalysts? A Study of Scientific Publications and Patents for Technological Forecasting.

The great potential of lipases is known since 1930 when the work of J. B. S. Haldane was published. After eighty-five years of studies and developments, are lipases still important biocatalysts? For answering this question the present work investigated the technological development of four important industrial sectors where lipases are applied: production of detergent formulations; organic synthesis, focusing on kinetic resolution, production of biodiesel, and production of food and feed products. The analysis was made based on research publications and patent applications, working as scientific and technological indicators, respectively. Their evolution, interaction, the major players of each sector and the main subject matters disclosed in patent documents were discussed. Applying the concept of technology life cycle, S-curves were built by plotting cumulative patent data over time to monitor the attractiveness of each technology for investment. The results lead to a conclusion that the use of lipases as biocatalysts is still a relevant topic for the industrial sector, but developments are still needed for lipase biocatalysis to reach its full potential, which are expected to be achieved within the third, and present, wave of biocatalysis.

A novel detergent-stable solvent-tolerant serine thiol alkaline protease from Streptomyces koyangensis TN650

An alkaline proteinase (STAP) was produced from strain TN650 isolated from a Tunisian off-shore oil field and assigned as Streptomyces koyangensis strain TN650 based on physiological and biochemical properties and 16S rRNA gene sequencing. Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS) analysis revealed that the purified enzyme was a monomer with a molecular mass of 45125.17-Da. The enzyme had an NH2-terminal sequence of TQSNPPSWGLDRIDQTTAFTKACSIKY, thus sharing high homology with those of Streptomyces proteases. The results showed that this protease was completely inhibited by phenylmethanesulfonyl fluoride (PMSF), diiodopropyl fluorophosphates (DFP), and partially inhibited by 5,5-dithio-bis-(2-nitro benzoic acid) (DTNB), which strongly suggested its belonging to the serine thiol protease family. Using casein as a substrate, the optimum pH and temperature values for protease activity were pH 10 and 70°C, respectively. The protease was stable at pH 7–10 and 30–60°C for 24h. STAP exhibited high catalytic efficiency, significant detergent stability, and elevated organic solvent resistance compared to the SG-XIV proteases from S. griseus and KERAB from Streptomyces sp. AB1. The stap gene encoding STAP was isolated, and its DNA sequence was determined. These properties make STAP a potential candidate for future application in detergent formulations and non-aqueous peptide biocatalysis.

Benzotriazole removal on post-Cu CMP cleaning**Project supported by the Major National Science and Technology Special Projects (No. 2009ZX02308).

This work investigates systematically the effect of FA/O II chelating agent and FA/O I surfactant in alkaline cleaning solutions on benzotriazole (BTA) removal during post-Cu CMP cleaning in GLSI under the condition of static etching. The best detergent formulation for BTA removal can be determined by optimization of the experiments of single factor and compound cleaning solution, which has been further confirmed experimentally by contact angle (CA) measurements. The resulting solution with the best formulation has been measured for the actual production line, and the results demonstrate that the obtained cleaning solution can effectively and efficiently remove BTA, CuO and abrasive SiO2 without basically causing interfacial corrosion. This work demonstrates the possibility of developing a simple, low-cost and environmentally-friendly cleaning solution to effectively solve the issues of BTA removal on post-Cu CMP cleaning in a multi-layered copper wafer.

Extraction and Biochemical Characterization of Peptidases from Giant Catfish Viscera by Aqueous Two-Phase System

Peptidases were extracted from the viscera of farmed giant catfish (Pangasianodon gigas) in an aqueous two-phase system (ATPS) of 15% (w/w) polyethylene glycol (PEG-2000) and 15% (w/w) sodium citrate. The recovery of the enzymes was 273% with 12-fold purification. Protein pattern, activity and inhibitory staining confirmed that the proteins with molecular weights of 12 and 31 kDa were a mixture of proteolytic enzyme. The optimum pH and temperature of the enzyme were 8.0 and 70C, respectively. Besides, it retained more than 50% of activity at the highest salt concentration (30% w/v). The enzyme was strongly inhibited by serine protease inhibitors (>80% inhibition), while low inhibition with cysteine-, aspartic- and metallo-protease inhibitors (<20% inhibition). The enzyme activity was extremely inhibited by the metal ions Ag+, Cu2+ and Fe2+. The peptidases from the giant catfish viscera have potential applications in food processing where high temperatures (60–70C) and/or high salt content are used, or even in detergent formulation. Practical Applications Extraction and characterization of a proteolytic enzyme from viscera, fishery processing by-product, could add value to it. According to its properties, the isolated peptidases could be potentially applied to food industry, especially in fish sauce production, protein hydrolysate production, or in neutraceutical and in detergent industry.

