title: The role of quorum sensing signalling in EPS production and the assembly of a sludge community into aerobic granules.
abstract: Quorum sensing (QS) signalling has been extensively studied in single species populations. However, the ecological role of QS in complex, multi-species communities, particularly in the context of community assembly, has neither been experimentally explored nor theoretically addressed. Here, we performed a long-term bioreactor ecology study to address the links between QS, organization and composition of complex microbial communities. The conversion of floccular biomass to highly structured granules was found to be non-random, but strongly and positively correlated with N-acyl-homoserine-lactone (AHL)-mediated QS. Specific AHLs were elevated up to 100-fold and were strongly associated with the initiation of granulation. Similarly, the levels of particular AHLs decreased markedly during the granular disintegration phase. Metadata analysis indicated that granulation was accompanied by changes in extracellular polymeric substance (EPS) production and AHL add-back studies also resulted in increased EPS synthesis. In contrast to the commonly reported nanomolar to micromolar signal concentrations in pure culture laboratory systems, QS signalling in the granulation ecosystem occurred at picomolar to nanomolar concentrations of AHLs. Given that low concentrations of AHLs quantified in this study were sufficient to activate AHL bioreporters in situ in complex granular communities, AHL mediated QS may be a common feature in many natural and engineered ecosystems, where it coordinates community behaviour.
authors.affiliation: 1] Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore [2] Advanced Environmental Biotechnology Centre (AEBC), Nanyang Environment and Water Research Institute (NEWRI), Nanyang Technological University, Singapore [3] The School of Civil and Environmental Engineering, Nanyang Technological University, Singapore.
authors.forename: Chuan Hao
authors.initials: CH
authors.lastname: Tan
authors.affiliation: Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore.
authors.forename: Kai Shyang
authors.initials: KS
authors.lastname: Koh
authors.affiliation: Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore.
authors.forename: Chao
authors.initials: C
authors.lastname: Xie
authors.affiliation: 1] Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore [2] Advanced Environmental Biotechnology Centre (AEBC), Nanyang Environment and Water Research Institute (NEWRI), Nanyang Technological University, Singapore [3] The School of Biological Sciences, Nanyang Technological University, Singapore.
authors.forename: Martin
authors.initials: M
authors.lastname: Tay
authors.affiliation: Advanced Environmental Biotechnology Centre (AEBC), Nanyang Environment and Water Research Institute (NEWRI), Nanyang Technological University, Singapore.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore.
authors.forename: Rohan
authors.initials: R
authors.lastname: Williams
authors.affiliation: 1] Advanced Environmental Biotechnology Centre (AEBC), Nanyang Environment and Water Research Institute (NEWRI), Nanyang Technological University, Singapore [2] The School of Civil and Environmental Engineering, Nanyang Technological University, Singapore.
authors.forename: Wun Jern
authors.initials: WJ
authors.lastname: Ng
authors.affiliation: 1] Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore [2] The School of Biological Sciences, Nanyang Technological University, Singapore [3] Centre for Marine Bio-Innovation and School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Rice
authors.affiliation: 1] Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore [2] The School of Biological Sciences, Nanyang Technological University, Singapore [3] Centre for Marine Bio-Innovation and School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia.
authors.forename: Staffan
authors.initials: S
authors.lastname: Kjelleberg
mesh_terms: D054742:Acyl-Butyrolactones / Q000032:analysis / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism; D018441:Biofilms; D019149:Bioreactors / Q000382:microbiology; D017753:Ecosystem; D053038:Quorum Sensing; D012722:Sewage / Q000382:microbiology*
chemical_list: D054742:Acyl-Butyrolactones; D012722:Sewage