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Thomson R, Le C, Wang L, Batstone DJ, Zhou Y, Oehmen A. Higher order volatile fatty acid metabolism and atypical polyhydroxyalkanoate production in fermentation-enhanced biological phosphorus removal. WATER RESEARCH 2025; 280:123503. [PMID: 40121909 DOI: 10.1016/j.watres.2025.123503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 03/11/2025] [Accepted: 03/13/2025] [Indexed: 03/25/2025]
Abstract
Enhanced biological phosphorus removal (EBPR) is an established wastewater treatment process, but its wider implementation has been limited by factors like high temperature and low carbon availability. Fermentation-enhanced EBPR (F-EBPR) processes have shown promise in addressing these limitations, but the underlying mechanisms are not fully understood. This study investigates the metabolism of higher order (C4-5) volatile fatty acids (VFAs) in F-EBPR systems using a combination of carbon isotope labelling and shotgun metagenomic sequencing analyses. Results show that butyrate (HBu) uptake leads to the formation of both typical (C4-5) and atypical (C6+) polyhydroxyalkanoates (PHAs) through a combination ofβ-oxidation and standard condensation pathways, while the putative role of HBu oxidisers were identified relative to substrate composition in F-EBPR processes. Metagenomic analysis reveals the presence of genes required for higher order VFA metabolism in both polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs). This study also highlights the limitations of current models in describing F-EBPR processes and emphasises the need for improved models that account for higher order VFA metabolism and microbial community dynamics.
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Affiliation(s)
- R Thomson
- School of Chemical Engineering, University of Queensland, St Lucia QLD 4072, Australia
| | - C Le
- Asian School of the Environment, Nanyang Technological University, 637141, Singapore
| | - L Wang
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201600, PR China
| | - D J Batstone
- Australian Centre for Water and Environmental Biotechnology, University of Queensland, St Lucia QLD 4072, Australia
| | - Y Zhou
- Advanced Environmental Biotechnology Center, Nanyang Technological University, 637141, Singapore.
| | - A Oehmen
- School of Chemical Engineering, University of Queensland, St Lucia QLD 4072, Australia.
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Pelevina A, Gruzdev E, Berestovskaya Y, Dorofeev A, Nikolaev Y, Kallistova A, Beletsky A, Ravin N, Pimenov N, Mardanov A. New insight into the granule formation in the reactor for enhanced biological phosphorus removal. Front Microbiol 2023; 14:1297694. [PMID: 38163067 PMCID: PMC10755871 DOI: 10.3389/fmicb.2023.1297694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 11/15/2023] [Indexed: 01/03/2024] Open
Abstract
While granulated activated sludge exhibits high productivity, the processes of granule formation are incompletely studied. The processes of granule formation and succession of communities were investigated in a laboratory sequencing batch reactor (SBR) under conditions for enhanced biological phosphorus removal (EBPR) using microbiological and molecular techniques. Active consumption of acetate, primarily by the phosphate-accumulating organisms (PAO), commenced at day 150 of cultivation. This was indicated by the high ratio of molar P-released/acetate uptake (0.73-0.77 P-mol/C-mol), characteristic of PAO. During this period, two types of granule-like aggregates formed spontaneously out of the activated sludge flocs. The aggregates differed in morphology and microbial taxonomic composition. While both aggregate types contained phosphorus-enriched bacterial cells, PAO prevailed in those of morphotype I, and glycogen-accumulating organisms (GAOs) were predominant in the aggregates of morphotype II. After 250 days, the elimination of the morphotype II aggregates from the reactor was observed. The subsequent selection of the community was associated with the development of the morphotype I aggregates, in which the relative abundance of PAO increased significantly, resulting in higher efficiency of phosphorus removal. Metagenomic analysis revealed a predominance of the organisms closely related to Candidatus Accumulibacter IС and IIС and of Ca. Accumulibacter IIB among the PAO. Based on the content of the genes of the key metabolic pathways, the genomes of potential PAO belonging to the genera Amaricoccus, Azonexus, Thauera, Zoogloea, Pinisolibacter, and Siculibacillus were selected. The patterns of physicochemical processes and the microbiome structure associated with granule formation and succession of the microbial communities were revealed.
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Affiliation(s)
- Anna Pelevina
- Winogradsky Institute of Microbiology, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Evgeny Gruzdev
- K.G. Skryabin Institute of Bioengineering, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Yulia Berestovskaya
- Winogradsky Institute of Microbiology, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Alexander Dorofeev
- Winogradsky Institute of Microbiology, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Yury Nikolaev
- Winogradsky Institute of Microbiology, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Anna Kallistova
- Winogradsky Institute of Microbiology, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Alexey Beletsky
- K.G. Skryabin Institute of Bioengineering, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Nikolai Ravin
- K.G. Skryabin Institute of Bioengineering, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Nikolai Pimenov
- Winogradsky Institute of Microbiology, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Andrey Mardanov
- K.G. Skryabin Institute of Bioengineering, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
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