Microflora involved in textile dye waste removal

Textile dyes are heavily used in factories for coloring different cloth materials. This work was designed to identify microorganisms capable of removing textile dyes, either by biodegradation or by biosorption. We expected to isolate microorganisms adapted to high dye concentrations from sites near textile industry complex. An experiment was conducted to study the efficiency of the isolates in removing textile dyes. The tested dyes were used as carbon and nitrogen sources for isolation of soil and/or water microorganisms capable of removing textile dyes wastes from factories effluent. The results indicated the low efficiency of both bacteria and actinomycetes in clean-up the effluent from the waste dyes in 10-21 days. On the other hand six fungal isolates were obtained by plating factory effluent on Martin's medium and media containing dyes as the sole source of carbon and nitrogen for growth. These isolates fell in two genera, Aspergillus and Trichoderma. Results of these studies revealed the potential capacity of these fungi to decolorize the tested dyes in comparatively short time (2-24 hours) indicating strong efficiency of dye bioremediation by the fungal isolates. Since the process involved is mostly fast interaction between the fungal mycelium and the dye in the media, the possible mechanism could be based on a biosorption of such chemicals on the intact fungal biomass, rather than direct biodegradation of the compounds.     

Adsorptive removal of textile dyes from aqueous solutions by dead fungal biomass

Dead fungal biomass prepared from Phanerochaete chrysosporium and Funalia trogii was tested for their efficiency in removal of textile dyes. The effects of contact time, initial dye concentration, amount of dead biomass and agitation rate on dye removal have been determined. Removal of all dyes required a very short time (60 min). Experimental results show that, P. chrysosporium was more effective than F. trogii . An increase in the amount of dead biomass positively affected of the dye removal. The removal efficiency of different amount of biomass was in order 1 g > 0.5 g > 0.2 g > 0.1 g. The highest removal was obtained at 150-200 rpm. Slightly lower removing activities were found at lower agitation rates. This study showed that it was possible to remove textile dyes by dead biomass of P. chrysosporium .     

Enhancing bioremoval of textile dyes by eight fungal strains from media supplemented with gelatine wastes and sucrose

Eight Aspergillus strains were found to be successful in removing textile dyes from liquid media. These fungal strains were grown on medium containing: gelatine wastes and sucrose, as sources of nitrogen and carbon to test the possible speed up of the dyes removing while fungus biomass is building up in the media. The growth of fungal strains ranged from 10 to 110 mg biomass dry weight/100 ml medium. This growth induced high decolorization percentages, which ranged 33-95% within eight days. Two textile dyes Direct brown and Polar red were included in the study. The growth of the fungal strains as well as decolorization percentage of the dyes increased after 5, 6, and 8 days from incubation time with most tested strains. With Direct brown dye the strains number 2, 5, 31 and 37 recorded the highest percentage of decolorization (91, 92, 93 and 95 respectively) after incubation for 6 days. Fungal strains Aspergillus 5 and 31 gave the highest mycelium dry weight being 110 mg. Most of fungal strains induced 86 to 95 percentage of decolorization after 6 days incubation with Polar red dye. The possible toxicity of the remaining supernatant media after fungal biomass removal was tested by Ames test to assess the residual mutagenic agents remaining after dye removal, using three strains of Salmonella typhimurium (TA 1535, TA 1537, TA 1538). The results showed that the toxicity of the dyes, measured by Ames test could be removed by the dye absorption on the fungal biomass.     

Decolourisation of diverse industrial dyes by some Phlebia spp. and their comparison with Phanerochaete chrysosporium

Three species of Phlebia, viz. P. brevispora, P. fascicularia and P. floridensis have been evaluated for their potential to decolourise eight industrial dyes including; reactive yellow, reactive orange, reactive red, rathidol scarlet, coracryl black, coracryl pink, coracryl violet and coracryl red. The cultures used for the present study were pre adapted by growing these on yeast glucose agar medium supplemented with Poly-R 478, a reference dye. The fungal cultures were grown in mineral salts broth and harvested after different incubation periods to obtain their cell free enzyme extracts which were then used to assess their ability to decolourise the above mentioned dyes. The extracts obtained from the cultures grown for six days significantly decolourised the tested dyes. The study revealed Phlebia spp. to be better dye decolourisers than Phanerochaete chrysosporium.     

