A new insight in enhancing phosphate enrichment in biofilm process: Comparison of the key metabolic pathways in highly-efficient and dominant PAOs based on metagenomics

Min Ni; Yimeng Zhao; Yang Pan; Dapeng Li; Yong Huang; Zhiqiang Chen; Lu Li; Zuowei Song

doi:10.1016/j.jenvman.2023.118114

A new insight in enhancing phosphate enrichment in biofilm process: Comparison of the key metabolic pathways in highly-efficient and dominant PAOs based on metagenomics

J Environ Manage. 2023 Sep 1:341:118114. doi: 10.1016/j.jenvman.2023.118114. Epub 2023 May 8.

Authors

Min Ni¹, Yimeng Zhao², Yang Pan³, Dapeng Li⁴, Yong Huang⁴, Zhiqiang Chen⁵, Lu Li⁴, Zuowei Song⁶

Affiliations

¹ School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China; Jiangsu Key Laboratory of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China.
² School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China.
³ School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China; National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou, 215009, China. Electronic address: panyang@mail.usts.edu.cn.
⁴ School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China; National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou, 215009, China.
⁵ Harbin Institute of Technology, Harbin, 150006, China.
⁶ Novoprotein, Suzhou, 215200, China.

PMID: 37163833
DOI: 10.1016/j.jenvman.2023.118114

Abstract

The formation of dominant phosphate-accumulating organisms (PAOs) is essential for the high enrichment of phosphate in biofilm sequencing batch reactors (BSBR) for phosphorus recovery. The dominant PAOs in the biofilm process have not been isolated and purified, and the key metabolic pathways that promote the formation of dominant PAOs are still unclear. In this study, four strains of highly-efficient PAOs were obtained by an innovative isolation procedure. The relationship between the abundance of highly-efficient and dominant PAOs and the phosphate removal ability was compared. We found that the abundance of PAOs was positively correlated with the phosphate removal efficiency in vitro pure culture and complex biofilm process. Metagenomics analysis revealed that compared with highly-efficient PAOs cultured in vitro, dominant PAOs in biofilms had unique key metabolic pathways, F-ATPases and N-Acyl homoserine lactones (AHLs). F-ATPases are important for maintaining the proton motive force (PMF) required for the uptake of carbon sources by PAOs, and AHLs are participating in phosphate metabolism through quorum sensing (QS) mediated secretion of extracellular polymeric substance (EPS). The formation of dominant PAOs was promoted by optimizing carbon source uptake and phosphate metabolism. This study revealed that the difficult isolation of dominant PAOs was due to the AHLs-mediated QS, and we identified the key pathways regulating the formation of dominant PAOs in biofilms through genomics analysis. Our findings provide insights in enhancing phosphate enrichment in BSBR by modulating the components of microbial community under the low concentration of carbon source consumption.

Keywords: AHLs; Dominant PAOs; Highly-efficient PAOs; PMF; Phosphate enrichment.

MeSH terms

Acyl-Butyrolactones
Biofilms
Bioreactors
Carbon
Extracellular Polymeric Substance Matrix*
Metabolic Networks and Pathways
Phosphates*
Sewage

Substances

Phosphates
Acyl-Butyrolactones
Carbon
Sewage