Protein profiles of phosphorus- and nitrate-removing activated sludge systems

Samples from laboratory-scale activated sludge systems operating under spec ific conditions which differ in phosphate-removing capabilities were obtain ed from the University of Cape Town. The total protein content of samples o f these systems was used and the proteins separated with SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Analysis of the total proteins was employe d as a fingerprint to type and compare the diversity of the bacterial commu nities of P-and ri-removing systems. Samples of six activated sludge system s (three N- and P-removing and three N-removing) were used in this study. P rotein profiles indicated a high (>70%) correlation for all the systems. No difference was observed in the protein profiles of the bacterial communiti es of N- and P-removing or N-removing systems. We can therefore conclude th at the same bacterial communities were present in P- and N-removing systems .