Purification and biochemical characterization of two detergent-stable serine alkaline proteases from Streptomyces sp. strain AH4

Streptomyces sp. strain AH4 exhibited a high ability to produce two extracellular proteases when cultured on a yeast malt-extract (ISP2)-casein-based medium. Pure proteins were obtained after heat treatment (30 min at 70 °C) and ammonium sulphate fractionation (30-60 %), followed by size exclusion HPLC column. Matrix assisted laser desorption ionization-time of flight mass spectrometry analysis revealed that the purified enzymes (named SAPS-P1 and SAPS-P2) were monomers with molecular masses of 36,417.13 and 21,099.10 Da, respectively. Their identified N-terminal amino acid displayed high homologies with those of Streptomyces proteases. While SAPS-P1 was optimally active at pH 12.0 and 70 °C, SAPS-P2 showed optimum activity at pH 10.0 and 60 °C. Both enzymes were completely stable within a wide range of temperature (45-75 °C) and pH (8.0-11.5). They were noted to be completely inhibited by phenylmethanesulfonyl fluoride and diisopropyl fluorophosphates, which confirmed their belonging to the serine proteases family. Compared to SAPS-P2, SAPS-P1 showed high thermostability and excellent stability towards bleaching, denaturing, and oxidizing agents. Both enzymes displayed marked stability and compatibility with a wide range of commercial laundry detergents and significant catalytic efficiencies compared to Subtilisin Carlsberg and Protease SG-XIV. Overall, the results indicated that SAPS-P1 and SAPS-P2 can be considered as potential promising candidates for future application as bioadditives in detergent formulations.

Coproduction of detergent compatible bacterial enzymes and stain removal evaluation.

Most of the detergents that are presently produced contain the detergent compatible enzymes to improve and accelerate the washing performance by removing tough stains. The process is environment friendly as the use of enzymes in the detergent formulation reduces the utilization of toxic detergent constituents. The current trend is to use the detergent compatible enzymes that are active at low and ambient temperature in order to save energy and maintain fabric quality. As the detergent compatible bacterial enzymes are used together in the detergent formulation, it is important to co-produce the detergent enzymes in a single fermentation medium as the enzyme stability is assured, and production cost gets reduced enormously. The review reports on the production, purification, characterization and application of detergent compatible amylases, lipases, and proteases are available. However, there is no specific review or minireview on the concomitant production of detergent compatible amylases, lipases, and proteases. In this minireview, the coproduction of detergent compatible enzymes by bacterial species, enzyme stability towards detergents and detergent components, and stain release analysis were discussed.

Synthesis of zeolite A from Ethiopian kaolin

Zeolite A is synthesized using natural kaolin from Ethiopia. Raw kaolin and mechanically purified kaolin from Ansho, southern part of Ethiopia, have been surveyed. The starting kaolin and the final zeolite A samples were characterized by X- Ray Diffraction (XRD), elemental analysis (ICP), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA) and Cation Exchange Capacity (CEC). Metakaolinization was achieved by calcining the kaolin in air at 600 °C within 3 h, much lower than the temperatures previously reported in the literature. The optimization of the hydrothermal synthesis includes various NaOH concentrations at 100 °C, for different reaction time. Zeolite A with molar ratio SiO2/Al2O3 = 2.04 and Na2O/SiO2 = 0.44 was obtained with 90% crystallinity using solid/liquid (1.25 g/25 ml) and reaction time of 3 h which is significantly lower than the literature value that can reach up to 24 h. In this study, cubic crystal with rounded edge of zeolite A having cation exchange capacity of 295 mg CaCO3/g (4.6 meq Ca2+/g) of anhydrous zeolite is obtained that can be a good candidate for detergent formulation.

