title: Metabolic behavior and enzymatic aspects of denitrifying EBPR sludge in a continuous-flow anaerobic-anoxic system.
abstract: The metabolic aspects of enhanced biological phosphorus removal (EBPR) were investigated for the first time in a continuous-flow anaerobic-anoxic plant fed with acetate, propionate, or substrates which are involved in the tricarboxylic acid and/or glyoxylate cycle, i.e., fumarate, malate, or oxaloacetate, as the sole carbon source. Although the polyphosphate-accumulating organisms (PAOs) population remained stable with any carbon source examined, no typical EBPR metabolism was observed during fumarate, malate, or oxaloacetate utilization. Specific enzymatic activities related to EBPR were determined in activated sludge homogenates and directly correlated with the nutrient metabolic rates. The experimental results indicated the direct involvement of alkaline phosphatase, pyrophosphatase, and exopolyphosphatase in the denitrifying EBPR process. Metabolic aspects of glyoxylate cycle enzymes are discussed with regard to the biomass anaerobic and anoxic activity. Process performance was highly influenced by the kind of substrate utilized, indicating that specific metabolic pathways should be followed to favor efficient EBPR.
authors.affiliation: Laboratory of Wastewater Management and Treatment Technologies, Department of Environmental Engineering, Democritus University of Thrace, Vas. Sofias 12, 67100, Xanthi, Greece, izafiri@env.duth.gr.
authors.forename: Ilias
authors.initials: I
authors.lastname: Zafiriadis
authors.forename: Spyridon
authors.initials: S
authors.lastname: Ntougias
authors.forename: Anastasios G
authors.initials: AG
authors.lastname: Kapagiannidis
authors.forename: Alexander
authors.initials: A
authors.lastname: Aivasidis
mesh_terms: D017766:Acid Anhydride Hydrolases / Q000378:metabolism; D000469:Alkaline Phosphatase / Q000378:metabolism; D000693:Anaerobiosis; D005650:Fumarates / Q000378:metabolism; D008293:Malates / Q000378:metabolism; D062907:Oxaloacetic Acid / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D011122:Polyphosphates / Q000378:metabolism; D011755:Pyrophosphatases / Q000378:metabolism; D012722:Sewage / Q000382:microbiology*
chemical_list: D005650:Fumarates; D008293:Malates; D011122:Polyphosphates; D012722:Sewage; D062907:Oxaloacetic Acid; C030298:malic acid; D000469:Alkaline Phosphatase; D010744:Phosphoric Monoester Hydrolases; D017766:Acid Anhydride Hydrolases; D011755:Pyrophosphatases; C020137:exopolyphosphatase