Characterizing community dynamics and exploring bacterial assemblages in two activated sludge systems.

Area of Science:

• Environmental microbiology
• Wastewater treatment biotechnology
• Metagenomics

Background:

• Activated sludge (AS) bacterial communities are critical for municipal wastewater treatment plant (WWTP) performance.
• Understanding factors influencing AS bacterial community structure is essential for optimizing WWTP operations.

Purpose of the Study:

• To identify key factors affecting bacterial assemblages in activated sludge.
• To elucidate the variation patterns of bacterial communities over time in WWTPs.

Main Methods:

• Collection of time-series activated sludge samples from two WWTPs over two years.
• Metagenomic sequencing to analyze bacterial community composition and structure.
• Statistical analysis of environmental factors and bacterial abundance data.

Main Results:

• Significant seasonal shifts and successional patterns were observed in bacterial communities at genus and species levels.
• Temperature was identified as a decisive factor for long-term bacterial assemblage patterns.
• Taxa abundance distribution followed exponential formulations, with persistent taxa comprising approximately 90% of the community, ensuring stable treatment performance.

Conclusions:

• Environmental factor changes cause bacterial structure variations, but species interactions promote community recovery and stability.
• Functional cooperation among bacterial species is a dominant factor shaping AS microbial assemblages.
• Rare bacterial groups may hold potential for removing emerging pollutants.