Enzymatic Dye Research Articles

Enzymatic coloration of polyamide fabrics and its comparison with conventional dyeing

AbstractAmong the textile wet processes, the colouring process is the process step that causes the most environmental pollution. New approaches that support sustainable production instead of environmentally harmful processes are extensively researched in the literature. When considering substitution of chemical processes with environmentally friendly methods, one of the issues that comes to mind is enzymatic processes. It is noteworthy that in recent years, interesting and promising studies on the use of laccase enzymes in textile dyeing have been published in the literature. However, studies on enzymatic colouring are still very limited and sufficient success has not been achieved especially on polyamide. The aim of this study is to develop an environmentally friendly enzymatic dyeing method, which can be an alternative to dyeing polyamide knitted fabrics with 1:2 metal complex dyes according to the exhaustion method. For this purpose, various phenol and amine compounds, and their mixtures were used as precursor, and the colours that can be obtained by enzymatic colouring have been determined. In addition, optimisation of enzymatic colouring conditions (enzyme concentration, temperature and time) was carried out for the precursors that gave the best results in terms of colour and fastness. Furthermore, enzymatic dyeing was compared with conventional 1:2 metal complex dyeing in terms of technical and economic aspects. The reaction pathways in enzymatic coloration with laccase enzyme by using various precursors were also explained by Fourier‐transform infrared (FTIR) analysis.

Understanding the biodegradation pathways of azo dyes by immobilized white-rot fungus, Trametes hirsuta D7, using UPLC-PDA-FTICR MS supported by in silico simulations and toxicity assessment

No biodegradation methods are absolute in the treatment of all textile dyes, which leads to structure-dependent degradation. In this study, biodegradation of three azo dyes, reactive black 5 (RB5), acid blue 113 (AB113), and acid orange 7 (AO7), was investigated using an immobilized fungus, Trametes hirsuta D7. The degraded metabolites were identified using UPLC-PDA-FTICR MS and the biodegradation pathway followed was proposed. RB5 (92%) and AB113 (97%) were effectively degraded, whereas only 30% of AO7 was degraded. Molecular docking simulations were performed to determine the reason behind the poor degradation of AO7. Weak binding affinity, deficiency in H-bonding interactions, and the absence of interactions between the azo (-NN-) group and active residues of the model laccase enzyme were responsible for the low degradation efficiency of AO7. Furthermore, cytotoxicity and genotoxicity assays confirmed that the fungus-treated dye produced non-toxic metabolites. The observations of this study will be useful for understanding and further improving enzymatic dye biodegradation.

Enzymatic Dyeing of Wool Fibers with Enhancement of Strength Using Laccase as Catalyst

ABSTRACT Laccase-catalyzed polymerization of catechol on wool yarns was explored in this study, their dyeing performance and physical properties were also analyzed. Wool yarns were pretreated by chemical (Na2CO3) and plasma treatment. Catechol oligomers were then deposited or cross-linked on wool fibers through laccase-catalyzed reaction. It was shown that both chemical (Na2CO3) and plasma pretreatment could promote the subsequent dyeing process. Besides, the capacity of laccase to oxidize catechol was observed by UV-vis spectra. The FTIR spectra and SEM observation confirmed the coating of oligomers on wool. The results show that laccase-catalyzed reaction could be an efficient methodology for the in-situ coloration and performance enhancement in tensile strength, abrasion resistance, alkali solubility and antioxidant activity of wool.

