Degradation of Direct Red 28 by Alcaligenes sp. TEX S6 Isolated from Aeration Tank of Common Effluent Treatment Plant (CETP), Pali, Rajasthan

摘要

Pali city in Rajasthan has been a major environmental concern in the terms of extensive water pollution caused by the textile industries. The textile effluents are characterized by remarkably strong colour, high pH, BOD and COD. The major culprits are the direct diazo dyes and one such dye is Direct Red 28. To develop an effective bioprocess for dye degradation, bacteria were screened from different stages of the common effluent treatment plant situated in Mandia Road, Pali. The most potential bacteria was an isolate from aeration tank and characterized as Alcaligenes sp. TEX S6 by 16S rDNA sequencing. The dye removal efficacy of the strain was expressed as a reduction in absorbance maxima of the dye. The strain removed the dye (0.15 g/L) up to 86% within 48 hours of static incubation utilizing fructose and peptone at 37oC and pH 7. The inoculum concentration had no effect on the decolourisation process. A significant increase in bioefficacy of the strain was observed with respect to abiotic control. TLC chromatogram and FTIR spectra of the pure dye compound and the decolourised dye was suggestive of enzymatic degradation in accordance with biodecolourisation.