ABSTRACT:

Bacterial isolates obtained from textile effluents were identified based on cultural and biochemical characteristics. Selected strains were tested for their ability to decolourise blue reactive dye using the conical flask assay without agitation. The physicochemical parameters of the effluents tested were within WHO limits: TDS (138-256mg/L), Conductivity (88-189μS/cm), pH (7.2-8.4) and Turbidity (0.00). The decolourisation activities of the strains were only visible as from day 5, and spectrophotometric analysis revealed that rates did not improve significantly within the following 48 hours of observation. The strains examined and their decolourisation efficiencies were as follows: Pseudomonas sp., 66.2%; Bacillus sp., 41.9%; Enterobacter aerogenes, 33.1%; Micrococcus luteus, 31.6% and Staphylococcus aureus, 23.5%. On media without an additional carbon source, decolourisation rates were reduced with the highest recorded by Enterobacter aerogenes at 17.1%. Therefore, optimization enhances the dye decolourisation potential of the bacteria.