Purification and characterization of halo-alkali-thermophilic protease from Halobacterium sp. strain HP25 isolated from raw salt, Lake Qarun, Fayoum, Egypt.

A total of 33 halophilic protease producers were isolated from different salt samples collected from Emisal salt company at Lake Qarun, Fayoum, Egypt. Of these strains, an extremely halophilic strain that grew optimally at 30 % (w/v) NaCl was characterized and identified as Halobacterium sp. strain HP25 based on 16S rRNA gene sequencing and phenotypic characterization. A halo-alkali-thermophilic protease was purified in three successive steps from the culture supernatant. The purified halophilic protease consisted of a single polypeptide chain with a molecular mass of 21 kDa and was enriched 167-fold to a specific activity of 6350 U mg(-1). The purified enzyme was active over a broad pH range from 6.0 to 11.0, with maximum activity at pH 8.0, exhibited a broad temperature range from 30 to 80 °C with optimum activity at 60 °C, and was active at salt concentrations ranging from 5 to 25 % (w/v), with optimum activity at 17 % NaCl (w/v). The K M and V max values of the purified halophilic protease with casein as a substrate were 523 µg mL(-1) and 2500 µg min(-1) mL(-1), respectively. In addition, this enzyme was stable in the tested organic solvents and laundry detergents such methanol, propanol, butanol, hexane, Persil and Ariel. The unusual properties of this enzyme allow it to be used for various applications, such as the ripening of salted fish. Furthermore, its stability and activity in the presence of organic solvents and detergents also allow the use of this enzyme for further novel applications and as an additive in detergent formulations.

Functional zinc(II) phthalocyanines bearing Schiff base complexes as oxidation catalysts for bleaching systems

Oxidation catalysis is used to increase the performance of hydrogen peroxide in laundry bleach applications. Bleach catalysts provide cost‐effective, energy‐saving and environmentally friendly bleach systems yielding perfect stain removal at lower temperatures. This comparative study is based on the synthesis of bis[bis(salicylhydrazonephenoxy)manganese(III)] phthalocyaninatozinc(II) (2), bis[bis(salicylhydrazonephenoxy)cobalt(III)] phthalocyaninatozinc(II) (3) and bis[bis(salicylhydrazonephenoxy)iron(III)] phthalocyaninatozinc(II) (4) as tri‐nuclear complexes consisting of two Schiff base complexes substituting a zinc phthalocyanine. Complexion on the periphery to obtain complexes 2, 3, 4 was performed through the reaction of a Schiff base‐substituted phthalocyanine using MnCl2⋅4H2O, CoCl2⋅6H2O or FeCl3⋅6H2O salts in basic condition in dimethylformamide. Fourier transform infrared, 1H NMR, 13C NMR, UV–visible, inductively coupled plasma optical emission and mass spectra were applied to characterize the prepared compounds. The bleach performances of the three phthalocyanine compounds 2, 3, 4 were examined by the degradation of morin as hydrophilic dye. The degradation progress in the presence of catalysts 2, 3, 4/H2O2 combination in aqueous solution was investigated using an online spectrophotometric method. It was found that the catalysts 2, 3, 4 exhibited better bleaching performance at 25 °C than tetraactylethylethylenediamine as bleach activator used in powder detergent formulations for stain removal. Copyright © 2015 John Wiley &amp; Sons, Ltd.

Impact strength distribution of placebo enzyme granules

Enzyme granules are used in laundry detergent formulations to improve washing quality at lower temperatures than commonly used with traditional formulations. However, any dust generated from their handling in manufacturing plants poses a health risk to operators. Therefore, current enzyme granule manufacturing produces strong granules that resist plant stresses and hence do not easily break. There are however indications that a very small number of granules are substantially weaker than the rest. This would have implications on the Coefficient of Variations (CV) of enzyme dust analysis. It is highly desirable to have a low value of Coefficient of Variation (CV) of enzyme dust to ensure confidence in the test results. The CV is largely influenced by the testing rig performance, but its minimum value is limited by the material characteristics. This work sets out to evaluate the minimum CV that is possible to get for the sample mass tested, by quantifying the number of outliers by impact testing using placebo granules. The outcome is a methodology for specifying the minimum possible CV that can be obtained from a given test material.

