title: Microbial characterization of biofilms in domestic drains and the establishment of stable biofilm microcosms.
abstract: We have used heterotrophic plate counts, together with live-dead direct staining and denaturing gradient gel electrophoresis (DGGE), to characterize the eubacterial communities that had formed as biofilms within domestic sink drain outlets. Laboratory microcosms of these environments were established using excised biofilms from two separate drain biofilm samples to inoculate constant-depth film fermentors (CDFFs). Drain biofilms harbored 9.8 to 11.3 log(10) cells of viable enteric species and pseudomonads/g, while CDFF-grown biofilms harbored 10.6 to 11.4 log(10) cells/g. Since live-dead direct staining revealed various efficiencies of recovery by culture, samples were analyzed by DGGE, utilizing primers specific for the V2-V3 region of eubacterial 16S rDNA. These analyses showed that the major PCR amplicons from in situ material were represented in the microcosms and maintained there over extended periods. Sequencing of amplicons resolved by DGGE revealed that the biofilms were dominated by a small number of genera, which were also isolated by culture. One drain sample harbored the protozoan Colpoda maupasi, together with rhabtidid nematodes and bdelloid rotifers. The microcosm enables the maintenance of stable drain-type bacterial communities and represents a useful tool for the modeling of this ecosystem.
authors.affiliation: School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Manchester M13 9PL, United Kingdom.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: McBain
authors.forename: Robert G
authors.initials: RG
authors.lastname: Bartolo
authors.forename: Carl E
authors.initials: CE
authors.lastname: Catrenich
authors.forename: Duane
authors.initials: D
authors.lastname: Charbonneau
authors.forename: Ruth G
authors.initials: RG
authors.lastname: Ledder
authors.forename: Alexander H
authors.initials: AH
authors.lastname: Rickard
authors.forename: Sharon A
authors.initials: SA
authors.lastname: Symmons
authors.forename: Peter
authors.initials: P
authors.lastname: Gilbert
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D018441:Biofilms / Q000254:growth & development*; D015169:Colony Count, Microbial; D003470:Culture Media; D004275:DNA, Ribosomal / Q000032:analysis; D017753:Ecosystem; D004591:Electrophoresis, Polyacrylamide Gel; D005285:Fermentation; D006798:Housing; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S; D017422:Sequence Analysis, DNA; D014881:Water Supply
chemical_list: D003470:Culture Media; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S