title: Analysis of microbial community composition in a lab-scale membrane distillation bioreactor.
abstract: OBJECTIVE
  Membrane distillation bioreactors (MDBR) have potential for industrial applications where wastewater is hot or waste heat is available, but the role of micro-organisms in MDBRs has never been determined, and thus was the purpose of this study.
  
  
  RESULTS
  Microbial communities were characterized by bacterial and archaeal 16S and eukaryotic 18S rRNA gene tag-encoded pyrosequencing of DNA obtained from sludge. Taxonomy-independent analysis revealed that bacterial communities had a relatively low richness and diversity, and community composition strongly correlated with conductivity, total nitrogen and bound extracellular polymeric substances (EPS). Taxonomy-dependent analysis revealed that Rubrobacter and Caldalkalibacillus were abundant members of the bacterial community, but no archaea were detected. Eukaryotic communities had a relatively high richness and diversity, and both changes in community composition and abundance of the dominant genus, Candida, correlated with bound EPS.
  
  
  CONCLUSIONS
  Thermophilic MDBR communities were comprised of a low diversity bacterial community and a highly diverse eukaryotic community with no archea detected. Communities exhibited low resilience to changes in operational parameters. Specifically, retenatate nutrient composition and concentration was strongly correlated with the dominant species.
  
  
  CONCLUSIONS
  This study provides an understanding of microbial community diversity in an MDBR, which is fundamental to the optimization of reactor performance.
authors.affiliation: Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore City, Singapore; School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore.
authors.forename: Q
authors.initials: Q
authors.lastname: Zhang
authors.forename: G
authors.initials: G
authors.lastname: Shuwen
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.forename: A G
authors.initials: AG
authors.lastname: Fane
authors.forename: S
authors.initials: S
authors.lastname: Kjelleberg
authors.forename: S A
authors.initials: SA
authors.lastname: Rice
authors.forename: D
authors.initials: D
authors.lastname: McDougald
mesh_terms: D001105:Archaea / Q000302:isolation & purification; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D044822:Biodiversity; D019149:Bioreactors / Q000382:microbiology*; D057168:Distillation; D056890:Eukaryota / Q000145:classification / Q000302:isolation & purification; D005374:Filtration; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid
chemical_list: D012722:Sewage
keywords: community composition; community diversity; membrane biofouling; membrane distillation bioreactor; thermophiles