Malachite Green Decolorization Research Articles

Partial removal and detoxification of Malachite Green and Crystal Violet from laboratory artificially contaminated water by Pleurotus ostreatus

<p>The triphenylmethane dyes Malachite Green (MG) and Crystal Violet (CV) are cationic dyes and mix with domestic wastewater when dumped; increasing, among others, the chemical and biological demand of oxygen and can cause acute toxicity at different trophic levels. Promoting the removal (decolorization) of MG and CV, and laccase activity (54.8 ± 8.9 and 30.6 ± 2.9 UL-1 respectively) by using <em>P. ostreatus</em> viable biomass needed parameters such as pH (4.5 and 6.0), temperature (25 to 30 °C), stirring speed (120 rpm), percentage of inoculum (2% v/v), and dye concentration (20 and 10 mg L-1). In adsorption studies, it was showed that an acidic pH favors the adsorption of both dyes and the model of pseudo-second order describes best the phenomenon of adsorption. Finally, the germination index (GI), using <em>Lactuca sativa</em> seeds for the initial dyes solutions, was <50%; demonstrating its high phytotoxic effect. When dye solutions were treated with viable biomass, the GI increased, leaving open the possibility to performing future research to determine if the aqueous solutions, post-treated with <em>P. ostreatus</em>, could be used in treatments that generate less toxic water which could be used in processes that do not require potable water.</p>

Facile green synthesis of functional nanoscale zero-valent iron and studies of its activity toward ultrasound-enhanced decolorization of cationic dyes

For the first time, an integrated green technology by coupling functional nanoscale zero-valent iron (NZVI) with ultrasound (US) was innovatively developed for the enhanced decolorization of malachite green (MG) and methylene blue (MB). The functional NZVI (TP-Fe) was successfully fabricated via a facile, one-step and environmentally-benign approach by directly introducing high pure tea polyphenol (TP), where TP contenting abundant epicatechin was employed as reductant, dispersant and capping agent. Note that neither additional extraction procedure nor protection gas was needed during the entire synthesis process. Affecting factors (including US frequency, initial pH, dye concentration, and reaction temperature) were investigated. Results show that TP-Fe exhibited enhanced activity, antioxidizability and stability over the reaction course, which could be attributed to the functionalization of TP on NZVI and the invigorating effect of US (i.e., improving the mass transfer rate, breaking up the aggregates of TP-Fe nanoparticles, and maintaining the TP-Fe surface activity). The kinetics for MG and MB decolorization by the TP-Fe/US system could be well described by a two-parameter pseudo-first-order decay model, and the activation energies of MG and MB decolorization in this new system were determined to be 21 kJ mol−1 and 24 kJ mol−1, respectively. In addition, according to the identified reaction products, a possible mechanism associated with MG and MB decolorization with the TP-Fe/US system was proposed.

Degradation and detoxification of the triphenylmethane dye malachite green catalyzed by crude manganese peroxidase from Irpex lacteus F17.

Malachite green (MG), a recalcitrant, carcinogenic, and mutagenic triphenylmethane dye, was decolorized and detoxified using crude manganese peroxidase (MnP) prepared from the white rot fungus Irpex lacteus F17. In this study, the key factors (pH, temperature, MG, Mn(2+), H2O2, MnP) in these processes were investigated. Under optimal conditions, 96% of 200mgL(-1) of MG was decolorized when 66.32UL(-1) of MnP was added for 1h. The K m, V max, and k cat values were 109.9μmolL(-1), 152.8μmolL(-1)min(-1), and 44.5s(-1), respectively. The decolorization of MG by MnP followed first-order reaction kinetics with a kinetic rate constant of 0.0129h(-1). UV-vis and UPLC analysis revealed degradation of MG. Furthermore, seven different intermediates formed during the MnP treatment of 0.5h were identified by LC-TOF-MS. These degradation products were generated via two different routes by either N-demethylation of MG or the oxidative cleavage of the C-C double bond in MG. Based on ecotoxicity analyses performed on bacteria and algae, it was confirmed that MG metabolites produced by the MnP-catalyzed system were appreciably less toxic than the parent compound. These studies indicate the potential use of this enzyme system in the clean-up of aquatic and terrestrial environments.

