Biodegradation of dyes

The azo class of synthetic dyes represents one of the most industrially used dyes as well as a major class of environmental contaminants, which possess one or more azo bonds (ÀN¼NÀ) along with aromatic rings and sulfonic groups. Due to its recalcitrant nature and toxicity for animals and human beings, the elimination of these dyes from the environment is essential. The present study focuses on the biodegradation of such azo dye, malachite green (MG), through a potent ligninolytic fungus, Aspergillus flavus (F10). A. flavus (F10) completely decolorized MG (150 mg L À1) within 6-8 days in optimized Kirk's basal medium under static aerobic conditions at pH 5.8. Sucrose and sodium nitrate were efficient carbon and nitrogen sources, respectively. The products obtained after degradation were examined using UV-vis spectrophotometry, Fourier transform IR spectroscopy, and liquid chromatography-mass spectroscopy. The metabolic intermediate products were identified as N-demethylated and N-oxidized metabolites, including primary and secondary arylamines, which confirms the involvement of laccase and manganese peroxidase in decolorization and degradation of MG. The end products of MG degradation were nontoxic. A. flavus (F10), immobilized by entrapment on natural and synthetic polymeric matrices was found to be a more efficient degrader of MG as compared to free cells.

Textile industry is the most avid user for dyes. Rapidly growing interest in developing more synthetic commercial dyes from its native to endeavour human needs contributed to aesthetic problems to the environment and public health. Increasing concerns about colours in the effluents lead to worldwide efforts to develop more effective colour removal processes. However, the physical and chemical treatment methods of the discharge effluents are not economically feasible even if some of them are inefficient nowadays. Furthermore, liberating the hazardous product from secondary pollution from these methods acquires valid waste management system. Without proper discharge, azo dyes and associated chemicals may induce mutagenesis leading to toxicity in aquatic plants and animals. Utilization of mycoremediation of dyes as green chemistry technology has yet become a promising approach due to its clear picture of cost, eco-friendly and environmentally benign process as an alternative green solution to replace or supplement for current and future environmental issues. The bioremediation using fungi was reported to be more tolerant than bacteria and more efficient for decolorization as well as degradation of toxic chemicals. However, white-rot fungi are well known for their outstanding ability in bioremediation process. Their ability to produce highly non-specific extracellular enzymes allows them to degrade a wide array of pollutants resembling dyes and its derivatives. White-rot fungi secrete one or more of the three principle ligninolytic enzymes: lignin peroxidase (LiP, E.C. 1.11.1.14), Mn-dependent peroxidase (MnP, E.C. 1.11.1.13) and phenol oxidase (laccase) (Lac, E.C. 1.10.3.2) and other peroxidases. The present review discusses comprehensively the science and technology of biodegradation and fungal bioremediation of synthetic dyes.

Carbazole is a nitrogen heterocyclic compound released into the environment, used as a chemical feed stock for the production of dyes, medicines and plastics. Carbazole and their derivatives are detected in atmospheric samples, river sediments, marine water and ground water. Enriched Mineral salts medium (MSM) broth was used to isolate bacteria able to use carbazole as a sole Carbon and Nitrogen and plate assay using MSM agar plate was developed to select carbazole degrading microorganisms. Ten different bacterial isolates were obtained which were capable of utilizing carbazole as the only sole source of carbon and nitrogen added. From the obtained ten isolates C:1, C:2 and C: 3 were from marine water samples, C:4, C:5 and C:6 from marine soil samples, C:7 and C:8 from Pond water samples and C:9, C:10 were from garage soil samples. All isolates were further studied for their "Bioavailability assay" by using different stress and favourable conditions, among all C: 2 isolate showed the maximum considerable and noticeable result in MSM medium. From the bioavailability assay results carbazole degradation studies was carried out using C: 2 isolate by adding 100 ppm and 500 ppm concentration of carbazole in MSM broth medium from which the concentration of carbazole reduced to 8.33 ppm and 50 ppm in 144 hours containing 100 ppm and 500 ppm respectively. Immobilization studies were carried by immobilizing C: 2 isolate in the form of calcium-alginate beads and PVA-alginate beads. Study of Mechanical stability of calcium-alginate and PVA-alginate beads was checked by sonication. PVA-alginate beads were more stable than calcium-alginate beads. Viability of the immobilized cells was tested by calculating colony forming units using both the types of beads, PVA-alginate beads shows more viability than calcium-alginate beads. Carbazole degradation studies with immobilized cells was done by taking absorbance OD600, the concentration reduced to 41.66 ppm and 33.33 ppm in 144 hours using Calcium-alginate beads and PVA-alginate beads respectively containing 100 ppm concentration of carbazole and 241.6 ppm and 120.8 ppm respectively containing 500 ppm concentration of carbazole.

