Metagenomic analysis revealed community-level metabolic differences between full-scale EBPR and S2EBPR systems

Area of Science:

• Environmental Microbiology
• Wastewater Treatment Technologies
• Metagenomics

Background:

• Conventional Enhanced Biological Phosphorus Removal (EBPR) faces stability challenges.
• Side-Stream Enhanced Biological Phosphorus Removal (S2EBPR) is a promising alternative, but its mechanisms are not fully understood.
• Metagenomic analysis can reveal microbial community differences between EBPR and S2EBPR.

Purpose of the Study:

• To compare the microbial community structures and functional potentials of EBPR and S2EBPR systems.
• To identify key microbial players and metabolic pathways involved in phosphorus removal under different configurations.
• To investigate the utility of polyphosphate metabolism genes for differentiating between EBPR and S2EBPR.

Main Methods:

• Comparative metagenomic analysis of three EBPR and three S2EBPR activated sludge communities.
• Analysis of microbial taxonomy, functional pathways, and polyphosphate metabolism marker genes (ppk and ppx).
• Assessment of diversity indices and abundance of specific microbial genera.

Main Results:

• S2EBPR communities exhibited greater genus-level diversity variance and a higher overall diversity index than EBPR.
• EBPR systems showed higher abundance of Ca. Accumulibacter, while S2EBPR favored fermentative PAOs like Ca. Phosphoribacter and Ca. Promineifilum.
• Exopolyphosphatase gene (ppx) phylogeny provided better distinction between EBPR and S2EBPR than polyphosphate kinase gene (ppk).

Conclusions:

• S2EBPR and EBPR harbor distinct microbial communities and phosphorus-accumulating organism profiles.
• Metagenomics, particularly analysis of specific genes like ppx, can elucidate operational configuration impacts on microbial communities.
• Findings offer insights for optimizing wastewater phosphorus removal processes through understanding microbial dynamics.