Microbial community analysis of a full-scale DEMON bioreactor

Area of Science:

• Environmental Microbiology
• Wastewater Treatment Engineering
• Biotechnology

Background:

• Autotrophic nitrogen removal technologies, particularly the aerobic/anoxic deammonification (DEMON) process, are increasingly used for treating digested sludge liquor.
• The DEMON process utilizes anammox metabolism within a single bioreactor through alternating aeration cycles for nitrogen removal.
• Microbial community composition in full-scale DEMON bioreactors has not been previously reported.

Purpose of the Study:

• To characterize the bacterial community structure of a full-scale DEMON bioreactor.
• To provide a high-resolution analysis of the microbial assemblage in an operational DEMON system.
• To understand the ecological roles of identified microorganisms in bioreactor performance.

Main Methods:

• Pyrosequencing-based metagenomic analysis was employed to study the bacterial community.
• The study focused on a full-scale DEMON bioreactor at the Apeldoorn wastewater treatment plant.
• Comparison with previous lab-scale DEMON bioreactor studies using other techniques.

Main Results:

• The DEMON bioreactor was identified as a complex ecosystem.
• Key bacterial groups, including ammonium-oxidizing bacteria and anammox bacteria, were found to coexist.
• Numerous other bacterial phylotypes were identified, suggesting diverse functional roles within the bioreactor.

Conclusions:

• Metagenomic analysis via pyrosequencing offers new insights into DEMON bioreactor functioning.
• Exhaustive identification of microorganisms enhances understanding of their role in bioreactor performance.
• Pyrosequencing is a valuable tool for in-depth microbiological investigations of bioreactors.