Exploring Malaysian Household Consumers Acceptance towards Eco-friendly Laundry Detergent Powders

Due to the current environmental pressures and ever-rising prices of petrochemical feedstock, the detergentindustry is gradually moving towards the development of green and eco-friendly products. However, besides theproduction cost, the challenge for today’s detergent formulators still lies in increasing the quantity of green andeco-friendly surfactants in laundry detergent formulations without compromising their performance. Realizingthis, research was undertaken to develop the Asian market preferred low-density laundry detergent powders byincorporating green palm oil based surfactant (known as MES) and also by eliminating the use ofenvironmentally damaging phosphate-builders in the detergent formulation. Prior to commercialization of thisnewly developed eco-friendly low-density laundry detergent powder, a pilot survey was attempted over 112respondents using mall-intercept approach in one of the popular shopping complex in Kuala Lumpur city withthe aim to study consumers' preferences (format, brand, origin) and their purchasing behaviour(awareness/knowledge and perception) towards both commercial and MES based laundry detergent powders.The pilot survey results have indicated that the majority of respondents has high affinity towards green andenvironmental benefits offered by MES based laundry detergent powders. These positive results imply hugemarket potential for MES based laundry detergent powders and through effective marketing strategies andproduct awareness activities, this product is likely to attain success in the marketplace.

Characterization of an alkaline protease with high quality bating potential in leather processing from Bacillus licheniformis MZK05M9 mutant

An alkaline protease from Bacillus licheniformis MZK05M9 (BlM9), a mutant strain developed in our laboratory, has been partially purified and characterized for its robustness and eco-friendly application potential in processing of hides and skins for leather manufacturing and detergent industries. The enzyme was purified 2.70 fold with specific activity of 1624U/mg in comparison to crude enzyme extract by using ammonium sulfate precipitation, dialysis and Sephadex G-75 column chromatography. The molecular mass of the enzyme was 27.2 kDa as judged by SDS–PAGE. The purified protease had a pH optimum of 8.5 and temperature optimum of 55°C. According to the inhibition profiles obtained with the various protease inhibitors, it was confirmed that the partially purified protease belongs to the serine protease type. The activity of partially purified enzyme was enhanced by calcium, magnesium, barium, potassium and manganese ions and strongly inhibited by mercury ion. In addition, the protease showed remarkable stability in the presence of 1% SDS; 1, 3 and 5% Triton X-100 and H2O2, which comprise the common bleach-based detergent formulation. The enzyme was found equally efficient to a commercial enzyme Oropon K (one of the commercial enzymes imported into Bangladesh for bating purpose) in bating of animal hide as proved by different comparative qualitative tests such as tensile strength, percent of elongation, stitch tears strength, water vapor permeability, grain crack strength and tongue tear strength tests. In addition, the stability profile (pH, temperature and surfactants) and blood stain removal data also revealed its suitability for application in detergent industry.

Characterization of a new, recombinant thermo-active subtilisin-like serine protease derived from Shewanella arctica