Decolorization of Methylene Blue and Malachite Green by Immobilized Desmodesmus sp. Isolated from North Jordan

Decolorization of Methylene Blue and Malachite Green by Immobilized Desmodesmus sp. Isolated from North Jordan

Biodegradation of malachite green by a novel copper-tolerant Ochrobactrum pseudogrignonense strain GGUPV1 isolated from copper mine waste water

Malachite green (MG) is a triphenyl methane cationic dye which is used to color fabrics and is employed as food additive, food coloring agent and medical disinfectant. MG is found to be toxic to aquatic organisms, animals including humans. Copper is a commonly found metal in environment due to anthropogenic activities. Most of the microorganisms show sensitivity toward it. This adversely affects their growth and activity. In the present study, biodegradation of MG by a copper-tolerant bacterium has been investigated. Biodegradation was confirmed by UV–Vis and FTIR spectroscopy. The metabolites generated after degradation of MG were identified by LC/MS and a plausible pathway of MG degradation has been elucidated. Microbial and phyto toxicity of generated metabolites were also evaluated. A strain belonging to Ochrobactrum pseudogrignonense strain GGUPV1 was discovered from copper mine waste water. This bacterium could tolerate as high as 50 mM copper sulfate in minimal medium. It was observed that this bacterium could degrade 400 mg/L of MG in minimal medium. Decolorization of MG was also observed in presence of copper sulfate in the medium. Degradation of MG was confirmed by UV–Vis and FTIR spectroscopy. GC/MS study indicated that metabolites generated after degradation of MG were nontoxic to Staphylococcus aureus. This is the first report showing degradation of MG by Ochrobactrum pseudogrignonense. This strain can be successfully employed for degradation of MG.

Artificial neural network modeling of biotreatment of malachite green by Spirodela polyrhiza: Study of plant physiological responses and the dye biodegradation pathway

Phytoremediation is an environmental friendly and sustainable means of pollutant remediation through the use of plants. The ability of duckweed (Spirodela polyrhiza L.) for decolorization of malachite green was evaluated. Effect of some operational parameters such as initial plant biomass, the reaction time, initial dye concentration, pH and temperature on dye removal efficiency was determined. The importance of each parameter was assessed by artificial neural network (ANN) modeling and the plant initial biomass and pH were found to be the most important factors. The findings indicated that ANN provided reasonable predictive performance (R2=0.98). The metabolic fate of the dye was proposed by identification of 6 intermediate compounds produced during this process by GC–MS technique. Some physiological responses of the plant were studied at 10 and 20mg/L of the dye. The activities of antioxidant enzymes were increased at high concentration of the contaminant but there was a significant decrease in photosynthetic pigments content at 20mg/L of malachite green.

Modeling of decolorization of synthetic reactive dyestuff solutions with response surface methodology by a rapid and efficient process of ultrasound-assisted ozone oxidation

The present study investigates the results of decolorization of Malachite Green (MG), Reactive Black 5 (RB5), and Reactive Yellow 145 (RY145) in aqueous solutions based on a rapid and novel process of ultrasound-assisted ozonation. A Placket–Burman design (PBD) as a factorial design was used to quantify and screen the significant effects of the seven factors on decolorization efficiency: temperature (oC), initial pH, probe position (height from bottom of reactor, mm), reaction time (min), ozone concentration (g/L), mixing speed (rpm), and ultrasonic power (W). Probe position and mixing speed were not found as significant after considering the regression and ANOVA results of PBD. A Box–Behnken design (BBD) as a kind of response surface methodology, with remaining five factors at three levels was set to demonsrate the interactions. The best-fit multi non-linear regression (MNLR) models were derived by using the results of BBD. According to BBD, the maximum decolorization efficiency of 99.31, 99.86, and 99.52% were obtained consistently at the lowest initial pH of 2, the highest reaction time of 30 min, and ozone concentration of 0.15 g/L for MG, RB5, and RY145, respectively. The best-fit MNLR models were cross-validated (R2pred) accounting for 81.02–88.25% and were expressed (R2adj) accounting for 93.01–95.70% of variation in decolorization efficiency.

