Isolation and Characterization of Dye Decolorizing Bacteria from The Textile Dye Effluents

Abstract

The most significant challenge confronted by the textile industries is the discharge of dye effluents which contains toxic chemicals posing a considerable threat to environmental pollution. Biological method of treating effluents using bacteria is one of the renewed and accepted method in effluent treatment. The present study aims to isolate and characterise the dye decolorizing bacteria from the effluent samples of a dye industry from Chinnalapatti, Tamilnadu. The dye effluents were collected from the effluent plant of a leading dye industry and the Physiochemical parameters were analysed.  The samples were plated in a Nutrient Agar and bacterial isolation were performed according to the standard microbiological procedures. The bacterial isolates identified by biochemical identification were tested for its efficiency to decolorize Methyl red and crystal violet dyes. Among the three isolates S1showed 98% decolorizing efficiency in reducing Methyl red dye and 92% efficiency in decolorizing crystal violet dye. Sample S2 showed 85% activity in decolorizing methyl red dye and 86% activity in decolorising Crystal violet dye. S3 showed a low decolorizing activity compared to S1 and S2. Both of these phenotypically identified isolates are subjected to molecular identification by 16s gene amplification and gene sequencing. The obtained FASTA sequence were analysed for the phylogenetic relationship and submitted to NCBI. The potential isolate that has the capacity to decolorise the dyes were identified as Bacillus Tropicus and Pseudomonas mosselli. This study proves that these bacterial strains can be used as a potential bioremediation agent in decolorizing the dye effluents.