Bioremediation Of Textile Dyes Research Articles

Genetic Diversity and Dye-Decolorizing Spectrum of Schizophyllum commune Population.

Synthetic dyes are widely used in various industries and their wastage causes severe environmental problems while being hazardous to human health, leading to the need for eco-friendly degradation techniques. The split-gill fungus Schizophyllum commune, which is found worldwide, has the potential to degrade all components of the lignocellulosic biomass and is a candidate for the treatment of synthetic dyes. A systematic molecular analysis of 75 Korean and 6 foreign S. commune strains has revealed the high genetic diversity of this population and its important contribution to the total diversity of S. commune. We examined the dye decolorization ability of this population and revealed 5 excellent strains that strongly decolorized 3 dyes: Crystal Violet, Congo Red and Methylene Blue. Finally, comparison of dye decolorization ability and the phylogenetic identification of these strains generalized their genetic and physiological diversity. This study provides an initial resource for physiological and genetic research projects as well as the bioremediation of textile dyes.

Applicability of enzymes produced from different biotic species for biodegradation of textile dyes

The industrial wastewater contains a large amount of toxic pollutants that cause severe biotic risk and deterioration of environmental quality when discharged untreated/partially treated. Among the industrial sectors, the colourant industry-produced wastewater has more complex and hazardous composition in terms of toxicity of pollutants. In the recent past, numerous bioremediation techniques based on whole cells (bacteria, fungi and plants) or enzymes have been investigated for the treatment of dye-contaminated wastewater. The enzyme-driven treatment system has been found to be an effective for achieving satisfactory decolourization of dye-contaminated wastewater in less time, cost, labour and ecological risk. The enzyme-mediated decolourization of dye occurs through either degradation or biotransformation mechanism under optimal environmental conditions. The enzyme activity is limited by the operational factors such as reactivity of dye, pH, temperature, co-substrate and electron donor. In this regard, the present paper reviews the potential of enzymes, extracted from different biota (such as bacteria, fungi, algae and plants), to decolourize dyes from contaminated wastewater. It has been observed that the enzyme activity varies with the class of enzyme, its source and targeted substrate. The enzymes belonging to the class oxidoreductase are chief biological agents involved in bioremediation of textile dyes. The peroxidase enzymes are found to be very effective against wide classes of industrial dyes, with more tolerability to high temperature ~ 60 °C and wide range of operational pH 3–11. These enzymes are easily available as it can be extracted from bacteria, fungi, algae and plants. It has been observed that the dye decolourization efficiency of enzymes is higher in an immobilized state than in soluble form.

Purification and Characterization of Lignin Peroxidase Isozymes from Humicola grisea (Traaen) and Its Application in Bioremediation of Textile Dyes

PEROXIDASES have numerous important applications in industries and biodegradation of organopollutants , so there is a need to explore more and more sources of enzymes with different characteristics. In the present study, lignin peroxidases (LiPs) producing by fungus Humicola grisea were extracted and purified using gel filtration and ion exchange chromatography. Protein and heme protein were eluted in different peaks about 6 of these peaks had LiP activity and this is an indication that LiP in H. grisea was isoenzymes. Four of these isoenzymes were characterized regarding their molecular mass, optimum temperature and optimum pH for activity, substrate concentration and effect of some metal ions. The four purified isoenzymes have maximum activities at different temperatures, where optimum temperature for H2 and H4 isoenzyme were at 60 oC, and the optimum temperatures for H1 and H3 were at 40 oC and 30 oC, respectively. The maximum activities of the four isoenzymes were within the acidic range. The different LiP isoenzymes showed different Km and Vmax values representing the varied affinity of the four isoenzymes using veratryl alcohol as a substrate. Km values for H1, H2, H3 and H4 were 5.26, 5.0, 1.3 and 1.4, respectively. While Vmax values for the same isoenzymes were 1.25, 0.8, 0.87 and 1.1, respectively.

Acid Dye Biodegradation Using Saccharomyces cerevisiae Immobilized with Polyethyleneimine-Treated Sugarcane Bagasse

Chemical reagents used by the textile industry are very diverse in their composition, ranging from inorganic compounds to polymeric compounds. Strong color is the most notable characteristic of textile effluents, and a large number of processes have been employed for color removal. In recent years, attention has been directed toward various natural solid materials that are able to remove pollutants from contaminated water at low cost, such as sugarcane bagasse. Cell immobilization has emerged as an alternative that offers many advantages in the biodegradation process, including the reuse of immobilized cells and high mechanical strength, which enables metabolic processes to occur under adverse conditions of pH, sterility, and agitation. Support treatment also increases the number of charges on the surface, thereby facilitating cell immobilization processes through adsorption and ionic bonds. Polyethyleneimine (PEI) is a polycationic compound known to have a positive effect on enzyme activity and stability. The aim of the present study was to investigate a low-cost alternative for the biodegradation and bioremediation of textile dyes, analyzing Saccharomyces cerevisiae immobilization in activated bagasse for the promotion of Acid Black 48 dye biodegradation in an aqueous solution. A 1 % concentration of a S. cerevisiae suspension was evaluated to determine cell immobilization rates. Once immobilization was established, biodegradation assays with free and immobilized yeast in PEI-treated sugarcane bagasse were evaluated for 240 h using UV–vis spectrophotometry. The analysis revealed significant relative absorbance values, indicating the occurrence of biodegradation in both treatments. Therefore, S. cerevisiae immobilized in sugarcane bagasse is very attractive for use in biodegradation processes for the treatment of textile effluents.