A　bench-scale　UCT　(University　of　Cape　Town)-type　membrane　bioreactor　(UCT-MBR)　fed　with　low-strength　synthetic　wastewater　was　operated　to　investigate　phosphorus　removal　with　reference　to　poly-phosphate　accumulating　organisms　(PAOs)　and　denitrifying　poly-phosphate　accumulating　organisms　(DPAOs).　A　series　of　kinetic　assays　of　PAOs　and　DPAOs　were　also　conducted　to　analyze　the　metabolic　activities　of　PAOs　and　DPAOs.　Results　showed　that　93%　of　chemical　oxygen　demand　(COD)　and　77%　of　total　nitrogen　could　be　removed　at　0.08　kgCOD　kg(-1)　MLSS　d(-1)　and　0.015　kgN　kg(-1)　MLSS　d(-1)　loading　(MLSS:　mixed　liquor　suspended　solids).　Removal　efficiencies　of　total　phosphorus　increased　during　the　experimental　phase,　with　an　ultimate　removal　efficiency　of　96.1%.　Kano　and　Kaer　increased　from　1.95　and　6.29　mgPO(4)(3-)　-P　g(-1)　MLSS　h(-1)　to　5.47　and　11.13　mgPO(4)(3-)-P　g(-1)　MLSS　h(-1)　for　DPAOs　and　PAOs　respectively,　with　the　increased　ratio　of　DPAOs　to　PAOs　from　31　to　49%　implying　DPAO　metabolic　activity　increased　faster　than　that　of　PAOs　during　the　DPAO　accumulation　phase.　Pano-uptake　increased　by　6.6　mg　L-1　and　the　ratio　of　PTano-uptake　to　PTupt　increased　from　58.97　to　91.62%.　The　ratio　of　DPAOs　to　PAOs　tended　to　stabilize　at　around　50%　over　time.