Abstract

The initial selections of bacterial strains were based on effective decolourization of the medium by visible observation and UV-Vis spectral analysis. The operational parameters for dye degradation by the bacterial strains was observed from 6.5 to 7.5 pH range, 35 to 45°C with 100 mg/l dye concentration in static condition for 3 days incubation. The FTIR analysis reveals the modification of the functional groups after bacterial treatment. The reduction of toxicity after bacterial treatment was confirmed using Vigna radiataphytotoxicity study. It was concluded that the native bacterial strains isolated from the sludge environment possess high dye degrading ability. Further characterization of these bacterial strains and their enzymes are necessary for intense field application study.

Key words: Azo dyes, native bacteria, FTIR, toxicity, Vigna radiata, optimization.