Assessing the bioremediation potential of indigenously isolated Klebsiella sp. WAH1 for diclofenac sodium: optimization, toxicity and metabolic pathway studies.

Among the various pharmaceutical pollutants, diclofenac sodium (DFS), a widely prescribed non-steroid anti-inflammatory drug is detected in the aquatic environment at concentrations which can be harmful to living organisms. Present study illustrates the isolation and characterization of strain Klebsiella pneumoniae WAH1 from activated sludge and its ability to degrade DFS as sole source of carbon and energy. The growth and degradation capacity of K. pneumoniae WAH1 under different conditions of pH, temperature, rotation speed, and inoculum age were evaluated using optical density and liquid chromatography-mass spectroscopy (LCMS). The results show that K. pneumoniae WAH1 can grow well with DFS as its sole source of carbon and degrade 79.14% of DFS (10 mg L-1) within 72 h. Based on chemical structure of intermediates detected through LCMS, it is inferred that degradation pathway advanced by hydroxylation, decarboxylation, and dechlorination reactions. Toxicity studies revealed the non-toxic nature of the end-products of DFS degradation after 72 h. The findings suggest that K. pneumoniae WAH1 has an excellent potential for bioremediation of DFS in industrial wastewaters.