Laccase-catalyzed enzymatic dyeing of cotton fabrics

As some synthetic dyes are regarded to be toxic, mutagenic and carcinogenic, the search for eco-friendly alternatives for the synthesis of dyes and coloration has gained importance. For this reason, this study focused on finding new eco-friendly alternatives for coloring cotton. 100% cotton knitted fabrics were subjected to enzymatic coloration using a commercial laccase enzyme and various precursors. After determining the colors, the effect of pH on the enzymatic dyeing process was investigated. Then the optimization of reaction conditions was also realized statistically for the precursors giving the best results in terms of color. With the aim of obtaining further improvements in color-yield values obtained in enzymatic dyeings, the effect of the pretreatment process and the use of ultrasound were also investigated. Furthermore, the reaction pathways in enzymatic coloration were explained and results were confirmed by means of Fourier Transformed Infrared analysis. As a result of experimental studies, red and lilac colors could be successfully obtained on cotton for the first time in the literature. In this way, the theoretical basis of enzymatic dye synthesis and dyeing of cotton was clarified comprehensively. Furthermore, technical (color reproducibility; washing, rubbing, light and perspiration-fastness values; and UV protection factor), economical (chemical, energy and water consumption required for dyeing (including aftertreatments) of 1 kg fabric) and ecological aspects of enzymatic dyeings were compared with reactive dyeing. According to the experimental results it was found that biological treatment alone was enough for wastewater of enzymatic coloring, while chemical treatment will also be needed in reactive dyeing wastewater. Furthermore, color reproducibility, evenness and UV protection properties of dyed samples were comparable with that of reactive dyeings. However, in terms of the fastness levels achieved, the enzymatic coloring was far behind the reactive dyeing.

Laccase-catalyzed simultaneous dye synthesis and cotton dyeing by using plant extracts as dye precursor

Natural dyes are gaining importance in recent years due to their advantages in terms of ecology, but the need of heavy metal salt (mordant) usage is an important limitation for their use. For this reason, it is very important to find alternative methods for textile dyeing with industrial dye plants. At this point, enzymatic processes are an important alternative. One of the most recent applications of enzymes in textile dyeing is laccase assisted coloration of textile materials. In this study, laccase-catalyzed enzymatic dye synthesis was used to dye cotton fabrics with St. John’s wort and white onion peel extracts as an alternative to conventional mordants. For this aim, experiments were conducted at various laccase enzyme concentrations, plant extract solution concentrations, temperatures and times and results of color yield values were evaluated statistically. Furthermore, effect of enzymatic dyeing on the fastness values of these natural dyes was also investigated. According to the experimental results it was observed that enzyme concentration, plant extract concentration, time and temperature parameters on enzymatic dyeing with both St. John’s wort and onion peel extract was statistically significant (p < 0.05). The optimum conditions were 1 g/L enzyme, 40 g/L plant extract, 60 °C, 3 h for St. John’s wort. On the other hand, for white onion peel, optimum results were obtained with 1 g/L enzyme and 40 g/L plant extract at 80 °C for 2 h. Besides, in the natural dyeings made by adding laccase enzyme to the dye bath, the colors obtained are darkened and washing, rubbing and light fastness values were improved.

Degradation of Anthraquinone Dyes from Effluents: A Review Focusing on Enzymatic Dye Degradation with Industrial Potential.

Up to 84 000 tons of dye can be lost in water, and 90 million tons of water are attributed annually to dye production and their application, mainly in the textile and leather industry, making the dyestuff industry responsible for up to 20% of the industrial water pollution. The majority of dyes industrially used today are aromatic compounds with complex, reinforced structures, with anthraquinone dyes being the second largest produced in terms of volume. Despite the progress on decolorization and degradation of azo dyes, very little attention has been given to anthraquinone dyes. Anthraquinone dyes pose a serious environmental problem as their reinforced structure makes them difficult to degrade naturally. Existing methods of decolorization might be effective but are neither efficient nor practical due to extended time, space, and cost requirements. Attention should be given to the emerging routes for dye decolorization via the enzymatic action of oxidoreductases, which have already a strong presence in various other bioremediation applications. This review will discusses the presence of anthraquinone dyes in the effluents and ways for their remediation from dyehouse effluents, focusing on enzymatic processes.