Malachite green decolorization by the filamentous fungus Myrothecium roridum – Mechanistic study and process optimization

The filamentous fungus Myrothecium roridum isolated from a dye-contaminated area was investigated in terms of its use for the treatment of Malachite green (MG). The mechanisms involved in this process were established. Peroxidases and cytochrome P-450 do not mediate MG elimination. The laccase of M. roridum IM 6482 was found to be responsible for the decolorization of 8–11% of MG. Thermostable low-molecular-weight factors (LMWF) resistant to sodium azide were found to be largely involved in dye decomposition. In addition, MG decolorization by M. roridum IM 6482 occurred in a non-toxic manner. Data from antimicrobial tests showed that MG toxicity decreased after decolorization. To optimize the MG decolorization process, the effects of operational parameters (such as the medium pH and composition, process temperature and culture agitation) were examined. The results demonstrate that M. roridum IM 6482 may be used effectively as an alternative to traditional decolorization agents.

Enhancement of laccase production and malachite green decolorization by co-culturing Ganoderma lucidum and Trametes versicolor in solid-state fermentation

Optimization of laccase production in white-rot fungi has been extensively studied. Metallic and aromatic compounds have been found to enhance enzyme production, but the development of bioremediation as an application field of this enzyme requires clean technologies. In this work, co-cultivation of Ganoderma lucidum and Trametes versicolor was performed, showing remarkable enhancement of laccase activity. Dual cultures were assayed for malachite green degradation (MG) in solid state fermentation (SSF) using a sawdust-based medium. The time for achieving complete decolorization of MG in co-cultivation was markedly shorter than that observed in monocultures. Dual-species treatment did not differ in wood dry weight loss and lignin, cellulose and hemicellulose degradation, compared to monocultures; but the selectivity index (lignin loss/cellulose loss) of dual cultures was markedly higher than those attained by monocultures. Moreover, a modified isoenzymatic laccase pattern was observed, showing one isoenzyme that was absent in monocultures. Dual cultures were able to decolorize and detoxify the dye more efficiently than the monocultures. The noticeable increase in laccase activity along with the more efficient decolorization and detoxification of MG by co-cultures of G. lucidum and T. versicolor in SSF makes this system a viable strategy for large scale application of white-rot cultures in bioremediation.

Preparation of heterogeneous bio-Fenton catalyst for decolorization of Malachite Green

Titanium dioxide (TiO2) and Fe3O4 magnetite particles were coated on spherical Kissirises; and glucose oxidase (GOx) enzyme was immobilized on Kissiris/Fe3O4/TiO2 by physical adsorption. Performance of the prepared biocatalyst in decolorization of Malachite Green dye was investigated. Ninety-nine percent Malachite Green decolorization was obtained after 120 min by using 2 g of the heterogeneous bio-Fenton catalyst at initial dye concentration of 20 mg/L, initial glucose concentration of 20 mM, pH 5.5 and temperature of 40 °C. In this process, in contrast to conventional Fenton's reaction, external hydrogen peroxide and ferrous ion sources were not used.

Laccase-catalyzed decolorization of malachite green: performance optimization and degradation mechanism.