Proteases represent the commercially most relevant enzyme family with applications in the chemical, cosmetic and pharmaceutical industry. For the personal care industry, both cold-active and thermo-active protease variants are of particular interest for detergent formulation. We have identified a gene sequence encoding a putative subtilisin-like serine protease in a gene library of the psychrophilic bacterium Shewanella arctica (DSM 16509, JCM 14208). The recombinant protein (67kDa, 644 amino acids) product was flanked by 4.4kDa (38 a.a.) signal sequence. Initial in-silico sequence analysis and protein modelling revealed the dominant alpha helical structural features embedding the catalytic residues Asp-180, His-213 and Ser-364, which form the canonical catalytic triad of subtilisin-like serine proteases. Further, in the N-terminal region a subtilisin-N domain was detected between residues Asp-55 and Thr-135. Phylogenetic analysis indicated that this enzyme can be classified as subtilisin-like serine protease with 73% amino acids identity to its closest characterized relative, the putative protease of Pseudoaltermonas sp. This is the first report of a detailed biochemical characterization of Shewanella spp. derived protease activity. The recombinant protein (28.18mg/L), termed SaP, was purified to homogeneity from a crude E. coli lysate with an activity of 0.52U/mg. Surprisingly, although derived from psychrophilic bacteria, SaP is active over a very broad temperature (T=0–80°C) and pH (pH 6–10) range, with optimal proteolytic activity at 60°C and pH 8. The unique enzyme displayed an activity half-life of 45h and 1.5h at 40°C and 70°C, respectively. The specific activity of SaP (Kcat/Km: 71.14s−1M−1) toward the model substrate casein is comparable to other prokaryotic serine proteases. The enzyme activity was not affected by various metal ions or non-specific protease inhibitors, which positions SaP for industrial application operating over a broad temperature range, such as household detergent formulations.

Insight on biochemical characteristics of thermotolerant amylase isolated from extremophile bacteria Bacillus vallismortis TD6 (HQ992818)

Halotolerant bacterium Bacillus vallismortis (HQ992818) was isolated from saltern sediments in India, and produced significantly high levels extracellular amylase. A detailed investigation on the culture conditions including period of incubation, media pH, and inoculum size in addition to different sources of carbon and nitrogen, metal ions, NaCl, and amino acids was carried out for optimized production. Maximum amylase production (62 U/mL) was attained after 26 h of incubation. The optimized conditions for maximal production of amylase were found to be 1% NaCl, pH 8, temp 37°C, 1% starch, 1% sodium nitrate, phenyl alanine (0.01%) and calcium chloride (10 mM). The biochemical characteristics of the extracellular amylase were studied with respect to change in temperature, pH and metal ions. The enzyme was found to be optimally active in the temperature range of 40–70°C and pH 8. Activation of the enzyme by Ca2+ (135%), Fe2+ (113%) and Mg2+ (109%) occurred at 5 mM concentration and strongly inhibited by Hg2+, Zn2+ and Mn2+ occurred at 10 mM. Significant compatibility of the enzyme with the commercial laundry detergents and the results of washing performance test confirmed its effectiveness. Available data on the optimized culture conditions enables for easily adaptable setup of large scale production of the enzyme for use in detergent formulations.

Functional Characterization and Low-Resolution Structure of an Endoglucanase Cel45A from the Filamentous Fungus Neurospora crassa OR74A: Thermostable Enzyme with High Activity Toward Lichenan and β-Glucan.

Biomass is the most abundant and short-term renewable natural resource on Earth whose recalcitrance toward enzymatic degradation represents significant challenge for a number of biotechnological applications. The not so abundant but critically necessary class of GH45 endoglucanases constitutes an essential component of tailored industrial enzyme cocktails because they randomly and internally cleave cellulose molecules. Moreover, GH45 glucanases are core constituents of major-brand detergent formulations as well as enzymatic aid components in the cotton processing industry, clipping unwanted cellulosic fibers from cotton (cellulosic)-based tissues. Here we report on a recombinant high-yield Neurospora crassa OR74A NcCel45A production system, a single-band GH45 endoglucanase purification, and a complete enzyme functional characterization. NcCel45A is a bimodular endoglucanase showing maximum activity at pH 6.0 and 60 °C, while most active against lichenan and β-glucans and lesser active toward filter paper, carboxymethylcellulose, and phosphoric acid-swollen cellulose. Gluco-oligosaccharide degradation fingerprinting experiments suggest cellopentaose as the minimal length substrate and ThermalFluor studies indicate that NcCel45A displays excellent stability at elevated temperatures up to 70 °C and pHs ranging from 5 to 9. Remarkably, we show that NcCel45A is uniquely resistant to a wide-range of organic solvents and small-angle X-ray scattering show a monkey-wrench molecular shape structure in solution, which indicates, unlike to other known cellulases, a non-fully extended conformation, thus conferring solvent protection. These NcCel45A unique enzymatic properties maybe key for specific industrial applications such as cotton fiber processing and detergent formulations.

