Kim, Hak-Woo Oh, Hyun-Suk Kim, Sang-Ryoung Lee, Ki-Baek Yeon, Kyung-Min Lee, Chung-Hak Kim, Seil Lee, Jung-Kee 2024-01-20T12:31:06Z 2024-01-20T12:31:06Z 2022-01-25 2013-05 0175-7598 https://pubs.kist.re.kr/handle/201004/128080 Quorum sensing gives rise to biofilm formation on the membrane surface, which in turn causes a loss of water permeability in membrane bioreactors (MBRs) for wastewater treatment. Enzymatic quorum quenching was reported to successfully inhibit the formation of biofilm in MBRs through the decomposition of signal molecules, N-acyl homoserine lactones (AHLs). The aim of this study was to elucidate the mechanisms of quorum quenching in more detail in terms of microbial population dynamics and proteomics. Microbial communities in MBRs with and without a quorum quenching enzyme (acylase) were analyzed using pyrosequencing and compared with each other. In the quorum quenching MBR, the rate of transmembrane pressure (TMP) rise-up was delayed substantially, and the proportion of quorum sensing bacteria with AHL-like autoinducers (such as Enterobacter, Pseudomonas, and Acinetobacter) also decreased in the entire microbial community of mature biofilm in comparison to that in the control MBR. These factors were attributed to the lower production of extracellular polymeric substances (EPS), which are known to play a key role in the formation of biofilm. Proteomic analysis using the Enterobacter cancerogenus strain ATCC 35316 demonstrates the possible depression of protein expression related to microbial attachments to solid surfaces (outer membrane protein, flagellin) and the agglomeration of microorganisms (ATP synthase beta subunit) with the enzymatic quorum quenching. It has been argued that changes in the microbial population, EPS and proteins via enzymatic quorum quenching could inhibit the formation of biofilm, resulting in less biofouling in the quorum quenching MBR. English SPRINGER Microbial population dynamics and proteomics in membrane bioreactors with enzymatic quorum quenching Article 10.1007/s00253-012-4272-0 1 APPLIED MICROBIOLOGY AND BIOTECHNOLOGY, v.97, no.10, pp.4665 - 4675 APPLIED MICROBIOLOGY AND BIOTECHNOLOGY 97 10 4665 4675 N scie scopus 000318716700040 2-s2.0-84877751341 Biotechnology & Applied Microbiology Biotechnology & Applied Microbiology Article BIOFILM FORMATION BACTERIA ADHESION MOTILITY Membrane bioreactor (MBR) Quorum sensing Acylase Pyrosequencing Proteomics