Isolation, characterization and decolorization of textile dyes by a mixed bacterial consortium JW-2

Soil samples collected from dye contaminated sites of Jetpur, Gujarat were exploited for isolation of dye decolorizing organism. A microbial consortium JW-2 was selected based on its efficiency, showing maximum and faster decolorization of textile dyes. The consortium consisted of three isolates. Identification of isolates by 16SrRNA technique revealed that the organisms were Paenibacillus polymyxa, Micrococcus luteus and Micrococcus sp. The concerted metabolic activity of these isolates led to complete decolorization of Reactive Violet 5R (100 ppm) within 36 h whereas individual isolates could not show decolorization even on extended incubation. The culture exhibited good decolorization ability in the pH range from 6.5 to 8.5 and temperature from 25 to 37 c. The consortium showed complete decolorization utilizing low amount of cosubstrates like glucose (0.1% w/v) and yeast extract (0.05% w/v) and could also utilize a cheaper carbon source like starch in place of glucose as an alternative co-substrate. The consortium had the ability to decolorize nine different dyes amongst 10 tested. Potential of this consortium JW-2 to clecolorize textile effluent containing a mixture of textile dyes is to be carried out using appropriate bioreactors. (c) 2006 Elsevier Ltd. All rights reserved.