Biodegradation and Detoxification of Reactive Red 250 by Pseudomonas aeruginosa CR-25

The major sources generating a large amount of colored effluents are textile dyeing and printing industries. Untreated effluents from dyestuff production and dyeing mills may be highly colored and thus particularly objectionable and offensive if discharged into water. Bioremediation addresses the limitations of these conventional techniques by bringing about the actual destruction of many organic contaminants at a reduced cost. The bacterium Pseudomonas aeruginosa CR-25 was identified by 16S rRNA gene sequence analysis (GenBank: EU109736). CR-25 isolated from textile effluent decolorized and biotransformed Reactive Red 250 (RR250) to aromatic amines benzidine and 4-chloro aniline. Further incubation under aerobic conditions led to the complete degradation of these intermediates. The decolorization activity of RR250 was analyzed under various nutritional and environmental parameters. The toxicity of cell-free culture (obtained after decolorization) was carried out on the germination of seeds of Arachishypogia, Cicerarientum, Triticumvulgare and Phaseolusmungo. Seeds irrigated with cell-free culture under static culture condition demonstrated toxic effects and obtained after sequential static-shaking culture condition reduced toxic effects. Decolorization and degradation potential of CR-25 can be exploited for bioremediation of polluted sites.