Extraction and optimization of Penicillium sclerotiorum strain AK-1 pigment for fabric dyeing

Recently, the demand for fungal pigments has increased due to their several benefits over synthetic dyes. Many species of fungi are known to produce pigments and a large number of fungal strains for pigment production are yet to be extensively investigated. The natural pigment from sustainable natural sources has good economic and industrial value. Many synthetic colorants used in textile and various industries have many harmful effects on the human population and environment. Pigments and coloring agents may be extracted from a wide range of fungal species. These compounds are among the natural compounds having the most significant promise for medicinal, culinary, cosmetics, and textile applications. This study attempts to isolate and optimize the fermentation conditions of Penicillium sclerotiorum strain AK-1 for pigment production. A dark yellow-colored pigment was isolated from the strain with significant extractive value and antioxidant capacity. This study also identifies that the pigment does not have any cytotoxic effect and is multicomponent. The pigment production was optimized for the parameters such as pH, temperature, carbon and nitrogen source. Fabric dyeing experiments showed significant dyeing capacity of the pigment on cotton fabrics. Accordingly, the natural dye isolated from P. sclerotiorum strain AK-1 has a high potential for industrial-scale dyeing of cotton materials.     

Screening of filamentous fungi for the decolorization of a commercial reactive dye

The aim of this work is to verify the ability of 19 isolates of 13 different fungal species to decolorize the reactive dye blue‐BF‐R. The isolates of Pleurotus pulmonarius, P. ostreatus, P. ëous, P. citrinopileatus, Lentinus edodes, Phanerochaete chrysosporium, Schizophyllum commune, Agaricus blazei, Ganoderma sp. and four isolates obtained from textile effluent were evaluated in minimum liquid medium. In addition, seven of them were also evaluated on solid medium, and both media were both added 0.5 g dye/l. All isolates evaluated on solid medium decolorized the dye. The isolates Phanerochaete chrysosporium CCB478 and Lentinus edodes CCB047 were the ones that presented the fastest and slowest growth, respectively. Despite the isolate of the textile effluent had grown on solid medium, it did not decolorize the dye. All the isolates of the genus Pleurotus, except the isolate Pleurotus ëous CCB440, decolorized the dye in liquid medium. They presented decolorization percentage ranging from 39% to 51%. The absorbance ratio (Abs₅₉₀/Abs₄₅₅) of the culture medium inoculated with these isolates decreased throughout the experiment indicating the fungal dye degradation. The others presented decolorization percent below 8%. The isolates of Pleurotus, except the isolate Pleurotus ëous CCB440, were able to decolorize and to degrade the commercial reactive dye blue‐BF‐R. The results indicate their potential to be used in the treatment of effluents containing this dye. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Occupational Asthma Induced by the Reactive Dye Synozol Red-K 3BS

Various reactive dyes can elicit occupational asthma in exposed textile industry workers. To date, there has been no report of occupational asthma caused by the red dye Synozol Red-K 3BS (Red-K). Here, we report a 38-year-old male textile worker with occupational asthma and rhinitis induced by inhalation of Red-K. He showed positive responses to Red-K extract on skin-prick testing and serum specific IgE antibodies to Red-K-human serum albumin conjugate were detected using an enzyme-linked immunosorbent assay. A bronchoprovocation test with Red-K extract resulted in significant bronchoconstriction. These findings suggest that the inhalation of the reactive dye Red-K can induce IgE-mediated occupational asthma and rhinitis in exposed workers.     

The prevalence of specific IgE and IgG to reactive dye-human serum albumin conjugate in workers of a dye factory and neighboring factories

Previous studies suggest that reactive dyes can induce IgE mediated bronchoconstrictions. To evaluate the significance of specific IgE and IgG antibodies in workers exposed to reactive dyes, we studied the prevalence of Black GR-specific IgG by enzyme linked immunosorbent assay, as well as Black GR-specific IgE by RAST, in 176 workers employed in 1 reactive dye factory and 4 neighboring factories. Six employees of reactive dye asthma who were working in factories near the reactive dye factories were noted. The prevalence of specific IgE antibodies in the neighboring factories was higher than in that of the reactive dye factory. The prevalence of specific IgG was highest in the reactive dye factory, and those of the neighboring factories were markedly lower. It was suggested that IgE mediated sensitization to reactive dye could have occurred in employees who were working in neighboring factories, and the prevalence of reactive dye-specific IgG antibody could be used as an in direct method of assessing the exposure of workers to reactive dye.     

