Potential microbial functions and quorum sensing systems in partial nitritation and anammox processes
Zhaolu Feng1, Mengqi Gu1, Yuepeng Sun1
1Shenzhen International Graduate School, Tsinghua University, Shenzhen, China.
Summary
Microbial interactions in partial nitritation-anaerobic ammonium oxidation (PNA) processes involve nitrogen conversion and acyl-homoserine lactone (AHL) signaling. Key bacteria like Candidatus_Kuenenia and Nitrosomonas drive PNA, while heterotrophs manage AHL communication.
Area of Science:
- Microbiology
- Environmental Science
- Biotechnology
Background:
- Partial nitritation-anaerobic ammonium oxidation (PNA) processes host diverse microbial communities crucial for nitrogen cycling.
- Balancing anaerobic ammonium oxidation bacteria and ammonia-oxidizing bacteria is challenging due to microbial complexity.
- Microbial interactions, including nitrogen metabolism and information exchange, are vital for PNA efficiency.
Purpose of the Study:
- To investigate microbial functions in nitrogen conversion within PNA systems.
- To examine the role of acyl-homoserine lactones (AHLs)-based quorum sensing (QS) in PNA microbial communication.
- To identify key microorganisms and their roles in nitrogen metabolism and QS.
Main Methods:
- Metagenomic analysis to identify functional genes related to nitrogen conversion and QS.
- Quantification of AHLs to understand signaling molecule dynamics.
- Correlation analysis to link microbial populations with specific functions.
Main Results:
- Candidatus_Kuenenia (anammox bacteria) and Nitrosomonas (ammonia-oxidizing bacteria) were identified as key PNA functional bacteria.
- Nitrospira dominated nitrite-oxidizing bacteria (NOB) activity, with some heterotrophs potentially performing similar functions.
- AHLs, including N-octanoyl-, N-decanoyl-, and N-dodecanoyl-homoserine lactone, were prevalent, likely synthesized by nitrogen-converting microbes and heterotrophs.
- Specific heterotrophs, Saccharophagus and Leptospira, were found to sense and degrade AHLs, respectively.
Conclusions:
- The PNA system relies on a complex interplay between nitrogen-converting microorganisms and heterotrophs.
- AHL-based QS is a significant communication mechanism in PNA, with specific bacteria synthesizing and others responding to these signals.
- Understanding these microbial interactions provides insights for optimizing PNA process performance.
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