*2.1. Sample Collection*

Activated sludge samples were collected in the period between September 2011 and February 2012, twice a month (except January) from the basin of the incoming untreated waste water at a sewage treatment plant (>500,000 population equivalent, wastewater load 1200 L/min) at the area of Graz, Styria/Austria. Wastewater entry into this treatment plant contained mainly domestic waste water and wastewater from hospitals in the area. The sludge samples were collected using sterile wide-mouth bottles. They were transported to the laboratory in a cooling box, where they were immediately stored in a refrigerator at 4–8 ◦C until processing within 24 h. In total, eleven sludge samples were collected in six measuring series.
