Diversity and ecophysiology of novel polyphosphate accumulating organisms

Comprehensive surveys from full-scale wastewater treatment plants consistently show high abundance of potential polyphosphate accumulating organisms (PAO) in full-scale plants besides the well-studied Candidatus Accumulibacter. However, the diversity, ecophysiology and functionality of these organisms remain largely unresolved. Targeted laboratory-scale experiments combined with monitoring the microbial evolution and microbial performance showed a diverse community with several novel PAO candidates. By using the new ecosystem-specific reference database MiDAS 3 for high-resolution amplicon analyses and design of novel highly specific FISH probes, several novel species within the genus Tetrasphaera and other genera were revealed as potential PAOs. By combining cycle studies with Raman-FISH for ecophysiological studies, the relative contribution of the different novel PAOs to P-removal under different conditions can be resolved.