Biodegradation of synthetic dyes by some bacterial strains isolated from soil

Abstract

In present study, 19 bacterial strains were isolated from different type of soil (Danube –Delta Biosphere Reserve), molecularly identified (16S rDNA sequencing), and tested for their textile dye biodegradation potential and tolerance level to heavy metals and high salinity. The strains Pseudomonas sp., Bacillus sp. andThalassospira sp. were found to degrade ˃ 72.64% RO16 dye, but only Pseudomonas putida removed (56% decolorization) the RB4 dye.Also, was found a good tolerance to salinity (8% NaCl) in case of Pseudoarthrobacter sp., Enterobacter sp., Thalassospira sp.,Bacillus sp., and Pseudomonas sp. strains. Most of the bacterial strains tolerated 70 ppm of cromium (Cr6); only two strains, Cupriavidus respiraculi and Pseudomonas putida showed maximum tolerance to 70 ppm cadmium (Cd2+); all strains of Pseudomonas sp.showed tolerance to 100 ppm lead (Pb2+). The selected strains could be used in bioremediation process of industrial dye waste waters.