Optimizing enzymatic dyeing of wool and leather

This work reports on the environmental friendly enzymatic dyeing of wool and leather performed at low temperature and mild pH conditions without any dyeing auxiliaries. The substrates have been dyed with “in situ” generated pigment by means of laccase-catalyzed oxidative coupling of dye modifier 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and dye precursor 1,3-benzenediol in a batchwise process. The process reaction variables (laccase, precursor and modifier concentrations, temperature and dyeing time) were optimized by response surface methodology using an appropriate experimental design. The temperature, precursor concentration, interaction between precursor and modifier and time are the most important factors in the dyeing process. The best-optimized wool dyeing conditions (2 h reaction time, 50 μl laccase (0.1 U), 500 mM precursor, 10 mM modifier at 40 °C) were then successfully applied onto leather material. The enzymatic-dyeing optimized process can be successfully performed on wool and leather at low temperature and mild pH obtaining different hues and depths of shades by varying the modifier concentration and time. The colouring enzymatic system has a good reusability (which has a huge advantage in terms of cost reduction) and washing durability and is comparable in terms of fastness properties to the traditional dyeing process for both wool and leather.

Toxicity of enzymatically decolored textile dyes solution by horseradish peroxidase.

The oxidative systems including enzymatic systems have been widely studied as an alternative for textile effluents treatment. However, studies have shown that some oxidative processes can produce degradation products with higher toxicity than the untreated dye. In this work, enzymatic dye decolorization was evaluated by horseradish peroxidase enzyme (HRP) and the toxicity of discoloration products was evaluate against Daphnia magna, Euglena gracilis algae, and Vibrio fischeri. Dye decolorization kinetics data were evaluated and the pseudo-second-order model showed the best-fitting to the experimental data. In addition, it was observed an increased acute and chronic toxicity associated with the decolorization efficiency. The Reactive Blue 19 and Reactive Black dye showed the highest toxicity against D. Magna (16 toxicity factor) and V. Fischeri (32 toxicity factor) after enzymatic decolorization. For the chronic toxicity against D. Magna, Reactive Red was the only dye with no fertility inhibition. In relation to toxicity tests with E. gracilis algae, it was not observed photosynthetic inhibition for all dyes. This study verified the viability of the enzyme horseradish peroxidase in the textile dyes decolorization and the importance to evaluate the decolorization products.

Enzymatic treatment of methyl orange dye in synthetic wastewater by plant-based peroxidase enzymes

The search for effective and sustainable methods to degrade and remove recalcitrant dyes from textile effluents is a major research endeavor, owing to the escalating environmental and health concerns arising from the discharge of coloured effluents into water bodies. Plant-based peroxidases represent a reliable bio-resource for sustainable treatment of coloured effluents with the capacity to offer a continuous process for high throughput operation. The present study investigates the potential use of soybean peroxidase and Luffa acutangula (luffa) peroxidase, extracted from bio-wastes of soybean hulls and luffa skin peels respectively, for enzymatic degradation of azo dye methyl orange from liquid effluents. The enzymatic dye removal process was studied based on the consistent enzymatic activities of crude soybean peroxidase and luffa peroxidase extracts, which were 0.373UmL−1 and 0.355UmL−1 respectively. The effects of several process parameters including reaction time, pH, temperature, enzyme dosage, initial dye concentration and hydrogen peroxide concentration were investigated to optimise the performance of the enzymatic treatment process. Soybean peroxidase demonstrated a maximum dye decolourisation efficiency of 81.4% under the conditions of 1h incubation at 30°C using 2mM of hydrogen peroxide, 0.5mL crude soybean peroxidase and 30mgL−1 methyl orange at pH 5.0. Also, luffa peroxidase yielded a maximum decolourisation efficiency of 75.3% under the conditions of 40min at 40°C using 2mM hydrogen peroxide, 1.5mL crude luffa peroxidase and 10mgL−1 methyl orange at pH 3.0.

Aqueous thermostabilization of Pleurotus florida NCIM 1243 laccase and its potential application in Acid Black 10BX dye decolorization: process optimization

