Identification and Characterization of Indigenous Bacteria with Textile Dye Degrading Potential

Abstract

Although there are natural dyes available, the rapid expansion of the textile industry has led to the development and widespread use of synthetic dyes. Synthetic dyes provide several functional advantages, but their excessive persistence, effluents and toxicity can cause a serious hazard to the water streams and environment due to their synthetic origin and intricate structure. Consequently, the increasing demand for these dyes necessitates effective strategies for mitigating dye-associated water pollution. The present work aimed to explore indigenous bacterial isolates directly from dye contaminated sites and reveal their dye degrading capabilities. In this study, four samples were collected from dye-contaminated sites to isolate and identify bacterial strains capable of decolorizing media supplemented with reactive red and reactive blue dyes. The isolated strains were purified, and their morphological characteristics were studied. Strains exhibiting substantial decolorization activity were selected for further analysis based on their performance in dye-reduction assay. Among the isolates, strains RB4-1, RB6-1, RD4-1, BB5-2, and BB5-1 demonstrated 91%, 88%, 89%, 83%, and 89% reductions in dye absorbance, respectively. Following 16S rRNA gene sequencing, these strains were identified as Salmonella enterica, Enterobacter cloacae, Citrobacter farmeri, Proteus mirabilis, and Klebsiella pneumoniae. In conclusion, the identified strains were capable of decolorizing dye with potential to be used as sustainable and cost-effective agents for bioremediation.