Biodecolorization of Orange II dye by native Bacillus sp. and Staphylococcus sp. in simulated medium

Abstract

The discharge of textile dye effluent without proper treatment poses several problems to plants, animals and humans. Biodecolorization offers an ecofriendly cost-effective clean technology for remediating such toxic color compounds from aquatic environments. In the present study, two potential bacteria were isolated from textile dye effluent employing minimal salt medium and identified as Bacillus sp. and Staphylococcus sp. following morphological and biochemical tests. The bacterial isolates were tested for orange II dye decolorization in minimal salt medium. Both the bacteria were highly tolerant to dye up to 250 mg l-1. Whereas, increasing level of orange II dye exerted inhibitory effects on bacterial growth and decolorization. Maximum 68% (by Staphylococcus sp.) and 73% (by Bacillus sp.) orange II decolorization was observed at initial 100 mg orange II dye l-1, pH 7.0 and 35°C under static conditions during 36 h incubation. The results indicate the possible use of these indigenous bacteria in eco-friendly sequential anoxic-oxic treatment strategy.