Enrichment and characterization of a psychrophilic 'Candidatus Accumulibacter phosphatis' culture. (October 2017)

• Record Type: Journal Article
• Authors: Tian, W.D.; Ma, C.; Lin, Y.M.; Welles, L.; Lopez-Vazquez, C.; van Loosdrecht, M.C.M.
• Is Part Of: International biodeterioration & biodegradation. Volume 124(2017)
• Page Start: 267
• Page End: 275
• Publication Date: 2017-10
• Subjects: EBPR -- Low temperature -- Candidatus Accumulibacter phosphatis -- Psychrophilic conditions; Biodegradation -- Periodicals; Bioremediation -- Periodicals; Biodegradation -- Periodicals; Biodégradation -- Périodiques; Biorestauration -- Périodiques; Electronic journals; 620.11223
• DOI: 10.1016/j.ibiod.2017.03.030
• Languages: English
• ISSNs: 0964-8305

Abstract

Abstract: Enhanced Biological phosphorous removal (EBPR) processes, often operated at low temperatures, are utilised world-wide, but currently little is known regarding enrichment cultures and the characteristics of active organisms (" Candidatus Accumulibacter phosphatis" ( Accumulibacter )) under psychrophilic conditions. This study assesses the long-term performance, metabolic activity, microbial community characteristics and sludge morphology in an EBPR community enriched from activated sludge at 10 °C. Long solid retention times (SRT) and low temperatures resulted in the dominance of Accumulibacter type II over type I. Despite changes in the microbial community, P-removal efficiencies did not show obvious differences and although no specific measures were implemented, the enriched Accumulibacter -PAO culture formed stable dense granules. A high level of Alginate-like exopolysaccharides (ALE) were observed, with a large number of Guluronic acid-Guluronic acid (GG) blocks derived from the biomass at 10 °C. This characteristic favors sludge granulation, increasing the mechanical strength of granules formed, which encourages solid-liquid separation and consequently, contributes to the stable operation of EBPR systems. Highlights: P-removal performance was not affected by prevalence of specific PAO I and IIA. PAO IIA formed large granules without implemented measures to enhance granulation. At 10 °C, long SRT favors PAO IIA over PAO I. Psychrophilic PAO can accumulate ALE up to 52 ± 5% (VSS/VSS).