Abstract

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Novel bacterial strains capable of decolorizing textile dyes were isolated from dye contaminated soil obtained from the vicinity of African Textiles Industry Challawa, Kano - Nigeria. The Carcinogenic azo dye Congo red used widely in various industrial processes poses terrific environmental concern, causing major health problems to human beings. In the present study, decolourization of Congo red by newly isolated antibiotics sensitive novel bacterial strains from dyes contaminated soil of a treatment plant capable of decolorizing organic dyes were investigated and identified as Rhodococcus rhodochrous and Pseudomonas aeruginosa strains by 16S rDNA gene sequence analysis. Decolorization of Congo red dye using these bacterial strains was assayed by screening and optimizing various parameters to determine the optimal conditions required for maximum decolourization. Rhodococcus rhodochrous and Pseudomonas aeruginosa showed maximum decolourization upon incubation for 24 hrs at 37 °C and pH 7. Enhanced decolourization was achieved by amendment with glucose and peptone as well as carbon and nitrogen sources in the culture medium. The bacterial strains showed great potential in the decolourization of Congo red dye up to 96.1 % for Rhodococcus rhodocchrous and 91.1 % for Pseudomonas aeruginosa in the aqueous environment at optimal conditions. High performance liquid chromatography (HPLC) analysis confirmed that dye decolourization occurred due to the breakdown of dye molecules into colourless end products. The less toxic nature of the dye degraded products was observed by microbial toxicity assay of agricultural significant bacteria and this can be exploited for the bioremediation of different classes of textile dyes and their derivatives containing waste

Keywords: : Antibiotics sensitive, bacterial strains, decolourization, microbial toxicity, textile dyes