Reduction in the mutagenicity of synthetic dyes by successive treatment with activated sludge and the ligninolytic fungus, Irpex lacteus

Synthetic dyes are released in wastewater from textile manufacturing plants, and many of these dyes are genotoxic. In the present study, the mutagenicity of azo, anthraquinone, and triphenyl methane dyes was investigated before and after successive biodegradation with activated sludge and the ligninolytic fungus, Irpex lacteus. Two biodegradation systems were used to reduce the genotoxicity of dyes that were not efficiently inactivated by activated sludge alone. Mutagenicity was monitored with the Salmonella reversion assay conducted with the base-pair substitution detector strains, TA100 and YG1042, and the frame-shift detector strains, TA98 and YG1041, with and without rat liver S9. All dyes except for Congo Red (CR) were mutagenic with S9 activation. Assays conducted with the dyes indicated that only the azo dye Reactive Orange 16 (RO16) was mutagenic in both TA98 and TA100. Methyl Red and Disperse Blue 3 (DB3) were mutagenic in TA98, YG1041 and YG1042, while Reactive Black 5 was mutagenic in YG1041 and YG1042. Remazol Brilliant Blue R (RBBR), Crystal violet (CV) and Bromophenol Blue (BPB) were mutagenic only in TA98, but the toxicity of the latter two dyes complicated the evaluation of their mutagenicity. CR was not mutagenic in any of the tester strains. Biodegradation studies conducted with RO16 and DB3 indicated that the two-step biodegradation process reduced the mutagenic potential of RO16 and DB3 to a greater extent than activated sludge alone; the mutagenicity of the two dyes was reduced by 95.2% and 77.8%, respectively, by the two-step process. These data indicate that the combined biodegradation process may be useful for reducing the mutagenicity associated with wastewater from textile factories that contain recalcitrant dyes.     

Binding of hepatitis virus particles to immobilised procion blue-HB and cibacron blue 3GA

Two chemically similar triazine dyes, coupled to chromatographic gels, have been investigated for their ability to bind and retain hepatitis B surface antigen marker of the hepatitis B virus. Both dyes, Procion Blue-HB and Cibacron Blue 3GA, were effective in removing viral particles from plasma protein solutions. A number of combinations of dye and gel support have been tried, to obtain optimal binding. A Cibacron Blue-Trisacryl adsorbent achieved almost complete retention (greater than 99.5%) of HBsAg before breakthrough occurred. Binding was better at reduced flow rates and on large pore gel matrices, suggesting that steric restrictions limit the interaction. The interaction is directly between immobilised dye and the viral particle, rather than through plasma albumin, which also binds to these affinity adsorbents. These findings are important in the use of immobilised triazine dyes for plasma protein purification. Furthermore, the interaction may be utilised either for the removal of HB viral particles from plasma or as a rapid method of their purification.     

Hematoxylin substitutes. A study of phenocyanin TC and the use of afterchrome mordanting in histology.

A practical, simple synthesis of the obsolete mordant dye, phenocyanin, was devised, proceding from gallocyanin and resorcinol with acid and heat. The dye gave promise of good performance in metachrome iron mixtures, but because of excessive precipitation, the practice of afterchroming was taken from textile dyeing usage, and proved very successful. Of a number of metallic salts tried, Fe II proved to be the best, then Cu II and Fe III. The stain acts as a cationic dye on nucleic acids and other acidic tissue components: acid mucins, cartilage, mast cells, corpora amylacea, etc. The afterchroming process renders the stain much more resistant to various extraction agents and even moderately resistant to acid alcohol. Color values are quite comparable to those obtained with hematoxylin-eosin when an eosin counterstain is used. Nuclei basophilic cytoplasm, Nissl granules, and bacteria color dark blue; cartilage, mast cells, and some acid mucins, deep violet. Staining with the 1% solution was essentially unaltered from neutrality down to 1.2 N HCl, pH 0.68, and dilution of the dye to 0.05% in 1% conc. HCl (pH 1.2) still gave excellent nuclear, RNA, and mast-cell staining. At 0.02% and pH 1.2, nuclear staining was distinctly weakened; mast cell granules were still dark violet.     