Describes a new technique for the analysis of natural dyes on textile fibers. The use of m-(trifluoromethyl)-phenyltrimethylammonium hydroxide (TMTFTH) extraction and derivatization, followed by gas chromatography-mass spectrometry (GC-MS), has proven to be a simple and fast technique for the analysis of indigo dye on textiles. Not only does the procedure allow for the identification of the main dye component, indigotin, but it also provides information on the degradation of indigo on textiles, a topic that has received limited attention in conservation literature. This article discusses compounds formed through the reactions of TMTFTH with indigotin and the main degradation products of indigo, 2-aminobenzoic acid, isatin, and isatoic anhydride. In addition, a new degradation product has been tentatively identified as 2-benzyl-3-indolinone. The occurrence of these degradation products was investigated in samples obtained from an Indian textile from the Sultanate period (13th-15th centuries) belonging to the Fine Arts Museums of San Francisco, woven, in large part, from indigo-dyed blue silk fibers. During a period of storage, pale yellow discolorations gradually appeared on tissue paper used to wrap the textile. Analysis of the tissue paper determined an abundance of indigo degradation products, in particular anthranilic acid (2-aminobenzoic acid). These compounds formed on the textile fibers through oxidative degradation and subsequently volatilized to the surface of the paper and also to the neighboring fibers.

The release of azo dyes especially methyl red into the environment is of great concern due to coloration of natural water, toxicity, mutagenicity and their biotransformation product. Economical and bio-friendly approaches are needed to remediate dye contaminated waste water from various industries. In this study, Staphylococcus aureus capable of degrading azo dye was isolated from waste dump site. The isolate was studied for their ability to decolorize Methyl Red (MR) using UV spectrophotometer at 430 nm at 3 different concentrations (250, 500 and 750 mL) under aerobic condition for the period of 12 days. The 62, 58 and 50% methyl red decolorizations were recorded in 750, 500 and 250 mL dilution respectively at the end of 12 day. The results of this study suggest the potential of Staphylococcus aureus for the treatment of waste water containing methyl red.

The human protein GPN2 collaborate in the biogenesis of RNA polymerase II, was expressed like recombinant protein in E. coli and was purified by Immobilized Metal Affinity Chromatography with nickel (IMAC). The use of IMAC in proteins expressed in E. coli recuperate many impurities and is necessary other chromatographic steps. The amino acids glutamic acid and arginine increase the solubility of proteins, this suggest that the combined use of them make easy the purification process. We use both amino acids in the purification of the GPN2 protein obtaining the sample completely pure but with low performance. For that we interchange arginine for lysine and we get a better performance of the quantity of GPN2 in pure form. Finally, was revealed by Polyacrylamide Gel Electrophoresis (SDS-PAGE) and stained with Coomassie blue. The Bradford method quantifies a concentration of 2mg/ml