Malachite green (MG) was decolorized by laccase (LacA) of white-rot fungus Cerrena sp. with strong decolorizing ability. Decolorization conditions were optimized with response surface methodology. A highly significant quadratic model was developed to investigate MG decolorization with LacA, and the maximum MG decolorization ratio of 91.6% was predicted under the conditions of 2.8 U mL-1 LacA, 109.9 mg L-1 MG and decolorization for 172.4 min. Kinetic studies revealed the Km and kcat values of LacA toward MG were 781.9 mM and 9.5 s-1, respectively. UV–visible spectra confirmed degradation of MG, and the degradation mechanism was explored with liquid chromatography–mass spectrometry (LC-MS) analysis. Based on the LC-MS spectra of degradation products, LacA catalyzed MG degradation via two simultaneous pathways. In addition, the phytotoxicity of MG, in terms of inhibition on seed germination and seedling root elongation of Nicotiana tabacum and Lactuca sativa, was reduced after laccase treatment. These results suggest that laccase of Cerrena was effective in decolorizing MG and promising in bioremediation of wastewater in food and aquaculture industries.

Isolation and characterization of malachite green-removing yeast from a traditional fermented fishery product

The screening of malachite green (MG)-degrading microorganisms was carried out using various sources, namely, fish farms and a traditional fermented fishery product in Myanmar and Thailand. The enrichment culture method was performed using MG-containing broth media, and colonies that showed the decolorization of MG on plate media were isolated as MG-degrading candidates. From the results of the sequencing of the D1/D2 domain of the 26S rRNA gene, strain M3, a representative strain of MG-degrading candidates was identified as a halotolerant yeast, Debaryomycesnepalensis. Liquid chromatography-tandem mass spectrometry (LC–MS/MS) analysis indicated that during the incubation of this strain, the MG concentration gradually decreased and eventually reached undetectable levels. Conversely, the concentration of leucomalachite green (LMG) increased, and the final amount of LMG in the broth culture was estimated to be approximately 40 % of the initial MG amount. In addition, results of proton nuclear magnetic resonance spectroscopy (1H-NMR) analysis also showed that MG and the tautomer of MG or other aromatic decomposition products of MG were not detected as a major component at the end of incubation. These results suggest that strain M3 removed MG and changed approximately 40 % to LMG and 60 % to some metabolites other than LMG.

Feasibility and assessment of the phytoremediation potential of duckweed for triarylmethane dye degradation with the emphasis on some physiologicalresponses and effect of operational parameters

Phytoremediation is a low-cost and effective technology that removes pollutants, such as dye-containing effluents, from the environment through the use of plants. In the present study, the potential of Lemna minor L. for decolorization and degradation of the triarylmethane dye malachite green was investigated. The results revealed that the decolorization ability of the plant species is as high as 88%. The effect of some operational parameters (initial dye concentration, temperature, pH, and amount (weight) of plant) on the efficiency of biological decolorization process was determined. The metabolic fate of the dye was proposed by identifying 8 intermediate compounds produced during this process by gas chromatography-mass spectrometry. Some physiological responses of the plant were evaluated under 10 and 20 mg/L of the dye, with notable increases in superoxide dismutase and peroxidase activities at high concentrations. The results suggested that dye treatment induced oxidative stress and demonstrated duckweed's capacity to upregulate its antioxidative defense.

Efficiency of Carbohydrate Additives on the Stability of Horseradish Peroxidase (HRP): HRP‐Catalyzed Removal of Phenol and Malachite Green Decolorization from Wastewater

AbstractThe present study was undertaken to develop a cost effective stabilized horseradish peroxidase (HRP) for removal of phenol and decolorization of malachite green from synthetic wastewater. As revealed by enzyme stabilization assays, guar gum and galactose improved the stability of HRP successfully in solution state as compared as other additives such as pectin, carrageenan, or starch, respectively. In order to enhance the stability of HRP, combination of galactose and guar gum were effectively optimized together along with pH by constructing an appropriate response surface methodology (RSM). The RSM results suggest 18.25% of galactose and 0.35% of guar gum for maximum stabilization of HRP at 60°C, pH 7.4. In this study, optimization of removal of phenol and decolorization of malachite green using stabilized HRP was successfully carried out. Various process parameters such as aqueous phase of pH (7.4), concentration of enzyme (1.8 U/mL), phenol concentration (0.1 mM), and reaction time of 180 min were optimized effectively to achieve maximum removal of phenol from synthetic waste water. Dye decolorization studies indicated that stabilized HRP (1.2 U/mL) required lower concentration than the native enzyme (2 U/mL) to obtain similar decolorization efficiency. In addition, stabilized enzyme successfully decolorized the dye at 60°C, pH 7.2.

