MOLECULAR CHARACTERIZATION AND AEROBIC BIODEGRADATION OF MALACHITE GREEN AND METHYL RED DECOLORISING BACTERIA ISOLATED FROM EFFLUENT CONTAMINATED SOIL

Klebsiella pneumoniae KP 13, able to decolourise Methyl red and Malachite green was isolated and characterised from laboratory effluent contaminated soil from Hislop College, India. The strain identification was carried out by 16S r DNA method. This isolate was capable of utilizing Methyl red and Malachite green as sole source of carbon. The medium contained 200 mg/L of di- ammonium hydrogen phosphate and 1000 mg/L yeast extract in tap water. Dye degradation was carried out under optimum conditions of pH (7) and temperature (37°C) with vigorous shaking. Klebsiella pneumoniae KP 13 culture could be decolorising in Malachite green and Methyl red to the extent of 85% and 93% respectively in 24 hours. The decolourised samples of Methyl red showed the presence of nitrites which indicates that the mode of biodegradation is aerobic and toxic aromatic amines are thus not being formed in anaerobic biodegradation. Thus, the strain of Klebsiella pneumoniae KP 13 can be applied for aerobic degradation of recalcitrant azo and triphenylmethane dyes.