Role of white rot fungus Funalia trogii in detoxification of textile dyes

Toxic and genotoxic effects of the textile dyes on organisms suggest the need for remediation of dyes before discharging them into the environment. For this reason, the ability of Funalia trogii pellets to detoxify textile dyes was investigated and evaluated. Although, textile dyes are toxic substances for many microorganisms, the pellets were able to decolorize and detoxify the azo dyes used. Astrazon Blue and Red dyes inhibit growth of F. trogii and S. aureus on solid medium in a concentration dependent manner. The toxicity of these dyes on a fungus, F. trogii and a bacterium, S. aureus was significantly decreased after pretreatment with fungal pellets.     

Genotoxicity of degradation products of textile dyes evaluated with rec-assay after PhotoFenton and ligninase treatment.

Fourteen textile and biological dyes, belonging to the azo, triphenylmethane, anthraquinone, heterocyclic, oxazine, and methine/polymethine groups, were degraded using the PhotoFenton treatment (PFT) and the Phanerochaete chrysosporium crude ligninase enzyme (ED) treatment. The genotoxicity of the dyes and of their degradation products were assessed with the rec-assay. We found that the genotoxicity depended on the dye and on the method of degradation. In general, PFT was better than ED in decreasing the genotoxicity. Basic dyes showed complete or maximum loss of genotoxicity, whereas the vat group was more resistant. The azo group showed varied results. Crystal Violet was the only dye whose genotoxicity increased after PFT. Our results suggest that PFT and ED are two effective treatment methods to reduce the genotoxicity of dyes in waste waters.     

Evaluation of biotoxicity of textile dyes using two bioassays

The toxicity of eight textile dyes was evaluated using two bioassays namely: Ames test and seed germination test. The Ames test is widely used for the evaluation of hazardous mutagenic effect of different chemicals, as a short-term screening test for environmental impact assessment. The eight-textile dyes and Eithidium bromide dye (as positive control) were tested with five "his" Salmonella typhimurium strains: TA 100; TA 98; TA 1535; TA 1537; TA 1538. Using six concentrations of each dye (2.5 microg/ml, 4.5 microg/ml, 9 microg/ml, 13.5 microg/ml, 18 microg/ml, and 22.5 microg/ml) revealed that, most of the dyes were mutagenic for the test strains used in this study. The high concentrations of dye eliminated microbial colonies due to the high frequency of mutation causing lethal effect on the cells.In this work the phytotoxicity of different soluble textile dyes was estimated by measuring the relative changes in seed germination of four plants: clover, wheat, tomato and lettuce. The changes in shooting percentages and root length as affected by dye were also measured. Seed germination percent and shoot growth as well as root length were recorded after 6 days of exposure to different concentrations of textile dyes in irrigation water. The results show that high concentrations of dyes were more toxic to seed germination as compared with the lower concentrations. However, the low concentrations of the tested dyes adversely affected the shooting percent significantly.     

Isolation and characterization of microorganisms capable of decolorizing various triphenylmethane dyes

Various soil and sludge samples collected from the vicinity of textile dyeing industries and waste disposal sites were used for enrichment of microbial population in the presence of triphenylmethane (TPM) dye Acid Violet-17 (AV-17). Twenty-five (25) isolates were screened for their ability to decolorize AV-17 dye added at a rate of 10 mgl(-1) in mineral salts medium (MSM) agar plates. Five bacterial isolates belonging to Bacillus sp., Alcaligenes sp. and Aeromonas sp. were selected on the basis of their higher decolorization ability and were used to develop a bacterial consortium. The consortium was able to efficiently decolorize various TPM dyes viz. Acid Violet-17 (86%), Acid Blue-15 (85%), Crystal Violet (82%), Malachite Green (82%) and Brilliant Green (85%). The consortium will be further used for designing efficient and cost effective treatment system for effluents of textile processing industries (TPI).     

Application of response surface analysis for biodegradation of azo reactive textile dye using Aspergillus foetidus

This paper reports the application of experimental design methodology for the optimization of decolourization of azo reactive textile dye Remazol Red RR and reduction of chemical oxygen demand (COD) using fungal isolate Aspergillus foetidus. Response surface methodology (RSM), involving central composite design matrix in three most important input variables; temperature, pH and initial dye concentration was employed. A total of 20 experiments were conducted in the study towards the construction of a quadratic model. This demonstrated the benefits of approach in achieving excellent predictions, while minimizing the number of experiments required. Very high regression coefficient between the variables and the responses indicated excellent evaluation of experimental data. Under optimized conditions fungal isolate was capable to decolourize Remazol Red RR up to 86.21% and COD reduction up to 55.43% was achieved during the experimental setup. Enzymatic activity indicated excellent outcome under the optimal process conditions. The experimental values agreed with the predicted ones, indicating suitability of the model and success of RSM approach in optimizing the process.     

