Biodegradation of Direct Red-28 by Bacillus sp. Strain DRS-1 Under Aerobic Conditions and Analysis of Phytotoxicity Levels

Discharge of Azo dyes into the environment that generates toxicity and mutagenesis is a major concern in society; alternate ecofriendly approaches are needed to remediate the dye-contaminated wastewaters discharged from a range of textile industries. The only way to make the environment pollution free is by means of microorganisms. In this study, a potential bacterium capable of degrading the Red-28 azo dye was isolated from the dye-contaminated effluents by decolorization of Red-28 and with various culture conditions for bacterial biomass production as temperature, pH, and agitation rates with concentration of dye, carbon sources, various nitrogen sources, and various metal ions. The strain was identified as Bacillus sp. DRS-1 is based on the 16S rDNA gene sequence. The identified Bacillus consortium was shown to decolorize which was observed through biomass activity and decolorization with batch assay, optimum at 45 °C and pH 8.0. The degraded sample was further monitored through HPLC, FTIR, and GC–MS; it was cross-checked with the processed water quality profiles by the Ministry of Text tiles, Government of India. The decolorization was studied by various immobilization matrices and phytotoxicity experiments with bacterial consortium of Bacillus sp DRS-1. The results showed that maximum decolorization was with Ca-alginate matrix. The present study was suggested as a direction for the development of successful large-scale biotechnological progression for the removal of dyes and by-products in textile effluents.