In the present investigation, aqueous stabilization of laccase from Pleurotus florida (NCIM 1243) at high temperatures using polysaccharide additives for decolorization of Acid Black 10BX was reported. The stabilization experiments suggest that the combinatorial effect of pectin and carrageenan improved the enzyme stability as compared as individual additives. Hence, combination of pectin and carrageenan were selected to construct an appropriate Response surface methodology (RSM) to enhance the enzyme stability in acidic solutions. Additionally, pH value was taken as a variable to optimize the polysaccharide additives. The optimum values of variables obtained for maximum laccase stabilization at higher temperature are pectin, 0.31%, carrageenan, 0.3% and pH, 4.4 with predicted percentage residual activity of 93.77%. The experimental validation of laccase stabilization was found to be 90.8% using optimized variables. Furthermore, the series of enzymatic dye decolorization experiments were performed to obtain optimum process parameters for maximum decolorization efficiency. Various process parameters such as enzyme concentration (10U/ml), dye concentration (10mg/l), temperature (25°C) and reaction time (150min) were successfully optimized to achieve maximum decolorization rate. Results of the experimental data reveled that stabilized laccase has the great potential for Acid Black 10BX decolorization at 60°C than that of native enzyme at pH, 4.4. This investigation enlighten that pectin and carrageenan plays an important role in laccase stabilization and its low cost found to be a good support for large-scale application in biodegradation process.

Effect of a non-ionic surfactant, Merpol, on dye decolorization of Reactive blue 19 by laccase.

Abstract Laccase is a multi-copper oxidase that can decolorize textile dyes. There is increasing interest in its use to treat textile wastewaters which also contain auxiliary chemicals such as surfactants and salts. This investigation examines the effect of Merpol, a non-ionic surfactant, on the decolorization of Reactive blue 19, an anthraquinone dye, and on the oxidation of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) by Trametes versicolor laccase. The results show that the surfactant had little effect on the enzyme or on ABTS oxidation which followed Michaelis–Menten kinetics. However, Reactive blue 19 decolorization was inhibited with increasing Merpol concentration. Spectroscopic analysis of the dye with Merpol and analysis of the kinetic data show that decolorization rates depended on an interaction between the dye and the surfactant. The proposed inhibition by a substrate depletion model in which the dye concentration decreases as a dye molecule binds to a surfactant molecule and/or is sequestered into micelles fits the data suitably and the model was validated by estimating the inhibition constant from independent saturation equilibrium binding assays. This study is the first to investigate the kinetic effect of a surfactant on the enzymatic dye decolorization and to show the depleting effect of Merpol on Reactive blue 19.

Decolorisation of synthetic dyes by crude laccase from Rigidoporus lignosus W1

AbstractBACKGROUND: Effluents from the dyeing process containing dyes are difficult to degrade biologically. Therefore enzymatic dye decolorisation has received considerable attention recently. In this study the dye decolorisation potential of crude laccase from the white rot fungus Rigidoporus lignosus W1 was demonstrated on an anthraquinone dye, Remazol Brilliant Blue R (RBBR), and a triphenylmethane dye, malachite green (MG). Effects of pH, temperature and ionic strength on laccase activity and decolorisation efficiency were investigated.RESULTS: Native polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate PAGE confirmed the decolorisation ability of the crude enzyme on RBBR and MG. A single laccase with a molecular mass of about 40 kDa appeared to be involved in the process. Efficient enzymatic decolorisation without redox mediator was achieved, with 39 mg L−1 MG being removed within 2 h and 160 mg L−1 RBBR within 1 h at 60 °C and pH 4.5. Although the laccase activity was inhibited in the presence of NaCl, it was renatured gradually in low concentrations of NaCl (&lt;0.8 mol L−1), resulting in unusual dye decolorisation kinetics. Surprisingly, unusual storage stability at alkaline pH was observed, with the laccase activity being enhanced 1.5–2‐fold after 3 h of incubation.CONCLUSION: Crude laccase with unusual storage stability from the fungus R. lignosus W1 showed excellent decolorisation ability on RBBR and MG without redox mediator. This laccase would seem to be a good candidate for application in dye decolorisation and textile effluent biotreatment. Copyright © 2008 Society of Chemical Industry

