Effects of ibuprofen and tetracyline on extracellular polymer production

Extracellular polymer substances (EPS) comprised of proteins, carbohydrates, and other biomolecules, are important for microbiological communities. The EPS provides benefits to wastewater treatment communities (WWTC) such as antibiotic resistance, and community structure. Therefore EPS can be viewed as a valuable health marker of WWTC and therefore it is important to determine effects of contaminants entering wastewater treatment plants (WWTPs) on EPS. WWTC were exposed to the non‐steroidal anti‐inflammatory drug (NSAID) Ibuprofen at 16 ng/mL and 100 ng/mL, and the antibiotic tetracycline at 50 ng/mL to determine how EPS and growth were affected. EPS was analyzed using high performance liquid chromatography (HPLC), Bradford protein analysis, and Anthrone carbohydrate analysis. It was determined that EPS content was lower at both Ibuprofen concentrations, enhanced with tetracycline, and comparable to control when both were present. Changes could not be linked to protein or carbohydrate concentration. Growth inhibition occurred in the presence of both drugs but not each individually, suggesting that Ibuprofen may increase tetracycline sensitivity through EPS inhibition.