Manganese peroxidases from Ganoderma applanatum degrade β-carotene under alkaline conditions.

A β-carotene-degrading enzyme activity was observed in liquid cultures of the basidiomycete Ganoderma applanatum. Supplementing the cultures with β-carotene induced the bleaching activity. Purification via hydrophobic interaction, ion exchange and size exclusion chromatography followed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) resulted in a single protein band. LC-ion-trap-MS analyses and gene amplification identified two manganese peroxidase isoenzymes with 97.8 % identity on the amino acid level. These showed an estimated molecular mass of 48 kDa and an isoelectric point of 2.6. Properties not yet described for other manganese peroxidases were hydrogen-peroxide-independent catalysis and two maxima of the bleaching activity, a distinct one at pH 5 and a lower one at pH 8. During simulated washing studies, the applicability of the isoenzymes for the brightening of carotenoids under alkaline conditions was proven. The new enzymes may replace common bleaching agents to produce environmentally more compatible detergent formulations.

IMPACT OF 4-NONYLPHENOL ON TESTOSTERONE PRODUCTION IN MICE LEYDIG CELLS

Nonylphenol (NP) is an important environmental toxicant and potential endocrine disrupting chemical. It is also the primary final biodegradation product of nonylphenol polyethoxylate, a non-ionic surfactant that is frequently incorporated into detergent formulation. Several studies have reported adverse effects of NP on the male reproductive system, including hormonal changes and testicular abnormalities. However, its mechanisms are not clearly understood. In the present study, experiments were performed to examine the effects of 4-nonylphenol on the testosterone production in mice Leydig cells. Interstitial (Leydig) cells were cultured with addition of 0.04, 0.2, 1.0, 2.5 and 5 μg/mL of 4-nonylphenol and compared with control. Concentrations of testosterone in the media were determined using enzyme linked immunosorbent assay (ELISA). Hormone production significantly (P

Integrated synthesis of zeolites 4A and Na–P1 using coal fly ash for application in the formulation of detergents and swine wastewater treatment

Several researchers have reported zeolite synthesis using coal ash for a wide range of applications. However, little attention has been given to green processes, including moderate synthesis conditions, using waste as raw material and effluent reuse or reduction. In this study, Brazilian coal fly ashes were used for integrated synthesis of zeolites 4A and Na–P1 by two different routes and under moderate operating conditions (temperature and pressure). Both procedures produced zeolites with similar conversions (zeolite 4A at 82% purity and zeolite Na–P1 at 57–61%) and high CEC values (zeolites 4A: 4.5meqCa2+g−1 and zeolites Na–P1: 2.6–2.8meqNH4+g−1). However, process 1 generated less effluent for the zeolite mass produced (7mLg−1), with low residual Si and Al levels and 74% of the Si available in the coal fly ash incorporated into the zeolite, while only 55% is used in process 2. For use as a builder in detergents, synthetic zeolite 4A exhibited conformity parameters equal to or greater than those of the commercial zeolite adopted as reference. Treatment of swine wastewater with zeolite Na–P1 resulted in a high removal capacity for total ammoniacal nitrogen (31mgg−1).

Influence of Special Clays as Builder in Ecological Detergents

Abstract The aim of this work is to determine the influence of certain clay micro particles added to detergent formulation to act as builders in removal of impurities (detersive power) during the washing of a standard cotton fabric (EMPA), and also to determine the whiteness of the fabric and its softness after washing. Sepiolite was used separately and together with bentonite, in the form of micro particles. Bentonite is held to have a softening effect on cotton. A whitener was added to the detergent formulations to compensate for a possible effect of diminished whiteness in the washed fabric. Scanning electron microscope images of the fibres were taken to show deposition of the builders on the fabric. A non-toxic microemulsified solvent, dimethylsulfoxide (DMS), suitably microdispersed with use of an amphoteric surfactant as emulsifier, was added to improve the performance of the detergent formulations used, notably enhancing the detergency obtained in the presence of the clay microparticles tested.