The overall aim of the interdisciplinary research project “PharmCycle” is to reduce the contamination of the aquatic environment with antibiotics by developing sustainable antibiotics, improving the environmental risk assessment of antibiotics, and reducing the discharges of antibiotics in the wastewater outlet. An overview of the holistic approach and first results are given.

The first step is to design sustainable antibiotics, which are effective against target organisms but, after their use, are less toxic, and are rapidly and completely degradable. To develop sustainable antibiotics, two different approaches (subprojects) are applied within PharmCycle: First, a re-design of the existing antibiotics with chemical and in silico methods (“Benign by Design”). Second, sustainable peptide-based antibiotics are produced with biotechnological methods. In the second step, the environmental risk assessment for antibiotics in the framework of the authorization process and for monitoring purposes is improved. There is a lack of data for the environmental risk assessment of antibiotics on the European market. With more transparency of these data, the environmental risk assessment for active substances and for the class of antibiotics can be improved. The aim is to increase the data availability by applying the Aarhus convention and by providing legal access to environmental information. Beside other shortages in the environmental risk assessment required by the European legislation, the effects of antibiotics directly applied in marine aquacultures are not assessed by marine prokaryotic test systems. Therefore, a marine cyanobacteria test was developed, which is more sensitive to selected priority antibiotics than the marine eukaryotic algae test (DIN EN ISO 10253) required by the European Medicines Agency. Marine cyanobacteria are of high importance for the nitrogen cycle and primary production. Moreover, they seem to play an important role with respect to climate change. To reduce the emission of antibiotics used as human pharmaceutical products to the aquatic environment, the third step focusses on the main pathway, the wastewater. Investigations to improve the wastewater treatment of priority antibiotics and sustainable antibiotics are conducted by a combination of methods: activated sludge units, activated carbon adsorption, and membrane filtration systems.

With the aim of improving the environmental risk assessment of antibiotics and to reduce the emission of antibiotics to the aquatic environment, an interdisciplinary approach is applied which includes the analysis of the German, European, and international law and the development of new legal instruments.