title: Spatial and successional dynamics of microbial biofilm communities in a grassland stream ecosystem.
abstract: Biofilms represent a metabolically active and structurally complex component of freshwater ecosystems. Ephemeral prairie streams are hydrologically harsh and prone to frequent perturbation. Elucidating both functional and structural community changes over time within prairie streams provides a general understanding of microbial responses to environmental disturbance. We examined microbial succession of biofilm communities at three sites in a third-order stream at Konza Prairie over a 2- to 64-day period. Microbial abundance (bacterial abundance, chlorophyll a concentrations) increased and never plateaued during the experiment. Net primary productivity (net balance of oxygen consumption and production) of the developing biofilms did not differ statistically from zero until 64 days suggesting a balance of the use of autochthonous and allochthonous energy sources until late succession. Bacterial communities (MiSeq analyses of the V4 region of 16S rRNA) established quickly. Bacterial richness, diversity and evenness were high after 2 days and increased over time. Several dominant bacterial phyla (Beta-, Alphaproteobacteria, Bacteroidetes, Gemmatimonadetes, Acidobacteria, Chloroflexi) and genera (Luteolibacter, Flavobacterium, Gemmatimonas, Hydrogenophaga) differed in relative abundance over space and time. Bacterial community composition differed across both space and successional time. Pairwise comparisons of phylogenetic turnover in bacterial community composition indicated that early-stage succession (≤16 days) was driven by stochastic processes, whereas later stages were driven by deterministic selection regardless of site. Our data suggest that microbial biofilms predictably develop both functionally and structurally indicating distinct successional trajectories of bacterial communities in this ecosystem.
authors.affiliation: Division of Biology, Kansas State University, Manhattan, KS, 66502, USA. veacham@ornl.gov.|Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA. veacham@ornl.gov.
authors.forename: Allison M
authors.initials: AM
authors.lastname: Veach
authors.affiliation: Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
authors.forename: James C
authors.initials: JC
authors.lastname: Stegen
authors.affiliation: Division of Biology, Kansas State University, Manhattan, KS, 66502, USA.|Department of Plant Biology, University of Illinois, Urbana-Champaign, Urbana, IL, 61801, USA.
authors.forename: Shawn P
authors.initials: SP
authors.lastname: Brown
authors.affiliation: Division of Biology, Kansas State University, Manhattan, KS, 66502, USA.
authors.forename: Walter K
authors.initials: WK
authors.lastname: Dodds
authors.affiliation: Division of Biology, Kansas State University, Manhattan, KS, 66502, USA.
authors.forename: Ari
authors.initials: A
authors.lastname: Jumpponen
mesh_terms: D001419:Bacteria / Q000145:classification*; D018441:Biofilms; D002734:Chlorophyll; D000077194:Chlorophyll A; D065948:Grassland; D007615:Kansas; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S; D045483:Rivers / Q000382:microbiology*; D014871:Water Microbiology
chemical_list: D012336:RNA, Ribosomal, 16S; D002734:Chlorophyll; D000077194:Chlorophyll A
keywords: DNA barcoding; algae; bacteria; community ecology; microbial biology