Astrazon Red dye decolorization by growing cells and pellets of Funalia trogii

The dye decolorization activity of fungal pellets has been compared with another method based on the decolorization of dye by growing cells. The pellet method was more advantageous than the growing cell method. The growing cells of F. trogii decolorized 21% of the dye in distilled water medium and 16% in stock basal medium in 24 h. On the other hand, Funalia trogii pellets rapidly decolorized the Astrazon Red dye, mono-azo textile dye, in 24 h, without any visual sorption of any dye to the pellets. The effect of various supplements on longevity of decolorization by free pellets was also tested. Glucose and cheese whey supplementation improved dye decolorization performance of the pellets and remained high and stable for 10 days. We also tested the dye decolorization ability of pellets immobilized on activated carbon. These pellets showed the stable dye decolorization activity during the repeated batch experiments. The study revealed that dye decolorization by pellets is more effective method than the growing cell method.     

Relationship of chemical structures of textile dyes on the pre-adaptation medium and the potentialities of their biodegradation by Phanerochaete chrysosporium

Azo dye derivatives of azobenzene constitute the largest group of dyes used in the textile industry and possess recalcitrant chemical groups, such as those of azo and sulphonic acid. Some microorganisms are able to degrade these aromatic compounds. In the present work, decolourisation of culture media containing azo dyes by the ligninolytic fungus Phanerochaete chrysosporium was achieved under nitrogen-limited conditions. The dyes used in the study are derivatives of meta- or para-aminosulphonic or aminobenzoic acids and include in their structures groups such as guaiacol or syringol, which are bioaccessible to the lignin degrading fungus P. chrysosporium. The aim of this study was to pre-adapt the microorganism to the structure of the dyes and to establish the relationships of the chemical structure of the dye present in the pre-adaptation medium with the chemical structure of the dye to be degraded. The azo dye used in the pre-adaptation medium that gave the best overall decolourisation performance was a meta-aminosulphonic acid and guaiacol derivative. The azo dye derivative of a meta-aminobenzoic acid and syringol showed a better performance in the decolourisation assays. Preliminary GC-MS studies indicated the formation of a nitroso substituted catechol metabolite, a precursor of aromatic ring cleavage, which was confirmed to occur by an enzymatic assay. The presence of this type of metabolite allows the establishment of a possible metabolic pathway towards mineralisation.     

Reactive dyes as vital indicators of bone growth

Certain reactive dyes of the procion M and remazol group were effective for vital staining of growing bones. These compounds appear to form covalent bonds with the protein matrices and are preserved in situ after decalcification. Dye concentrations in sera of animals receiving one injection were followed. There was a precipitous drop in optical density in the first 24 hours; the remainder of the dye was largely cleared from the serum in 11–21 days. Dye concentrations and staining of bone were correlated. The width of the stained bone appeared to be related to rate of growth and disappearance of dye from the blood. On electrophoresis, the dyes moved with the albumin fraction. Dialysis and electrophoresis experiments favored the conclusion that they form covalent bonds with the protein. Growth of the rabbit mandible at 5–13 weeks, was studied by microscopy in decalcified sections. Using multicolored dyes, the sites of growth were marked in known sequence and sites of resorption were identified by interruption of stained zones. Principles of growth and remodelling advanced by Enlow were confirmed and the growth pattern of the rabbit mandible was elucidated.     

Disturbance of metachromasia of dye/polyanion systems by stoichiometric amounts of cetylpyridinium chloride

The disturbance of metachromasia of a dye/polyanion system by cetyl pyridinium chloride (CPCl) has been estimated quantitatively from the difference of the amounts of dye left in the aqueous layer after carbon tetrachloride extraction of the metachromatic solution in the presence and absence of CPCl, as well as from conductometric titration of the dye/polyanion solution with CPCl. Results show that CPCl, unlike sodium chloride, displaces the dye ions from the polyanions almost stoichiometrically. This special behaviour of CPCl has been assigned to its tendency to form hydrophobic bonds. As dyes methylene blue and crystal violet, as polyanions chondroitin sulfate and heparin have been used.