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ISSN: 2349-8889 Volume-9, Issue-2(March2022) https://doi.org/10.31033/ijrasb.9.2.26 International Journal for Research in Applied Sciences and Biotechnology www.ijrasb.com Biodegradation of Azo Dye by Bacterial Species Isolated from Dye Contaminated Area of Jetpur, Gujarat Dhruti Bhalani 1 , Madhavantee Kasundra 2 and Dharmesh Sherathia 3 1 Faculty of Science, Department of microbiology, College of Computer Science and Information Technology, Junagadh - 362001, Gujarat, INDIA. 2 Faculty of Science, Department of microbiology, College of Computer Science and Information Technology, Junagadh - 362001, Gujarat, INDIA. 3 Faculty of Science, Department of microbiology, College of Computer Science and Information Technology, Junagadh - 362001, Gujarat, INDIA. 3 Corresponding Author: dharmesh.microbio@gmail.com ABSTRACT The varieties of synthetic azo dyes are widely used in textile industries to generate range of color tones in the textile and paper industries. Such textile dyes are toxic for the animals, birds and human along with environment. It is needful to remove those dyes from the effluent. The degradation of such dyes is accompanied by the involvement of dye degradating microorganisms. The purpose of this research is to isolate, identify, and screen bacterial species capable of decolorizing reactive pink, congo red, and malachite green. Soil and water samples were collected from the dye contaminated area of Jetpur, Gujarat, India. Dye degradating bacteria were isolated and selected through primary and secondary screening. The effect of yeast extract amount on the dye degradation properties of bacteria was examined using a visible spectrophotometer. After secondary screening MD2, MD8, MD20, MD31, MD33 and MD34 were selected for further analysis. All isolated are able to degrade reactive pink, congo red, and malachite green after 120hrs of incubation at a 4mgl -1 concentration of yeast extract. Dye degradation remains constant for 4 mgl -1 and 2 mgl -1 but gets reduced in 1 mgl -1 of yeast extract concentration. Wheat germination rate in control was 65% compared to 96%, 88%, and 85% in MD2, MD8, MD20 respectively. Sorghum germination rate in control was 62% while in isolates no MD31, MD33, MD34 were 96%, 87%, 83% and 65%. Keywords- Reactive pink, Malachite green, Congo red, Dye degradation, Toxicity assay, Yeast extract, Spectrophotometer. I. INTRODUCTION Dyeing is a well-established method of altering the color properties of various substrates. Azo dyes are used to color a variety of items, including textile, leather, plastic, food and pharmaceuticals, as well as to make paints and for printing [1][2][3]. India produces approximately 80,000 tons of dyestuff and pigments [4]. According to estimates, there are 10,000 different textile dyes commercially accessible worldwide, with annual output of 7× 10 5 metric tons; 30% of these colors are utilized in excess of 1000 tons per year [5][6]. Textile dye comprises colors, causing artistic harm as well as preventing light diffusion in the water, resulting in a drop in dissolved oxygen levels and has an impact on the rate of photosynthesis in aquatic life. The presence of colors in aquatic bodies causes an aesthetic problem and can be harmful to public health [7]. Majority of these dyes are water soluble and are absorbed through inhalation. Skin contact with these dyes can cause allergic reactions as well as cancer [8][9][10]. Because of their extensive applicability and uses, azo dyes are the most common constituents of such pollution, and they are found in large quantities in textile industrial effluents. Microorganisms are used in industrial biological wastewater treatment systems to eliminate toxins from the environment. The majority of azo dyes are carcinogenic, poisonous and mutagenic [11] and may be harmful to aquatic life [12]. Biological treatments provide various advantages, including low cost, ease of use, lesser volumes of excess sludge produced, and high flexibility, as they may be applied to a wide range of effluents. Textile industry effluents are hazardous, containing a high level of color (from reactive dyes and chemical residues), acidic and alkaline pollutants, and high amounts of organic compounds [13]. It is critical to develop effective and environmentally friendly bioremediation systems [14]. Chemical precipitation, Filtration, coagulation, adsorption, chemical oxidation, photolysis, reduction, chemical flocculation, usage of activated carbon, and other physicochemical techniques can be used to treat industrial effluents containing a range of colors [15]. The survival and adaptation of microorganisms during the treatment procedures are critical to the success of these treatment systems [16][17]. The goal of this study is to isolate, identify, and screen bacterial species that can decolorize a range of colors. The breakdown of organic matter is carried out by the microorganisms utilized. The general goal of bioremediation is to increase native organisms natural biodegradation potential by providing adequate environmental conditions for degradation to reduce dye