Enzymatic reduction of azo and indigoid compounds

A customer- and environment-friendly method for the decolorization azo dyes was developed. Azoreductases could be used both to bleach hair dyed with azo dyes and to reduce dyes in vat dyeing of textiles. A new reduced nicotinamide adenine dinucleotide-dependent azoreductase of Bacillus cereus, which showed high potential for reduction of these dyes, was purified using a combination of ammonium sulfate precipitation and chromatography and had a molecular mass of 21.5 kDa. The optimum pH of the azoreductase depended on the substrate and was within the range of pH 6 to 7, while the maximum temperature was reached at 40 degrees C. Oxygen was shown to be an alternative electron acceptor to azo compounds and must therefore be excluded during enzymatic dye reduction. Biotransformation of the azo dyes Flame Orange and Ruby Red was studied in more detail using UV-visible spectroscopy, high-performance liquid chromatography, and mass spectrometry (MS). Reduction of the azo bonds leads to cleavage of the dyes resulting in the cleavage product 2-amino-1,3 dimethylimidazolium and N approximately 1 approximately ,N approximately 1 approximately -dimethyl-1,4-benzenediamine for Ruby Red, while only the first was detected for Flame Orange because of MS instability of the expected 1,4-benzenediamine. The azoreductase was also found to reduce vat dyes like Indigo Carmine (C.I. Acid Blue 74). Hydrogen peroxide (H(2)O(2)) as an oxidizing agent was used to reoxidize the dye into the initial form. The reduction and oxidation mechanism of Indigo Carmine was studied using UV-visible spectroscopy.

Protein interactions in enzymatic processes in textiles

Enzymes are the catalysts of all reactions in living systems. These reactions are catalysed in the active sites of globular proteins. The proteins are composed by amino acids with a variety of side chains ranging from non-polar aliphatic and aromatic to acidic, basic and neutral polar. This fact allows to a globular 3D protein to create in the active site all ranges of microenvironments for catalysis. Major advances in microbial technology and genetics allow recently the broad range of enzymatic applications in the industry. Enzymatic processes have been increasingly incorporated in textiles over the last years. Cotton, wool, flax or starches are natural materials used in textiles that can be processed with enzymes. Enzymes have been used for desizing, scouring, polishing, washing, degumming, peroxide degradation in bleaching baths as well as for decolourisation of dyehouse wastewaters, bleaching of released dyestuff and inhibiting dye transfer. Furthermore many new applications are under development such as natural and synthetic fibres modification, enzymatic dyeing, finishing etc. Most of the textile processes are heterogeneous where an auxiliary as a dye, enzyme, softener or oxidant have to be taken from the solution to the fibre. These processes require the presence of surface-active agents, ionic force "balancers", buffers, stabilisers and others, and are characterized with high turbulence and mechanical agitation in the textile baths. In this paper it is intended to understand and discuss the major protein interactions within textile processes and to try to anticipate troubleshooting possibilities when enzymes are used. It can be expected that an enzyme protein can interact with all chemical agents in solution due to the large variety of side chains of the outer-amino-acids in the large 3D structure of the protein. Without the aim of being exhaustive various points will be discussed where protein interactions are important for textile processing.

Decolourization of azo dyes and a dye industry effluent by a white rot fungus Thelephora sp.

A white rot fungus Thelephora sp. was used for decolourization of azo dyes such as orange G (50 microM), congo red (50 microM), and amido black 10B (25 microM). Decolourization using the fungus was 33.3%, 97.1% and 98.8% for orange G, congo red and amido black 10B, respectively. An enzymatic dye decolourization study showed that a maximum of 19% orange G was removed by laccase at 15 U/ml whereas lignin peroxidase (LiP) and manganese dependent peroxidase (MnP) at the same concentration decolourized 13.5% and 10.8%, orange G, respectively. A maximum decolourization of 12.0% and 15.0% for congo red and amido black 10B, respectively, was recorded by laccase. A dye industry effluent was treated by the fungus in batch and continuous modes. A maximum decolourization of 61% was achieved on the third day in the batch mode and a maximum decolourization of 50% was obtained by the seventh day in the continuous mode. These results suggest that the batch mode of treatment using Thelephora sp. may be more effective than the continuous mode for colour removal from dye industry effluents.

