title: Microbial community dynamics and biogas production from manure fractions in sludge bed anaerobic digestion.
abstract: OBJECTIVE
  To elucidate how granular sludge inoculum and particle-rich organic loading affect the structure of the microbial communities and process performance in upflow anaerobic sludge bed (UASB) reactors.
  
  
  RESULTS
  We investigated four reactors run on dairy manure filtrate and four on pig manure supernatant for three months achieving similar methane yields. The reactors fed with less particle rich pig manure stabilized faster and had highest capacity. Microbial community dynamics analysed by a PCR/denaturing gradient gel electrophoresis approach showed that influent was a major determinant for the composition of the reactor communities. Comparisons of pre- and non-adapted inoculum in the reactors run on pig manure supernatant showed that the community structure of the nonadapted inoculum adapted in approximately two months. Microbiota variance partitioning analysis revealed that running time, organic loading rate and inoculum together explained 26 and 31% of the variance in bacterial and archaeal communities respectively.
  
  
  CONCLUSIONS
  The microbial communities of UASBs adapted to the reactor conditions in treatment of particle rich manure fractions, obtaining high capacity, especially on pig manure supernatant.
  
  
  CONCLUSIONS
  These findings provide relevant insight into the microbial community dynamics in startup and operation of sludge bed reactors for methane production from slurry fractions, a major potential source of biogas.
authors.affiliation: Department of Biotechnology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
authors.forename: A S R
authors.identifier: http://orcid.org/0000-0002-6214-4662
authors.initials: AS
authors.lastname: Nordgård
authors.affiliation: Department of Process, Energy and Environmental Technology, Telemark University College (TUC), Porsgrunn, Norway.
authors.forename: W H
authors.initials: WH
authors.lastname: Bergland
authors.affiliation: Department of Process, Energy and Environmental Technology, Telemark University College (TUC), Porsgrunn, Norway.
authors.forename: R
authors.initials: R
authors.lastname: Bakke
authors.affiliation: Department of Biotechnology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
authors.forename: O
authors.initials: O
authors.lastname: Vadstein
authors.affiliation: Department of Biotechnology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
authors.forename: K
authors.initials: K
authors.lastname: Østgaard
authors.affiliation: Department of Biotechnology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
authors.forename: I
authors.initials: I
authors.lastname: Bakke
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D056804:Biofuels / Q000382:microbiology*; D019149:Bioreactors / Q000382:microbiology*; D002417:Cattle; D008372:Manure / Q000382:microbiology*; D059013:Microbial Consortia; D012722:Sewage / Q000382:microbiology*
chemical_list: D056804:Biofuels; D008372:Manure; D012722:Sewage
keywords: biodegradation; denaturing gradient gel electrophoresis; granules; microbial structure; polymerase chain reaction