Dicloxacillin Degradation with Free-Living Bacteria

Abstract

Environmental problems such as bacterial resistance have been generated by indiscriminate use of antibiotics, because free-living bacteria have a great ability to adapt to unfavorable environmental, since they develop several defense mechanisms such as genetic resistance, in response of being in contact with this contaminant present in its environment, which is why they acquire special importance due to its biodegradation capacity. In this study, the biodegradation of 40 μg/mL of dicloxacillin with free-living bacteria was evaluated. Wastewater samples were collected from a hospital, from which five resistant strains were isolated, characterized, and identified: Pseudomonas aeruginosa, Citrobacter freundii, Klebsiella pneumoniae, and two different strains of Escherichia coli, being the last one, the most resistant according to the determination of the minimum inhibitory concentration, so degradation was carried out with this strain and in bacterial consortium. Biodegradation was quantified by high-resolution liquid chromatography (HPLC) and the results showed that both the consortium and Pseudomonas aeruginosa are highly efficient because the degradation of the antibiotic was 100%, in a time of 3.5 h and 52 h, respectively, and even metabolize the degradation products.