Bacterial bioremediation of textile effluent dyes contaminated sites

Abstract

Water and soil pollution caused by industrial effluent has become an alarming threat to environmental safety. This is mainly because of the direct discharge of textile effluents into the water bodies, without any pre-treatments. To resolve this, microbial bioremediation is used for the effective removal of the dyes and toxic compounds present in textile effluents. The textile dye-degrading isolates (3A, 4A, 5B and 6B) were isolated from the soil samples collected at the dye contaminated sites. Synthetic textile dyes, Brill Red 3BN and Blue SE2R obtained from the textile dyeing units were used as positive control for this study. The genus of the dye degrading isolates was identified by morphological and biochemical characterization. Based on the results, the isolates were belonged to the genus Pseudomonas. All four strains are producing both pyomelanin (brown) and pyoverdine (green) pigments during their growth. Maximum tolerance concentration (MTC) test, growth kinetics, decolorization and degradation studies were performed to analyze the dye degrading potential of isolates. Strain 3A and 6B showed more than 80% of decolorization up to 2500 ppm dye mix within 5 days of incubation. Isolates used textile dye as their sole carbon source for their growth and development. The biodegraded dye was analysed by GC-MS to measure the dye degrading ability of isolates.