title: Impact of butyrate on microbial selection in enhanced biological phosphorus removal systems.
abstract: Microbial selection in an enhanced biological phosphorus removal system was investigated in a laboratory-scale sequencing batch reactor fed exclusively with butyrate as a carbon source. As reported in the few previous studies, butyrate uptake was slow and phosphorus (P) release occurred during the entire anaerobic period. Polyphosphate-accumulating organism (PAO), i.e. Candidatus Accumulibacter phosphatis (named as Accumulibacter), glycogen-accumulating organisms (GAOs), i.e. Candidatus Competibacter phosphatis (named as Competibacter) and Defluviicoccus-related, tetrad-forming alphaproteobacteria (named as Defluviicoccus) were identified using fluorescence in situ hybridization analysis. The results show that Accumulibacter and Defluviicoccus were selected in the butyrate-fed reactor, whereas Competibacter was not selected. P removal was efficient at the beginning of the experiment with an increasing percentage relative abundance (% RA) of PAOs. The % RA of Accumulibacter and Defluviicoccus increased from 13% to 50% and 8% to 16%, respectively, and the % RA of Competibacter decreased from 8% to 2% during the experiment. After 6 weeks, P removal deteriorated with the poor correlation between the percentage of P removal and % RA of GAOs.
authors.affiliation: a Department of Chemical Engineering , Tuskegee University , 522E Luther Foster Hall, Tuskegee , AL 36088 , USA.
authors.forename: Shamim A
authors.initials: SA
authors.lastname: Begum
authors.forename: Jacimaria R
authors.initials: JR
authors.lastname: Batista
mesh_terms: D020562:Betaproteobacteria / Q000235:genetics / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D002087:Butyrates / Q000378:metabolism*; D020563:Gammaproteobacteria / Q000235:genetics / Q000378:metabolism; D017404:In Situ Hybridization, Fluorescence; D010758:Phosphorus / Q000378:metabolism*; D012244:Rhodospirillaceae / Q000235:genetics / Q000378:metabolism*; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D002087:Butyrates; D014874:Water Pollutants, Chemical; D010758:Phosphorus
keywords: EBPR; GAO; PAO; butyrate; microbial selection