Synthesis, characterization and photocatalytic properties of Er-doped PbSe nanoparticles as a visible light-activated photocatalyst

In this study, undoped and Er-doped PbSe (ErxPb1−xSe) nanoparticles were successfully synthesized through a facile hydrothermal method. Synthesized nanoparticles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and photoelectron spectroscopy (XPS) techniques. Photocatalytic activity of undoped and Er-doped PbSe was evaluated by photocatalytic decolorization of Malachite Green (MG) under visible light irradiation. XRD analysis confirmed that the samples were crystallized in face-centered cubic PbSe phase. SEM images demonstrated that the size distributions of the undoped and 4% Er-doped PbSe particles were in the range of 60–70nm and 50–60nm, respectively. XPS analysis represented that Er ions were successfully incorporated into the PbSe crystal lattice. Decolorization efficiency was increased from 64.89%, in the presence of undoped PbSe, to 95.60% in the presence of 4% Er-doped PbSe at 75min of irradiation time. The order of inhibitory effect of different inorganic ions was found to be as Cl−>F−>HCO3−>CO32−. The presence of peroxydisulfate as enhancer significantly increased the decolorization efficiency. Synthesized nanoparticles exhibited good reusability after 10 sets of photocatalytic reaction. The photocatalytic degradation process can be explained in terms of pseudo-first-order kinetic model. The main degradation intermediates produced in the photocatalytic degradation of MG were identified by gas chromatography coupled to mass spectrometry (GC–MS) analysis, and a possible pathway was proposed.

Decolorization of triphenylmethane dyes by wild mushrooms

Triphenylmethane dyes such as Crystal Violet (CV) and Malachite Green (MG) are common textile dyes. MG, which is toxic to humans, is widely used in aquaculture as an antifungal agent. In this study, 56 mushroom strains from 12 species of wild mushrooms were examined on dye-containing PDA plates to evaluate their potential for the bioremediation of synthetic dyes. Pycnoporus coccineus, Coriolus versicolor, and Lentinula edodes showed fair growth on CV, but only a few survived on MG. However, a decolorization experiment in an aqueous system revealed that the growth on MG-containing solid medium did not directly match the decolorization of MG in the aqueous system. C. versicolor IUM0061 grew well on both MG and CV plates, but could not decolorize MG in the reaction mixture. Conversely, HPLC analysis revealed that P. coccineus IUM0032, which could not grow on the MG plate, completely mineralized MG within 3 days. A subsequent enzyme activity assay revealed a high lignin peroxidase activity in the reaction mixture, indicating that lignin peroxidase is the key enzyme involved in degradation of MG in P. coccineus IUM0032.

Mesoporous nanostructures of Nb2O5 obtained by an EISA route for the treatment of malachite green dye-contaminated aqueous solution under UV and visible light irradiation

A series of mesoporous Nb2O5 photocatalysts was synthesized via an evaporation-induced self-assembly (EISA) method using NbCl5 and Pluronic P123 as precursor and templating agent, respectively. The obtained samples are subsequently calcined at 380, 480 and 580°C and are assigned as mNb2O5-380, mNb2O5-480 and mNb2O5-580, respectively. For comparison, niobia samples were also prepared by a simple hydrolysis method and condensation of niobium chloride in the absence of templating agents assigned as bulk sample. All materials were characterized by XRD, FE-SEM, UV–vis DRS, FTIR, TG/DTA and BET techniques. It is exciting that the absorption edge of the EISA samples calcined at higher temperatures shifts several nanometers to the visible region compared with hydrolysis synthesized and commercial samples in the UV–vis absorption spectra, indicating their absorbance extended in the visible region. The photocatalytic decolorization of malachite green (MG) over the photocatalysts under UV and visible light sources was also investigated. We found the photocatalytic activity of mNb2O5-380 with about 140m2g−1 surface area was higher than that of the commercial Nb2O5 and TiO2 P25 photocatalysts and synthesized bulk sample for MG decolorization under visible light irradiation, whereas TiO2 P25 showed higher photocatalytic activity under UV irradiation. The decolorization kinetics of MG was followed by a first-order reaction with an apparent rate constant of k=1.0×10−2min−1 for the mNb2O5-380 photocatalyst, the sample with the highest activity among all as-prepared samples under visible radiation. Meanwhile, the maximum decolorization of MG under visible light was obtained at 0.5gL−1, 5mgL−1 and 8.2 as optimum values for the dosage of mNb2O5-380 photocatalyst, dye concentration and pH, respectively.

