Screening of soil bacteria as potential agents for drugs biodegradation: a case study with clofibric acid

BACKGROUND: Clofibric acid (CLF), the main pharmacologically active metabolite of blood lipid regulating pharmaceutical clofibrat, etofibrat, etofyllinclofibrat is one of the most widely reported drugs found in water. It is hardly or not degraded by the conventional technology used in wastewater treatment plants. RESULTS: Sixteen new filamentous bacteria belonging to genus Streptomyces spp. isolated from different Romanian soil samples and three strains from a collection of microorganisms (MIUG) were morphologically characterized, tested based on their resistance against clofibric acid toxicity and then investigated as bioremediation agents. Only five Streptomyces spp. isolates coded MIUG 4.88, MIUG 4.89, LP1, LP2, SNA, showed high CLF tolerance at most of the concentrations tested (0.2, 0.5, 1, 5, 8 mg L-1). CONCLUSION: The data obtained showed that only the strain Streptomyces MIUG 4.89 presents promising potential for clofibric acid biodegradation, with an elimination yield of 35%, which was not reported for this class of bacteria to date. However, further research is needed for optimization of the CLF biodegradation conditions to enhance its bioremediation yield especially in polluted aquatic systems. (C) 2016 Society of Chemical Industry.