Community biofilm-formation, stratification and productivity in serially-transferred microcosms. Issue 24 (18th November 2020)

• Record Type: Journal Article
• Authors: Jerdan, Robyn; Cameron, Scott; Donaldson, Emily; Iungin, Olga; Moshynets, Olena V; Spiers, Andrew J
• Is Part Of: FEMS microbiology letters. Volume 367:Issue 24(2020)
• Publication Date: 2020-11-18
• Subjects: air–liquid (A–L) interface biofilm -- bacterial communities -- community-aggregated traits -- community change -- experimental microcosm -- productivity; Microbiology -- Periodicals; 579
• DOI: 10.1093/femsle/fnaa187
• Languages: English
• ISSNs: 0378-1097

Abstract

ABSTRACT: The establishment of O2 gradients in liquid columns by bacterial metabolic activity produces a spatially-structured environment. This produces a high-O2 region at the top that represents an un-occupied niche which could be colonised by biofilm-competent strains. We have used this to develop an experimental model system using soil-wash inocula and a serial-transfer approach to investigate changes in community-based biofilm-formation and productivity. This involved 10 transfers of mixed-community or biofilm-only samples over a total of 10–60 days incubation. In all final-transfer communities the ability to form biofilms was retained, though in longer incubations the build-up of toxic metabolites limited productivity. Measurements of microcosm productivity, biofilm-strength and attachment levels were used to assess community-aggregated traits which showed changes at both the community and individual-strain levels. Final-transfer communities were stratified with strains demonstrating a plastic phenotype when migrating between the high and low-O2 regions. The majority of community productivity came from the O2 -depleted region rather than the top of the liquid column. This model system illustrates the complexity we expect to see in natural biofilm-forming communities. The connection between biofilms and the liquid column seen here has important implications for how these structures form and respond to selective pressure. Abstract : Serial-transfer of bacterial communities in experimental microcosms alters community-aggregated biofilm traits at the community and individual-strain level and selects for stratified communities with migration recolonising regions after each transfer.