title: Survival strategies of polyphosphate accumulating organisms and glycogen accumulating organisms under conditions of low organic loading.
abstract: Enhanced biological phosphorus removal (EBPR) is usually limited by organic carbon availability in wastewater treatment plants (WWTPs). Polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) were operated under extended periods with low organic carbon loading in order to examine its impact on their activity and survival. The decrease in organic carbon load affected PAOs and GAOs in different ways, where the biomass decay rate of GAOs was approximately 4times higher than PAOs. PAOs tended to conserve a relatively high residual concentration of polyhydroxyalkanoates (PHAs) under aerobic conditions, while GAOs tended to deplete their available PHA more rapidly. This slower oxidation rate of PHA by PAOs at residual concentration levels enabled them to maintain an energy source for aerobic maintenance processes for longer than GAOs. This may provide PAOs with an advantage over GAOs in surviving the low organic loading conditions commonly found in full-scale wastewater treatment plants.
authors.affiliation: Requimte/CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, 2829-516 Caparica, Portugal.
authors.forename: Mónica
authors.initials: M
authors.lastname: Carvalheira
authors.affiliation: Requimte/CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, 2829-516 Caparica, Portugal.
authors.forename: Adrian
authors.initials: A
authors.lastname: Oehmen
authors.affiliation: Requimte/CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, 2829-516 Caparica, Portugal; Instituto de Biologia Experimental e Tecnológica (IBET), Av. da República (EAN), 2784-505 Oeiras, Portugal.
authors.forename: Gilda
authors.initials: G
authors.lastname: Carvalho
authors.affiliation: Requimte/CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, 2829-516 Caparica, Portugal. Electronic address: amr@fct.unl.pt.
authors.forename: Maria A M
authors.initials: MAM
authors.lastname: Reis
mesh_terms: D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D006003:Glycogen / Q000378:metabolism*; D009930:Organic Chemicals; D010758:Phosphorus / Q000302:isolation & purification; D011122:Polyphosphates / Q000378:metabolism*; D018505:Waste Management
chemical_list: D009930:Organic Chemicals; D011122:Polyphosphates; D010758:Phosphorus; D006003:Glycogen
keywords: Enhanced biological phosphorus removal (EBPR); Glycogen accumulating organisms (GAO); Maintenance processes; Organic loading; Polyphosphate accumulating organisms (PAO)