title: Successional change in microbial communities of benthic Phormidium-dominated biofilms.
abstract: Benthic cyanobacterial blooms are increasing worldwide and can be harmful to human and animal health if they contain toxin-producing species. Microbial interactions are important in the formation of benthic biofilms and can lead to increased dominance and/or toxin production of one or few taxa. This study investigated how microbial interactions contribute to proliferation of benthic blooms dominated by the neurotoxin-producing Phormidium autumnale. Following a rainfall event that cleared the substrate, biofilm succession was characterised at a site on the Hutt River (New Zealand) by sampling every 2-3 days over 32 days. A combination of morphological and molecular community analyses (automated ribosomal intergenic spacer analysis and Illumina™ MiSeq sequencing) identified three distinct phases of succession in both the micro-algal and bacterial communities within P. autumnale-dominated biofilms. Bacterial composition shifted between the phases, and these changes occurred several days before those of the micro-algal community. Alphaproteobacteria and Betaproteobacteria dominate in the early phase; Alphaproteobacteria, Betaproteobacteria, Sphingobacteria and Flavobacteria in the mid-phase; and Sphingobacteria and Flavobacteria in the late phase. Collectively, the results suggest that succession is driven by bacteria in the early stages but becomes dependent on micro-algae in the mid- and late stages of biofilm formation.
authors.affiliation: School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington, New Zealand.
authors.forename: Katie A
authors.initials: KA
authors.lastname: Brasell
authors.forename: Mark W
authors.initials: MW
authors.lastname: Heath
authors.forename: Ken G
authors.initials: KG
authors.lastname: Ryan
authors.forename: Susanna A
authors.initials: SA
authors.lastname: Wood
mesh_terms: D020561:Alphaproteobacteria / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification; D041963:Bacteroidetes / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification; D018441:Biofilms; D018533:Biomass; D000458:Cyanobacteria / Q000145:classification* / Q000254:growth & development / Q000302:isolation & purification*; D004269:DNA, Bacterial / Q000235:genetics; D017753:Ecosystem; D005068:Eutrophication; D009520:New Zealand; D010802:Phylogeny; D058974:Phylogeography; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D045483:Rivers / Q000382:microbiology; D017422:Sequence Analysis, DNA; D014871:Water Microbiology
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S