<p>The <i>ppk1</i> genes of the reconstructed Accumulibacter genomes are indicated in green, while those from clone library of sludges A and C are colored in orange. Seven and nine partial <i>ppk1</i> gene sequences with 99% identity were obtained from sludge A and C respectively. Reference sequences attached with their accession numbers are extracted from NCBI database. Node labels refer to bootstrap support values and <i>Rhodocyclus tenuis ppk1</i> gene is employed as the outgroup sequence.</p