Enzymatic Decolorization of Malachite Green Dye by a Newly Isolated Bacillus Cereus Strain wwcp

Enzymatic decolorization of Malachite Green (MG) dye was studied using crude enzyme from a newly isolated Bacillus cereus strain wwcp1. 98% decolorization efficiency was achieved within 24 hours using an initial dye concentration of 1.0 x 10 -5 M. Batch experimental results revealed that the decolorization process was highly dependent on contact time, initial MG concentration, aqueous solution temperature and pH. Biodegradation of MG dye was monitored spectrophotometrically and metabolites confirmed by thin layer chromatography (TLC). The comparison of TLC chromatograms before and after decolorization confirmed that crude protease enzyme had the ability to degrade MG dye. The results provide evidence that the crude enzyme from Bacillus cereus strain wwcp1 is an effective and potential candidate for industrial wastewater treatment.

Screening of Trametes strains for efficient decolorization of malachite green at high temperatures and ionic concentrations

Trametes (synonym Coriolous) species are the most important sources for laccases with attractive properties. Several Trametes species were screened for their ability to produce laccase and decolorize malachite green (MG). Trametes trogii Berk S0301 was chosen for further study because it showed the highest 2,2′-azino bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) oxidization ability, which is closely correlated with MG decolorization. The laccase activity of T. trogii Berk S0301 was enhanced up to 34.3-fold and 5.6-fold by Cu2+ (1.5 mM) and Tween 80 (7 g L−1), respectively. Mn2+, Mg2+, Zn2+, Co2+ and Na+ (100 mM) only slightly (less than 10% inhibition) affected MG decolorization by the crude laccase of T. trogii Berk S0301. MG was decolorized effectively at pH 4.5–7.0 and 30–80 °C with an optimum decolorization at pH 6 and 50–70 °C. Phyto- and micro-toxicity tests revealed that less toxic metabolites were formed after laccase treatment. The present work demonstrates that strain T. trogii Berk S0301 and its laccase may facilitate novel and more efficient bio-catalytic process applications.

Purification and characterization of a laccase from Coprinopsis cinerea in Pichia pastoris

A modified laccase gene, CcLCC6, from Coprinopsis cinerea was chemically synthesized according to the yeast codon bias and expressed in Pichia pastoris. The main properties of laccase, effects of ions and inhibitors, and optimal condition for decolouring malachite green (MG) were investigated in this study. The optimal pH level and temperature of laccase are 3.0 and 40 °C, respectively. The metal ions Mn²⁺, Zn²⁺, Fe³⁺ and Al³⁺ could inhibit laccase activity, as well as 1 mM of sodium dodecyl sulphate and sodium thiosulphate. 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), as a mediator, was necessary in decolorizing MG. The optimal pH and temperature for MG decolorization were 3.0 and 50 °C, respectively. Approximately 0.02 μM recombinant laccase could effectively decolour 0.05 mM of MG in 1 h. CcLCC6I could inhibit the toxicity of MG to P. pastoris. This is the first report on the successful expression in P. pastoris of CcLCC6I and its enzymatic property. Laccase can also be considered as a candidate for treating industrial effluent containing MG.