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= Decolonization of Textile Dyes By Fresh water Cyanobacteria =

= Introduction =

Synthetic dyes are recalcitrant molecules that constitute the main residue found in the effluent of the textile dyeing industry. Dyes used in textiles are used to color the original raw material and therefore product. Dyes can be synthetic, which means they are scientifically made with chemicals, or natural. Dyeing is usually processed into textiles through a combination of water and the synthetic or natural dyes. Textile dyes represent a large group of organic substances that impose undesirable effects on the environment. An emerging ecological concern is the effluents from the textile industry and the dyeing-related processes that were not conveniently treated before they are introduced into the natural environment reaching reservoirs and water stations. Dyes are heavily employed in several industries, primarily textile industries. Without effective treatment, they can draw significant attention from the environmental authorities because they are easily visualized in any polluted water body. However, depending on the dye type and the application, the final stage of the dye can significantly contribute to the release of waste of several chemical substances with variable composition. Cyan bacteria have a wide and varied impact on natural ecosystems and can act causing beneficial or noxious effects to the health of humans and animals. Compared with some physical, chemical treatment the biological treatment has high significance due to its cost effectiveness and Eco-friendliness. Among this the marine cyan bacteria have a unique function system in the removal of colors from textiles. Cyanobacteria are a group of photosynthetic bacteria, some of which are nitrogen-fixing, that live in a wide variety of moist soils and water either freely or in a symbiotic relationship with plants or lichen-forming fungi. They range from unicellular to filamentous and include colonial species. Colonies may form filaments, sheets, or even hollow spheres. This project showed the ability of cyanobacteria in degradation of textile dyes (Direct blue and Indigo) at different concentrations and conditions. We see that% decolonization increased more when kept under shaking condition than that of static conditions with increase in concentration. After adding factors such as ammonium sulfate, starch and sodium chloride the decolonization percentage increased rapidly than under any other conditions. Hence proving that fresh water Cyanobacteria is a good and economical alternative in degradation of textile dyes from water bodies.

= Role of Cyanobacteria in the decolonization of Textile Dyes =

Cyanobacteria have a wide and varied impact on natural ecosystems and can act causing beneficial or noxious effects to the health of humans and animals. Some of these oxygenic photoautotrophic organisms are important primary producers of combined nitrogen some species possess high nutritional value and some species are of economic importance. The representatives of this microbial group have large distribution in the natural ecosystems, habituating freshwater, marine and terrestrial environments. Cyanobacteria colonize places of extreme conditions, such as Arctic and Antarctic areas, thermal sources and areas with little or no illumination. The cyanobacterial diversity is attributed to the wide variety of structural and functional aspects of their cellular morphology and to variations in their metabolic strategies.The metabolic diversity of cyanobacteria is reflected in their ability to survive in such a variety of environments.

= Conclusion =

•	Green, filamentous with mucilagenous sheath cyanobacteria was isolated from water sample. •	In case of both the dyes, Direct blue and Indigo there was a decrease in 1% of decolourisation with the increase of dye.Concentration under static condition. Percentage of decolourisation for Indigo was less compared to that of direct blue. •	In case of shaking condition,both the dyes Direct Blue and Indigo showed a remarkable increase with the percentage of decolourisation of dye with the increase in the concentration of both the dyes. •	In case of direct blue initially there was a decrease in the amount pf chlorophyll till 30mg/l but considerable increase was notedat 40and 50mg/l concentration of the dye. Compared to that of chlorophyll, carotenoid showed a uniform increase in the amount with increase in dye concentration. •	In case of indigo the amount of chlorophyll was morecompared to that of direct blue. While the amount of carotenoid increase was similar to that of direct blue. •	Effect of both the direct blue and indigowas studied with the help of lactophenol-cotton blue staining.At 10mg/l concentration the filaments of cyanobacteria were intact with profuse mucilage. While at higher concentration 50mg/l the number of filaments were reduced,partially broken and amout of mucilage was less. Effect on the change in morphology of cyanobacteria at 50mg/l of indigo was much more compared to that of direct blue. •	To increase the percentage of decolourisation of direct blue and indigo effect of three factors- Ammonium Sulphate,Starch and NaCl was studied. It was found that on addition of factors there was an increase in percentage of decolourisation compared to that of the control. It was observed that the percentage of decolourisation was greater in case of indigo compared to that of direct blue. •	The viabilityof the cells of cyanobacteria was proved by ethidium bromide and acridine orange staining and its observation under fluorescent microscope. At 10mg/l(S1) green filaments were observed in case of direct blue while red in case of indigo. At 50mg/l (S5) all the filaments treated with indigo were red while in case of direct blue very few green cells observed among the red cells. •	Thus number of dead cells were more in case of indigo compared to that of direct blue. Therefore effect of indigo was severe in case of cyanobacteria compare to that of direct blue. •	Thus it can be concluded that isolated freshwater filamentous cyanobacteria could be utilised in the decolourisation of (direct blue and indigo) textile dyes and successfully used for bioremedation studies.

= References =

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