Fig. 4

Detection of phosphate accumulating bacteria by fluorescence in situ hybridizations (FISH). Detection of PAO using a mixture of 16S rRNA gene specific probes PAO462, PAO651 and PAO846 in activated sludge from series A3 (a) and A4 (b). Detection of Accumulibacter phosphatis clade II using 16S rRNA gene specific probe Acc-II-444 in biofilm from series A4 (c) and Actinobacterial PAO using 16S rRNA gene specific probe Actino658 in biofilm from series A3 (d). In all cases, all bacteria were detected by a mixture of 16S rRNA gene probe EUB338, EUB338II and EUB338III. All bacteria appear green, while specific probes appear yellow/orange due to dual labelling with green and red. Images captured by Katarzyna Drzewiecka