Biological decolorization of the synthetic dye RBBR in contaminated soil

Soil contaminated with the synthetic dye Remazol Brilliant Blue R (RBBR) was treated independently with the wheat straw-grown white rot fungus Irpex lacteus, a bacterial consortium isolated from a dye-polluted soil and a coculture comprising both I. lacteus and the bacterial consortium. Both I. lacteus and the coculture removed RBBR (decrease in absorbance at 578 nm) gradually during a 49-day incubation time to 76 and 78%, respectively. The bacterial consortium alone, however, decolorized RBBR starting after 14 days with a final RBBR removal of 89%. Using controls with heat-killed cultures almost no decolorization occurred. The decolorization by the coculture did not show an increased RBBR removal as compared to the individual cultures. This might be explained by the observation that I. lacteus inhibited growth of the bacterial consortium.