• A moderately halophilic bacterial strain was isolated that effectively degraded DB-1. • HBRA was identified to be Marinobacter sp. • Deduction of possible biotransformation pathway for DB-1. • Toxicity evaluation of DB-1 and its degraded metabolites. a b s t r a c t The ability of halophiles to survive in the extreme salt concentrations has gained them the importance of being used in the treatment of industrial waste waters. A moderately halophilic bacterial strain with the ability to degrade the complex azo dye Direct Blue-1 (DB-1) was isolated from sea water and identified as Marinobacter sp. strain HBRA. Complete decolorization of DB-1 (100 mg L −1) was achieved in 6 h at 37 • C, pH 8 and with 70 g L −1 NaCl. Decolorization was analyzed by UV–vis spectrophotometer. The FT-IR spectrum revealed that Marinobacter sp. strain HBRA specifically targeted azo bond (N N) at 1631 cm −1 to break down Direct Blue-1. Formation of metabolites at different retention times in HPLC indicated degradation. Biotransformation pathway for DB-1 was proposed based on LC–MS. Phytotoxicity study revealed the less toxic nature of the metabolites compared to the dye. Genotoxicity with Allium cepa confirmed the cytotoxic nature of DB-1 by inducing several chromosomal abnormalities compared to the negligible effects of degraded metabolites. The current study is the first report on the detoxification of DB-1 by Marinobacter sp. strain HBRA.

A novel analytical method using HPLC–MS/MS operating in selected reaction monitoring (SRM) for evaluation of fungi efficacy to decolorize Remazol Brilliant Blue R (RBBR) dye solution was developed, validated and applied. The method shows high sensibility allowing the detection of 4.6 pM of RBBR. Four fungal strains were tested in liquid medium, three strains of Aspergillus (Aspergillus aculeatus, Aspergillus flavus and Aspergillus fumigatus) and Phanerochaete chrysosporium. All fungi were able to degrade the dye,
with efficiencies ranging from 40% for P. chrysosporium up to 99% for A. flavus during a 30-day incubation period. During the experiment, increased accumulation of degradation products was observed in A. flavus cultures containing RBBR. Through the use of full scan HPLC–MS technique it was possible to propose the biogenesis of the microbial metabolic degradation pathway. Screening using microorganisms and RBBR may be hereafter used to investigate microbial biodegradation of high toxicity molecules such as dioxins.

Reactive Black 5 (RB5) is one of the most common synthetic reactive dyes that requires treatment due to its effect on the water ecosystems and human health (e.g., cancer), therefore, it needs to be treated. This study aimed to decolorize RB5 dye using the immobilized brown-rot fungus, Gloeophyllum trabeum, on sodium alginate (SA). The immobilized beads involved two variations, living and dead fungus (biomass), entrapped into 2% (w/v) SA and solidified by chilled CaCl 2. The result showed that the immobilized G. trabeum biomass exceeded the abilities of the living fungus after 7 days of incubation. Using the spectrophotometric method, the RB5 decolorization percentages by immobilized living and dead fungus were 13.35% and 53.08%, respectively. The decolorization abilities were affected by several factors, such as dye concentration, temperature, pH, and static or agitated conditions. Optimum conditions for decolorizing RB5 by dead fungus G. trabeum beads were incubation time 7 days, initial dye concentration 50 mg/L, pH 7.0, temperature 40 C, and under shaking conditions. Meanwhile, for living fungus G. trabeum beads, the initial concentration was 50 mg/L, pH 3.0, temperature 25 C, and under static conditions. In addition, the isothermal adsorption kinetics of RB5 by the dead and living fungus beads followed the Langmuir and Freundlich model, respectively.

Biodcolorization of crystal violet (C V) was investigated in aquatic system. C V decolorizing bacterium (designated isolate AT 17) was isolated from effluent sample using enrichment technique by clear zone formation. Based on morphological, physiological and 16S rDNA, this bacterium was identified as Pseudomonas geniculata. It was capable of using C V as a sole source of carbon. Nutrient agar medium inhibited C V decolorization but mineral salt medium (MSM) increased C V decolorization. C V decolorizing by P. geniculata was found to be optimum at pH 7 and 35°C. Additional carbon sources (i.e., glucose) and nitrogen sources (i.e., peptone, yeast extract and beef extract) inhibited completely C V decolorization. On the ather hand, ammonium chloride and ammonium sulphate increased the C V decolorization. Ammonium chloride was the best inorganic nitrogen source in C V decolorization. Incubation period for 7 days was the optimum for C V decolorization. P. geniculata was able to decolorize 99% of C V completely in liquid medium at pH 7 and 35 °C after 7 days comparing with uninoculated medium(control). There was no toxicity of detected C V after 7 days of incubation with P. geniculata on Bacillus subtilis as microbial bioassay test. The dissipation of C V was coinciding with increasing P. geniculata biomass in C V contaminated water. This study has shown that P.geniculata C V could be applied to remediate Chemical pollutants - contaminated water.

