Current World Environment

Azo dyes are widely used in textile industry. Unused dyes, consisting mainly non biodegradable released along with waste water streams without any proper pre-treatment which cause nuisance for environment and accumulate in flora as well as fauna. These also exhibit allergic, carcinogenic and mutagenic properties for human beings. Isolation and screening of azo dye degrading bacteria are economic in biodegradation and detoxification. In the present study, 200 waste water samples were collected from dye-contaminated sites of textile industries and bacterial species such as Bacillus subtilis, Pseudomonas aeruginosa and Psuedomonas putida were isolated and identified. Evaluation of decolorizing properties of these bacteriae were done by UV-Vis spectroscopy (A_max 596 nm) in different concentrations using different carbon sources such as Hans’s medium and GYP medium. Maximum decolourisation of 0.1% azo dyes were recorded to be 89.0%, 91% and 86% in Hans medium containing charcoal source by Bacillus subtilis, Pseudomonas aeruginosa and Psuedomonas putida respectively at 24 hrs. These bacterial isolates may be utilized in large scale for pre-treatment for ecological balance by avoiding water pollution.