Work

Higher order volatile fatty acid metabolism and atypical polyhydroxyalkanoate production in fermentation-enhanced biological phosphorus removal

Year: 2025

Type: article

Abstract: • Combination of β-oxidation and condensation processes form atypical PHAs in F-EBPR • Putative role of higher order VFA oxidisers identified in the PAO/GAO metabolism • Current EBPR models inadequately describe F-EBPR and higher order VFA metabolism • Microbial community dynamics play a crucial role in F-EBPR performance • Improved models for higher order VFAs and atypical PHAs are needed for F-EBPR 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 (C 4–5 ) 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 (C 4–5 ) and atypical (C 6+ ) 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. Metabolic interactions between key populations responsible for anaerobic uptake and storage of HAc to HVa and associated isomers under F-EBPR conditions.

Source: Water Research

DOI: 10.1016/j.watres.2025.123503

Authors: R. Thomson, C. Le, L. Wang, D.J. Batstone, Y. Zhou, A. Oehmen

Institutions: The University of Queensland, Nanyang Technological University, Shanghai University of Engineering Science

Language: English

Topic: Wastewater Treatment and Nitrogen Removal

Subfield: Pollution

Field: Environmental Science

Domain: Physical Sciences

SDG: Responsible consumption and production

Open Access status: hybrid

Estimated APC paid: $4,660