Screening and Identification of Azo Dye Decolourizers from Mangrove Rhizospheric soil

Abstract

Removal of synthetic textile dye poses a challenge to the textile industry and a threat to environment flora and fauna. These dyes are marginally degradable and recalcitrant, hence alternatives to physical and chemical techniques like various bioremediation studies involving plants, plant roots, single or consortium of microbes have been used as environment friendly methods for the removal of textile dye. In the present study potent bacteria for dye decolourization were isolated from rhizospheric soil collected from Kamothe, Navi Mumbai, India. Of the 20 isolates obtained after enrichment, seven isolates were used for further screening of efficient decolourization ability in MBM media containing 10% glucose, 2.5% trace metal solution and 0.1% of MO dye concentration. Physiological parameters to optimize the decolourization of dye at optimum pH, temperature and incubation time was studied for all the seven isolates. UV-vis and Fourier Transform Infrared spectroscopy were used to investigate dye decolorization. The seven isolates were characterized morphologically, biochemically, and molecular identification of these strains were performed by 16S rRNA sequence analysis. The isolates were identified as Bacillus paramycoides, Pseudomonas taiwanensis, Citrobacter murliniae, Acinetobacter pitti, Exiguobacterium acetylicum, Psychrobacter celer, and Aeromonas taiwanensis. Out of these Aeromonas taiwanensis has shown exceptional capacity by 100% decolorization of azo dye in minimum time.