Antibiotic and heavy metal resistance properties of bacteria isolated from the aeration lagoons of common effluent treatment plant (CETP) of tannery industries (Unnao, India)

In the present study, 12 aerobic bacterial strains were isolated from the common effluent treatment plant (CETP) of tannery industries and identified as Alcaligenes sp. (FJ55942), Pantoea sp. (FJ55943), Bacillus megaterium (FJ55944), B. marisflavi (FJ55945), B. subtilis (FJ55946), B. megaterium (FJ55947), B. cereus (FJ55948), B. pumilus (FJ55949), Pseudomonas sp. (FJ55950), Bacillus sp. (FJ55951), B. subtilis (GU193980) and Klebsiella pneumoniae (GU193981) having closest relationship with Agrobacterium larrymoorie bacterium. Further, the results of antibiotic and heavy metal resistant studies have shown that all the bacterial isolates of initial and final aeration lagoons were intermediate for ciprofloxacin and tetracycline, except Alcaligenes sp. and Pantoea sp. In addition, the bacterial isolates of initial aeration lagoon have shown a wide range of MIC values ranging from 90-650, 60-250, 150-800, 600-700, 400-650, 90-600, 400-600 and 60-500 μg mL for Cr, Cu, Zn, Fe, Ni, Pb, Mo and As; while that of final aeration lagoon, it was 140-600, 60-250, 600-700, 550-700, 400-650, 100-300, 400-650 and 200-400 μg mL for Cr, Cu, Zn, Fe, Ni, Pb, Mo and As, respectively. All these bacterial isolates were found to have a wide range of multi-drug and multi-metal resistant property, indicating that industrial effluents are organically enriched medium supporting the fast growth and spreading of antibiotics and heavy metals resistant microbes in the environment.