16S rRNA assessment of the influence of shading on early-successional biofilms in experimental streams.
Elevated nutrient levels can lead to excessive biofilm growth, but reducing nutrient pollution is often challenging. There is therefore interest in developing control measures for biofilm growth in nutrient-rich rivers that could act as complement to direct reductions in nutrient load. Shading of rivers is one option that can mitigate blooms, but few studies have experimentally examined the differences in biofilm communities grown under shaded and unshaded conditions. We investigated the assembly and diversity of biofilm communities using in situ mesocosms within the River Thames (UK). Biofilm composition was surveyed by 454 sequencing of 16S amplicons (∼400 bp length covering regions V6/V7). The results confirm the importance of sunlight for biofilm community assembly; a resource that was utilized by a relatively small number of dominant taxa, leading to significantly less diversity than in shaded communities. These differences between unshaded and shaded treatments were either because of differences in resource utilization or loss of diatom-structures as habitats for bacteria. We observed more co-occurrence patterns and network interactions in the shaded communities. This lends further support to the proposal that increased river shading can help mitigate the effects from macronutrient pollution in rivers.
NERC Centre for Ecology & Hydrology, Wallingford, OX10 8BB, UK kleh@ceh.ac.uk.
Katja
K
Lehmann
NERC Centre for Ecology & Hydrology, Wallingford, OX10 8BB, UK.
Andrew
A
Singer
NERC Centre for Ecology & Hydrology, Wallingford, OX10 8BB, UK.
Michael J
MJ
Bowes
Queen Mary University of London, London, UK.
Nicola L
NL
Ings
NERC Centre for Ecology & Hydrology, Wallingford, OX10 8BB, UK.
Dawn
D
Field
Imperial College London, Department of Life Sciences, Silwood Park Campus, SL5 7PY, UK.
Thomas
T
Bell
D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000254:growth & development; D001483:Base Sequence; D018441:Biofilms / Q000145:classification / Q000254:growth & development*; D017377:Diatoms / Q000235:genetics / Q000382:microbiology; D017753:Ecosystem; D004739:England; D005068:Eutrophication / Q000502:physiology*; D058889:Molecular Typing; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D045483:Rivers / Q000382:microbiology*; D017423:Sequence Analysis, RNA; D013472:Sunlight; D014871:Water Microbiology
D012336:RNA, Ribosomal, 16S
biofilm composition; biofilm diversity; networks; riparian shading