Characterization of Azo-dyes Degrading Microbes Isolated from Textile wastewater and Optimization of various Environmental Parameters

Abstract Azo dyes are highly recalcitrant, persistent, and toxic compounds, extensively used in the textile industry. The untreated discharge of dye effluents from the textile industry poses severe environmental and health risks. The objective of this research was to identify and characterize bacterial strains that effectively decolorize and degrade azo dyes widely used in textile industries (Mono azo dye Methyl red; diazo dye Direct yellow12, and triazo dye Acid Black 210) from textile waters. After subsequent screening of 89 isolates, the current research was able to identified 4 isolates as novel strains utilizing the 16S rRNA gene sequencing technique. The novel strains belonged to the Sphingomonas, Pseudomonas, Shewanella, and Priestia species. The unique sequences of these bacterial strains have been submitted to the GenBank database under the accession numbers “OQ202071”, “PP708911”, “PP708909” and “PP086977” respectively. A thorough assessment of physiochemical parameters was conducted to optimize for maximum decolorisation for all four strains. Further, to proceed enzyme study and statistical optimization of Priestia Flexa species was conducted. A Central composite design (CCD) and Response surface methodology (RSM) have been applied for synergistic effects of process parameters, namely pH, initial dye concentration, and temperature on the decolorisation of the model dyes. Fourier Transform Infrared Spectroscopy (FTIR) was further employed to analyze and confirm the degradation of the three dyes.