The azo class of synthetic dyes represents one of the most industrially used dyes as well as a major class of environmental contaminants, which possess one or more azo bonds (-N=N-) along with aromatic rings and sulfonic groups. Due to its recalcitrant nature and toxicity for animals and human beings, the elimination of these dyes from the environment is essential. The present study focuses on the biodegradation of such azo dye, malachite green (MG), through a potent ligninolytic fungus, Aspergillus flavus (F10). Aspergillus flavus (F10) completely decolorized MG (150 mg L−1) within six to eight days in optimized Kirk's basal medium under static aerobic conditions at pH 5.8. Sucrose and sodium nitrate were efficient carbon and nitrogen sources, respectively. The products obtained after degradation were examined using UV-vis spectrophotometry, Fourier transform infrared spectroscopy, and liquid chromatography-mass spectroscopy. The metabolic intermediate products were identified as N-demethylated and N-oxidized metabolites, including primary and secondary arylamines, which confirms the involvement of laccase and manganese peroxidase in decolorization and degradation of MG. The end products of MG degradation were nontoxic. Aspergillus flavus (F10), immobilized by entrapment on natural and synthetic polymeric matrices was found to be a more efficient degrader of MG as compared to free cells.

The present study reveals the potentials of macrofungi namely Calocybe indica for decolourization of dye. Azo dyes are released in large quantities into the environment from textile industries. These dyes are recalcitrant to microbial degradation, causing problems in the usual biological treatment of the industrial effluents. Pollution is particularly associated with the reactive azo dyes, because of their strong colour which leads to aesthetic problems and obstructs light penetration and oxygen transfer into water bodies. Biomass production varied with different fungal isolates in the decolurization of dyes. The decolorization of viscose orange-A was found to be 78.54 and 94.72%, with Calocybe indica-1 and Calocybe indica-2 respectively after 15 days of incubation. The decolorization of direct green PLS, was found to be 81.56% and 66.41 with Calocybe indica-1 and Calocybe indica-2 respectively after 15 days of incubation. Among the two fungi, Calocybe indica-1 produced the maximum fungal biomass. Fungal isolates showed a highly correlation between the dry weight of the fungi and colour removal percentage.

The main aim of the current study is to isolate a fungi with laccase activities to be used for transformation of phytochemicals isolated from the same environment as an approach to produce novel pharmaceutical products. In our study, laccase producing fungi was isolated from samples taken from a tropical trees barks which grown in the International Islamic University Malaysia, Kuantan campus using different chromogenic substrates on the agar plates such as ABTS, Tannic Acid, Azure B and Guaiacol. It was found the isolated fungi ...

Malachite green (MG) degradation by Saccharomyces cerevisiae, Candida albicans and their consortium isolated from textile effluent, were investigated under aerobic condition using 20 mg of the dye in 250 ml, 500 ml and 750 ml of mineral salt medium for a periods of 12 days. Biodegradation activities were monitored using UV Spectrophotometer at 617 nm wavelength. The results shows 48%, 68% and 70% degradation by Saccharomyces cerevisiae for 250 ml, 500 ml and 750 ml dilutions respectively at the end of 12 days, while 48%, 65% and 68% degradation by Candida albicans were observed for 250 ml, 500 ml and 750 ml dilutions respectively at the end of 12 days. 52%, 70% and 77% degradation by their consortium for 250 ml, 500 ml and 750 ml dilutions respectively at the end of 12 days were also observed. The results of this study revealed the ability of Saccharomyces cerevisiae, Candida albicans and their consortium for the treatment of effluent containing malachite green dye.

