Decolorization of triphenylmethane dyes and textile and dye-stuff effluent by Kurthia sp.

A number of soil and water samples were collected from the vicinity of effluent treatment plant of a textile and dyeing industry. Several organisms were screened for their ability to decolorize triphenylmethane group of dyes. A Kurthia sp. was selected on the basis of rapid dye decolorizing activity. Under aerobic conditions, 98% color was removed intracellularly by this strain. A number of triphenylmethane dyes, such as magenta, crystal violet, pararosaniline, brilliant green, malachite green, ethyl violet and textile and dyestuff effluent used in this study. The rates of decolorization of magenta (92%) crystal violet (96%) malachite gr een (96%) pararosaniline (100%) and brilliant green (100%) were found to be more than that of ethyl violet (8%). After the decolorization of most of the dyes, viable cell concentration of the Kurthia sp. reduced significantly. In the case of ethyl violet, viable cell concentration was almost negligible after decolorization. The extent of decolorization of synthetic effluent (98%) was more in comparison to textile and dye-stuff effluent (56%). After biotransformation, the extent of COD reduction of the cell free extracts of triphenylmethane dyes was higher (more than 88%, except in the case of ethyl violet, 70%) in comparison to textile and dye-stuff effluent. (C) 1999 Elsevier Science Inc. All rights reserved.