title: More Efficient Media Design for Enhanced Biofouling Control in a Membrane Bioreactor: Quorum Quenching Bacteria Entrapping Hollow Cylinder.
abstract: Recently, membrane bioreactors (MBRs) with quorum quenching (QQ) bacteria entrapping beads have been reported as a new paradigm in biofouling control because, unlike conventional post-biofilm control methods, bacterial QQ can inhibit biofilm formation through its combined effects of physical scouring of the membrane and inhibition of quorum sensing (QS). In this study, using a special reporter strain (Escherichia coli JB525), the interaction between QS signal molecules and quorum quenching bacteria entrapping beads (QQ-beads) was elucidated through visualization of the QS signal molecules within a QQ-bead using a fluorescence microscope. As a result, under the conditions considered in this study, the surface area of QQ-media was likely to be a dominant parameter in enhancing QQ activity over total mass of entrapped QQ bacteria because QQ bacteria located near the core of a QQ-bead were unable to display their QQ activities. On the basis of this information, a more efficient QQ-medium, a QQ hollow cylinder (QQ-HC), was designed and prepared. In batch experiments, QQ-HCs showed greater QQ activity than QQ-beads as a result of their higher surface area and enhanced physical washing effect because of their larger impact area against the membrane surface. Furthermore, it was shown that such advantages of QQ-HCs resulted in more effective mitigation of membrane fouling than from QQ-beads in lab-scale continuous MBRs.
authors.affiliation: School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Korea.
authors.forename: Sang H
authors.initials: SH
authors.lastname: Lee
authors.affiliation: School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Korea.
authors.forename: Seonki
authors.initials: S
authors.lastname: Lee
authors.affiliation: School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Korea.
authors.forename: Kibaek
authors.initials: K
authors.lastname: Lee
authors.affiliation: School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Korea.
authors.forename: Chang H
authors.initials: CH
authors.lastname: Nahm
authors.affiliation: School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Korea.
authors.forename: Hyeokpil
authors.initials: H
authors.lastname: Kwon
authors.affiliation: Singapore Membrane Technology Center, Nanyang Technological University , Singapore 637141, Singapore.
authors.forename: Hyun-Suk
authors.initials: HS
authors.lastname: Oh
authors.affiliation: Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology , Seoul 02792, Korea.
authors.forename: Young-June
authors.initials: YJ
authors.lastname: Won
authors.affiliation: Department of Environmental Engineering, Kyungpook National University , Daegu 41566, Korea.
authors.forename: Kwang-Ho
authors.initials: KH
authors.lastname: Choo
authors.affiliation: School of Chemical and Biological Engineering, Seoul National University , Seoul 08826, Korea.
authors.forename: Chung-Hak
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Department of Environmental Engineering, Yonsei University , Wonju 26493, Korea.
authors.forename: Pyung-Kyu
authors.initials: PK
authors.lastname: Park
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D057219:Biofouling; D019149:Bioreactors / Q000382:microbiology*; D003470:Culture Media / Q000737:chemistry; D008566:Membranes; D053038:Quorum Sensing
chemical_list: D003470:Culture Media