Wastewater from textile industry effluents contains high amounts of colored and toxic compounds that can interrupt aquatic life systems when they are discharged to the environment without being treated. The physicochemical characteristics of effluents typically have a wide range of pHs and salinities, which are difficult for conventional techniques to remove. In addition, a limited number of microorganisms with the ability to grow and produce degradative enzyme systems can survive under those condition. Therefore, identifying microorganisms that are capable of decolorizing and degrading textile dyes under various pHs and salinities is needed. Among the fifteen strains tested in this study, Pestalotiopsis sp. NG007 exhibited the strongest ability to grow and decolorize Reactive Red 4 under saline conditions at pH 8. The ability of this strain to decolorize three textile dyes: Reactive Green 19, Reactive Orange 64 and Reactive Red 4, was investigated in a liquid medium and bioreactor system using immobilized mycelia. The fungus displayed a high decolorization capacity (20-98%) over 3 days in a wide range of pHs (pH 3-12) and salinities (0-10% w/v). In the bioreactor system, immobilized mycelia of the strain exhibited the ability to decolorize textile dyes by both adsorption (6-53%) and degradation (34-41%) mechanisms. This study demonstrated that Pestalotiopsis sp. has the potential to decolorize textile dye effluents containing a wide range of pHs and salinities.

The azo class of synthetic dyes represents one of the most industrially used dyes as well as a major class of environmental contaminants, which possess one or more azo bonds (-N=N-) along with aromatic rings and sulfonic groups. Due to its recalcitrant nature and toxicity for animals and human beings, the elimination of these dyes from the environment is essential. The present study focuses on the biodegradation of such azo dye, malachite green (MG), through a potent ligninolytic fungus, Aspergillus flavus (F10). Aspergillus flavus (F10) completely decolorized MG (150 mg L−1) within six to eight days in optimized Kirk's basal medium under static aerobic conditions at pH 5.8. Sucrose and sodium nitrate were efficient carbon and nitrogen sources, respectively. The products obtained after degradation were examined using UV-vis spectrophotometry, Fourier transform infrared spectroscopy, and liquid chromatography-mass spectroscopy. The metabolic intermediate products were identified as N-demethylated and N-oxidized metabolites, including primary and secondary arylamines, which confirms the involvement of laccase and manganese peroxidase in decolorization and degradation of MG. The end products of MG degradation were nontoxic. Aspergillus flavus (F10), immobilized by entrapment on natural and synthetic polymeric matrices was found to be a more efficient degrader of MG as compared to free cells.

The antifungal activity of 14 anthracene-based synthetic dyes and 6 reference compounds was measured on 36 fungal strains and the data matrix was evaluated separately by principal component analysis (PCA) and using a spectral mapping technique (SPM). The dimensionality of the maps of principal component loadings and variables and the selectivity maps was reduced to two by non-linear mapping. Except for two compounds, the dyes showed marked antifungal activity. Calculations proved that both the strength and selectivity of the biological effect of anthracene-based dyes were highly dependent on the chemical structure of the dye and on the type of fungi. PCA and SPM revealed different aspects of the antifungal activity, therefore, their simultaneous application in future quantitative structure-activity relationship studies is highly recommended.

Decolourization of reactive dyes wastewater supplemented with 1 mg/l cationic polymer (Organo Pol.) in a down flow hanging sponge (DHS) system was investigated at different HRTs and OLRs. The results obtained revealed that, increasing the HRT from 1.7 to 5 h, significantly increased the removal efficiencies of color and COD i.e. at a HRT of 5 h, and OLR not exceeding 2.8 g COD/l d, the reactor achieved removal efficiencies of 66.5 _ 7.07% for COD t and 90.12 _ 3.13% for color. However, at longer HRT of 6.0 h, the decolorization process was substantially dropped, due to high salinity content in the influent.