Effect of Some Process Parameters in Enzymatic Dyeing of Wool

This article reports on the dyeing of wool using an enzymatic system comprising laccase; dye precursor, 2,5-diaminobenzenesulfonic acid; and dye modifiers, catechol and resorcinol. Enzymatic dyeing was performed as a batchwise process at the temperature and pH of maximum enzyme activity. The effects of the process variables reaction time, enzyme, and modifier concentration on fabric color were studied, according to an appropriate experimental design. Different hues and depths of shades could be achieved by varying the concentration of the modifiers and the time of laccase treatment. The duration of the enzymatic reaction appeared to be the most important factor in the dyeing process. Thus, the dyeing process, performed at low temperature and mild pH, was advantageous in terms of reduced enzyme and chemical dosage.

In vitro pharmacology of cryptophycin 52 (LY355703) in human tumor cell lines.

Cryptophycin 52 (LY355703) is a new member of the cryptophycin family of antitumor agents that is currently undergoing clinical evaluation for cancer chemotherapy. The mechanism of action of the cryptophycin class of compounds is associated with an action on microtubules. This report details the pharmacological profile of this new clinical compound in a panel of human tumor cell lines. Antiproliferative effects of cryptophycin 52 were measured indirectly by detection of the metabolic reduction of alamarBlue. Cytoxicity was assessed by enzymatic dye activation (calcein AM) combined with dye exclusion (ethidium homodimer) and by clonogenicity assay. Cell cycle effects were evaluated using flow cytometry and fluorescence microscopy. Both antiproliferative and cytotoxic effects of cryptophycin 52 were concentration- and time-dependent. IC50 values for antiproliferative activity in both solid and hematologic tumor cell lines were in the low picomolar range, and without exception, were significantly below values for the antimitotic agents paclitaxel and vinblastine. Flow cytometry and microscopic examination of tumor cells treated with cryptophycin 52 indicated that they accumulated in the mitotic phase of the cell cycle. Cryptophycin 52 was tested for its sensitivity to multidrug-resistance in several paired cell lines in which a sensitive parental line was matched with a multidrug-resistant derivative line. The resistant lines have been shown to over express Pgp and/or MRP multidrug-resistance transport factors. Compared to other antimitotic agents (paclitaxel, vinblastine, vincristine), the potency of cryptophycin 52 was shown to be minimally affected in multidrug-resistant cells compared to their sensitive parental lines. Cryptophycin 52 has potent antimitotic, antiproliferative and cytotoxic activity in in vitro human tumor cell models. It is significantly more potent and less sensitive to multidrug resistance mechanisms than other antimitotic antitumor agents currently used in cancer therapy. These characteristics may translate into therapeutic advantages for the clinical use of cryptophycin 52 in cancer chemotherapy.

Localization of NADH oxidase on the surface of human polymorphonuclear leukocytes by a new cytochemical method.

The ultrastructural localization of NADH oxidase, a possible enzyme in the increased oxidative activity of polymorphonuclear leukocytes (PMN) during phagocytosis, was studied. A new cytochemical technique for the localization of H2O2, a product of NADH oxidase activity, was developed. Cerous ions, in the presence of peroxide, form an electron-dense precipitate. Resting and phagocytically stimulated PMN were exposed to cerous ions at pH 7.5 to demonstrate sites of NADH-dependent, cyanide-insensitive H2O2 production. Resting PMN exhibites slight activity on the plasma membrane; phagocytizing PMN had extensive deposits of reaction product localized within the phagosome and on the plasma membrane. Peroxide involvement was demonstrated by the inhibitory effect of catalase on cerium precipitation; the surface localization of the enzyme responsible was confirmed by using nonpenetrating inhibitors of enzymatic activity. A correlative study was performed with an NADH-dependent, tetrazolium-reduction system. As with cerium, formazan deposition on the surface of the cell was NADH dependent, cyanide insensitive, and stimulated by phagocytosis. Superoxide dismutase did not inhibit tetrazolium reduction, as observed cytochemically, indicating direct enzymatic dye reduction without superoxide interposition. These findings, combined with oxygen consumption studies on resting and stimulated PMN in the presence or absence of NADH, indicate that NADH oxidase is a surface enzyme in human PMN. It is internalized during phagocytosis and retains its peroxide-generating capacity within the phagocytic vacuole.