(IMAGE) University of Vienna Caption This is a cell aggregate of Nitrospira bacteria (pink) in activated sludge from a wastewater treatment plant. The colony contains several thousand Nitrospira cells. Colonies of other bacteria are depicted in green. The bacteria were visualized by fluorescence in situ hybridization. Credit Copyright: Holger Daims Usage Restrictions The image may only be used with appropriate caption or credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.