Isolation, characterization, identification and antimicrobial susceptibility testing of bacteria associated with pharmaceutical waste water treatment

Abstract

The pharmaceutical industries in Bangladesh are one of the most developed hi-tech sectors within the country's economy. The rapid development of pharmaceutical industries resulted in the production of huge amounts of pharmaceutical effluents. These wastes contain several types of toxins including heavy metals and pharmaceutical compounds, which have high toxicity for human and environment. The traditional technologies are not effective to remove both antibiotic compounds and heavy metals. But combination of both chemical & biological or biochemical treatment is the most economical and environment friendly method of treating effluents. Therefore, this study is aimed to evaluate the efficiency of ‘Effluent Treatment Plant (ETP)’ operated in a multi-product facilities and designed to treat effluents both by chemical & biological methods, to evaluate the physico-chemical parameters and bioburden (microbial load) of the raw water as well as treated water, to isolate and identify some bacteria associated with the pharmaceutical waste water treatment; and to assess antibiotic sensitivity pattern of the isolated bacteria. The physico-chemical study [like pH, Total Suspended Solid (TSS), Total Dissolved Solid (TDS), Total Solid (TS), Dissolved Oxygen, Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD), Oil & Grease and bioburden] of the raw water as well as treated water and microbiological study [type of bacteria associated with waste water treatment and their sensitivity & resistance to specific antibiotics] were conducted as per the approved procedure of Incepta Pharmaceuticals Ltd. The results revealed that all physico-chemical parameters of raw water as well as treated water were within the prescribed limit as per the Department of Environment (DOE) of Bangladesh and there was no significant variation during the entire operation period. It was also shown that, microbial load was satisfactory, which indicates that the organism present in the ETP can tolerate the stress of the effluents. In this study, out of 30 isolates, 7 different bacteria could be identified viz. Micrococcus luteus, Bacillus subtilis, Stenotrophomonas maltophilia, Empedobacter brevis, Tatumella ptyseos, Klebsiella pneumonia, and Streptococcus sanguinis. The antibiotic sensitivity pattern of the identified bacteria were also performed and found that, some of the isolates were resistant to all the 5 antibiotics used. It can be concluded that the functionality of the biological part of the ETP is good enough and it indicates the organisms present in the biological part of the ETP has the involvement in the pharmaceutical waste water treatment.