Multiple Approaches Towards Decolorization and Reuse of a Textile Dye (VB-B) by a Marine Bacterium Shewanella decolorationis

Abstract

Textile dye Victoria Blue-B (VB-B) was approached in two different ways: one to get rid of the color for its easy disposal to the environment, and the other is to reuse the decolorized water for coloring the same dye. Shewanella decolorationis (MBTD16) isolated from Dona Paula Bay, identified by 16S rRNA gene and its action over decolorization was monitored by Fourier transform infrared spectroscopy, UV–Vis spectrum, and a color scanner. Dye removal index increased L*, a*, and b* to 91.585, −2.856, and −0.132 against 62.29, −4.93, and −20.75 within 42 h as a first report. A maximum extent of decolorization (94.83 %) could be achieved with minimum dye concentration of 50 mg L−1. The colored water treated by free and immobilized bacterial cells tested to reuse (VB-B dye) could give 35–50 % more color than the original. Process parameters optimized to achieve maximum decolorization indicated pH 7, temperature 32 ± 2 °C, inoculum size 8 % with co-substrates of glucose and yeast extract 5 g L−1 for its supremacy. Synthesis of lignin peroxidase and tyrosinase augmented in strain S. decolorationis only after being exposed into the dye signifies the enzymes in decolorization, and it was confirmed through one-way ANOVA. Results obtain by this work could suggest that S. decolorationis can be used very well to decolorize the textile dye, and the same water could be recycled to get back its original color by adding around half the quantity of dye. Thus, by the use of water, dye and pollution levels could be minimized.