Degradation potential of nocardia spp. and e. coli against some commonly used dyes

Different native bacterial strains were isolated from the dye effluent and were acclimatized and screened for the degradation experiments against five commonly used dyes viz. Methyl Red, Methyl Orange, Erichrome Black, Crystal Violet and Malachite Green. RGL and MRL values for these bacterial strains against the dyes were evaluated by keeping them on solid culture media or Dye Modified Media (DMM). The relative decolorization potential of bacterial strains was determined by growing them in liquid media and its modifications. From the screening experiments several bacterial isolate strains emerged as ‘Degrader strains’ that possess a good deal as they displayed good values of MRL and RGL against various dyes in DMM. It was found that these degrader strains were Nocardia spp. and E. coli that displayed a good deal of decolorization against all the dyes tested. Best results were obtained for Nocardia spp. followed by E. coli against all the tested dyes. Most accessible dyes for decolorization by these bacterial strains were Erichrome Black and Methyl Orange. Nocardia spp. displayed a maximum decolorization percentage of 54% against Methyl Orange and 51% against Methyl Red dye.