Isolation of a quorum quenching bacterium effective to various acyl-homoserine lactones: Its quorum quenching mechanism and application to a membrane bioreactor

Soyoung Ham, Hwa Soo Ryoo, Yongsun Jang, Sang Hoon Lee, Ji Yoon Lee, Han Shin Kim, Jeong Hoon Lee, Hee Deung Park

Research output: Contribution to journalArticlepeer-review

Abstract

Biofouling, caused by microbial biofilm formation on the membrane surface and in pores, is a major operational problem in membrane bioreactors (MBR). Many quorum quenching (QQ) bacteria have been isolated and applied to MBR to reduce biofouling. However, for more effective MBR biofouling control, novel approaches for isolating QQ bacteria and applying them in MBR are needed. Therefore, Listeria grayi (HEMM-2) was isolated using a mixture of different N-acyl homoserine lactones (AHLs). HEMM-2 degraded various AHLs, regardless of the length and oxo group in the carbon chain, with quorum sensing (QS) inhibition ratios of 47–61%. This QQ activity was attributed to extracellular substances in HEMM-2 cell-free supernatant (CFS). Furthermore, the HEMM-2 CFS negatively regulated QS-related gene expression, inhibiting Pseudomonas aeruginosa and activated sludge-biofilm formation by 53–75%. Surprisingly, when the HEMM-2 CFS was directly injected into a laboratory-scale MBR system, biofouling was not significantly affected. Biofouling was only controlled by cell suspension (CS) of HEMM-2, indicating the importance of QQ bacteria in MBR. The HEMM-2 CS increased operation time to reach 0.4 bar, a threshold transmembrane pressure for complete biofouling, from 315 h to 371 h. Taken together, HEMM-2, which is effective in the degradation of various AHLs, and its applicable method to MBR may be considered a potent approach for controlling biofouling and understanding the behavior of QQ bacteria in MBR systems.

Original languageEnglish
Article number140735
JournalChemosphere
Volume347
DOIs
Publication statusPublished - 2024 Jan

Bibliographical note

Publisher Copyright:
© 2023 Elsevier Ltd

Keywords

  • Activated sludge
  • Biofilm formation
  • Biofouling control
  • Pseudomonas aeruginosa
  • Quorum sensing

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • General Chemistry
  • Pollution
  • Public Health, Environmental and Occupational Health
  • Health, Toxicology and Mutagenesis

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