Table 1. Species identification in the selected DGGE bands (the bands are labeled in Fig. 5)^a.

Bands	Closest relatives (Accession no.)	Identity(%)	Origin
Wa	Uncultured gamma proteobacterium (HQ341388)	97	activated sludge from a phosphorus removal bioreactor
Wd	Uncultured bacterium (FJ356055)	96	anaerobic:aerobic lab-scale EBPR activated sludge system
We	Uncultured bacterium (FJ534989)	100	anaerobic fermentation reactor with the mixture of waste activated sludge and carbohydrate
Wf	Uncultured bacterium (HQ010712)	98	anaerobic/aerobic/anoxic multistage sequencing batch reactor with the carbon source of acetic acid for nitrogen and phosphorus removal
Wg	Uncultured Rhodocyclaceae bacterium (GU123151)	99	activated sludge from a wastewater treatment plant which was operated with an anaerobic (1h)-aerobic (4h) process
Wh	Uncultured bacterium (HM596318)	95	activated sludge cultivated to produce PHAs
Wj	Uncultured Thauera sp. (GU257672)	98	activated sludge in a membrane bioreactor
Wk	Thiothrix sp. (JF824663)	100	bacterial mat
Wl	Uncultured bacterium (FJ623321)	98	aerobic sequencing batch reactor under aerobic feeding and discharge conditions with the carbon source of waste activated sludge alkaline fermentation liquid
Wm	Uncultured Rhodocyclaceae bacterium (HQ003474)	97	Carrizo shallow lake
Wn	Uncultured beta proteobacterium (CU918807)	96	mesophilic anaerobic digester which treats municipal wastewater sludge
Wo	Uncultured gamma proteobacterium (GU066593)	100	polyphosphate-accumulating granular sludge

^aThe partial sequences of the 16S rRNA genes obtained in this study were submitted to the GenBank database under accession numbers JQ280451-JQ280451.