Factors affecting Accumulibacter population structure in full- and laboratory-scale biological reactors with...

Area of Science:

• Environmental microbiology
• Wastewater treatment technologies
• Microbial ecology

Background:

• Accumulibacter is a key bacterial group in biological phosphorus removal.
• Understanding Accumulibacter population dynamics is essential for optimizing wastewater treatment.
• Previous studies have focused on laboratory settings, with limited data from full-scale plants.

Purpose of the Study:

• To investigate the structure and diversity of the Accumulibacter lineage in full-scale wastewater treatment plants.
• To compare Accumulibacter populations between laboratory and full-scale systems.
• To identify factors influencing Accumulibacter clade abundance and their correlation with phosphorus removal efficiency.

Main Methods:

• Longitudinal study over three years in six full-scale wastewater treatment plants.
• Comparison with a laboratory-scale reactor.
• Analysis of bacterial community structure using clade-specific probes.
• Correlation analysis with operational parameters like BOD, COD, N, and P loading.

Main Results:

• Accumulibacter dominated the laboratory reactor (69%) with limited clades (IA, IIA,C,D).
• In full-scale plants, Accumulibacter represented up to 12%, correlating with nutrient loading.
• Clade IA abundance varied with temperature, while clades IIA,C,D showed opposite trends.
• A significant uncharacterized fraction (31-62%) of Accumulibacter was observed in full-scale plants.
• Industrial influent led to low diversity, similar to the lab reactor.

Conclusions:

• High Accumulibacter abundance alone does not guarantee efficient phosphorus removal.
• The presence and abundance of specific clades are critical for effective phosphorus removal.
• Further research is needed to characterize the unrevealed Accumulibacter fraction and its role in wastewater treatment.