Activated sludge prokaryote and eukaryote characterization in a pulp mill facility using amplicon sequencing

Area of Science:

• Environmental Microbiology
• Molecular Ecology
• Biotechnology

Background:

• Pulp and paper industry wastewater treatment relies on activated sludge (AS) systems.
• Current monitoring methods show limited correlation with chemical parameters.
• Microbial community composition significantly impacts AS reactor efficiency.

Purpose of the Study:

• To comprehensively profile prokaryotic and eukaryotic microbial communities in pulp mill AS using metabarcoding.
• To evaluate metabarcoding as a tool for routine microbial community surveillance in wastewater treatment.
• To establish a baseline for microbial communities in AS for improved environmental management.

Main Methods:

• Utilized MinION and Illumina sequencing for 16S (prokaryotic) and 18S (eukaryotic) amplicon sequencing.
• Analyzed microbial communities in extended aeration-activated sludge from a pulp mill.
• Compared metabarcoding results with traditional microscopy-based assessments.

Main Results:

• Eukaryotic communities dominated by Protists (Ciliophora), Rotifers (Animalia), and Fungi (Cryptomycota).
• Prokaryotic communities revealed dominant genera such as Terrimonas, Defluviicoccus, and Methylocaldum.
• Metabarcoding provided deeper insights than microscopy, showing consistent taxonomic trends and highlighting specific dominant groups.

Conclusions:

• Metabarcoding is a feasible and powerful tool for comprehensive microbial community analysis in pulp mill AS.
• Characterization of both prokaryotic and eukaryotic communities is crucial for effective reactor operation and environmental management.
• This study establishes a baseline for microbial communities, paving the way for linking microbial data with process patterns.